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Willodeu Photovoltaics Design Solar 2003
Photovoltaics ay iies Praise for Solar Energy International Quite possibly the best 10 days of instruction I've received on any topic! The enthusiasm and technical expertise of the SEI staff is encouraging in light of the problems of the world's energy demands.Thanks! -Participant,PV Design &Installation,2002 The course was exactly what I had hoped for.It covered all of the key areas and built on them in each successive chapter.Well planned and increasingly challenging.Well worth the cost and I am looking forward to applying the knowledge to my own design.The contacts and links were exceptional and will be used over and over again. -Alan Greszler,Participant,PV Design Online workshop,2003 This class was perfect and exactly what I needed in order to get started with a career in the PV/RE industry. -Participant,Advanced PV,2002 I feel totally inspired to go home and apply what I have learned. The instructors were a dynamic team who worked together very well ...very complimentary.I would come back for sure!!! -Participant,Women's PV,2002 T will definitely return to SEY and suggest to anyone who is interested in renewables to attend an SEI workshop. Thank you so much for providing my first real step towards living a path with a heart. -Participant,Women's PV,2002 This was a great introduction to solar energy. I got much more out of it than I was expecting. -Participant,PV Design &Installation,2003 Could not ask for a better introduction,overview,and practical experience for PV system design and installation --Thanks SEI! -Fred Sharkey,Participant,PV Design &Installation,2003 The instructors were extraordinary.I have never experienced greater commitment,patience,patience,patience, educational skills,technical skills,and care from anyone. They're high on my "admired persons”list. -Brian Burke,Participant,PV Design &Installation,2003 Praise continued Another incredible workshop -I am so happy with the education I have received and with the connections I have made. Incredible people at an incredible organization! -Participant,SEI workshops,2002 This class concludes a full curriculum of the most intense and informative and well-directed courses I could imagine having the good fortune to participate in.Thank you very much! -Jon Crowley,Participant,SEI workshop,2003 Design and Installation Manual es Paste eeOe Peasant allCam: Design and Installation Manual Renewable Energy Education fora Sustainable Future SOLAR ENERGY INTERNATIONAL New SOcIETY PUBLISHERS D edicated to the two billion people on this planet without access to electricity,in the hope that many will get electricity from solar energy,and to all the pioneers currently generating their own sustainable power with photovoltaics. Contents List of Figures .....0...cetteeectneeeeens ix List of Tables and WorksheetS .........0.cc cece cee eee cee teen eee xi Acknowledgments and Disclaimer ..0.0.0.0...occ tees xii Preface ooccccccece eee eee e eee ene ere xiv Chapter 1:An Overview of Photovoltaics 1.1 The Development of Photovoltaics 0.0.0...0c c cece cece ene n nes 2 1.2 Current and Emerging Opportunities 6.0.0...0.000 e eee eeeee eeeeees 2 1.3.Advantages of Photovoltaic Technology .........eee ee eeeee vee eeeneees 3 1.4 Disadvantages of Photovoltaic Technology ........6 cece ec eee eee 3 1.5 Environmental,Health,and Safety Issues...cee ceceeee 3 1.6 Photovoltaic System Components 0.0...cece eects 4 1.7.Photovoltaic System Types ......cv vee eevee eeeeeveeeeeeeeeeteeteeees 4 Chapter 2:Photovoltaic Electric Principles 2.1 Terminology ....0.00 ccc ccc cece eet ene e nett eee nees 10 2.2 Matching Appliances to the System oo.eee eee eee eens 11 2.3.Electrical Circuits 2.0...eect ee etn t ene e eben eee 1] 2.4 Series and Parallel Circuits in Power Sources ....0.ccc e cece eee eee eens 12 2.5 Series and Parallel Circuits in Electric Loads «0.1...0...cece cece eee ees 14 Series and Parallel Wiring Exercises...cece cece ccc cece teens 15 Solutions to Wiring Exercises...0.0...ee eee eee eee eee ete e tees 21 Chapter 3:The Solar Resource 3.1 Solar Radiation Fundamentals .....0...cee e eee ce eee eee eee neees 28 3.2 Gathering Site Data...eecteteeeeeeneeee 32 3.3.Completing the Solar Site Analysis 2.0...0c ccc ee eee cece tent e eens 33 Chapter 4:Electric Load Analysis 4,] 4.2 4.3 4.4 Using Energy Efficiently 2.0.0...0 occcececenceeee 40 Electrical Load Requirements ......2...ccc eee eee cette eee 40 Calculating Load Estimates .......0...e cece ceceeeeences 4] Considerations for Calculating Load Estimates ..........000 eee eee ee eee 44 Chapter 5:Photovoltaic Modules 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Photovoltaic Principles...2...ce eee eens 48 Module Types ....0...ceceeneeeeeenna 49 Module Performance ......0...cece cee tee e eee nee nes 49 Factors of Module Performance ........0.cee eects 50 Photovoltaic Arrays 2.0...cece cece ee eee eee teen eens wee 53 -Mounting Photovoltaic Modules ©...2...ecceeeeae 54 Diodes oo.ccc ceceeeeeeeeeeeeeeneaeeenes 56 Chapter 6:Batteries 6.1 6.2 6.3 6.4 6.5 Battery Types and Operation 2.00...6.eee eee eee 60 Battery Specifications ............00000000.wee eect et eee eee ene 62 Battery Safety ..........4 We ee eee ee ete ene e tne eens 67 Battery Sizing Exercise 66...ccceectteens 68 Battery Wiring Configuration «6.6.0.0...0...e cece cece eee 70 Chapter 7:PV Controls 7.1 7.2 7.3 7.4 Controller Types ............eee eee eee eee wees 74 Controller Features...0...cee ee eet ene e beeen eens 75 Specifying a Controller...0...cc ccc cece cee cence nee anes rn 76 Controller Sizing Exercise bocce cceeeseteeavuveuutntevetevetteeeeres .77 Chapter 8:Inverters 8.1. 8.2 8.3 8.4 Inverter Operating Principles 6.6...cece ccc cece eee eee eee 80 Inverter Features 2.0...cececeeeeeeeeeee tenes80 Inverter Types:2.ee.e cece ence cece nent nent eter ene n eet en eens 81 Specifying an Inverter...cc eee eee eee tenn eee 82 Xi Chapter 9:Photovoltaic System Wiring 9.1 9.3 9.4 9.5 9.6 Chapter 10: 10.1 10.2 10.3 10.4 Chapter 11: 11.1 11.2 11.3 -114 11.5 Chapter 12: 12.1 12.2 12.3 12.4 Chapter 13: 13.1 13.2 13.3 13.4 13.5 xii Introduction 1.0...ceeeetteeteteteenies 86 Wire Size oo eee ee eee eee ee eee eens 88 Overcurrent Protection 1.0.0.0...ccc cece eee eet ene eee eee 104 Disconnects .....cc cece eee ee eee ees weeeeenenteeeeee 106 Grounding 1...cc ee eee ene nett eens 106 Sizing Photovoltaic Systems Introduction to Sizing PV Systems 1.11...cece eee ete eee nes 112 Design Penalties 2.0...cece cette ett tte teens 112 Sizing Worksheet 2...eee te een nnes 113 Sample Syster Exercise...0.een eens 115 Utility-Interactive Systems Introduction...0.ccc eectnnneae Leeeees 122 Utility-Interactive Systems 0...ccc eeete eet eens 122 System Sizing and Economics 21...0.cece eee cee eee cence tenes 126 Net Metering...0c.cece eee ee eee ene eee beck eee eeeee 127 Obtaining an Interconnection Agreement,..........eee cece eee eee 128 integrating Photovoltaics into Buildings Introduction .......6.eee eee Ledeeneeeencecenceeae ee teens 134 Retrofitted PV Systems 2.0...cece ceceeeeenneees 134 BIPV Options ..0...c cee ence eee ene ene n etnies 134 Costs/Benefits 0.0...0.cee cee eee eee t eee tenes 137 Photovoltaic System Applications Tools and Appliances...ccc ccc cece cece eect e teeter etes 140 Lighting 2.0...ccc eee eee nee ene tenet n ene eee 141 Water Pumping .2...cece cece cence tence cent n ene tenet enes 145 Refrigeration 6...cece ccc eee e eee n ee een eens 149 Hybrid Systems with Generators 6...ceceeeeeeeees 150 Chapter 14:Photovoltaic Installation 14.1 Preparing for the Installation 2.0...0.ee cee eens 154 14.2 Toolsand Materials 2.0...ccc ee cece eee ees 154 14.3 Photovoltaic Array Installation 2.0...0.eceneeeee 157 14.4 Battery Installation 2.0...eee ce eee 159 14.5 Controller &Inverter Installation 00.0...eeeceeeeee 160 14.6 Photovoltaic System Wiring 6.6.66.ccc ceceeeeee 161 14.7.PV System Installations Final Checklist 2.0.0.0....eee eee eee 163 Chapter 15:Maintenance and Troubleshooting 15.1 Materials and Tools List 2.0...2.cee eee ete 168 15.2 Maintaining PV Components ......0...0c cece eect tenes 168 15.3.Maintaining Appliances 1...ccc 169 15.4 Troubleshooting Common System Faults oc cevecuestveeeeuereeveteees 170 15.5 Troubleshooting Wiring Problems Using a Multimeter ................0..171 15.6 Troubleshooting Specific Problems ...........002s cee eee eens 174 Chapter 16:Safety and PV Installation 16.1 Introduction ......eneeeeEnerEtenetnee 180 16.2 Basic Safety...eceeeeeteeteeeeenes 180 16.3 Hazards 2.0...cc ene ttn nen beeen ene nes 182 16.4 Safety Equipment ...0...cece eet eens 183 16.5 Site Safety ..1.ete e bbe een e bette tebe e ee 184 16.6 First Aid 2...eee cece ccc cence eee b nen n tenet ences 185 _Appendix A:Glossary ...1.0.00...ceceeennents 189 Appendix B:Solar Data...0.0.0...ceeteeneene 199 Appendix C:Sun Charts 0.0...0.eee cece ete ene nee eeen eee 273 Appendix D:System Sizing Worksheets co eceeeeeseteevereuenererererers+281 Resource Guide ....0.0...ccc cee ete nent een eee ennnes 297 =>311 xiii xiv Figure 1-2: Figure 1-1: Figure 1-3: Figure 1-4: Figure 2-1: Figure 2-2: Figure 2-3: Figure 2-4: Figure 2-5: Figure 2-6: Figure 2-7: Figure 3-1: Figure 3-2: Figure 3-3: Figure 3-4: Figure 3-5: Figure 3-6: Figure 3-7: Figure 3-8: Figure 4-1: .Figure 5-1: Figure 5-2: Figure 5-3: Figure 5-4: Figure 5-5: Figure 5-6: Figure 5-7: Figure 6-1: Figure 6-2: Figure 6-3: Figure 6-4: Figure 6-5: _Figure 6-6: Figure 8-1: Figure 8-2: List of Figures DC System with Batteries ©...0.n nee 5 Day Use System...0.cnet eee teens 5 System with DC and AC Loads ......00.0 e cece cece cee ce cenceenes 6 Utility-interactive System without Batteries...0.00...e cece eee ee ees 7 Electrical Circuits .0.0.0.0 cece eee c eee eee nett teen teen ees 11 PV Modules in Series 2...ccc eeteens 12 PV Modules in Parallel ..00...cece cee cette eens 12 PV Modules in Series and Parallel 20.0.2.eeeee 13 Batteries in Series and Parallel .....cee eee eee te eee ene teens 13 Loads in Series oo...eee cect eee eee eee ences 14 Loads in Parallel 0...eee eee ene tees cette 14 The Sun's Path Throughout the Year-Northern Latitudes .......Lees 28 Magnetic Declination in the United States .........00...c eee eee eee 29 World Magnetic Declination Chart ......066.06 e cece eee eee eee BO Azimuth and Altitude for all Northern Latitudes .................05.30 EffectofTiltAngle ......0.cece ese cence eee eens veeeeeee 3d . Effects of Array Tilt on Energy Production ...............obec eee eee 32 The Solar Window ............4005eee Siete nena ee 33 Visualizing the Four Sides of the Solar Window ............--hates 37 Watts Consumed by Common Phantom Loads .....eeeeeeeeee 4 ModuleI-V Curve...0.0 ccc ce eee ees eeeeeeeeAY Effect of Insolation on Module Performance ........bene eeeeeeeee 50 Effect of Cell Temperature on Module Performance ...........-.+445-51 Effect of Shading on Module Performance .........0050s eee eens 52 Effect on Voltage with Dissimilar Modules Wired in Series ...........4.53 Effect on Voltage with Dissimilar Modules Wired in Parallel............54 Basic Mounting Strategies ©...6...cece cece eee eee ences 55 Cut-away of a Standard Lead Acid Battery Cell..............5.teens 60 Number of Battery Cycles to Daily Depth of Discharge ...............64 Effects of Temperature on Battery Capacity ...........-.05,seen eee 65 12-Volt Battery Configurations eee eee eee eee eee ene e eens 67 24-Volt Battery Configurations .......6...ccc cette ees 71 48-Volt Battery Configurations ..........eee eee eee eee cee c eee nns 72 Common Waveforms Produced by Inverters 2...0.0...c ce eee 81 Efficiency of a 4000-Watt Inverter 6.0.6.0 e cece eee eee e eee ee ees 83 adeliceaaaTneetaereeeeENceesaeEPS Figure 9-1:AC and DC Load Schematic ...............4.Lecceeneeee 102 Figure 9-2:Equipment Grounding Schematic ......6.006 c cece eee e ee 107 Figure 9-3:System and Equipment Grounding Schematic .............0..00005 108 Figure 9-4:Grounding ......06...cece eee eee'eeeeeeeeees 110 Figure ]1-1;Grid-Tie System without Battery backup .......0..00000eeeeueens 124 Figure 11-2:Grid-Tie with Battery Backup ....20...eee eee 125 Figure 11-3:Uninterruptible Power Supply System .......006.66 126 Figure 11-4:Net Metering:Utility-Interactive System ...........00000 eeee eee 127 Figure 12-6:PV Facade -Sawtooth Design .......6.-000 ce cece ee even ee eens 136 Figure 13-1:Pump Curves ........0.000 cee eee deenreeceeeetenes 147 Figure 13-2:Hybrid System with Generator ..0.6.00.cc eee eeeeee 152 XV Xvi List of Tables and Worksheets Table 3-1:Vertical Angle from Horizon to Four Sides of Solar Window ............36 Stand-Alone Electric Load Worksheet (abbreviated)........0.0 c eee eee eee e eee 43 Table 4-1:Typical wattage requirements for common appliances ..........0.00005 45 Table 6-1:Voltage Set Points for Lead-Acid Batteries in a 12-volt system .........-.62 Table 6-2:Effect of discharge rate on battery capacity ......-2.0.eee eee eee 64Table6-3:Battery temperature multiplier at various temperatures ....veveeeeeeees 66 Table 6-4:Liquid electrolyte freeze points,specific gravity,and voltage ............66 Table 6-5:Battery Sizing Worksheet .....0.0 cece cee eee teen ees 69 Table 6-6:Answers to the Battery Sizing Exercise «1.1...see eee eee eee eee eee 70 Table 7-1:Controller Sizing Worksheet...0.66.c cece ence eee eens 77 Table 7-2:Answers to the Controller Sizing Exercise...0...e ee ee eee eee eee 77 Table 8-1:Inverter Sizing Worksheet 6.6...eeecetteeeteee 84 Table 8-2:Answers to the Inverter Sizing Exercise 2...6.0 eee e eee eens eeeeae 84 Table 9-1:Wire Types 2...ccc ce eee nent eens 86 Table 9-2:Color Coding of Wires 60...cece cece eee bene d eee e ee eeeees 87 Table 9-3:Cable Types...0...ccc eee eee tenets 88 Table 9-4:Ampacity of Copper Wire 62...cece cece cence teen eet ees 89° Table 9-5:Length of 12 V Wire for 2%Voltage Drop ...........vs Le ceeeeeeees 91 Table 9-6:Length of 24 V Wire for 2%Voltage Drop...eee eee ete eee eee 92 Table 9-7:Length of 48 V Wire for 2%Voltage Drop...eee cece eee eee eee 93. Table 9-8:Length of 12 V Wire for 5%Voltage Drop...6.cece ee eee eae eae 94 Table 9-9:Length of 24 V Wire for 5%Voltage Drop....6.eee ee eee eens 95 Table 9-10:Length of 48 V Wire for 5%Voltage Drop ...-1...seen eee eee eee 96 System Wire Sizing Worksheet 20.2.0...cece cece eects 101 Table 9-12:Voltage Drop Index Chart .........00.eee eeeeeeeeeees 103 System Sizing Worksheets ............4.eee eee eee rete nee e ee eees 116-118 Utility-Interactive System Sizing Worksheet ........0:eee e cece eenees 131-132Table13-1:Surge Power Requirements for 120V AC Tools ..1.0...eee eee eee eee 140 Table 13-2:Lamp Characteristics ..........Lecce cee cence eee e eee e eee 142 Installation -Tools and Materials Lists 2.0...0...cece cece cece eee tenes 155 Table 14-1:Sample Installation Materials ................eee eee eee eens 156 Acknowledgments Solar Energy International extends a great big thank you to:Steve McCarney,Ken Olson,and Johnny Weiss,who began developing PV training materials while teaching together in the '80s;sincere gratitude goes to the dynamic SEI teachers,Laurie Stone,Ed Eaton,Justine Sanchez,and Carol Weis, who provided invaluable contributions to the fact-finding,researching and written composition of this book.Additional thanks go to the current administrative Staff of Sandy Pickard,Kathy Fountaine, Jeff Tobe,and Kevin Lundy.SEI would like to thank technical proofreaders Dan Rauch,SEI intern; Kevin Ulrich and the late Dan Dean of Solar Flare Institute,Paul Owens of San Juan Community' College,and Jay Peltz,of Peltz Power.We also wish to give thanks to John Wiles and the Southwest Technology Development Institute,National Renewable Energy Laboratory,Sandia National Laboratories,Juan Livingstone,Mark Colby,Jan Woofenden SEI's NW coordinator,the USGS,and the National Fire Protection Association,for supporting this project through technical contributions. Also,for book production help we thank cover our co-publisher New Society Publishing,Harlan Feder,Marianne Ackerman,Gregory Keith,Rachel Tomich and Melody Warford.We give a special thanks to Richard and Karen Perez and to the "Home Power”magazine crew for their enduring inspiration,generosity and dedication to hands-on renewable energy.Finally,we would like to warmly thank Mark Fitzgerald of the Institute for Sustainable Power for his strategic advice and guidance that has been instrumental to the development of this manual. Disclaimer Reference herein to any specific commercial product,process or service by trade name,trademark, manufacturer,or otherwise,does not necessarily constitute or imply the endorsement, recommendation or preference by the authors or publishers.The authors and publishers do not maintain that their methods and recommendations are exclusive to others for the design of photovoltaic power systems.Furthermore,no local,state,or federal code regulations have been referenced inthis manual.Performances of photovoltaic power systems may differ depending upon the nature of the particular application,the specific circumstances relevant to the application,and the quality of the installation.Neither the authors nor the publisher assume any legal liability for systems installed using any information,apparatus,product or process disclosed within this publication,or for the performance of systems installed using the information contained in this publication. Safety Disclaimer We encourage all users of this manual to work safely with photovoltaic systems.Use sound judgment with all photovoltaic equipment,assembly and installation practices on and off the worksite.Always consult a photovoltaic professional,local,and/or state electrical authority.U.S.users must follow National Electrical Code (NEC)practices.This book is not intended as a do-it-yourself manual.Solar Energy International disclaims responsibility for any injury,damage,or other loss suffered related to any information presented in this manual.The reader of this manual acknowledges the inherently dangerous nature of PV installation,general construction,and electrical work,and assumes all responsibility. XVil Preface The evolution of this manual has been a great adventure.It has grown organically,been rewritten,updated and revised many times by many solar professionals.In the early 80's,Steve McCarney,Ken Olson and Johnny Weiss originated a PV textbook for the Solar Training Program we were developing and team-teaching at Colorado Mountain College.Over the decade,with assistance from Luke Elliot and Dr.Mark McCray,different versions served as a teaching tools in conjunction with our vocational training.Later,asAppropriate'Technology Associates,Solar Technology Institute,and as Sustainable Technologies International,the manual became an important training aid.Since 1991,Solar Energy International (SEI),a 501(c)(3) nonprofit educational organization,has revised editions as part of its ongoing PV training programs. Now,the current SEI instructional team is proud to present Photovoltaics: Design and Installation Manual.This major new effort includes new chapters on System Wiring,Utility Interconnected Systems,and Building Integrated PV.All chapters,the Appendixes,and the glossary,have been significantly updated and expanded.The "textbook”format is performance-based and generally presents a non-product-specific approach. It is SEV's hope that this new manual will make a contribution to the growing understanding of PV system design and installation by providing a thorough basis for classroom education,laboratory training and hands-on field installation work. May the PV adventure continue! Johnny Weiss Executive Director,SEI April 2004 xix | Chapter 1 An Overview of Photovoltaics Contents: 1.1 The DevelopmentofPhotovoltaics ............00000ceeeeeee2 1.2 Current and Emerging Opportunities ............0.......2...2 1.3.Advantages of Photovoltaic Technology Love ec ee eeeeeeeuceaad 1.4 Disadvantages of Photovoltaic Technology ................2--.3 1.5 Environmental,Health,and Safety Issues oe.eee eee cece eee 31.6 PhotovoltaicSystemComponents Lov c cent eeeeseeesnesnst 1.7 PhotovoltaicSystemTypes...0...cece eee eee eee eee 4 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL |£The Development of11Photovoltaics Photovoltaic systems are solar energy systems thatproduceelectricitydirectlyfromsunlight.Photovoltaic (PV)systems produce clean,reliable-energy without consuming fossil fuels and can beusedinawidevarietyofapplications.A commonapplicationofPVtechnologyisprovidingpowerforwatchesandradios.On a larger scale,many utilities have recently installed large photovoltaic arrays toprovideconsumerswithsolar-generated electricity,orasbackupsystemsforcriticalequipment.Research into photovoltaic technology began over one hundred years ago.In 1873,British scientist Willoughby Smith noticed that selenium wassensitivetolight.Smith concluded that selenium'sabilitytoconductelectricityincreasedindirectproportiontothedegreeofitsexposuretolight.Thisobservationofthephotovoltaiceffectledmanyscientiststoexperimentwiththisrelativelyuncommonelementwiththehopeofusingthe material to create electricity.In 1880,Charles Frittsdevelopedthefirstselenium-based solar electric cell.The cell produced electricity without consuming anymaterialsubstance,and without generating heat. Broader acceptance of photovoltaics as a power .source didn't occur until 1905,when Albert Einstein offered his explanation of the photoelectric effect.Einstein's theories led to a greater understanding ofthephysicalprocessofgeneratingelectricityfromsunlight.Scientists continued limited research on the'selenium solar cell through the 1930's,despite its low efficiency and high production costs.In the early 1950's,Bell Laboratories began a search for a dependable way to power remotecommunicationsystems.Bell scientists discoveredthatsilicon,the second most abundant element onearth,was sensitive to light and,when treated withcertainimpurities,generated a substantial voltage.By-1954,Bell developed a silicon-based cell that achieved six percent efficiency.The first non-laboratory use of photovoltaic technology was to power a telephone repeater stationinruralGeorgiainthelate1950s.National.Aeronautics and Space Administration (NASA)scientists,seeking a lightweight,rugged and reliableenergysourcesuitableforouterspace,installed a PVsystemconsistingof108cellsontheUnitedStates' first satellite,Vanguard I.By the early 1960s,PVsystemswerebeinginstalledonmostsatellitesand spacecraft.Today,over 200,000 homes in the United Statesusesometypeofphotovoltaictechnology.Solarmodulescontributepowerto175,000 villages in over140countriesworldwide,producing thousands of jobs and creating sustainable economic opportunities.In2001,worldwide sales of photovoltaic products totaledover350megawattsandover$2 billion in the globalmarket.The applications include communications, refrigeration for health care,crop irrigation,waterpurification,lighting,_cathodic protection,environmental monitoring,marine and air navigation,utility power,and other residential and commercialapplications,The intense interest generated by currentphotovoltaicapplicationsprovidespromiseforthisrapidlydevelopingtechnology. |"Current and Emerging|rGx Opportunities Conventional fuel sources have created myriad environmental problems,such as global warming,acidrain,smog,water pollution,rapidly filling wastedisposalsites,destruction of habitat from fuel spills,and the loss of natural resources.Photovoltaic systems do not pose these environmental consequences.Today,the majority of PV modules use silicon as their majorcomponent.The silicon cells manufactured from onetonofsandcanproduceasmuchelectricityasburning 500,000 tons of coal.Photovoltaic technology also creates jobs.Solarindustriesdirectlyemploynearly20,000 people andsupportover200,000 jobs in areas such as glass andsteelmanufacturing,electrical and plumbingcontracting,architecture and system design,andbatteryandelectricalequipmentmanufacturing.By"some estimates,3,800 jobs are created for every $100 million in PV sales. The photovoltaic market grows each year.Economists have predicted that photovoltaics will bethemostrapidlygrowingformofcommercialenergyafter2030,with sales exceeding $100 billion.In fact, the use of solar and renewable energy is expected to double by the year 2010,which would create morethan350,000 new jobs.It is no surprise that thiclean,reliable source of electric power is regarded as the future of energy production. Santion 1.4 -1.2 1 3 Advantages of _,rte Photovoltaic Technology Photovoltaic systems offer substantial advantages over conventional power sources: *Reliability.Even in harsh conditions, photovoltaic systems have proven their reliability.PV arrays prevent costly power failures in situations where continuous operation is critical. *Durability.Most PV modules available today show no degradation after ten years of use.It is likely that future modules will produce power for 25 years or more. ¢Low Maintenance Cost.Transporting materials and personnel to remote areas for equipment maintenance or service work is expensive.Since PV systems require only periodic inspection and occasional maintenance,these costs are usually less than with conventionally fueled systems. *No Fuel Cost.Since no fuel source is required,there are no costs associated with purchasing,storing,or transporting fuel. *Reduced Sound Pollution.Photovoltaic systems operate silently and with minimal movement. *Photovoltaic Modularity.PV systems are more cost effective than bulky conventional systems.Modules may be added incrementally to a photovoltaic system to . increase available power. *Safety.PV systems do not require the use of combustible fuels and are very safe when properly designed and installed. *Independence.Many residential PV users cite energy independence from utilities as their primary motivation for adopting the new technology. *Electrical Grid Decentralization.Small-scale decentralized power stations reduce the possibility of outages on the electric grid. *High Altitude Performance.Increased insolation at high altitudes makes using photovoltaics advantageous,since power output is optimized.In contrast,a diesel PHOTOVOLTAIC ELECTRIC PRINCIPLES generator at higher altitudes must be de-rated because of losses in efficiency and power output. 1 A Disadvantages of:@&Photovoltaic Technology Photovoltaics have'some disadvantages when compared to conventional power systems: *Initial Cost.Each PV installation must be evaluated from an economic perspective and compared to existing alternatives.As the initial cost of PV systems decreases and the cost of conventional fuel sources increases, these systems will become more economically competitive. *Variability of Available Solar Radiation. Weather can greatly affect the power output of any solar-based energy system.Variations in climate or site conditions require modificationsin system design. *Energy Storage.Some PV systems use batteries for storing energy,increasing the size,cost,and complexity of a system. *Efficiency Improvements.A cost-effective use of photovoltaics requires a high-efficiency approach to energy consumption.This often dictates replacing inefficient appliances. *Education.PV systems present a new and unfamiliar technology:Few people understand their value and feasibility.This lack of information slows market and technological growth. | ,Environmental,Health,1 até and Safety Issues Electricity produced from photovoltaics is much safer and more environmentally benign than conventional sources of energy production.However, there are environmental,safety,and'health issuesassociatedwithmanufacturing,using,and disposing of photovoltaic equipment.; The manufacturing of electronic equipment is energy intensive.On the other hand,photovoltaic modules produce more electricity in their lifetimesthanittakestoproducethem.An energy break-even point is usually achieved after three to six years. As with any manufacturing process,producing Section 1.3 --1.5 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL photovoltaic modules often poses environmental andhealthhazards.Workers may be exposed to toxic and potentially explosive gases,diborane,hydrogen deselenide,and cadmiumcompounds.Manufacturers have made steps tominimizeenvironmentalandworkerhazardsby such as phosphine, implementing carefully designed industrial processes and monitoring systems.Safety for installation technicians is also aconcern.Only qualified personnel,using equipment'that complies with national safety standards,should install photovoltaic systems.The disposal of photovoltaic system componentsposesamoderateenvironmentalhazard.Most solarmoduleshaveanexpectedusefullifeofatleast20years.Most of the components can be recycled or -reused (for example,glass and plastic encasement,and aluminum frames),but semiconductor recycling is extremely limited. |6 Photovoltaic SystemigkComponents Photovoltaic systems are built from several important components:©Photovoltaic Cell.Thin squares,discs,orfilmsofsemiconductormaterialthatgeneratevoltageandcurrentwhenexposedto sunlight. *Module.A configuration of PV cells laminated between a clear superstrate(glazing)and an encapsulating substrate. *Panel.One or more modules (often usedinterchangeablywith"module”). *Array.One or more panels wired together at a specific voltage. °Charge Controller.Equipment that regulates battery voltage. +Battery Storage.A medium that stores directcurrent(DC)electrical energy. Inverter.An electrical device that changesdirectcurrenttoalternatingcurrent(AC). *DC Loads.Appliances,motors,and equipment powered by direct current. AC Loads.Appliances,motors,andequipmentpoweredbyalternatingcurrent. |7 Photovoltaic»«x &System Types Photovoltaic systems can be configured in manyways.For example,many residential systems usebatterystoragetopowerappliancesduringthenight.In contrast,water pumping systems often operateonlyduringthedayandrequirenostoragedevice.AlargecommercialsystemwouldlikelyhaveaninvertertopowerACappliances,whereas a system inamobilehomewouldlikelypoweronlyDCappliancesandwouldn't need an inverter.Somesystemsarelinkedtotheutilitygrid,while othersoperateindependently.Integrated Photovoltaic Battery-ChargingSystems:These systems incorporate all theircomponents,including the application,in a singlepackage.This arrangement may be economical whenitcomplimentsorreplacesadisposablebatterysystem.Small appliances,with a rechargeable battery and integrated PV battery-chargers,are a common example.Solar lanterns andphotovoltaicchargersforradiobatterieshaveworldwidemarketpotential.Kits for photovoltaicflashlights,clocks,and radios may eventually replacesimilarunitsthatuseexpensive,wasteful,disposable batteries.Day Use Systems:The simplest and leastexpensivephotovoltaicsystemsaredesignedfordayuseonly.These systems consist of modules wireddirectlytoaDCappliance,with no storage device.When the sun shines on the modules,the applianceconsumestheelectricitytheygenerate.Higherinsolation(sunshine)levels result in increased powet output and greater load capacity. complete Examples of day use systems include:*Remote water pumping for a storage tank. *Operation of fans,blowers,or circulators todistributethermalenergyforsolarwater heating systems or ventilation systems. *Stand-alone,solar-powered appliances such as calculators and toys. >yyy) oy YY) PV Array Figure 1-1 DAY USE SYSTEM Direct Current Systems With Storage Batteries: To operate loads at night or during cloudy weather,PV systems must include a means of storing electrical energy.Batteries are the most common solution.System loads can be powered from the batteries during the day or night,continuously or intermittently,regardless of weather.In addition,a battery bank has the capacity to _supply high-surge currents for a brief period,giving the system the ability to start large motors or to perform other difficult tasks.A simple DC system that uses batteries is illustrated in Figure 1-2.This system's basic >| Charge Controller -> PHOTOVOLTAIC ELECTRIC PRINCIPLES components include a PV module,charge controller, storage batteries,and appliances (the system's electrical load).. A battery bank can range from small flashlight- size barteries to dozens of heavy-duty industrial batteries.Deep-cycle batteries are designed to withstand being deeply discharged and then fully recharged when the sun shines.(Conventional automobile batteries are not well suited for use in photovoltaic systems and will have short effective lives.)The size and configuration of the battery bank depends on the operating voltage of the system and the amount of nighttime usage.In addition,local weather conditions must be considered in sizing a battery bank.The number of modules must be chosen to adequately recharge the batteries during the day. Batteries must not be allowed to discharge too deeply or be overcharged-either situation will damage them severely.A charge controller will prevent the battery from overcharging by automatically disconnecting the module from the battery bank when it is fully loaded.Some charge controllers also prevent batteries from reaching dangerously low charge levels by stopping the supply of power to the DC load.Providing charge control is critical to maintaining battery performance in all but the simplest of PV systems.; Direct Current Systems Powering Alternating Current Loads:Photovoltaic modules easily produce DC electrical power,but many common appliances require AC power.Direct current systems that power Storage Battery 12VDC Figure 1-2 DC SYSTEM WITH BATTERIES Section 1.7 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL PV Array DC Load Center 12VDC Storage Battery 12VDC>120VAC ND FRSC ERE Semis Pree Inverter 12VDC Branch Circuits .to AC Loads 120VAC AC Load Center Figure 1-3 SYSTEM WITH DC AND AC LOADS AC Joads must use an inverter to convert DC electricity into AC.Inverters provide convenienceandflexibilityinaphotovoltaicsystem,but addcomplexityandcost.Because AC appliances aremass-produced,they are generally offered in a widerselection,at lower cost,and with higher reliability than DC appliances.High quality inverters arecommerciallyavailableinawiderangeofcapacities. Utility Grid Systems: Photovoltaic systems that are connected to the utilitygrid(utility-connected,grid-tie,or line-tie systems)do not need battery storage in.their design becausetheutilitygridactsasapowerreserve.Instead ofstoringsurplusenergythatisnotusedduringtheday,the homeowner sells the excess energy to a localutilitythroughaspeciallydesignedinverter.Whenhomeownersneedmoreelectricitythanthe photovoltaic system produces,they can draw powerfromtheutilitygrid.See figure 1-4.If the utility grid goes down,the inverterautomaticallyshutsoffandwillnotfeedsolar-generated electricity back into the grid.This ensuresthesafetyoflinepersonsworkingonthegrid.Becauseutilicy-connected systems use the grid for storagethesesystemswillnothavepoweriftheutilitygridgoesdown.For that reason,some of these systems arealsoequippedwithbatterystoragetoprovidepowerintheeventofpowerlossfromtheutilitygrid.The Public Uctilities Regulatory Policies Act (PURPA)of 1978 requires electric utilities to Interconnected purchase power from qualified,small powerproducingsystemowners.The utilities must pay thesmallpowerproducersbasedontheir"avoidedcosts,”or costs the utility does not have to pay to” generate that power themselves.Additional termsandconditionsforthesepurchasesaresetbystate utiliry commissions and vary from state to state.While this law allows homeowners in areas with utility power to purchase photovoltaic systems andselltheirexcesspowertoanelectricutility,peoplecontemplatingdoingsoshouldrememberthatthisisrarelyaprofitableventureatthepresenttime.Some utility companies offer "netmetering”totheircustomers,where a single meter spins in either direction depending upon whether the utility isprovidingpowertothecustomerorthecustomerisproducingexcesspower.The customer ofindependentpowerproducerpaysorcollectsthenetvalueonthemeter.Net metering is very desirable to the independent power producer because he/she cansellpoweratthesameretailratethattheutility charges its customers.Hybrid Systems:Most people do not run theirentireloadsolelyofftheirPVsystem.The majorityofsystemsuseahybridapproachbyintegratinganotherpowersource.The most common form ofhybridsystemincorporatesagasordiesel-poweredenginegenerator,which can greatly reduce the initialcost.Meeting the full load with a PV system meansthearrayandbatteriesneedtosupporttheload Hy DC VoltageInput - Grid-Tie Inverter AC Voltage PHOTOVOLTAIC ELECTRIC PRINCIPLES Solar Power AC to Grid issihaanaayaahfeesesSoeepeeteoesaraeSPer g AC Utility Meter :Main Utility |Breaker Panel Output -_ Figure 1-4 UTILITY-INTERACTIVE SYSTEM WITHOUT BATTERIES under worst-case wéather conditions.This also means the battery pack must be large enough to power large loads,such as washing machines,dryers, and large tools.A generator can provide the extra power needed during cloudy weather and during periods of heavier than normal electrical use,and can also be charging the batteries at the same time.A hybrid system provides increased reliability because there are two independent charging systems at work. Another hybrid approach is a PV system integrated with a wind turbine.Adding a wind turbine makes sense in locations where the wind blows when the sun doesn't shine.In this case,consecutive days ofcloudyweatherarenotaproblem,so long as the wind turbine is spinning.For even greater reliability and flexibility,a generator can be included in a PV/Wind system.A PV/Wind/Generator system has all of the advantages of a PV/Generator system,with the added benefit of a third charging source for the batteries. oecti on 1.7 Chapter 2 IplesicPrinciElectrIcPhotovolta Contents: .10 Jil weeee ll Terminology 2.0...0.cee cece eee2.1 2.2 Matching Appliances to the System 2.3 Electrical Circuits ....... 2 14 .15 .21. wi2.4 Series and Parallel Circuits in Power Sources 2.5 Series and Parallel Circuits in Electric Loads .............0.05- Series and Parallel Wirin Exercises .......0c cece eee eee eeeo5 Solutions to Wiring Exercises .. eae epa eee| uee Desens PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 2.1am.E [Terminology Electricity is the flow of electrons through a circuit.The force or pressure of moving electrons in a circuitismeasuredasvoltage.The flow rate of electrons ismeasuredasamperage.The power of a system 1s measured as watts.A volt is the unit of force (electrical pressure)that causes electrons to flow through a wire.Volts areabbreviatedV,or expressed by the symbol E.Electrical'pressure is sometimes referred to as theelectromotiveforce(EMF).Some common voltagesusedinlight-duty electrical systems include 12v,24v,48y.Most homes use 120v and 240v systems.An ampere or amp is the unit of electricalcurrentflowingthroughawire.Amps are abbreviatedAorexpressedbythesymbolI(for intensity ofcurrent).Just as pipe is sized by the rate of waterpassingthroughit,a wire is sized according to therateofelectrons(amps)flowing through it.(Formoreinformationonwire-sizing methods, Chapter 9.)'A watt is a unit of electrical power equivalent toacurrentofoneampereunderapressureofonevolt.Watts indicate the rate at which an appliance useselectricalenergyortherateatwhichelectricalenergyisproduced,Since electricity consumers need togaugehowmuchelectricitytheyuse,the watt-hour refer to is an important measurement.An appliance that'consumes electrical energy at a rate of one watt foronehourwillhaveconsumedaquantityofelectricity equal to one watt-hour.To calculate watt-hours,there are two things you'll need to know: +An appliance's rated watts *The estimated duration of time the appliance will be operatedThetermwatt-hours probably sounds familiar,since utility companies bill their customers for thenumberofkilowatt-hours consumed.Kilowatt-hoursofelectricityareequalto1,000 watt-hours and are abbreviated kWh. Types of CurrentTherearetwotypesof electrical current.Alternatingcurrent(AC)is electric current in which direction offlowreversesatfrequent,regular intervals.This typeofcurrentisproduced.by alrernators.In analternator,a magnetic field causes electrons to flow first in one direction,Electric utility companies supply alternating current.Direct current (DC),the type of current produced bydirection.Batteries and photovoltaic modules then in the reverse direction. electrical generators,flows only in one provide DC current. Watts are equal to voltage times amperage.Watts =Volts x Amps Watts =Rate of energy use /productionWattsxHours=Watt-hours (Wh)=Quantity of energy use /production1,000Wh =1 Kilowatt-hour (kWh) Problem:How much electrical energy is consumed ifa100-watt light bulb is used for 10 hours?Solution:100 watts x 10 hours =1,000 watt-hours(or 1 kilowatt hour). 10 7 ,Matching Appliances toefxtheSystem Photovoltaic system designers adapt their systems by using the manufacturers'power ratings for appliances,in conjunction with a careful estimation of how long each appliance will be used.You can find an appliance's electrical rating and power requirements on the nameplate.To use the information on an appliance's nameplate and correctly match the electrical supply to the appliance's requirements,you must understand the terms discussed in this chapter,including watts, amps,volts,alterriating current,and direct current. When choosing an appliance for a PV system, there are two important rules that must be observed: *The voltage of an appliance must match the voltage supplied to it.The power source,such as a battery,generator,or photovoltaic module,determines the voltage supplied. *An appliance must be compatible with the type of current (AC or DC)that is supplied to it. fx eké Electrical Circuits An electrical circuit is the continuous path of electron flow from a voltage source,such as a battery or photovoltaic module,through a conductor (wire) Switch 12 Volt 12 Volt AN OVERVIEW OF PHOTOVOLTAICS to a load and back to the source.A simple electrical circuit is shown in Figure 2-1 as a schematic and a diagram.This example shows a single voltage source, a 12-volt battery,wired to a single load,a 12-volt, 24-watt light bulb,with a switch to turn the light on and off. The switch controls the continuity of current flow.If the switch is turned off (an open circuit),the wire between the source and the load is disconnected, and the light will be off.If the switch is turned on (a closed circuit),the wire between source and load is connected,and the light will shine.Relay switching devices are often used as controls to open or close a circuit.Relays are rated by voltage,type of current (AC or DC),and whether the circuit is normally open or closed. An electrical system can be compared to a waterpumpingsystem.A pump lifts two gallons of water per minute from a lower tank to an upper tank, increasing its height and pressure by 12 feet,the distance between the two tanks.The pressure created by the 12-foot height of the upper tank is like the 12- volt electrical pressure in the battery.The water falls at two gallons per minute from the upper tank and turns a water wheel,losing its height and pressure as it returns to the lower tank.The falling of water at two gallons per minute to turn the water wheel is like the two amp flow of electrons that powers the light and returns to the battery. Figure 2-14 ELECTRICAL CIRCUITS Section 2.2 -2.3 11 Pacer roe PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 2 d Series and ParallelfeCircuitsinPowerSourcesPhotovoltaicmodulesandbatteriesareasystem'sbuildingblocks.While cach module or battery has aratedvoltageoramperage,they can also be wiredtogethertoobtainadesiredsystemvoltage. Problem:When two 12 VDC,3 amp modules arewiredinseries,what is the resulting system voltage and current? Solution:A 24 VDC,3 amp system Load 24 Volts at 3 Amps Figure 2-2 pV MODULES IN SERIES Load 12 Volts at 6 Amps Figure 2-3 Series Circuits:When voltage sources are connected in series,thevoltageincreases.Series wiring does not increase the-amperage produced.Figure 2-2 shows two moduleswiredinseries.Note that series wiring connectionsaremadeatthepositive(+)end of one module to thenegative(-)end of another module.Series circuits can also be illustrated withflashlightbatteries.Flashlight batteries are oftenconnectedinseriestoincreasethevoltageandpowerahighervoltagelampthanonebatteryonlycouldpoweralone.Here are some rules concerning series Circuits:©When loads or sources are wired in series, voltages are additive.¢Current is equal through all parts of the circuit.¢In a series circuit,batteries are connectedend-to-end or positive (+)ro negative (-).Batteries placed in series will provide a totalvoltageequaltothesumofeachindividual battery voltage. Problem:When four 1.5V DC batteries areconnectedinseries,what is the resulting voltage? Solution:6 volts. Parallel CircuitsWhenloadsorsources are wired in parallel,currentsareadditiveandvoltageisequalthroughallpartsofthecircuit.To increase the amperage of a system,thevoltagesourcesmustbewiredinparallel.Figure 2-3showsPVmoduleswiredinparalleltogeta12V,6-amp system.Notice that parallel wiring increases thecurrentproducedanddoesnotincreasevoltage.Note:Parallel wiring is from :positive (+)topositive(+)and negative (-)to negative (-).Batteries are also often connected in parallel toincreasethetotalamps,which increases the storagecapacityandprolongstheoperatingtime. PV MODULES IN PARALLEL om tion,O A 12 Secor 2.4 AN OVERVIEW OF PHOTOVOLTAICS 24 Volts at 6 Amps -nNfo:lwo]oo?<E;Figure 2-4 PV MODULES IN SERIES AND PARALLEL .Load Series and Parallel Circuits 6vDC Systems may use a mix of series and parallel wiring to obtain required voltages and amperages.In Figure 2- 4,four 3-amp,12V DC modules are wired in series and parallel.Strings of two modules are wired in series,increasing the voltage to 24V.Each of these strings is wired in parallel to the circuit,increasing the amperage to 6 amps.The result is a 6-amp,24V DC system. 8 Amp-hours at 6 Volts PV Modules in Series and Parallel The advantages of a parallel circuit can be illustrated by observing how long a flashlight will operate before the batteries fully discharge,perhaps eight hours forafour-battery flashlight.To make the flashlight last twice as long,battery storage would have to be doubled., In Figure 2-5,four more batteries have been added in parallel to the original string of four batteries to increase storage (amps).This new group _could not be added in series because the total voltage would be 12 volts,which is not compatible with the six-volt lamp.The new string of batteries is wired in parallel,which increases the available current, thereby adding additional storage capacity and increasing the usage time. . Figure 2-5 BATTERIES IN SERIES AND PARALLEL 'Section 2.4 |13 Cater PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Cre+yi 4 Figure 2-6 LOADS IN SERIES WARNING!NEVER WIRE LOADS IN SERIES. Figure 2-7 LOADS IN PARALLEL ey x Series and Parallelfox&)Circuits in Electric Loads Like the photovoltaic modules and flashlight batteriesdescribedintheprevioussections,loads wired in series,parallel,or series/parallel configurations act similarly. Series Circuits Figure 2-6 shows two 6V light bulbs wired in series andsuppliedbya12Vbattery.The voltage drop caused byeachbulbis6V;thus the total voltage drop is 12V,which is equal to the 12V pressure in the battery. Loads in Series The two lights in Figure 2-6 are wired in series andarejointlycontrolled.If one light burns out,thecircuitwillbeopen,and all loads in the circuit willlosepower.Loads wired in series result in a voltagedropthatisadditive.The total voltage drop is equalrothesumofalltheloadsinthecircuit.Current is _equal through all loads in the circuit.Note:Never wire loads in series. Paraliel Circuits What happens when loads are wired in parallel?Remember how the batteries added to the flashlightinFigure2-5 did not increase the voltage supplied tothelamp?As loads are added in parallel,the voltagedropforeachremainsequaltothesourcevoltage.Current drawn from the source is increased with each load added in parallel.Electrical circuits are commonly wired with all the loads in parallel for the following two reasons:*Each load can be controlled individually. +Adding more loads does not affect theoperatingvoltageofanyotherload. 14 , c Series and Parallel Wiring Exercises Use the following worksheets to practice series and parallel wiring for 12-,24-,and 48-volt systems. Enter your answers in the blanks on each page or copy these pages for future practice.Draw lines to make your connections. Instructions: *Connect the photovoltaic modules (array) either in series or parallel or series/parallel to get the desired system voltage. *Calculate total module output for volts and amps. *Connect the array to a charge controller. *Connect batteries either in series or parallel to get the desired system voltage. *Calculate total battery bank voltage and amp- hour capacity. *Connect the battery bank to the charge controller. 15 SERIES AND PARALLEL WIRING EXERCISES Exercise 2-1:DESIGN A 12V SYSTEM WITH 12V PV MODULES PV ARRAY (12VDC nominal and 3.5A each) Total Volts = Total Amps = Total Volts = Total Amp-Hours = BATTERY STORAGE (6VDC and 350AH each) 16 SERIES AND PARALLEL WIRING EXERCISES Exercise 2-2:DESIGN A 24V SYSTEM WITH 12V PV MODULES PV ARRAY Total Volts = Total Amps = Total Volts = Total Amp-Hours = 17- SERIES AND PARALLEL WIRING EXERCISES Exercise 2-3:DESIGN A 48V SYSTEM WITH 12V PV MODULES PV ARRAY Total Volts = Total Amps = Total Volts = Total Amp-Hours = eRursom: ATTERY STORAGE 18 wepoyeepeeSERIES AND PARALLEL WIRING EXERCISES Exercise 2-4:DESIGN A 48V SYSTEM WITH 24V PV MODULES PV ARRAY BATTERY STORAGE Total Volts = Total Amps = Total Volts = Total Amp Hours = 19 SERIES AND PARALLEL WIRING EXERCISES 20 Exercise 2-5:DESIGN A 48V SYSTEM WITH 12V PV MODULES PV ARRAY 12VD0 Total Volts = Total Amps = Total Volts = Total Amp-Hours = Solutionsto Wiring Exercises Answer 2-1;12-VOLT SYSTEM WITH FOUR 12 VDC PV MODULES PV ARRAY (12VDC and 3.5 Amps each) Total Volts =12VDC (nominal) Total Amps =__14A__ Total Volts =__12 VDC Total Amp-Hours =_700AH BATTERY STORAGE (6VDC and 350AH each) 21 SERIES AND PARALLEL WIRING EXERCISE ANSWERS Answer 2-2:24-VOLT SYSTEM PV ARRAY istonedRee,Total Volts =__24VDC Total Amps =__7ASy -_nNok-uhGSQONoiseMageNaaRaBegonPdeTotal Volts=__24VDC__ Total Amp-Hours =350AH BATTERY STORAGE SERIES AND PARALLEL WIRING EXERCISE ANSWERS Answer 2-3:48-VOLT SYSTEM WITH EIGHT 12VDC PV MODULES PV ARRAY ee Total Volts =_48VDC Total Amps =__10A Total Volts=__-48VDC Total Amp Hours =_300AH ee |tamara ERY STORAGE 23 a SERIES AND PARALLEL WIRING EXERCISE ANSWERS Answer 2-4:48-VOLT SYSTEM WITH EIGHT 24VDC PV MODULES PV ARRAY Total Volts =_48VDC_ Total Amps =40A Total Volts =__48VDC Total Amp Hours =320AH BATTERY STORAGE 24 SERIES AND PARALLEL WIRING EXERCISE ANSWERS Answer 2-5:48-VOLT SYSTEM WITH SIXTEEN 12VDC PV MODULES PV ARRAY Total Volts =_48VDC_ Total Amps =__204 __ Total Volts =___48VDC Total Amp Hours =_720AH BATTERY 25 | Chapter 3. The Solar Resource Contents:| 3.1 Solar Radiation Fundamentals .......000.00cceeeeeseesees28 3.2 GatheringSiteData 1.2...ee eee ee ee 32 3.3.CompletingtheSolarSiteAnalysis ..............000...0....33 tI : 27 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL ««Solar RadiationwheFundamentals The term for solar radiation striking a surface at a particular time and place is insolation.Wheninsolationisdescribedaspower,it is expressed as a number of watts per square meter and usually presented as an average daily value for each month.On a clear day,the toral insolation striking the earth is about 1,000 watts per square meter.However, many factors determine how much sunlight will beavailableatagivensite,including atmospheric conditions,the earth's position in relation to the sun, and obstructions at the site. Although this book expresses insolation askilowatt-hours per square meter,it can also bedescribedinBTUs,Joules (J),or Langleys.The following equivalences can be used:1kWh/m?=3.412 BIU/ft =3.6MJ/m°?=1 Langley/85.93 = 1 peak sun hour. Solar radiation received at the earth's surface is subject to variations caused by atmospheric attenuation.The primary causes of this'phenomenon are the following: *air molecules,water vapor,and dust in the atmosphere scattering light *ozone,water vapor,and carbon dioxide in the atmosphere absorbing light Peak sun hours are the number of hours per day when the solar insolation equals 1,000 w/m?*.For example,5 peak sun hours =5 kWh/m?',where the .energy received during total daylight hours equals the energy received if the sun shines for 5 hours at 1000 w/m?. The earth's distance from the sun and the earths tilt also affect the amount of available solar energy. The earth's northern latitudes are tilted towards the sun from June to August,which brings summer to the northern hemisphere.The longer summer days and the more favorable tilt of the earth's axis create significantly more available energy on a summer day than on a winter day. In the northern hemisphere,where the sun is predominantly in the southern sky,solar collectors orphotovoltaicmodulesshouldpointtowardsthesouthernskytocollectsolarenergy.Designers should optimize solar collection by positioning the array totakefulladvantageofthemaximumamountof sunlight available at a particular location.Fortunately,the sun's path across the sky is orderly and predictable. SUMMER SOLSTICE (5 a.m.-7 p.m.) EQUINOX \(6 a.m-6 p.m.) WINTER SOLSTICE E (8 a.m.-4 p.m.) Figure 3-1 THE SUN'S PATH THROUGHOUT THE YEAR-NORTHERN LATITUDES CesmteyeyESETOYE ot 4 THE SOLAR RESOURCE ;Hm oe °19°20°19 ig°\ 7 14° :Ain : °1"15 10" 14°887 13° ; 12°8° ° 4 i1 3° 10°ye?2 ,.19g,3°2SFopgeoga degrees west ofmagneticsouth degrees eastof magnetic south 0° Figure 3-2 MAGNETIC DECLINATION IN THE UNITED STATES The site's latitude (the distance north or south of the earth's equator)determines whether the sun appears to travel in the northern or southern sky.For example,Denver,Colorado,is located at approximately 40 degrees north latitude,and the sun appears to move across the southern sky.At midday, the sun is exactly true south. Once a day,the earth rotates on its axis,which is tilted approximately 23.5 degrees from vertical.The sun appears to rise and set at different points on the horizon throughout the year because of this tilt.On the fall and spring equinoxes (September 21 and March 21)the sun appears to rise exactly due east of south and appears to set exactly due west of south. During the winter months,the sun appears to rise south of true east and set south of true west;in the summer months,it appears to rise north of true east and set north of true west.Figure 3-1 illustrates the solar position at different times of day and year. Orientation. The sun's apparent location east and west of true south is called azimuth,which is measured in degrees east or west of true south.Since there are 360 degrees in a circle and 24 hours in a day,the sun appears to move 15 degrees in azimuth each hour (360 degrees divided by 24 hours).Magnetic south or south on a compass is not the same as true south.A compass aligns with the earth's:magnetic field,which is not necessarily aligned with the earth's rotational axis. The deviation of magnetic south from true south is called magnetic declination.Refer to a map or ask a local surveyor for your location's magnetic declination. Figures 3-2 and 3-3 provide approximate magnetic declination for the United States and the world respectively.These maps are sufficient for our purposes. Daily performance will be optimized if fixed mounted collectors are faced true south or 0 degrees azimuth,which is the best generic orientation for 29 180°210°240°270°300°33 30°60°90°120°150°180° Zi Figure 3-3 WORLD MAGNETIC DECLINATION CHART N Figure 3-4 AZIMUTH AND ALTITUDE FOR ALL NORTHERN LATITUDES 30 Secon 3.4 locations in the Northern hemisphere.An array that deviates 30 degrees from true south will collect 90 percent of the sun's available energy on an average daily basis. A site in Montana has a magnetic declination of20degreeseast,meaning that true south is 20 degrees east of magnetic south.On a compasswiththenorthneedleat360degrees,true south is in the direction indicated by 160 degrees. Local climate characteristics should be carefully evaluated and taken into consideration.For example,you can compensate for early morning fog by adjusting the photovoltaic array west of south to gain additional late afternoon insolation. more sunlight per square foot falls on a perpendicular surface (90°angle to the sun's rays is optimal) THE SOLAR RESOURCE Tilt Angle The sun's height above the horizon is called altitude, which is measured in degrees above the horizon. When the sun appears to be just rising or just setting, its altitude is 0 degrees.When the sun is true south in the sky at 0 degrees azimuth,it will be at its highest altitude for that day.This time is called solar noon. A location's latitude determines how high the sun appears above the horizon at solar noon throughout the year.As a result of the earth's orbit around the sun with a tilted axis,the sun is at different altitudes above the horizon at solar noon throughout the year. less sunlight per square foot falls onaverticalsurface less sunlight persquarefootfalls on °a horizontal surface Figure 3-5 EFFECT OF TILT ANGLE Section 3.1 31 a PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Veaqonta!Surfs C (J Tilt =Latitude SolarInsolationonSurface(kWhim'/day)J J Month Figure 3-6 EFFECTS OF ARRAY TILT ON ENERGY PRODUCTION The highest average insolation will fall on acollectorwithatiltangleequaltothelatitude.Youmustconsiderspecificseasonalusecharacteristicsto optimize a system's performance.The following list outlines the optimum tiltangleofaphotovoltaicarrayfordifferentseasonal loads. *Year-round loads:Tilt angle equals latitude. *Winter loads:Tilt angle equals latitude plus 15 degrees. ¢Summer loads:Tilt angle equals latitude minus 15 degrees. Photovoltaic arrays work best when the sun's raysshineperpendicular(90 degrees)to the cells.Whenthecellsaredirectlyfacingthesuninbothazimuthandaltitude,the angle of incidence is "normal.”Figure 3-6 illustrates the effect of this tilt angle onavailablemonthlyinsolation.Note:Adjusting the tilt angle of the PV array te efx Gathering Site Data The first step in setting up a photovoltaic system is todeterminewhattimeoftheyearwillhavethelargest loads and then to select a month that you will use todesignthesystem.You will also need to gather solarinsolationdataforthesizingcalculations.Determining Design Month:Insolation data ismostoftenpresentedasanaveragedailyvalueforeachmonth.When sizing a system,it is important to use the correct month.If the load is constantthroughouttheyear,the design month will be themonthwiththelowestinsolation.The array shouldthenbeinstalledwithatiltanglethatyieldsthehighestvalueofinsolationduringthatmonth.Thisensuresthatthesystemisdesignedtomeettheloadandkeepthebatteryfullychargedintheworst month for the average year.If the load is variable for each month,you shouldusethesizingworksheetinAppendixDtocalculateseasonallycanincreasepowerproductionsignificantlyforyear-round loads.the design current for each month.The design Q5 C . 32 Section 3.2 current is the average daily load for the month divided by the monthly insolation.The month corresponding to the largest design current should be used as the design month. Gathering Insolation Data:Many locations around the world have years of weather records that will provide average data sufficient for designing PV systems.Appendix B contains average daily insolation availability for major cities worldwide,including figures for different tilt angles and tracking options. This type of data may also be available from meteorological stations,universities,government ministries,Internet,or other information depositories. If no long-term data is available for your specific site,the availability and amount of sunshine must be estimated.Even though local solar conditions may vary significantly from place to place,particularly in mountainous areas,you can estimate local weather by studying the variation in average data from several cities located around the proposed site. These trees cast a shadow on the collector between Sam and noon from November to February house with solar collector THE SOLAR RESOURCE 3 "y Completing the«tt Solar Site Analysis With the site data and an understanding of how the array should be oriented,you are now ready to evaluate the site and locate where the array will be installed. Identifying Shading Obstacles:Shading critically affects a photovoltaic array's performance.Even a small amount of shade on a PV panel can reduce the panel's performance by as much as 80%.For this reason,minimizing shading is much more important in PV system design than in solar thermal system design.Carefully determining solar access or a shade- free location is fundamental to cost-effective photovoltaic performance. Unwanted shading can occur from trees, vegetation,structures,other arrays,poles,and wires. As a general rule,an array should be free of shade from 9:00 AM until 3:00 PM.This optimum collection timeframe is called the solar window (see Figure 3-7).Shading is often a greater problem --Sun's Path 40°Northern latitude Figure 3-7 THE SOLAR WINDOW Section 3.3 33 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL during winter months when the sun's altitude is lowandshadowsarelonger.For locations in the northernhemisphere,December 21 should be used for worst- case shadow calculations. Whena site is selected,be sure that the followingparametersaremetandtaskscompleted: *Be sure that the array is not shaded from 9 AM to 3 PM on any day. *Be sure that the array is not shaded in any month of the year. *Identify the obstacles that shade the array between 9 AM and 3 PM. *Make recommendations to eliminate any shading,move the array to avoid shading,orincreasethearraysizetooffsetlossesdueto shading. Determining Solar Access with a Sun Chart You should carefully examine a site to identify any possible shading om your solar panels.This isaccomplishedbygettingaclearpictureofthesun'spathacrossthehorizonfromeasttowest.Onemethodforfindingasitewithgoodyear-roundexposureisthroughlong-term observation.Unfortunately,this is not always possible or practical.Fortunately,solar professionals have developed toolstoprovidequickinsighttothesolarwindowata specific location.The only type of "time”that truly makes senseforlivingorganisms(and solar energy collection)is"solar time.”Solar time signifies that at noon the sun | should be at its peak in the sky for the day.Thus,when we refer to solar noon,we mean maximum solar altitude.The invention of time zones marked a human attempt to link al]the site-specific solar timesthroughouttheworld.Time zones are merelyapproximations.The logic behind time zones is asfollows:since the earth rotates at a rate of 15 degrees per hour,a one hour time change exists every 15degreesoflongitude.Divide 360 degrees (a fullcircle)by 15 degrees and the resule is 24 hours;therefore,a time zone for every hour of day. Since solar altitude is of utmost importance to the designer,special charts are available for specificlatitudes.Appendix C shows sun charts for altitudeslocatedbetween28degreesand56degreesnorth latitude.Sun charts are also available from state energy offices or local solar suppliers. If a site is partially shaded,you can use a suncharttodeterminetheamountofavailablesunlight. These charts will help you locate the position of the sun in the sky at any time of the year and help youdetermineifyoursolarcollectorswillbeshadedfromdirectbeamradiationduringcriticaltimesoftheday or year.Find the appropriate chart for your latitudeinAppendixC.The curved solid lines represent thesun's path during the day.The top and bottom linesaredrawnforthesummerandwintersolstices.The lines between are the solstices represent the 21st day of each month of the year.The dotted lines represent the solar time of day.Note:When charting the sun's path,remember that the winter sun is ]ow in the sky. Commercially available solar siting devices have sun charts built directly into them and enable you to easily evaluate a site.There is,though,a simple waytoevaluatethesolaraccessofasitewithoutasitingdevice.To do this,you will need a compass and a waytomeasurealtitude;a protractor with a small weighthangingfromastringattachedtotheprotractor'scenterissufficientforsimplealtitudemeasurements. Use the following steps to evaluate the merit of a solar site. 1.Place yourself at the proposed center position of the collectors. 2.Use the compass to locate a bearing of 90 degrees east (be sure to account for magnetic declination -approximately 13 degrees east for Carbondale,CO). 3.Sight along this bearing with the protractortodeterminethealtitudeofanyobstructions, including vegetation,buildings,geographic features,and the horizon. 4.Mark the altitude of each obstruction on the chart. 5.Rotate 15 degrees towards the west and repeat steps 3 and 4. G6.Repeat steps 3,4 and 5 until you have reached 90 degrees west. 7.Connect the obstruction marks on the chart and shade everything below the line.A good solar site will have no shading between 9 a.m. and 3 p.m.on any day during the year. 34 of Determining solar access for low latitudes:If the site is located between 25 degrees south latitude and 25 degrees north latitude,you can use the following solar site evaluation method.All you need is one or two people,a compass,and the information from table 3-1. The following steps guide you through evaluating a site. Site Information: 1.Record the site location 2.Record the latitude 3.Record the magnetic declination of the site Establishing the Major Compass Directions: 4,Stand at the site of the PV array and move into a position where your eyes are level with the bottom of the lowest panel. 5.Locate true south using a compass. 6.Establish north-south line.Visually establish the north-south line with extended arms.Set landmarks if necessary. 7.Establish east-west line.Visually establish the east-west line with extended arms.Set landmarks if necessary. Visualizing the North and South Sides of the Solar Window: 8.Create a 90°angle for the north side-Extend one arm horizontally toward the north and the other straight above toward the zenith to create a 90°angle as shown in Figure 3-8. Have a friend stand several steps away to help you adjust your arms. 9.Divide the north arc.Visualize the 90°are created by your arms and divide the arc into halves,quarters,and then thirds as shown in Figure 3-8.Practice this with the aid of an observer until you achieve a reasonable accuracy. 10.Create a 90°angle for the south side and divide the arc.Repeat steps 8 and 9 for the south side. THE SOLAR RESOURCE 11.Find the solar window.Use Table 3-1 to find the north and south angles for the site's latitude.Mark the values for the north and south sides of the solar window in Figure 3-8. Evaluating the Solar Window: 12.Evaluate the north-south window.Visually sight the north and south sides of the solar window.This solar window must be clear of | obstructions or shading.If either one of these orientations is unacceptable,you must move the site to another location or remove the obstruction.If the north-south window is suitable,then continue with the east and west orientations. 13.Evaluate the 8 a.m.to 4 p.m.east-west window.Visually sight the east and west sides using the 8 a.m.to 4 p.m.window.Use Table 3-1 to find the angles for the site's latitude and mark the values in Figure 3-8.Note any shading in this window and if it could be removed easily.If this window is not suitable, repeat the evaluation for the 9 a.m.to 3 p.m. window. 14.Evaluate the 9 a.m.to 3 p.m.east-west window.Visually sight the east and west sides using the 9 a.m.to 3 p.m.window.Use Table 3-1 to find the angles for the site's latitude and mark the values in Figure 3-8.Note any shading in this window. 15.Assess the options of raising the array to avoid the obstructions or increasing the array capacity by 15 percent.If these options are not feasible,you should consider another site. If absolutely necessary,repeat the evaluation for the 10 a.m.to 2 p.m.window. 16.Evaluate the 10 a.m.to 2 p.m.east-west window.Visually sight the east and west sides using the 10 a.m.to 2 p.m.window.Use Table 3-1 to find the angles for the site's latitude and mark the values in Figure 3-8.If there is any shading in this window,you should locate another site.If this window is clear and you choose to use the site,you will need to increase the array capacity by 33 percent.Note that this poses a significant increase in the system cost. 2 35 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Evaluating the Site:19.Site Recommendations.Make a complete 17.Assess the site preparations.Using the list of the necessary site preparations and/or chosen solar window,determine if the work and/or cost needed to prepare the site,raise the array,or increase the array size Is acceptable. modifications to the array. *Remove the obstructions causing shade. How will this be done? *Increase the height of the PV array.How 18.If the additional work is not practical or the high above the ground? cost is not feasible,you should locate another site.If the preparations are acceptable,you should continue to step 19. *Increase the capacity of the array.What percentage increase and at what cost? Table 3-1 Vertical Angle from Horizon to Four Sides of Solar Window Latitudes:|7.5°N -7.5°S 7.5°-17.5°17.5°-25° Hemisphere Hemisphere North South North South North 60°67.5°45°75°30° South 60°45°67.5°30°75° East /West ; 8 am to 4 p.m.22.5°22.5°22.5°15°15° 9 am to 3 p.m.*30°30°30°22.5°22.5° 10 am to 2 p.m.**45°40°40°30°30° *For sites that do not satisfy the 8 a.m.to 4 p.m.solar window,but do satisfy the 9 a.m.to 3 p.m.solarwindow,increase the array capacity by 15 percent or mount the array with bottom of the lowest panel at least 1/3 the height of the obstruction.- **For sites that satisfy only the 10 a.m.to 2 p.m.solar window,increase the capacity of the PV array by 33 percent. THE SOLAR RESOURCE 45° 22.5° Figure 3-8 VISUALIZING THE FOUR SIDES OF THE SOLAR WINDOW Section 2.3 37 Chapter 4 Electric Load Analysis Contents:| 4.1 Using Energy Efficiently erect teers e eee 404.2 ElectricalLoadRequirements occ eenseee eres ee es 404.3 Calculating Load Estimates cette neetteeeeeneeeee es Al444.4 Considerations for Calculating Load Estimates ....... PHO TOVOLTAICS:DESIGN AND INSTALLATION MANUAL 4.7 Using Energy Efficiently Devices that operate using electrical power are oftenreferredtoasloads.They are usually the largest singleinfluenceonthesizeandcostofaphotovoltaicsystem.A photovoltaic system designer can minimizeaPVsystem's cost by efficiently using the energyavailable.A designer should thoroughly analyze theenergyrequirementstoidentifyenergyconservingopportunities.For example,powering an electricrangewithaPVsystemisusuallycost-prohibitive:Agasorwood-fired stove would be more appropriate.Heating water with a low-cost solar thermal collectorisaneconomicalalternativecomparedtousingaphotovoltaicorgassystem.This method of usingloadsthatarepoweredbygeneratingsystemsotherthanphotovoltaicsiscalledloadshifting.Designers should also be able to suggest usingmoreefficientapplianceswithinaphotovoltaic.system.For example,incandescent lamps can bereplacedwithefficientfluorescentlampsthatprovideequalilluminationanduseaboutonequarterthe power.In addition to load shifting and increasedequipmentefficiency,designers can lessen the needforadditionalelectricpowerbyimplementingthe following practices: ¢Living without unnecessary items. °Less use of appliances that demand large loads. *Doing a task more efficiently. Designing a system without an inverter and_using only direct current loads,if appropriatetoavoidinverterefficiencylosses. Doing tasks during sunlight hours tomaximizebatteryefficiency. Designers should involve system owners OFoperatorsinthedesignprocessandsysteminstallation.Their increased awareness will also reducetheneedforelectricpower,since they will be morelikelytousetheirelectricresourcemoreprudently. A eS Electrical Loadmt.fe Requirements Manufacturers'literature and equipmentnameplatesoftenlistthewattsrequiredforaload.When the watts required by a given load are notlisted,you will usually find volts and amps listedinstead.You can calculate the watts required by a load by multiplying volts times amperes.Table 4-1 on page 45 lists wartages for many common household loads. Cycling Loads Most loads.consume power continuously when theyareswitchedon.However,some loads will turnautomaticallythemselvesonandoffwhentheyareswitchedonandconnectedtoapowersource.A dutycycleisthepercentageoftimeanappliancethatis"on”is actually drawing power.Good examples ofsuchappliancesarerefrigeratorsandfreezers.Arefrigeratormayoperate50to60percentofthetime,depending on its efficiency.In addition,appliances that create or use heatusuallycycleonandoff.For example,electricblankets,irons,and cooking appliances.Thermostats control these types of appliances. Phantom Loads Many electrical loads draw power even when "off.”When estimating the energy use of a home,phantomloadsmustalsobetakenintoaccount.Phantomloadsaresmallloadsthatconstantlydrawpower,forexampleinstant-on television sets and applianceswithdigitalclocks,such as microwave ovens,VCRs,any item with a remote control,and some personalcomputers.Other phantom loads are appliances witha"wall-cube,”such as AC telephone machines,battery chargers,and dust busters.Phantom loadsmayseemnegligiblethoughtheyareusingpower24hrsaday7daysaweek.It is recommended to keepphantomloadstoaminimumbyeitherunpluggingthem,placing them on a switched circuit or a powerstrip.Figure 4-1 displays some common phantomloadsandthewattstheyconsume. 40 i : ii 1 ELECTRIC LOAD ANALYSIS Video Game ag Clock Radio |1.7 Cordless Phone #4 Answering Machine Security System |18.3 ] 1 _L i 0 5 10 15 20 Figure 4-1 WATTS CONSUMED BY COMMON PHANTOM LOADS Estimating Surge Requirements Surge requirements =Required watts x 3 When estimating an electrical load,surge loads are another factor.These are appliances with motors that draw more current when they start than when they are operating.For example,a power saw that uses 900 watts continuously might use up to 3,000 watts to start the motor.Consult the manufacturer or measure the load with an ammeter to determine surge requirements of specific loads.As a rough rule of thumb,minimum surge requirements may be calculated by multiplying the required watts of a load by three.(For specific surge requirements see manufacturet's equipment specifications.) #5;Calculating Load Estimates You can calculate the average daily electrical energy use in watt-hours as well as the total connected watts using the Load Estimation Worksheet on page 43. First,list the desired electric loads.If possible,obtain the quantity of each load and the electrical specifications,including alternating current and direct current voltages,amperage,and wattage of each load.Then list the average hours per day and days per week that the load will be used.Depending on the information you have available,you can either calculate or estimate these figures.Be sure to allow for seasonal variations in the use of the load and solar insolation. aae 41 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Electric Appliances to Avoid with PV Systems: *Space heaters e Water heaters Clothes dryer *Dishwasher Conventional refrigerator *Electric ranges Many electric loads that a designer would like toincludemaybecostprohibitivetopowerwithaphotovoltaicsystem.Usually a mix of load shiftingandincreasedequipmentefficiencycansignificantlyreducethecostofphotovoltaicsystems.A systemdesignerwillusuallychangetheelectricloadestimateseveraltimesbeforethefinalsystemisefficiently sized.The following examples are load-estimatingexercises.Using the Load Estimation Worksheet onpage43,calculate the average daily load in watt-hours for each example. Problem:A retired couple has sold their homeinthecityandnowliveinarecently-purchasedrecreationalvehicle.They follow the seasons,living in the desert near Apache Junction,Arizona,in the winter and in the mountainsnearLakeTahoe,California,in the summer.They treasure their new lifestyle's peace andquietandhaveresistedpurchasinganoisydieselgenerator.Their RV is equipped with propanefueledappliances,including their refrigerator,range,water heater,and space heater.They usekerosenelampsforreadingbutwouldusethesingle50-watt (12V direct current,4.17 amps)incandescent reading light in the RV more ofteniftheyhadasteadypowersource.They wouldliketoreadforfourhourseachnight,if powerwereavailable.Using the Load EstimationWorksheet(page 43),estimate their electricalloadandproposeasolution. Solution:12V X 4.17amps =50 watts X 7 daysperweek/7 days per week X 4 hours =200 DCwatthours/day.The electrical load could bereducedwithoutreducingtheavailablelightingbyusinga13-watt (12V direct current,1.08amps)fluorescent lamp and ballast.Recalculatetheestimateofthiscouple's electrical load,noting the effects of this substitution. Problem:A homeowner in a remote mountainous area near Colorado Springs,Colorado,wants to power the television andrefrigeratorinhiscabinwithaphotovoltaicsystem.His refrigerator is a 17-cubic-footmodel,rated at 500 watts (120V alrernatingcurrent,4.17 amps).He has timed its operationandsaysitruns30minuteseachhour(50percentofthetime).The cabin owner's smalltelevisionisratedat20watts(12V directcurrent,.1.67 amps).At first,he admits towatchingonlyonehouroftelevisionperday,but upon further questioning,he realizes hisfirstestimatedidnotaccountforanadditionalhoureachdayofnews,weather,and sports.Estimate the homeowner's load. Solution:Refrigerator:500 watts AC X 12hrs/day =6000 watt-hrs/day,TV:20 watts DCX2=40 watt-hrs/day DC.A responsible designer should suggest alternate,more cost-effective equipment for operating thehomeowner's refrigerator.The owner shouldconsiderswitchingtoapropaneorkerosenerefrigeratortoeliminatehislargestelectricalload.If these units are not available or cannotbeusedforsomereason,the owner shouldconsiderpurchasingamoreefficientdirect current refrigerator. ELECTRIC LOAD ANALYSIS Stand-Alone Electric Load Worksheet (abbreviated) Individual |Qty X Volts X Amps =Watts X Use X Use +.7 =Watt HoursLoadsACDChrs/day -days/wk days AC DC 7 NSEENDENENTNENTNENENTNENTNENTNITNENTNENIENDNIDNINITNENTNENENYNYONAC Total Connected Watts:AC Average Daily Load: DC Total Connected Watts:DC Average Daily Load: Sartion aALEtPA PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL *Recheck your numbers,but keep in mind this is only an estimate!&£«Considerations for *Remember that future loads may vary because«"<Calculating Load of the following: Estimates -People change Load estimations can be difficult to calculate due to -Seasons changethenumberofvariables.Consider the following ; , .'mating electrical |-Efficiency of loads may decrease with age isuggestionswhenestimatingelectricalloads.; -Appliances fail and will be replaced¢Consider all energy conservation,equipment8) efficiency,and load shifting opportunities.-People forget to turn appliances off *Use the correct load estimates.-Loads may be added. *Account for duty cycle when sizing,*Remember that not all appliances available inequipmentthatcyclesonandoff.alternating current are available in direct ¢Use manufacturer's literature when available,current.Make sure you can get the instead of generalized sources,such as the equipment you need and want for the system tables in this chapter.you are designing. Table 4-1 ELECTRIC LOAD ANALYSIS Typical wattage requirements for common appliances General household: Air conditioner (1 ton)..:1500 Alarm/security system ......3 Blow dryer............1000 Ceiling fan .........«10-50 Central vacuum ........750 Clock radio...ee eee eee 5 Clothes washer ........1450 Dryer (gas).........00.300 Electric blanket .........200 Electric clock ..........-,4 Furnace fan ........00-500 Garage door opener ......350 Heater (portable).......1500 Iron (electric).........1500 Radio/phone transmit .40-150 Sewing machine.........100 Table fan ........2.10-25 Waterpik ...........vee 100 Refrigeration: Refrigerator/Freezer .....540 22 ft*(14 hrs/day) Refrigerator/Freezer .....475 16 ft (13 hrs/day) Sun Frost refrigerator ....112 16 ft?(7 hrs/day) Vestfrost refrigr/freezer ....60 10.5 ft' Standard freezer .........440 14 ft (15 hrs/day) Sun frost freezer.........112 19 ft (10 hrs/day) Kitchen appliances: Blender ...............350 Can opener (electric).....100 Coffee grinder..........100 Coffee pot (electric)1200 Dishwasher ...........1500 Exhaust fans (3).........144 Food dehydrator ........600 Food processor .........400 Microwave (.5 ft?).......750 Microwave (.8 to 1.5 fr*).1400 Mixer Popcorn popper .........250 Range (large burner)....2100 Range (small burner)....1250 Trash compactor .......1500 Waffle iron ...........1200 Lighting: Incandescent (100 watt)..100 Incandescent light (60W)..60 Compact fluorescent .....16 (60W equivalent) Incandescent (40 watt)....40 Compact fluorescent .....11 (40W equivalent) Water Pumping: AC Jet Pump (4hp)......500 165 gal per day,20 ft.well DC pump for house ......60 pressure system (1-2 hrs/day) DC submersible pump ....50 (6 hrs/day) Entertainment: CB radio ........ce eee 10 CD player ......0...ee 35 Cellular telephone .......24 Computer printer .......100 Computer (desktop)...80-150 Computer (laptop).....20-50 Electric player piano ......30 Radio telephone .........10 Satellite system (12 ft dish).45 Stereo (avg.volume)......15 TV (12-inch black &white).15 TV (19-inch color).......60 TV (25-inch color)......130 VCR oo ceceeee 40 Tools: Band saw (14”)........1100 Chain saw (12”).......1100 Circular saw (7(4”)......900 Disc sander (9”).......1200 Drill (4)...cee eee 250 Drill (27)oo.eee eee 750 Drill 1”).........004.1000 Electric mower .......,1500 Hedge trimmer .........450 Weed eater......ccaee 500 45 Contents: 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Chapter 5 Photovoltaic Modules Photovoltaic Principles ....-- Module Types ..---+++++++> Module Performance eee eee Factors of Module Performance Photovoltaic Arrays ...---+-- Mounting Photovoltaic Modules Diodes ee eee . 47 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 5 4 :PrincorPhotovoltaicPrinciples Photovoltaic modules and arrays have proven to beareliablesourceofelectricalenergy,but they must beproperlydesignedasareliablesystemtobeeffective. This discusses the basic physical characteristics of photovoltaic modules and explainshowsomeclimateandsite-specific factors will affect chapter their performance.System designers and usersshouldbeawareofthesefactorswhenchoosing panels and designing photovoltaic systems.The basic unit of a photovoltaic system is thephotovoltaiccell.Cells are electrical devices about1/100th of an inch thick that convert sunlight intodirectcurrentelectricitythroughthephotovoltaiceffect.They do not consume fuel and have a life spanofatleast25years.PV cells have the potential toproduceasignificantamountofourelectricenergy.A module is an assembly of photovoltaic cellswiredinseriesorseries/parallel to produce a desiredvoltageandcurrent.Like small batteries,when PV-cells are wired in series,the voltage is additive whilethecurrentremainsconstant.Most cells produceapproximatelyone-half of a volt.Therefore,a 36-cellmodulewilltypicallyhaveanoperatingvoltageof18voltsunderstandardtestconditions,(STC)and anominalvoltageof12volts.The current output of -the module is dictated by the amount of surface area of an individual cell in the module.The PV cells are encapsulated within the module |framework to protect them from weather and otherenvironmentalfactors.Modules are available in avarietyofsizesandshapes.Typically,they are flatrectangularpanelsthatproduceanywherefrom5wattstoover200watts.The terms "module”and"panel”are often used interchangeably,though moreaccuratelyapanel'is a group of modules wiredtogethertoachieveadesiredvoltage.An array is agroupofpanelswiredtogethertoproduceadesired voltage and current. The Photovoltaic Reaction Photovoltaic cells do not need moving parts to createelectricalenergyfromthesun's energy.Whensunlightstrikesacell,electrons are 'excited andgenerateanelectricvoltageandcurrentthatiscarriedthroughwireswithinthecelltoanelectricalcircuit. We will describe the manufacturing process for single crystalline cells in order to help you understand the photovoltaic reaction.To manufacture single crystalline PV cells,silicon,oneoftheearth's most abundant elements,is purified andgrownintoacrystallinestructure.Silicon,in its pureform,is a semi-conductor,meaning its electricalpropertiesfallbetweenthoseofaninsulatorandaconductorandmakeitarelativelypoorconductorofelectricity.By adding special impurities to the siliconthroughaprocessknownas"doping,” silicon'snaturalpropertiesaremodifiedtobetterfacilitateanelectricflow.The impurities diffused in the silicon - boron and phosphorous -create a permanentimbalanceinthemolecularcharge,enhancing the silicon's ability to carry electrons.Once the silicon is grown into a cylinder-shapedcrystallinemass,it is sliced into wafers.The wafers thereby are then doped with either boron or phosphorous.When boron,which has an electron deficiency,isdiffusedintoawaferofsilicon,it creates a positively charged (p-type When phosphorous,which has an excess of electrons,is material material). diffused into the silicon,it creates a negativelychargedmaterial(n-type material).A crystallinesolarcellisawaferdopedononesidewithboron(+)and on the other side with phosphorous (-).TheregioncreatedbetweenthepositiveandnegativelayersiscalledtheP-N junction,When sunlight strikes a cell,it "knocks”looselyheldelectronsfromthesiliconlayer.These excitedelectronsareattractedtothepositivelychargedboronlayer,creating static electrical charge.The looseelectronsbuildanelectricalpressureattheP-Njunctionandbegintoflowthroughthemetalcontactsbuiltintothecell.All the contacts in a celljointogetherintoawirethatconnectsthefrontofonecelltothebackofanothercellinthemodule.This electrical circuit enables the electrons to flowthroughP-N junctions of each cell,building voltagewitheachcellwiredinseries.The voltage increase occurring at the P-Njunctionofeachcellhasanelectromotiveforceofapproximatelyone-half volt.The cell voltage isindependentofacell's size,although,current isaffectedbycellareaandsunlightintensity.The largeracell's area,the greater current it can produce.B P 5.2beaha Module Types Each photovoltaic module manufacturer uses specific designs and construction methods for fabricating wafers of silicon into a module.Once the wafers are formed,they are embedded with metal contacts to sweep electrons into the electrical circuit.The cells are covered with an anti-reflective coating to enhance sunlight absorption.The individual cells are then placed on a backing and wired together to achieve che desired voltage and current.This configuration of cells is framed and encapsulated to create a structural framework and to protect it from environmental factors.The following components of a photovoltaic module differentiate the various types of modules: *Cell material *Glazing material ¢Hardware,frame,and electrical connections The most important aspect of this process is the composition of the silicon crystalline structure.The crystalline material can be grown as a single crystal (single-cystalline),cast into an ingot of multiple crystals (poly-crystalline),or deposited as a thin film (amorphous silicon).The two types of crystalline silicon cells perform similarly,although single crystalline cells are slightly more efficient than poly- crystalline due to the poly-crystalline inter-grain boundaries within the cell.Thin film or amorphous silicon,which may also be deposited on a substrate or PHOTOVOLTAIC MODULES superstrate,is much more inexpensive to manufacture but is only about half as efficient as crystalline silicon cells.Other types of solar cells are currently being developed,such as cadmium telluride and gallium arsenide cells. ee?-Module Performance The total electrical energy output (wattage)of a photovoltaic module is equal to its output voltage multiplied by its operating current.Photovoltaic modules may produce current over a wide range of voltages,unlike voltage sources such as batteries, which produce current at a relatively constant voltage. The output characteristics of any given module are characterized by a performance curve,called an I- V curve,that shows the relationship between current and voltage output. Figure 5-1 shows a typical I-V curve.Voltage (V) is plotted along the horizontal axis.Current (I)is plotted along the vertical axis.Most I-V curves are given for the standard test conditions (STC)of 1000 watts per square meter irradiance (often referred to as one peak sun)and 25 degrees C (77 degrees F)cell temperature.It should be noted that STC represent the optimal conditions as a consistent means for measuring -rarely are these conditions recreated in outside environments.The I-V curve contains three significant points:Maximum Power Point (representing both Vmp and Imp),the Open Circuit Voltage (Voc),and the Short Circuit Current (Isc). 3.0 Isc Short Circuit Current ;; -Maximum Power Point2.5 Dee nnn nnn nnn nn nnn nnn nn nnn ne &Imp 2.0 -- 4E 1.5 ;- < 1.0 ---Voc Open0.5 Circuit Voltage 0.0 4 ttt +fot 0 5 10 15 20 25 Volts Figure 5-1 MODULE I-V CURVE (12VDC NOMINAL) News 49 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Maximum Power Point:This point,labeledVmpandImp,is the operating point at which themaximumoutputwillbeproducedbythemoduleatoperatingconditionsindicatedforthatcurve.Thevoltageatthemaximumpowerpointcanbedeterminedbyextendingaverticallinefromthecurvedownwardtoreadavalueonthehorizontalvoltagescale.The example in Figure 5-1 displays avoltageofapproximately17.3 volts at the maximum power.The current at the maximum power point can bedeterminedbyextendingahorizontallinefromthecurvetothelefttoreadavalueonthehorizontalcurrentscale.The example in Figure 5-1 displays acurrentofapproximately2.5 amps at the maximum power.The wattage at the maximum power point isdeterminedbymultiplyingthevoltageatmaximumpowerbythecurrentatmaximumpower.The poweroutputdecreasesasthevoltagedrops.Current andpoweroutputofmostmodulesdropsoffasthevoltageincreasesbeyondthemaximumpowerpoint.Open Circuit Voltage:This point,labeled Voc,isthemaximumpotentialvoltageachievedwhennocurrentisbeingdrawnfromthemodule.Since nocurrentisflowingthemoduleexperiencesmaximumelectricalpressure.The example in Figure 5-1displaysanopencircuitvoltageofapproximately21.4 volts.The power output at Voc is zero watts. Short Circuit Current:This point,labeled Isc,is the maximum current output that can be reached bythemoduleundertheconditionsofacircuitwithno resistance or a short circuit.The example in Figure 5-1 displays a current of approximately 2.65 amps.The power output at Isc is zero watts. B 4 Factors of ModulewePerformance Five major factors affect the performance output ofphotovoltaicmodules:load resistance,sunlightintensity,cell temperature,shading,and crystalline structure. Load Resistance:A load or battery determines the voltage at which the module will operate.Forexample,in a nominal 12-volt battery system,thebatteryvoltageisusuallybetween11.5 and 14 volts.For the batteries to charge,the modules must operateataslightlyhighervoltagethanthebatterybank voltage.When possible,system designers should ensurethatthePVsystemoperatesatvoltagesclosetothemaximumpowerpointofthearray.If a load'sresistanceigwellmatchedtoamodule's I-V curve,the module will operate at or near the maximum powerpoint,resulting in the highest possible efficiency.Astheload's resistance increases,the module will operateatvoltageshigherthanthemaximumpowerpoint,causing efficiency and current output to decrease. 3.0 1000 W/m? 2.5 800 W/m? 2.0 [- a 600 W/m? &15 f- 400 W/m? 1.0 200 W/m?; 0.0 +++-_+_os yy +++ 0 5 10 15 20 25 Volts Figure 5-2 EFFECT OF INSOLATION ON MODULE PERFORMANCE (12VDC NOMINAL) PHOTOVOLTAIC MODULES 3.0 25°C (77°F)2.5 30°C 40°C 2.0 [-50°C 60°C Pr 70°C =e 80°C (176°F) q 1.0 0.5 0.0 fp , 0 5 25 Volts Figure 5-3 EFFECT OF CELL TEMPERATURE ON MODULE PERFORMANCE (12VDC NOMINAL) Efficiency also decreases as the voltage drops below the maximum power point. This relationship between the load and photovoltaic array is particularly significant when an inductive load,such as a pump or motor,is powered directly by the array.A control device that tracks the maximum power point may be used to continuously match voltage and current operating requirements of the load to the photovoltaic.array for maximum efficiency. Intensity of Sunlight:A module's current output is proportional to the intensity of solar radiation to which it is exposed.More intense sunlight will result in greater module output.As illustrated in Figure 5-2, as the sunlight level drops,the shape of the I-V curve remains the same,but it shifts downward indicating lower current output.Voltage,although,is not changed appreciably by variations in sunlight intensity. 'Cell Temperature:As'the cell temperature rises above the standard operating temperature of 25 degrees C,the module operates less efficiently and the voltage decreases.As illustrated in Figure 5-3,as cell temperature rises above 25 degrees C (cell temp, not ambient air temp),the shape of the I-V curve remains the same,but it shifts to the left at higher cell temperatures indicating lower voltage output.Hear, in this case,may be thought of as electrical resistance to the flow of electrons.Effective current output may also be significantly decreased if the maximum power point of a module or array drops below the operating voltage of the load. Generally,between 80 and 90 degrees C,a module loses approximately 0.5 percent efficiency per degree Centigrade rise in temperature.Airflow under and over the modules is critical to remove heat to avoid high cell temperatures.A mounting scheme that provides for adequate airflow,such as a stand-off or rack mount,can maintain lower cell temperatures. Specially designed high temperature modules have more efficient cells or a greater number of cells to offset the lower voltage caused by higher temperatures. Temperature effects are more noticeable in systems without batteries,such as a utility connected systemwithoutbatteries.When a system has batteries they pull down the PV voltage to just above the battery voltage.Since the PV voltage is already lower it is often not as noticeable as in a system where there are not batteries.Designers would be well advised to refer to the module I-V curves for the panel they have selected and to consult the manufacturer for the module's specific application. 51 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 3.0 : Unshaded Module 2.5 > -2.TeTe 1 cell 25% _-- shaded 2.0 [-ot me ; , ma .ae 1 cell 50% ry an aa shaded S15 f-me . . <. a . 1 cell 75% 1.0 . shaded BE =1 cell 100% 08 . shaded ° 0.0 'a ee a 0 5 10 15 20 25 Volts Figure 5-4 EFFECT OF SHADING ON MODULE PERFORMANCE (1 2VDC NOMINAL) Shading:Even partial shading of photovoltaicmoduleswillresuleinadramaticoutputreduction.Some modules are more affected by shading thanothers.Figure 5-4 and Table 5-1 show the extremeeffectofshadingononecellofasinglecrystallinemodule.In Figure 5-4,one completely shaded cellreducesthismodule's output by as much as 75%.Some modules are less affected by shading than this example.Note:Remember that the array should not beshadedfrom9a.m.to 3 p.m.If there is shadingduringthisperiod,more modules will be needed toproduceadequatepower.The installer is responsible for selecting an appropriate site.Locating shading obstacles at the site is anextremelyimportantpartofasiteevaluation.Anentiresystem's performance can be diminished and aclient's investment undermined by underestimatingtheeffectsofshading,even partial shading.Somemanufacturersmakeuseofbypassdiodeswithinthemoduletoreducetheeffectofshadingbyallowingcurrenttobypassshadedcells.Bypass diodes aresemiconductordevicesthatpreventcurrentfromflowingintoshadedareas,although even with diodes,modules can be severely impacted by shading. Percent of One Cell Shaded Table 5-1 Effects of shading on module power Percent of Module Power Loss 0%0% 25 %25 % 50 %50 % 75 %66 % 100 %75 % 3 cells shaded 93 % ern Cope atinyen £74PsECHOTyO.4 ! \ ! i.bya%3 Photovoltaic Arrays An array consists of two or more photovoltaic panels wired to achieve a desired voltage and current.An array is usually mounted at a fixed angle from the horizontal,facing due south (in the Northern hemisphere).At solar noon on a clear day,such an array may receive 1000 watts of solar radiation per square meter.The array can convert about 10 percent of that radiation to usable electrical energy,resulting in approximately 100 watts of peak power per square meter of array. . Because the sun's position in the sky changes throughout the day and year,the array will receive varying amounts of sunlight.Since the array's power output is directly related to the amount of light it receives,an array rarely produces the maximum power possible.For example,an array in Albuquerque,New Mexico (35 degrees NL),which faces due south and is tilted at a 35-degree angle, receives 6.4 full-sun hours each day (averaged over a typical year).If the module is rated at 10 watts per square foot under full sun,1 square foot will produce 64 watt hours of energy each day. PHOTOVOLTAIC MODULES Wiring Dissimilar Modules Together Example 5-1 Two similar modules wired in series *module A:21 volts,5.4 amps *module B:21 volts,5.4amps *A and B in series:42 volts,5.4 amps *rotal watts:226.8 Two dissimilar modules wired in series *module A:21 volts,5.4 amps *module B:21 volts,2.8 amps a ¢Aand B in series:42 volts,3 amps | ¢total watts:126 When the modules of an array are wired together in series,the voltage is additive and the current remains constant.When the modules are wired together in parallel,the current is additive and the voltage remains constant.But what happens when two dissimilar modules are wired together? If two similar modules are wired together in series,the current remains the same and the voltage will double.However,when two dissimilar modules 6 ModuleA 5 - 4-- =2 3b...-----------b-e-Module A +Ba ie 7s Module B \ XN 2t-' \ \ \ 1 Tk \ 1} \ 0 F F \}A \ ' 0 5 10 25 30 35 40 45 Voltage Figure 5-5 EFFECT ON VOLTAGE WITH DISSIMILAR MODULES WIRED IN SERIES Section 5.5 53 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL are wired in series,the voltage is still additive,but the current will be only slightly greater than the current produced by the panel with the lowest current output in the series string. When two like modules are wired together in parallel,the voltage will remain the same,and thecurrentwilldouble.However,when two dissimilar modules are wired together in parallel,che current will still be additive,but the voltage will average between the two. Therefore,if there is a large difference in the output of the modules,it may be better to treat thedifferentmodulesasaseparatearrayratherthanto combine dissimilar modules in one array.The system designer is responsible for considering the implicationsofcombiningdissimilarmodulesanddecidinghowto configure the modules. Example 5-2 Two similar modules wired in parallel *module A:25 volts,3 amps *module B:25 volts,3 amps ¢A+B in parallel:25 volts,6 amps *total watts:150 Two dissimilar modules wired in parallel *module A:25 volts,3 amps *module B:21 volts,2.8 amps ¢A+B in parallel:23 volts,5.8 amps *total watts:133.4 px ¢«Mounting Photovoltaicwf}Modules The photovoltaic system designer must considermanyfactorswhenselectinganappropriatesiteformountingmodules.The location must be orientedtowardthesunandbefreeofshadingobstacles throughout the sun's daily and seasonal paths.Thesitemustbeinproximitytothepower-conditioning center to minimize line losses.The owners or operators of the system should be pleased with theaestheticsofthearrayandwhereitislocated. Depending on the locale,the site may also need toprovideprotectionfromtheftandvandalism.Finally, operators and designers should have easy access to perform routine maintenance. Once you have chosen the site,you can determine the type of mounting system best suited for the site and-the system application.There are various systems available for mounting a PV array, from simple bracket systems to complex dual axis 6 BL Module A+B ate F 3 Module A a Module B 2 = TR 0.0 ++4 ++ 0 5 10 15 20 25 30 Voltage Figure 5-6 EFFECT ON VOLTAGE WITH DISSIMILAR MODULES WIRED IN PARALLEL PHOTOVOLTAIC MODULES Roof Mount Ground Mount Pole Mount Figure 5-7 BASIC MOUNTING STRATEGIES trackers.The type of mounting system you choose will depend on the following factors: *orientation of the house *shading at the site ¢weather considerations *roof material *soil and/or roof load bearing capacity *system applications Bracket mount:In this system,two galvanized ' "poe >.steel angle brackets are bolted to a building's exterior walls or roof structure.A second pair of compatible brackets is attached to the end frames of the solar module.When the two sets of brackets are mated, they form a simple,durable,cost effective mounting system for a one module photovoltaic system.A simple bracket system can be used to mount a single solar module. Pole mount:This system uses a mounting hardware system bolted directly to a vertical pole that is securely cemented in the ground.A pole mount is a choice when attaching the array to the building is not desirable.Pole mounts can be used to mount arrays of up to twenty-four modest sized modules. Ground mount:This system uses a ground mounted atray support structure with a frame bolted directly to prepared footings.Standard support frames are commercially available or may be fabricated on site.CEVAMEaS55 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Roof mount:Four types of systems are commonlyusedwhenmountingaphotovoltaicarraytoaroof: *Rack mount:In this system,the photovoltaicmodulesaresupportedbyametalframeworkandaresetatapredeterminedangle. *Stand-off mount:In this system,thephotovoltaicmodulesaresupported by aFrameworkconstructedabovethefinished roof. *Direct mount:In this system,thephotovoltaicmodulesaremounted directly totheconventionalroofcoveringmaterialsand eliminate the need for a supporting framework and mounting rails. *Integrated mount:In this system,thephotovoltaicmodulesreplacetheconventionalroofcoveringandattach directly to the roof's rafters. Tracking Mounts:Trackers are classified as singleaxisordualaxistypes.Most single axis trackerspassivelyfollowthesun's azimuth but not its altitude.These trackers are a cost-effective,alternative schemeforsomeapplications.These units have no motors,controls,or gears,but rather use the changing weightofagaseousrefrigerantsealedwithintubestotrackthesun.Sunlight heats the refrigerant on one side causingtherefrigeranttoboil,expand as a gas,and condenseontheothercoolerside.This movement of refrigerantresultsinaweightshiftandcausesthetrackertomove.When the tracker faces the sun,both sides are evenlyheated,and the tracker remains in that position untilthesun's position changes,which causes the tracker toshiftagain.Single axis trackers can also be seasonallyadjustedtooptimizealtitudeangle.Note:some single axis trackers are motor drivenlikedual-axis trackers below.Dual-axis trackingmountstrackthesun's azimuth and altirude using alinearactuatormotorforeachaxis.These motors arecontrolledbyasensorandutilizepowerfromoneof the array's modules.Tracking units generally enhance a system's annualperformancebyapproximately25percentto30percent,but they can significantly increase the cost ofasystem.Trackers can increase system performance by15percentinthewinterand40percentinthesummer.Systems requiring larger loads 'during the summer months are ideal candidates for trackingsystems.In the summer,longer hours of effectiveinsolationareavailable,and a tracker will increase aPVsystem's collection potential.In contrast,winter-dominated loads are less likely to benefit significantly from trackers.Many system designers opt to use more .panels on a stationary mounting structure to avoid thecomplexitiesassociatedwithtrackingmounts.Youmustcarefullyevaluateeachsystemtodeterminetheeconomicviabilityoftrackersversusfixedmounts. peur mMmeteal6f Diodes When one module in an array is shaded,the outputoftheentirearraycanbedrasticallyreduced.The useofdiodescanminimizetheeffectsofshading.Adiodeisasemiconductordevicethatallowselectriccurrenttopassinonlyonedirection.In photovoltaicsystems,diodes may be used for several functions:tostopmodulesfrom"leaking”battery current at night,to mitigate the effects of shading,or to bypass a failed module.Blocking Diodes:This type of diode is placed inthepositivelinebetweenthemodulesandthebatterytopreventbatterycurrentfromreversingitsflowfromthebatteriestothearrayatnightorduringcloudyweather.Some controllers already contain a diode orperformthisfunctionbyopeningthecircuit.Bypass Diodes:This type of diode is wired inparallelwithamoduletodivertcurrentaroundthemoduleintheeventofshading.Bypass diodes arepre-wired in some modules and are usually sufficientunlessthearrayis48Vorgreater.When the array is48Vorgreaterorifexcessiveshadingexists,additional bypass diodes must be added.'Use the following configurations:*Bypass diodes are required on modules wiredinserieswithothers,but are not required on modules wired in a single parallel string. *Larger bypass diodes are required on parallelstringswiredinserieswithotherparallelstringsandareplacedacrosseachparallelstring.Isolation Diodes:Isolation diodes prevent thelossofcurrentintheeventthatonestringofmodulesinthearrayfails.Like bypass diodes,isolation diodesareusuallynotrequiredunlessthearrayis48voltsor greater. RA Example 5-3 Problem:A 12 volt system has 4 modules inparallel.Each module has a short circuit currentof2.5 amps.What size diode is required? Solution: 2.5 amps x 2 =5 amps5ampsx4modules=20 amp diode System designers should choose a diode with anampereratingofatleasttwicethemaximumcurrent it is expected to carry. PHOTOVOLTAIC MODULES Diodes are also rated for the maximum voltagetheywilltoleratewheninthereversemode.Theymustbesizedtoatleasttwicethevoltagetheywill withstand. Example 5-4 Problem:A 48 volt system needs a diode rated at what voltage? Solution:48 volts x 2 =96 volt diode Se VED Pano ed 57 Contents:6.1 Battery Types and Operation 6.2 Battery Specifications ....-- 6.3 Battery Safety ...--++++++> 6.4 Battery Sizing Exercise ...--6.5 Battery Wiring Configuration Chapter 6 Batteries 59 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL -Battery Types and.¢«§Operation Batteries store direct current electrical energy in chemical form for later use.In a photovoltaic system, the energy is used at night and during periods of cloudy weather.Batteries also serve as a portable power source for appliances,such as flashlights and radios.Since a photovoltaic system's power output varies throughout any given day,a battery storage system can provide a relatively constant source of power when the PV system is producing minimal power during periods of reduced insolation.Batteries can even power the loads when the PV array is disconnected for repair and maintenance.Batteries can also provide the necessary amounts of surge power required to start some motors. Batteries are not one hundred percent efficient. Some energy is lost,as heat and in chemical reactions,during charging and discharging. Therefore,additional photovoltaic modules must be added to a system to compensate for battery loss. Remember,there are several types of day-use systems that do not require batteries.A water pumping system can be designed to pump during the day to a storage tank.If water is needed at night,the water can be gravity fed from a storage tank located inter-cell ,«--Post Connector Negative Cover --]Strap Positive _Partition Strap Positive Separator Plate Negative . Plate Container Figure 6-1 CUT-AWAY OF A STANDARD LEAD ACID BATTERY CELL higher than the faucet or point of use.Some applications,such as greenhouse ventilation fans, proportionally require more electricity as the intensity of the sun increases.The fans are only needed and can only operate when the sun shines,an ideal use for PV-supplied power. Utility grid-connected photovoltaic systems do not necessarily require batteries,though they can be used as an emergency backup power source.Some inefficiency issues exist when using batteries in a grid-connected system.See chapter 11. Many battery types and sizes are available.Smaller sizes,commonly used in flashlights or portable radios, are available in the "disposable”(primary)or rechargeable (secondary)options.Rechargeable nickel cadmium (nicad)batteries are commonly used for large standby loads,such as industrial applications, daily loads in cold climates,and small portable appliances.These batteries may be re-charged using a solar or AC battery charger.Manufacturers of nicad batteries claim that nicads will last through more charge/discharge cycles than lead-acid batteries.A battery is charging when energy is being put in and discharging when energy is being taken out.A cycle is considered one charge-discharge sequence,which often occurs over a period of one day in residential photovoltaic systems. The following types of batteries are commonly used in PV systems: *Lead-acid batteries -Liquid vented -Sealed (VRLA-Valve Regulated Lead Acid) ©Alkaline batteries -Nickel-cadmium Nickel-iron Lead-Acid Batteries:In the United States,the battery most commonly used for residential scale photovoltaic applications is the lead-acid battery,which closely resembles an automotive battery.Automotive batteries,however,are not recommended for PV applications because they are not designed to be "deep- cycled.”They are designed to discharge large amountsofcurrentforashortdurationtostartanengineand then be immediately recharged by the vehicle's alternator or generator.Photovoltaic systems often require a battery to discharge small amounts of currentoverlongdurationsandtoberechargedunderirregular wh!60 'rrpebpruinyfeti: boke conditions.Deep cycle batteries can be discharged down as much as 80 percent state of charge.Anautomotivebatterymaylastforonlyafewphotovoltaiccyclesundertheseconditions.In contrast,deep cyclelead-acid batteries suitable for photovoltaic applications can tolerate these conditions,and,if properly sized and maintained,they will last from three to ten years,or even longer.This chapter primarily discusses the lead-acid battery system,since these batteries are rechargeable,widely available,relatively inexpensive,and available in a variety of sizes and options.They are alsocommonlyused,easily maintained,and reasonablylonglived.Lead-acid batteries may be categorizedintoliquidelectrolyte(liquid vented)and captiveelectrolyte(sealed or VRLA)subcategories.Liquid Vented:Liquid lead-acid batteries are likeautomobilebatteries.The battery is buile from positive and negative plates,made of lead and leadalloyplacedinanelectrolytesolutionofsulfuricacidandwater.Figure 6-1 shows the cross-section of a common 12-volt liquid lead-acid battery containing 6 individual 2-volt cells.As with the automobile battery,a voltage control is used to regulate thebatteryvoltage.As the battery nears full charge,hydrogen gas is produced and vented out of the battery. Caution!Hydrogen gas is very explosive ifcontained.No open flames or sparking can be allowed near a battery.Motor generators,gas space heaters,and gas water heaters must be isolated from a battery. Water is lost when the battery vents waste gasses, so it must be refilled periodically.Some batteries areequippedwithrecombinatorcellcapsthatcapture the gasses and return them to the battery as water.Deep cycle batteries will last longer if protected fromcompletedischarge.Controls with a low voltagedisconnect(LVD)protect batteries from complete discharge.Like an automobile battery,less capacity isavailablewhenthebatteryiscold,'and higher temperatures shorten battery life.Sealed Lead-Acid Batteries (VRLA):Unlike liquid vented batteries,sealed batteries have no caps,and thus no access to the electrolyte.They are not BATTERIES totally sealed -a valve allows excess pressure to escapeincaseofovercharging.This is referred to as a valve regulated lead acid battery (VRLA).Sealed batteriesareconsideredmaintenancefreebecauseyoudonot need to access the electrolyte. The two types of sealed batteries commonly used in photovoltaic systems are gel cell and absorbed glassmat(AGM).In traditional gel cell batteries,the electrolyte is gelled by the addition of silica gel thatturnstheliquidintoagelledmass.AGM batteries useafibroussilicaglassmattosuspendtheelectrolyte.This mat provides pockets that assist in the recombination of gasses generated during charging, and limit the amount of hydrogen gas produced. The main advantage of sealed batteries is that they are spill-proof.The gelled electrolyte cannot bespilled,even when broken.This allows them to besafelytransportedandhandled.For this reason,they are a RV or marine applications.They can be air-shipped in contrast to acommercialliquidlead-acid battery that needs to beshippeddry,then activated on site by the addition ofelectrolyte.They also do not require periodicmaintenance,such as watering or equalization.This makes them a good choice for very remote applications where regular maintenance is unlikely or not cost effective. Gel cell batteries cost more per unit of capacity compared to liquid lead-acid batteries.They aresusceptibletodamagefromoverchargingespeciallyinhotclimatesandhaveashorterlifeexpectancy than other battery types.It is important to remember that most sealed batteries must be charged to lower reasonable choice for voltages and at a lower amperage rate to prevent excess gas from damaging cells.Using Charge Controls with Lead Acid Batteries: Lead-acid batteries need a control to preventovercharginganddischarging.These controls,knownaschargecontrollers,work by monitoring batteryvoltage,which rises as the battery is charged and falls as the battery discharges.A charge controller is necessarybecauseoverchargingcausesexcessivelossofliquid electrolyte,which increases maintenance requirements and shortens battery life.Also,the deeper a battery is regularly discharged,the shorter its life.Thus,a chargecontrollerwithlowvoltagedisconnect(LVD)is often desirable to prevent deep discharge. a watt pny mmBEQTENSetNeSaat 61 PHO 62 TOVOLTAICS:DESIGN AND INSTALLATION MANUAL In home PV systems,the use of an automaticLVDshouldnotnegatetheend-user'sresponsibilitytomanagebatterystate-of-charge.LVD only protects the battery from over-discharging from DC loads.AC loads must bemanagedwithaninverterLVD.Many PVsystemdesignersconsidercontrollerswithLVDtobe"the last line of defense”to protectbatteriesfrombeingoverlydischarged. Each battery type has a slightly different chargeterminationvoltage(high voltage disconnect orHVD).With 2-volt nominal cell voltage,the safechargeterminationsetpointforleadacidbatteriesis2.35 -2.5 volts per cell.The low voltage disconnect(LVD)will also vary depending on the depth ofdischargedesired.Table 6-1 lists the typical voltagesetpointsforsealedandliquidlead-acid batteries.Always use the manufacturer's specifications if available..Alkaline Batteries:Alkaline batteries,such asnickel-cadmium and nickel-iron batteries,also havepositiveandnegativeplatesinanelectrolyte.Theplatesaremadeofnickelandcadmiumornickelandironandtheelectrolyteispotassiumhydroxide.Eachcellhasanominalvoltageof1.2 volts and the chargeterminationpointis1.65-1.8 volts per cell.Thesebatteriesareoftenexpensiveandmayhavevoltagewindowcompatibilityissueswithcertaininvertersandchargecontrols.An advantage is that they arenotasaffectedbytemperatureasothertypesofbatteries.For this reason,alkaline batteries areusuallyonlyrecommendedforcommercialorindustrialapplicationsinlocationswhereextremelycoldtemperatures(-50°F or less)are anticipated.In residential PV systems,typically liquid lead-acid batteries are the wisest choice.They usuallyconstituteasignificantpartofthetotalsystemcost.The majority of PV systems and components are designed to use lead-acid batteries.Despite the safety,environmental,and maintenance issues,batteries arenecessarytoprovidetheneededflexibilityand reliability ro a home PV system. Battery Specifications A photovoltaic system designer must consider thefollowingvariableswhenspecifyingandinstallingbatterystoragesystemforastand-alone photovoltaic system: ¢Days of autonomy ¢Battery capacity +Rate and depth of discharge °Life expectancy ¢Environmental conditions ¢Price and warranty ¢Maintenance schedule Days of Autonomy:Autonomy refers to thenumberofdaysabatterysystemwillprovideagivenloadwithoutbeingrechargedbythephotovoltaicarrayoranothersource.You must consider a system'slocation,total load,and types of loads to correctly determine the number of days of autonomy.General weather conditions determine the numberof"no sun”days,which is a significant variable indeterminingautonomy.Local weather patterns andmicroclimatesmustalsobeconsidered.For example,intheColoradomountains,storms range from anafternoonsummerthundershowertoathree-daywintersnowstorm.In humid climates,three-to four-week cloudy periods can occur.It may be cost-prohibitive to size a battery system capable of providingpowerinthemostextremeconditions.Consequently,most designers usually opt for a design based on theaveragenumberdaysofcloudyweatherordesignwithahybridapproachaddingageneratororwindturbine. Table 6-1 Voltage Set Points for Lead-Acid Batteries in a 12-volt system - Type Charge Termination Low Voltage Cutoff Sealed (VRLA)14.1 volts 11.6 volts Liquid 14.6 -15.0 volts 11.3 volts The most important factors in determining anappropriateautonomyforasystemarethesizeandtypeofloadsthatthesystemservices.It's importanttoanswerseveralquestionsabouteachload. ¢Is it critical that the load operate at all times? *Could an important load be "shed”or replaced by alternatives? °Is the load simply a convenience? The general range of autonomy is as follows: *2 to 3 days for non-essential uses or systems with a generator back-up. *5 to 7 days for critical loads with no other power source. : Note:The system designer must take into account that the PV array is typically sized to meet the daily load.If autonomy is built inco the system and no daily loads are "shed”the PV array might not be capable of fully recharging the battery bank.An alternate means of battery charging should be employed. Battery Capacity Batteries are rated by amp-hour (AH)capacity.The capacity is based on the amount of power needed tooperatetheloadsandhowmanydaysofstoredpowerwillbeneededduetoweatherconditions.Using a water analogy,you can think of a battery as a bucket,the stored energy as water and the AH capacity as the bucket size.The AH rating will tell you "how large your bucket ts”,Most battery manufacturers specify batterycapacityinamp-hours.In theory,a 100 AH batterywilldeliveroneampfor100hoursorroughlytwoampsfor50hoursbeforethebatteryisconsidered BATTERIES temperature,age,and recharging characteristics.Fundamentally,the required capacity is also affected by the size of the load.If the load is reduced,the required battery capacity is also reduced.Since it is easy to add photovoltaic modules to an existing photovoltaic system,a commonly held_misconception is that the entire photovoltaic system fully discharged.If more storage capacity is required -to meet a specific photovoltaic application requirement then batteries can be connected inparallel.Two 100 amp-hour 12-volt batteries wiredinparallelprovide200amp-hours at 12 volts.Highervoltagesareobtainedthroughserieswiring.Two 100amp-hour 12-volt batteries wired in series provide 100 amp-hours at 24 volts. Many factors can affect battery capacity, including rate of discharge,depth of discharge, is modular as well.However,manufacturers generally advise against adding new batteries to an old batterybank.Older batteries will degrade the performance of new batteries (since internal cell resistance is greater in older batteries)and could result in reducedsystemvoltagewhenwiredinseries.In addition,if you were to add batteries to an existing system,you would probably add them in parallel to increase amp-hour capacity and maintain system voltage.It'sadvisabletominimizeexcessive"paralleling”because this increases the total number of cells,thereby increasing the potential for failure from a bad cell.You should initially specify a slightly larger battery capacity than is needed because batteries losetheircapacityastheyage.However,if you greatlyoversizethebatterybank,it may remain at a stateofpartialchargeduringperiodsofreducedinsolation.This partial charge state can cause shortened batterylife,reduced capacity,and increased sulfation. Battery capacity should be determined by the overall load profile. Rate and Depth of Discharge The rate at which the battery is discharged directly affects its capacity.If a battery is discharged quickly, less capacity is available.Conversely,a battery that is discharged slowly will have a greater capacity.Forexample,a six-volt battery may have a 180 AHcapacityifdischargedover24hours.However,if thesamebatteryisdischargedover72hours,it will have a 192 AH capacity.A common battery specification is the battery's capacity in relation to the number of hours that it isdischarged.For example,when a battery is dischargedover20hours,it is said to have a discharge rate of C/20 or capacity at 20 hours of discharge.If a battery is discharged over 5 hours,the discharge rate is C/5.Note that the C/5 discharge rate is four times faster than the C/20 rate.Most batteries are rated at the C/20 rate.Table 6-2 lists a few batteries and their battery capacity at several discharge rates. 63 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Table 6-2 Effect of discharge rate on battery capacity 72 hour 24 hour 16 hour 12 hour 8 hour Model Volts/Unit AH capacity AH capacity.AH capacity AH capacity AH capacity C2 2 288 270 259 245 230 BG 6 192 180 173 162 (154 Al2 12 105 100 95 90 85 Note:always check manufacturer _discharged,even though some deep cycle batteries recommendations.can survive this condition the voltage will continually Similar consideration should be taken when charging batteries.Most flooded lead-acid batteriesshouldnotbechargedatmorethantheC/5 rate.Ifabatterywereratedat220AHattheC/20 rate,charging it ata C/10 rate would equal charging at 22amps(220 +10).Gel-cells,however,should never bechargedathigherthanaC/20 rate.Depth of discharge (DOD)refers to how muchcapacitywillbewithdrawnfromabattery.Most PVsystemsaredesignedforregulardischargesof40percentto80percent.Battery life is directly relatedtohowdeepthebatteryiscycled.For example,if abatteryisdischargedto50percenteveryday,it willlastabouttwiceaslongasifitiscycledto80percent.Lead-acid batteries should never be completely decrease.Nicad batteries,on the other hand,can be totally discharged without harming the battery andholdtheirvoltage.When the nicad is fullydischargeditmayreversepolarity,potentiallyharmingtheload.A manufacturer's specificationsheetwilllistthemaximumdepthofdischargefor any battery.Shallow cycling systems,discharging the batteryonly10to20percent,have two distinct advantages.First,in general,batteries that are shallow cycled willhavealongerlifespan.If a battery is only cycled to10percentDOD,it will last about 5 umes as long asonecycledto50percent.Second,a reserve AHcapacityisdesignedintothesystemforextendedcloudyweather.This is not to say that a larger battery 7000 6000 \- 5000 +-oyfom]3S#ofCycles3000 ;- 2000 -- 0 ++ 0 20 40 60 80 100 120 Daily Average Depth of Discharge Figure 6-2 NUMBER OF BATTERY CYCLES IN RELATION TO DAILY DEPTH OF DISCHARGE Pe 64 meets Or:ta.ceeog BATTERIES 120 100 F-fe)eoOooO||%ofRatedCapacityre)|-80 -60 -40 -20 20 40 80 Battery Temperature (°C) Figure 6-3 EFFECTS OF TEMPERATURE ON BATTERY CAPACITY capacity is always better,As discussed previously,if abatterybankisverylargewithrespecttothecapacityofthechargingsource,the batteries will not bechargedquicklyenoughtoreturnthemtoafullstateofcharge.This can result in sulfation and decreasedbatterylife.The most practical number to use whendesigningasystemIs50percentdepthofdischargeforthebeststorageversusCOSTfactor. Life ExpectancyMostpeoplethink of life expectancy in terms ofyears.Battery manufacturers,however,specify lifeexpectancyintermsofaquantityofcycles.Batterieslosecapacityovertimeandareconsideredto-be at theendoftheirlifewhen20percentoftheiroriginalcapacityislost,although they can still be used.Whensizingasysteminitially,this should be considered.Depth of discharge also refers to the percentageofabattery's rated amp-hour capacity that has beenused.Battery life (number of daily cycles)versusdepthofdischarge(in percent of battery capacity)tsshownforalowercostsealedbatteryinFigure6-2.For example,a battery that experienced shallowcyclingofonly25percentDODwouldbeexpectedtolast4000cycleswhileabatterycycledtoan80percentDODwouldlast1500cycles.If one cycleequaledoneday,the shallowly cycled battery would last for 10.95 years while the deeply cycled battery would last for only 4.12 years.This is only an estimate.Some batteries aredesignedtobecycledmorethanonceeachday.Inaddition,batteries degrade over time,affecting life expectancy. Environmental-Conditions Batteries are sensitive to their environment and areparticularlyaffectedbythetemperatureofthatenvironment.Higher voltage charge terminationpointsarerequiredtocompletechargingasabattery'stemperaturedrops(the opposite is true in warmertemperatures).Controllers with a temperaturecompensationfeaturecanautomaticallyadjustchargevoltagebasedonabattery's temperature.Manufacturers generally rate batteries at 77degreesF(25 degrees C).The battery's capacity willdecreaseatlowertemperaturesandincreaseathighertemperatures.A battery at 32.degrees F may be abletoachieveonly65to85percentofitsfullyratedcapacity.A battery at -22 degrees F will achieve only50percent.Battery capacity is increased at highertemperatures.Figure 6-3 illustrates the effects oftemperatureonbatteriesatthreedischargerates.Even though battery capacity decreases at lowertemperatures,battery life increases.Likewise,the 65 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL _at higher temperatures, 66 Table 6-3 Battery temperature multiplier at various temperatures Temperature Battery Temperature Multiplier 80°F /26.7°C 1.00 70°F /21,2°C 1.04 60°F /15.6°C 1.11 50°F /10.0°C 1.19 40°F /4.4°C 1.30 30°F /-1.1°C 1.40 20°F /-6.7°C 1.59 higher the battery temperature,the shorter the life of§y temp the battery.Most manufacturers say there is a 50 percent loss in life for every 15 degrees F increase over the standard 77-degree cell temperature.As far ” as capacity versus battery life,this tends to even out in most systems,as they will spend part of their lives and part at lower temperatures. When sizing a system,you can compensate for the effects of temperature by using a battery temperature multiplier.To find out the adjusted battery capacity needed,multiply the necessary battery capacity by the battery temperature multiplier in Table 6-3. Colder temperatures affect more than the battery's capacity.In extremely cold environments, the electrolyte can freeze.The temperature at which a battery will freeze is a function of its state of charge. When a liquid electrolyte battery is completely discharged,the electrolyte is principally water.The electrolyte in a fully charged battery is mainly sulfuric acid,which freezes at a much lower temperature.Table 6-4 lists the freezing point at various states of charge.To maintain a constant temperature,lead-acid batteries can be placed in an insulated (R20 extruded polystyrene)battery box. Nicad or sealed batteries are not as susceptible to freeze damage. Regardless of temperature concerns,batteries should be located in a sturdy enclosure (a battery box).Since liquid electrolyte batteries produce explosive hydrogen gas when charging,the enclosure or area where the batteries are located should be well vented.Even though a battery box helps to contain the gasses,other electric system components should be installed a reasonable distance away from the battery compartment.This reasoning is twofold. One,sparking from the electrical equipment could ignite the gasses.Two,the gasses are corrosive and will attack other system components.Ventilation problems can be addressed by using special re- combinators or catalytic converter cel]caps that capture hydrogen vent gas,recombine it with oxygen to create water,and return the liquid water to the battery electrolyte.A battery enclosure should also be used to contain acid in case the batteries leak. Always try to design systems with batteries as near as is safely possible to the loads and the array to minimize wire runs,thereby saving money on materials and reducing voltage drop. Measuring Battery State of Charge A voltmeter or a hydrometer can be used to measure a battery's state of charge.To properly check voltages, Table 6-4 Liquid electrolyte freeze points,specific gravity,and voltage _state of charge Freeze Point Specific Gravity )Voltage 100%-71 °F 1.260 12.70 75%-35 °F 1.237 12.50 50%-10°F .1.200 12.30 25%3 °F 1.150 12.00 0%17°F 1.100 11.70 _ ae42-VOLT CONFIGURATIONwith12-volt batteries in parallel 12-VOLT CONFIGURATIONwith6-volt batteries in series/parallel BATTERIES 48 op a 12-VOLT CONFIGURATIONwith2-volt batteries in series 12-VOLT CONFIGURATIONwith6-volt batteries in series Se Figure 6-4 12 VOLT BATTERY CONFIGURATIONS the battery should sit at rest for a few hours(disconnect from charging sources and loads).Table6-4 can be used to compare a 12V battery's voltage toitsstateofcharge.For a 24-volt system,multiply by2,and for a 48-volt system,multiply by 4.For gel cellbatteries,subtract 0.2 volts from the numbers in the table.Table 6-4 can also be used to determine abattery's state of charge by measuring the specificgravityofacellwithahydrometer.(See Chapter 16.) gh ar 3/0 Battery SafetyBatteriesusedinphotovoltaicsystems are potentiallythemostdangeroussystemcomponentifimproperlyhandled,installed,or maintained.Dangerouschemicals,heavy weight,and high voltages andcurrentsarepotentialhazardsthatcanresultinelectricshock,burns,explosion,ot corrosive damagetoyourselforyourproperty.Since battery technologyisconstantlyevolving,responsible designers and 67 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL users should continue their training on the aspects of battery technology covered in this chapter to insureproperhandlinganddesign.Specific manufacturer'sliteraturecanbeobtainedtohelpwithdesign, installation,and maintenance decisions.You should observe the following safety rules to insure proper and safe handling,installing,maintaining,and replacing of photovoltaic system batteries.*Remove any jewelry before working around batteries. *Use proper tools when assembling cells. Design the battery area to be properly ventilated. *Wear protective clothing (especially eyeprotection)while working on batteries. *Have baking soda accessible to neutralize acid spills. *Have fresh water accessible in case electrolyte splashes on skin or eyes.If an accident occursflushwithwaterforfiveto10minutes,then contact a physician. *Keep open flames and sparks away frombatteries.No smoking near any battery. °Discharge body static electricity before touching terminal posts. *Disconnect battery bank from any sources of charging or discharging before working on batteries. *Do not lift batteries by their terminal ports orbysqueezingthesidesofthebattery.Liftbatteriesfromthebottomorusecarrying straps. +Do not use metal hard hats or non-insulatedtoolsaroundbatteriestoavoidpossibleshock. Use tools with insulated or wrapped handles to avoid accidental short circuits. Follow the manufacturer's instructions. e Use common sense. A Battery Sizing Exercise Problem:Use Table 6-5 to specify a batterybankforthefollowingphotovoltaicsystem.(AcompletesystemsizingworksheetcanbefoundinAppendixD) The occupants ofa remote home near Ojai,California,are designing a photovoltaic systemtomeettheir1080watthoursperdayACelectricalload.They have decided on a 12-voltdirectcurrentsystemandfeeltheyneedtwodaysofautonomy.The maximum depth ofdischargetheydesireoverthattwo-day period is50percent.The occupants have tentativelyselectedtheModelAbatteryfromXYZ Manufacturer,a 6-volt battery rated at 200amp-hours.The occupants will keep thebattery(s)in a conditioned space that will bemaintainedat77degreesF. Solution:To start,de-rate for inverterinefficiencybydividingtheACAverage DailyLoad(1080 warts)by the standard inverterefficiencyfigure(90 percent or 0.9).MultiplytheresultingAverageAmp-Hours/Day (100)bytheDaysofAutonomy(2)and divide by theDischargeLimitorDOD(50 percent or 0.5)'and divide again by the Battery AH Capacityforthespecifiedbattery(200).The resultingfigureisthenumberofbatteriesinparallel(2).Next determine the number of batteries neededtoachievethesystemvoltagebydividingtheDCSystemVoltage(12)by the Bartery Voltage(6).Then multiply this number (2)by thenumberofbatteriesinparallel(2)to determine the Total Batteries needed (4). The answers are listed in Table 6-6.(Page 70) 68 Serdion ©4wotEERIEWee . BATTERIES Table 6-5 Battery Sizing Worksheet AC Average Inverter +4 DC Average . DCSystem =Average Amp-. Daily Load ,Efficiency Daily Load ,Voltage hours/Day [(>)+]+= Average X Days of .Discharge . BatteryAH =Batteries in Amp-hours/day Autonomy :Limit ,Capacity Parallel x =>> = DC System =Battery =Batteries X Batteriesin =Total Voltage :Voltage in Series Parallel Batteries = =xX -= Battery Specification Make:Model: PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 5 =Battery WiringeweConfiguration Batteries need to be configured to obtain the desiredvoltageandamp-hours.Using the design and batteryparametersfromtheexample,we can clearly see howasystem's batteries should be configured and wired.Two separate six-volt batteries rated at 200 AH eacharewiredinseriestoobtain12Vdirectcurrentand 200 AH.Two of these series strings are wired in parallel to achieve 12V direct current and 400 AH.Figure 6-4 and Figure 6-5 show examples of wiringconfigurationsfor12V,24V,and 48V battery banks.Note:To create an equal path length for electron flow through the batteries,you must wire intooppositesidesofthebatterybankkeepingthecablesequallength.See Figure 6-4 and Figure 6-5. Table 6-6 Answers to the Battery Sizing Exercise AC Average -Inverter DC Average DC System,'Average Amp- Daily Load "Efficiency Daily Load ,Voltage hours/Day [(1080 +4 \+N/A Jj +12 =l00 Average x Days of Discharge . BatteryAH Batteries in Amp-hours/day Autonomy Limit Capacity parallel 100 X 2 +5 +200 =2 : DC System :Battery =Batteries X Batteries in =Total Voltage Voltage in Series Parallel Batteries ' 2 +b =2 x 2.=4 Battery Specification Make:XYZ Model:A 70 Sertiqn GF, 24-VOLT CONFIGURATION with 12-volt batteries in series 24-VOLT CONFIGURATION 24-VOLT CONFIGURATION 24-VOLT CONFIGURATIONwith6-volt batteries in series/parallel with 6-volt batteries in series Figure 6-5 24-VOLT BATTERY CONFIGURATIONS with 2-volt batteries in series BATTERIES 71 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Figure 6-6 48-VOLT BATTERY CONFIGURATIONS "IN Contents: 7.1 Controller Types ---+--- 7.2,Controller Features .----7.3 Specifying a Controller ..7.4 Controller Sizing Exercise ase : -CAUTION:BATTERY .MAY OVERCHARGE WHENjoeSETPOREQUALIZE. Chapter 7 PY Controls 73 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL f .|Controller Types The photovoltaic control is a voltage regulator.The primary function of a conwoller is to prevent the battery from being overcharged by the array.Many PV controls also protect a battery from being overly discharged by the DC load.A PV charge control senses battery voltage.When the batteries are fully charged,the contro]will stop or decrease the amount of current flowing from the photovoltaic array into the battery.When the batteries are being discharged to a low level,many controllers will shut off the current flowing from the battery to the DC load(s). Charge controls come in many sizes,typically from just a few amps to as much as 60 amps;higher amperage units are available,but rarely used.If high currents are required,two or more PV controllers can be used.When using more than one controller,it is necessary to divide the array into sub-arrays.Each sub-array will be wired into its own controller and then they will all be wired into the same battery bank.There are four different types of PV controls. They are: *Shunt controls *Single-stage controls ©Multi-stage controls *Pulse controls Shunt controllers:Shunt controllers are designed for very small systems.They prevent overcharging by "shunting”or bypassing the batteries when they are fully charged.The shunt controller's circuitry monitors the battery voltage and switches excess current through a power transistor when a pre- set full charge value is reached.This acts like a resistor and converts the excess power into heat. Shunt controllers have heat sinks with fins that help to dissipate heat. These controllers may also incorporate a blocking diode to prevent current from draining back from the batteries through the solar array at night.Blocking diodes act like one way valves, allowing current to flow into the batteries duringcharging,and prevent back flowor leakage from batteries to the array at night. Shunt 'controllers are simply designed andinexpensive.The circuitry is completely sealed for environmental protection.They must be exposed to the open air to provide the ventilation required from the cooling fins.Their disadvantages are their limited load handling capability and requirements. ventilation Single-stage controllers:Single-stage controllers prevent battery overcharging by switching the current off when the battery voltage reaches a pre-set value called the charge termination set point (CTSP).The array and battery are automatically reconnected when the battery reaches a lower preset value called the charge resumption set point (CRSP).Some manufacturers incorporate a built-in timer to cycle the constant voltage charge during the end of the charging process to "top-off”the battery bank. Single-stage controllers use a sensor to break the circuit and prevent reverse current flow at night, instead of using a blocking diode.These controllers are small and inexpensive,eliminating the need for bulky heat sinks because they do not produce much heat.They have greater load handling capacity than shunt type controllers.Another advantage is they generally do not require significant ventilation. Multi-stage controllers:.These devices automatically establish different charging currents depending on the battery's state of charge.The full array current is allowed to flow when the bartery is at a low state of charge.As the battery bank approaches full charge,the controller dissipates some of the array power so that less current flows into the batteries. The "trickle”charge tapers off as the battery bank approaches a fully charged state. This charging approach is said to increase battery life.Like shunt controllers,heat is generated by the dissipation of power,requiring that multi-stage controllers be properly ventilated.These controllers generally have a relay type switch that prevents reverse "leakage”at night. Some manufactured units are designed to float the batteries by providing a constant voltage with only a small amount of current. Pulse controllers:These provide a "topping off” charge by rapidly switching the full charging current on and off when the battery voltage reaches a fully charged state (the pre-set charge termination point). The length of the charging current pulse gradually decreases as battery voltage rises.Blocking diodes may be used in these controllers. i é Controller Features In addition to preventing overcharging,controllers can have many other features that protect the batteries,provide a better user interface,and increase the flexibility of a PV system. Overdischarge Protection.Some controllers provide overdischarge protection to prevent batteries from being overly discharged.Like a parked car with its lights left on,photovoltaic system loads can easily over- drain batteries,dramatically shortening the life of the battery.Most photovoltaic systems provide protection for the battery against unmanaged discharge. Controllers prevent over-discharging by: *Temporarily turning off loads at a preset state-of-charge level. *Activating lights or buzzers to indicate low battery voltage. *Turning on a standby power supply. Turning off loads to prevent further battery discharge (until the photovoltaic modules or other power source recharge the battery to a minimum level)- is called load management or load shedding and is accomplished using a low voltage disconnect (LVD). If a controller performs load management,DC loads will automatically be shut down.Therefore,essential loads must be wired directly to the battery to avoid unplanned disconnection.In this case,battery over- discharging can still occur since the controller has been bypassed.It is also important to remember that charge controllers only control DC loads.The inverter LVD needs to be programmed to disconnect the AC loads. Lights or buzzers may also be used to indicate low battery voltage and prevent cutting off critical loads.If the system is designed for critical loads, such as a vaccine refrigerator in a rural health clinic, warning lights or buzzers might be essential. However,since loads can keep running after the user is warned,there is always the risk of over-discharging and shortening battery life. Stand-by power sources,such as engine generators,can be used to prevent over-discharging. Some controllers automatically start the backup power source to recharge the battery bank when the batteries reach a low charge state.When the batteries are fully charged,the controller turns off the auxiliary power sources,and the photovoltaic system resumes PV CONTROLS its charging operation. Optional Controller Features Optional features that are available for commercially manufactured PV controllers include: ¢Temperature Compensation.This option adjusts charging current in relation to ambient battery temperature. ¢Load Circuit Breaker.This option can replace a standard load fuse when accessibility to a fuse is difficult or undesirable. *Low Voltage Warning Beeper.This option sounds an audible alarm when the state-of- charge drops to a preset level. *Low Voltage Disconnect.This option automatically cuts off DC loads wired to the control when the battery discharges to a preset level. *Volt Meter.This feature is an analog or digital display of battery state-of-charge (voltage). ¢Ammeter.This feature is an analog or digital display of solar array and/or load output (current). *Amp-hour Meter.This feature is a digital display of battery capacity used or remaining. *Battery Charger Start Control.This option automatically turns on an auxiliary power source,such as a diesel generator. ¢Array Power Diverter.This option bypasses excess array charging power to non-critical loads. ¢Load Timers.This feature consists of mechanical clocks for timing loads requiring pre-set run times,for example security lights. *Complete Charge Light.This option indicates when battery has reached full charge voltage with small L.E.D.lights. *Enclosures.This option provides weather protection for exterior mounting applications. *Automatic Equalization.This option equalizes batteries automatically. *Maximum Power Point Tracking.This option optimizes array output. *Step Down Controller.This option steps down the PV array voltage to match the battery voltage. we 75 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL ()f rt Specifying a Controller A photovoltaic system controller must match thesystemvoltage.For example,a 12-volt controller isusedina12-volt system and a 24-volt controller in a24-volt system.Secondly,a controller must becapableofhandlingthemaximumloadcurrent(amperage)that will pass through the controller.System designers should note that some loads mightoperatedirectlyfromthebatteriesorthroughaninverterandnotpassthroughthecontroller.Thirdly,a controller must be able to handle the maximum PVarraycurrent.Use the maximum array amps at shortcircuitcurrent(which is greater than the operating amps)plus a 25 percent safety margin toconservativelydeterminethisfigure.The NECrequiresthatthePVarraycurrentbenomorethan80percentofthecontrollerrating.Some PV control manufacturers specify a generic battery voltage that the controller begins chargingandthevoltageitwillstopcharging.These set pointsmaybefixedorfield-adjustable.The system designermustaccuratelyspecifythesettingsiftheyaredifferentfromthemanufacturer's settings.Designers should specify a system controller using the worksheet in Table 7-1.. Although there are numerous optional features,system designers should consider using controllers with the following features: *Lights.Indicator lights can tell users andservicepeoplehowthesystemisoperating.Lights can indicate when the batteries arefullycharged,when the battery voltage is low,or when the LVD has shut off the loads. *Meters.Meters are used to monitor system performance.A voltmeter can provideinformationonthehealthofthebattery. Voltmeters that have a color-coded,expanded scale are easily read and understood.Red isusedtoindicateLVD,yellow for caution,and green for a fully charged battery.Whentrainedusersreportsystemproblems,a voltmeter reading may tell the service person what is wrong.While voltmeters are inexpensive,they really measure battery"pressure”and do not necessarily indicate thetruebatterystate-of-charge (SOC).An array ammeter indicates if the PV array is working by measuring how much current is flowing.An ammeter on the load side tells users how much power the loads are drawing.Not onlydometersallowuserstolearnaboutand maintain their system,but also,in caseproblemsarise,users can accurately report thesystem's status to maintenance personnel. »Temperature Compensation.When batterytemperatureislessthan15degreesC(59degreesF)or more than 35 degrees C (95degreesF),the charging voltage should beadjusted.Some controls have a temperaturecompensationsensortoautomaticallychange charging voltage. Under cold ambient air temperatures,a battery's internal resistance becomes higher.Therefore,charge current causes a greater increase in battery voltage atcoldtemperaturesthanatmildtemperatures,such as70degreesFor20degreesC.Under cold conditions,the CTSP will be reached sooner,before the battery has received the amp-hours required to fully chargeit.To resolve the situation,a PV control with a temperature compensation feature will increase theCTSPapproximately+5 mV/°C per battery cellfrom25C(+2.77 mV/°F from 77 F).Under high ambient temperatures the reverse is true;the PVcontrolwilldecreasetheCTSPtoaccommodatefor the elevated temperature.Many PV controls come in an integratedpackagecompletewithover-current protection,metering,and often an inverter.These integratedunits,called power centers,are pre-wired and pre-assembled.Most power centers mect NationalElectricalCodesafetystandardsanduseULapprovedcomponents.They also may incorporate weatherproof enclosures.One advantage in using a power center is that itcanbeinstalledquickly.If an inverter is included inthepackage,the user simply connects the batteries,PV array and the AC loads,and the system isoperational.Some centers also include inputterminalsforgeneratorandutilitypower.Anotheradvantage,besides easy installation,is that powercenterscontainingULlistedcomponentsmaypass building inspections more easily. 76 PV CONTROLS Table 7-1 Controller Sizing Worksheet Module Short Modules 125 =Array Short Controller -Listed Desired Circuit Current in Parallel Circuit Amps Array Amps Features X X 1.25 = DC Total DC System _Maximum DC Controller Connected Watts Voltage Load Amps Load Amps Controller Specification'|Make:Model: ft8es so .7 2"Controller Sizing Exercise Problem:A client wishes to simultaneouslypowerthree12-volt lights (30 watts)and a 12-volt television (14 watts)using a 12-volt photovoltaic system.Three modules wired in parallel are used in the system.Each modulehasapeakcurrentof2.95 amps and a shortcircuitcurrentof3.28 amps.Calculate the maximum PV array output used to size a controller. Solution:To calculate the maximum short circuit amps,multiply the Isc (3.28 amps)by 3 modules: 3.28 amps x 3 modules =9.84 amps Next,increase this figure by the safety factor. 9.84 amps x 1.25 safety factor =12.3 amps A controller capable of handling at least 12.3 amps from the PV array must be specified.To calculate the Maximum DC Load Amps,divide the DC Total Watts (104)by the System Voltage (12 volts). [(3 x 30 watts)+14 watts]+(12 volts)=8.66 amps Table 7-2 Answers to the Controller Sizing Exercise A controller capable of handling at least 12.3 amps must be specified. Module Short Modules 125 =Array Short Controller -Listed Desired Circuit Current in Parallel Circuit Amps Array Amps Features 3.28 X 3 X 125 =12.3 (2.3 DC Total DC System _Maximum DC Controller Connected Watts Voltage Load Amps Load Amps 104->12 =8 £4 q Controller Specification .Make::Model: Section 7.4 77 Contents: 8.1 Inverter Operating Principles 8.2 Inverter Features .......... 8.3.Inverter Types ............ 8.4 Specifying an Inverter ...... Chapter 8 Inverters 80 80 81 82 79 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL '¢Inverter Operating i Principles Alternating current is easier to transport over a long distance and has become the conventional modern electrical standard.Consequently,most common appliances or loads are designed to operate on alternating current.As you know,photovoltaic modules generate only direct current power.In addition,batteries can store only direct current power.Alternating current and direct current are,by nature,fundamentally incompatible.Therefore,a "bridge”--an inverter -is needed between the two. Historically,inverters have been a weak link in photovoltaic systems.Early inverters were unreliable and inefficient,imposing large penalties on overall system performance.System inefficiencies were compounded by the fact that most alternating current appliances used large amounts of power. Recent improvements in inverters and appliances have reduced this penalty and made inverters a viable "bridge”between direct current power sources and alternating current load requirements. The fundamental purpose of a photovoltaic system inverter is to change direct current electricity from PV modules (when connected with the utility grid)and batteries (in stand-alone or grid- tied/battery backup)to alternating current electricity, and finally to power alternating current loads. Inverters can also feed electricity back into the grid. Inverters designed to feed into the utility grid are referred to as grid-tied,line-tied,or utility-connected inverters.These inverters are used in large-scale PV power plants owned by utility companies that generate electricity for the grid,as well as in residential systems that feed electricity to the grid. Conversion Methods:Over the years,inverter manufacturers have used different'technologies to convert low voltage direct current electricity to higher voltage alternating current.The first inverters used a basic transistor to abruptly switch the polarity of the direct current electricity from positive to negative at close to 60 times per second,creating a square wave form.This relatively crude form of "alternating current”then passes through a transformer to increase the voltage. A transformer increases (or decreases)voltage by passing electricity through a primary transformer coil,inducing flow in the secondary transformer coil. If the number of windings in the secondary coil is greater than the number in the primary coil,then thevoltageinthesecondarycoilwillincreasedirectly proportionate to the number of windings in each coil.Stand-alone inverter transformers are designed to increase voltage to 117 or 230 volts alternating current (VAC)depending upon the country in which country the inverter will be used. The advent of sophisticated integrated circuits, field effect and high-frequency transformers has allowed the creation of lighter,more transistors, efficient inverters that produce a waveform closer to a true sine wave.Instead of converting the low voltage DC electricity directly to 120 or 230 VAC, they use a computerized multi-step process with variable timing cycles.For example,12 volts DC is changed to 160 volts at very high frequency AC (20 kilohertz).Next,high frequency AC is converted to 160 volts DC and finally inverted to the required system voltage and frequency.Specific inverter types will be discussed in more detail later in this chapter. :.Inverter Features A system designer should know the optimal features of an inverter when choosing one.Inverter features include the following: *High efficiency.The inverter should convert - 80 percent or more of the incoming direct current input into alternating current output. *Low standby losses.The inverter should be highly efficient when no loads are operating. *High surge capacity.The inverter should provide high current required to start motors or run simultaneous loads. *Frequency regulation.The inverter should maintain 60 Hz output (in the United States) over a variety of input conditions. *Harmonic distortion.The inverter should "smooth out”unwanted output peaks to minimize harmful heating effects on appliances. *Ease of Servicing.The inverter should contain modular circuitry that is easily replaced in the field. *Reliability.The inverter should provide dependable long-term low maintenance. 80 *Automatic warning or shut-off.The inverter should contain protective circuits that guard the system. *Power correction factor.The inverter should maintain optimum balance between the power source and load requirements. *Low weight.The inverter should facilitate convenient installation and service. *Battery charging capability.Many PV systems have a backup alternating current power source,such as a generator,to charge the batteries.A battery charging capability on an inverter allows the generator to charge the batteries through the inverter (by converting the AC to DC with appropriate voltage) instead of through a separate battery-charging component. *Low cost.The inverter's price should fit the system budget. Optional Inverter Features In addition to the primary functions listed above,the following are desirable features for an inverter: *Remote control operation:The inverter can be programmed and monitored from a remote location with a special unit. +Load transfer switch:Manual load switchingallowsoneinvertertomeetcriticalloadsincaseoffailure.This is designed to increase system reliability in systems that have multiple inverters. *Capability for parallel operation:In some systems it is advantageous to use multiple inverters.These inverters can be connected in parallel to service more loads at the same time.. Square wave Modified square wave INVERTERS *Capability for series operation:In systems with multiple inverters,this feature enables the inverter to operate higher voltage loads. Further Considerations:In stand-alone systems certain loads will cause problems for various inverters.Very small loads may be smaller than the "turn on point”of the inverter.Inverters with a stand-by or sleep mode wait for a certain wattage before they will turn on.Most inverters can be set to excite or turn on at different wattages,but very small loads can be problematic.Certain computers and electronic devices do not present a load until line voltage is available.In other words,the inverter iswaitingforaload,and the load is waiting for the inverter. Jax.Inverter Types There are two categories of inverters.The first category is synchronous or line-tied inverters,which are usedwithutility-connected photovoltaic systems.The second category is stand-alone or static inverters,which are designed for independent,utility-free power systems and are appropriate for remote photovoltaicinstallations.Some inverters may have features from both types to facilitate Future utility-connected options.Another classification for inverters is the type of waveform they produce.The three most common waveforms include the following: *square wave *modified square wave *sine wave These three waveforms are illustrated in Figure 8-1. Square-Wave Inverters:These units switch thedirectcurrentinputintoastep-function or "square” Sine wave re ey Figure 8-1 COMMON WAVEFORMS PRODUCED BY INVERTERS Saction 8.3 81 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL alternating current output.They provide little output voltage control,limited surge capability,and considerable harmonic distortion.Consequently, square wave inverters are only appropriate for small resistive heating loads,some small appliances,and incandescent lights.These inexpensive inverters can actually burn up motors in certain equipment. Modified Square-Wave Inverters:This type of inverter uses field effect transistors (FET)or silicon- controlled rectifiers (SCR)to switch direct current input to alternating current output.These complex circuits can handle large surges and produce output with much less harmonic distortion.This style of inverter is more appropriate for operating a wide variety of loads,including motors,lights,and standard electronic equipment like televisions and stereos.However,certain electronic devices may pick up inverter noise running on a modified square-wave inverter.Also,clocks and microwave ovens that run on digital timekeepers will run either fast or slow on modified square wave inverters.It is also not advised to charge battery packs for cordless tools on modified square wave inverters. . Sine-Wave Inverters:Sine-wave inverters are used to operate sensitive electronic hardware that requires a high quality waveform.They have many advantages over modified square wave inverters. These inverters are specifically designed to produce output with little harmonic distortion,enabling them to operate even the most sensitive electronic equipment.They have high surge capabilities and can start many types of motors easily. Some sine wave inverters can also feed electricity back into the grid.Most utility-connected inverters don't use a battery bank but instead connect directly to the public utility,using the utility power as a storage battery.When the sun is shining,electricity comes from the PV array via the inverter.If the PV array is making more power than is being used,the excess is sold to the utility power company through a second electric meter.If you use more power than the PV array can supply,the utility makes up the difference.Also,at night and during cloudy weather, all power comes from the grid. For more information on_utility-interactive systems,refer to Chapter 11. 9 A«st Specifying an Inverter When you are choosing an inverter for a stand-alone system,you should read and understand the specifications.When designing a system with a line- tied inverter,you must choose an inverter that has interface capabilities.Check with your service provider about their requirements.In this chapter, we will consider designing stand-alone systems that are not connected to the grid.Most inverters will list some,if not all,of the following ratings: Watts Output:This indicates how many watts of power the inverter can supply during standard operation.It is important to choose an inverter that will satisfy a system's peak load requirements.The inverter must have the capacity to handle all the alternating current loads that could be on art one time.For example,a system user may wish to power a 1000-watt saw and a 500-watt vacuum cleaner at the same time.A minimum of 1500 watts output would be required.However,system designers should remember that over-sizing the inverter could result in reduced system efficiency and increased system cost. Voltage Input or Battery Voltage:This figure indicates the DC input voltage that the inverter requires to run,usually 12,24,or 48.The inverter voltage must match the nominal photovoltaic system voltage.As an inverter's maximum rated alternating current wattage increases so does its direct current input voltage.It is common to find 1200-watt inverters with a 12-volt direct current input,whereas 2400-watt,12-volt inverters are rare.You would more likely find a 2400-watt 24-volt inverter.Larger wires and circuitry are needed to carry greater currents. Therefore,although it is possible to make a high wattage,low voltage inverter,the large size and heavy weight of the finished unit would not be practical.By producing higher voltage units,24 volts or greater, less amperage passes through the inverter allowing the use of smaller wires and components.Since it is essential to choose an inverter that's readily available, the inverter may actually dictate the system voltage. For example,if you want 3000 watts of alternating current power and can only find a 24-volt inverter to fill that need,you must design a 24-volt system. 82 INVERTERS Figure 8-2 EFFICIENCY OF A 4000-WATT INVERTER 100 %Efficiency594 50 }|+4 1 n 25 50 Watts Surge Capacity:Most inverters are able to waved their rated wattage for limited periods of time. This is necessary to power motors that can draw up to seven times their rated wattage during startup. Consult the manufacturer or measure with an ammeter to determine surge requirements of specific loads.As a rough "rule of thumb”minimum,surge requirements of a load can be calculated by multiplying the required watts by three.For surge requirements of common tools,refer to table 13-1. Frequency:This indicates how often electricity alternates or cycles.Most loads in the United States require 60 cycles per second (often expressed as 60 Hz).High quality equipment requires precise frequency regulation;variations can slowly damage equipment.Inverters are available to produce the frequency needed for international applications. 37200 6400 Voltage Regulation:This figure indicates how much variability will occur in the output voltage. Better units will produce a near constant output voltage. Efficiency:If you plan to operate che inverter frequently,a high efficiency unit is essential.Many inverter manufacturers claim high efficiency. However,inverters may only be efficient when operated at or near certain outputs,for example when a 300-watt inverter is used to power a 300-watt load.An inverter is often used to power loads at less than its rated capacity.Therefore,it is usually wise to choose a unit rated at a high efficiency over a broad range of loads.Figure 8-2 shows a sample efficiency curve of a 4000-watt inverter which is most efficient operating at 400 watts. 83 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Table 8-1 Inverter Sizing Worksheet AC Total .DC System Maximum DC Estimated Listed Desired Connected Watts *Voltage Amps Continuous Surge Warts Features Inverter Specification Make:Model: Inverter Sizing Exercise: Problem:A client living in the ChuskaMountainsnearWindowRock,Arizona,wants to power the following 120 volt alternating current loads with his 12-volt direct current photovoltaic system: *300-wart blender ¢1000-watt saw *640-watt vacuum ¢30-watt VCR The client also wants to run the saw and the VCR simultaneously.All other loads will be run - individually.Use Table 8-1:Inverter Sizing Worksheet to size the inverter. When designing a system,determine the following to select an inverter.Remember,in most cases a high efficiency unit is essential. Watts output:Because the user wants to simultaneously power the saw and VCR,the Alternating Current Total Connected Watts is 1000 watts plus 30 watts or 1030 watts.Thus,an inverter with at least 1030 watts output is required. Inverter input voltage or direct current system voltage:A 12-volt inverter rated for at least 1030 watts is appropriate,and this size is readily available. Alternating Current Toral Connected Watts divided by Direct Current System Voltage equals the Maximum Direct Current Amps Continuous. Surge capacity:Accounting for load surge requirements,the peak wattage of 1030 is multiplied by 3 to arrive at an Estimated Surge Watts requirement of 3090 watts.Remember that this is only a rule of thumb. Output voltage:Choose an inverter with a 120V output to match the alternating current load voltage. Waveform.'In this case,a modified sine wave inverter will satisfy the requirements of the VCR and large motor loads. Frequency:A unit capable of producing 60 cycles per second alternating .current should be specified to match the requirements of the loads. Table 8-2 Answers to the Inverter Sizing Exercise AC Total .DC System Maximum DC Estimated Listed Desired Connected Watts *Voltage Amps Continuous Surge Watts Features 1030 -12 =85.8 3090 Modified Sine Inverter Specification Make:Model: 84 i {H i ' | ) i ', i 0) Chapter 9 Photovoltaic System Wiring oo Conients:9.1 Intwoduction ...screeeeeereeetreesesteteressst esses:+BO9.3 Wire Size vee e tet ett teense ecer eee ss BB9.4 Overcurrent Protection cece eeetsrsttneeeeseterges LO49,5 Disconnects cer eetteteneetteeessses ss 1069.6 Grounding cree eeteetteteseeeteeterssesss 106 85 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL @ oo . oe :Y k }Introduction Historically,photovoltaic systems have been installed without referencing and applying the National Electrical Code (NEC).Untrained persons had commonly installed these systems.Today,PV system installations must be in compliance with the NEC to ensure that they will be safe and functional.In this PV textbook our intention is to provide you with a basic understanding of the NEC requirements and good system design practices for PV systems. However,we do not cover every aspect of electrical wiring here,nor do we cover every aspect of NEC Article 690 (Solar Photovoltaic Systems).This chapter is designed to be used in conjunction with the 2005 edition of the National Electrical Code. This chapter references the 2005 National Electrical Code*book.A copy of the NEC can be purchased at most electrical supply houses. Direct current wiring systems are substantially different from conventional household alternating current wiring systems.DC systems generally use lower voltage and the current flows only in one direction.Because DC systems use lower voltage they often have larger wire sizes compared to AC systems. PV systems often consist of both DC and AC circuits.Alternating current and direct current wiring systems are not compatible and must be separated. Wire Types:Wire types differ in conductor material and insulation.The two common conductor materials used in residential and commercial wiring are copper and aluminum.Copper has a greater conductivity than aluminum and therefore can carry more current than aluminum wire of comparable size.Aluminum is less durable than copper in smaller gauges and may break or be weakened during installation;it is not permitted by the NEC for interior home wiring.Aluminum wire is less expensive than copper and is often used in larger gauges for underground or overhead service entrances and for commercial applications. Table 9-1 Wire Types | Type Covering Max.Location Insulation Outer Temp Provisions Covering THHN Heat Resistant 90°C Dry or Damp Flame Retardant &_Nylon Thermoplastic 194°F Heat Resistant Thermoplastic Jacket THW Moisture &Heat 75-90°C Dry or Wet Flame Retardant &Moisture None Resistant Thermoplastic 167-194°F &Heat Resistant Thermoplastic THWN Moisture &Heat 75°C Dry or Wet Flame Retardant &Moisture Nylon Resistant Thermoplastic 167°F &Heat Resistant Thermoplastic Jacket TW Moisture Resistant 60°C Dry or Wet Flame Retardant &None Thermoplastic 140°F Moisture Resistant Thermoplastic UF -Underground Feeder &Branch =60-75°C Service Entrance Moisture and Heat Resistant -_Integral with Circuit Cable-Single Conductor 140-167°F insulation USE -Underground Service Entrance.75°C Service Entrance Moisture and Heat Resistant Moisture Cable-Single Conductor 167°F Resistant Non-metallic Covering Note:A more complete table can be found in the NEC,Table 310.13. 386 ricaaSeESOTEPAd1 PHOTOVOLTAIC SYSTEM WIRING Alternating Current (AC)Wiring Table 9-2 Color Coding of Wires Direct Current (DC)Wiring Color Application Color Application Black Ungrounded Hot Red (not NEC requirment)Positive White Grounded Conductor |White Negative or Grounded Conductor Green or Bare Equipment Ground Green or Bare Equipment Ground Red and any other color Ungrounded Hot The conductor itself may be solid or stranded.Stranded conductors consist of many small wires thatallowthewiretobehighlyflexible.This flexibilitymakesstrandedwiretherecommendedchoicewhen a larger wire size is required.Insulation covering wire can provide protectionfromheat,abrasion,moisture,ultraviolet lightand/or chemicals.The NEC designates what types ofwiremaybeusedforvariousapplications.ThefollowinglistandTable9-1 indicate the application of various types of wire: *THHN is commonly used in dry,indoor locations. «THW,THWN,and TW can be used indoors or for wet outdoor applications in conduit. *UF and USE are good for moist or underground applications. Wires that will be exposed to sunlight must be labeled "Sunlight Resistant.”.Electrical wire insulation is color coded todesignateitsfunctionanduse.Technicians shouldunderstandthecolor-coding of conventionalelectricalwiretoensuresafeandefficientinstallation,troubleshooting,and repair.Disregarding the colorcodingofwiteorusingitincorrectlyisasafetyhazardandviolatestheNEC.Table 9-2 lists the color codes used in alternating current and direct currentsystems.When using this table,designers shouldnotewhetherthewiringisbeingusedforalternatingcurrentordirectcurrent.It is also important to knowthatlargerconductors(#4 AWG and larger)usuallyhaveonlyblackcoloredinsulation.Therefore,it is allowable to use colored electrical tape or paint ontheselargerconductorstocolorcodethewireendswhereelectricalconnectionsaremade. Cables and Conduit Two or more insulated conductors having an overallcoveringarecalledacable(NEC 800.2).As with wire,the protective covering on cables is rated for specificuses,such as resistance to moisture,ultraviolet light,heat,chemicals,or abrasion.The following list andTable9-3 indicate the application for various types of cable: *NM is most commonly used for dry,indoor locations (NEC 334.10A). *NMC can be used in dry,moist,or damp locations such as laundry rooms or basements (NEC 334.10B). ¢UF is permitted for interior wiring in wet,dry,or corrosive locations (NEC 340.10). ¢UF and USE cable are permitted for useunderground,including direct burial in theearth(NEC 338.2 &340.2). When exposed to sunlight,Type UF cableidentifiedasSunlightResistantmustbeused(NEC 690.31B).For PV module interconnections,you canusetypesSE,UF,USE,and USE-2 single-conductorcables(NEC 690.31 b).Type TC Power and ControlTrayCableareavailablewhenflexibletwo-conductorcableisneeded(See NEC 336 for more).While cablecanbeusedinPVsystemwiring,installers oftenchoosetousesingleconductorsinconduitinsteadof cable. Section 9.1 87 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Conduit is a metal or plastic pipe that contains wires and offers a protective enclosure for the wires. Conduit is often used in PV systems where wires need to be concealed or protected.Liquidtight,a flexible nonmetallic conduit,is often used to connect module junction boxes.Single conductors,such as THWN-2,are passed through the conduit to make the electrical connections.Another common conduit used in PV systems is polyvinyl chloride (PVC)pipe. This is a rigid and nonmetallic conduit.A typical place to see PVC is between a pole mounted array junction box and a disconnect box in the battery room.PVC can be buried or attached to walls to protect the wires from damage.As with wire,when using PVC,it is important to select a type that is appropriate for the installation. Tables in this chapter,and in the National Electric Code (NEC)list the maximum number and size wire which can be run within the given conduit sizes.Using too large a wire or too many wires within conduit will result in overheating and damage to the wire''s protective insulation. 1 Wire Size Wire size selection requires you to consider two important criteria: ¢Ampaciry *Voltage Drop Ampacity refers to the current carrying ability of a wire.The larger a wire is,the greater its capacity to carry current.Using wire with a lower ampacity than _ wire that carries a larger current will overheat the wire.Overheating means wasted energy and inefficiency,and can result in melted insulation,a short circuit,or fire.The National Electrical Code has rated various wire sizes and types for the maximum amperage they can safely carry (NEC 310.15).Table 9-4 shows an example of the ampacity of copper wires taken from Table 310.16 in the NEC. Wire size is given in terms of American Wire Gauge (AWG).A larger wire has a greater ampacity and will be designated by a smaller AWG number,up to #]AWG wire.For example,a #14 AWG wire is smaller than a #10 AWG wire.After #1 AWG wire, wire size increases with higher AWG numbers followed by the /0 symbol (pronounced as "aught”). For example,#2/0 AWG wire is smaller than #4/0 AWG wire.Beyond #4/0 AWG wire,wire size is measured in kemils. Note:Table 9-4 is a simplified chart.It does not reflect information for temperature derating.See NEC Tables 310.16 and 310.17 for a complete listing of conductor sizes and types,their related ampacity,and temperature deration., When sizing wire in a PV system,you start by finding out the maximum current load.This is the greatest current going through the circuits of the PV Table 9-3 Cable Types For more information see Cable Type Name NEC Article AC Armored Cable 320 MC -Metal-Clad Cable 330 NM,NM-C Nonmetallic-Sheathed Cable 334 UF Underground Feeder and 340 Branch-Circuit Cable USE Underground Service 338 Entrance Cable TC Power and Control Tray Cable 336 ea88,SHAG TENS te, PHOTOVOLTAIC SYSTEM WIRING Table 9-4 Ampacity of Copper Wire In Conduit or Cable Single Conductors in Free Air AWG UK THW USE,THWN UE THW USE,THWN 14 15 15 20 20 12 20 20 25 25 10 30 30 40 40 8 40 50 60 70 6 55 65 80 95 4 70 85 105 125 2 95 115 140 170 1/0 125 150 195 230 2/0 145 175 225 265 3/0 165 200 260 310 For a more complete table see NEC cables 310.16 and 310.17 system at one time.For the wire run from the PV panels to the controller or battery,use the short circuit current multiplied by the number of panels in parallel. -For the wire from the battery to the DC service panel, use the total load amps.Once you know the current, multiply it by 125%,so that the conductor never carries more than 80%of its rated capacity.This safety precaution must be done on all wire runs in a PV system.NEC 690.8 requires an additional safety factor to be included in the wire that connects the PV array to the batteries,or the PV array to the inverter in a batteryless system.This is to handle any extra current produced by the panels caused by reflection or exceptionally sunny days.The short circuit current must be multiplied by an additional 125%to ensure the proper size conductor and to meet code.(Refer to the following for a sample problem.) Example 9-1 Problem:A photovoltaic array has a short circuit current of 40 amps and the system has a DC load of 20 amps.Determine the type and gauge of wire that is required. Solution:Find the total amps for each sectionofwire.Wire run from array to battery:40 x1.25 x 1.25 =62.5.The wire must have an ampacity that can handle 62.5 amps.Based on Table 9-4,using THWN in conduit,the wire needed is #6 AWG.Wire run from battery to loads:20 x 1.25 =25.The wire must have an ampacity that can handle 25 amps.Based on. Table 9-4,using THWN in conduit,the wire needed is #10 AWG. So far we have only discussed wire sizing based on ampacity.The second consideration in choosing the correct wire size is voltage drop.Voltage drop is the loss of voltage due to a wite's resistance and length.It is important to consider efficient design practices to minimize energy loss.A PV system's efficiency can be improved when using properly sized wire.This reduces the line loss of the wire. Voltage drop in wire is a function of the following three parameters: °Wire gauge *Length ofwire *Current flow in the wire The greater a wire's length,the greater resistance to current flow.Excessively long wire runs will result in loss of power to the load and lower system efficiency.It will also reduce the life expectancy of most appliances 89 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL and equipment.Inductive loads,such as motors,are particularly sensitive to voltage drop.Using a larger wire size,decreasing the current flow,or decreasing the length of wire are all solutions to reduce voltage drop. As a PV system designer,you will need to choose the appropriate wire size to design efficient systems with low voltage drop in addition to passing NEC safety requirements.A good design practice is to keep the wiring voltage loss between 2%and 5%. Although 5%loss is acceptable,PV designers often try for 2%losses or less because of the expense of PV panels.Remember that energy Jost in wire runs is money lost! Tables 9-5 through 9-10 list the recommended maximum one-way length for a 2%or a 5%voltage drop for various wire sizes depending upon the needed current and the system voltage.The table values include an allowance for the fact that the wire - must travel the distance twice,once to the load and then back. Note:When using the voltage drop tables to size wire you do not need to include NEC safety factors when calculating the current for each wire run. For an explanation on using the tables,refer to the Wiring Problem Example on page 97.Values given below the stepped line in the lower left corner of these tables must be verified using the NEC,Table 310.16.The conductor may not be large enough to pass NEC requirements.The blank values at the lower left indicate where the wires ampacity is definitely exceeded. Complete the following two examples to practice -calculating line losses using the voltage drop tables. Example 9-2 Problem:A 12-volt battery bank provides power to a 12-volt outdoor security light.The light draws 2 amps and is 40 feet from the direct current load center.What wire size will ensure line losses are not more than 2%voltage drop in the branch circuit? Solution:Table 9-5 is the appropriate table to use for 12 volts at a 2%voltage drop.Find the load current,2 amps,in the left hand column. Read across to the right until you find the first number that is greater than or equal to the one way distance to the light or 40 feet.This is 60.1 feet.Read straight up to find the minimum wire size.The answer is #10 AWG wire. Example 9-3 Problem:A 48-watt,12V direct current light is wired directly to a battery bank.A maximum of 5%voltage drop is allowable from the voltage source to the load.Whar size wire will you choose if the light is 110 feet from the battery bank? Solution:Table 9-8 is the appropriate table to use for a 12-volt system with a 5%voltage drop.First,find the amperage of the load in the left hand column.In this case,the amperage would be 48 watts divided by 12 volts,or 4 amps.Read across the chart to the right until you find the first maximum one-way distance that is greater than or equal to 110 feet.This is 119.4 feet.Read straight up to find the minimum allowable wire size.The answer is #8 AWG wire. Note:When designing a system,always consider that the system owner may want to add more loads to the system without running new wire,particularly if the wire is buried or inaccessible.In this example, adding another 2 amp load at the same distance will require a #6 wire. Wire Sizing Charts Maximum One-Way Wire Lengths for Less than 2%Voltage Drop Tables 9-5,9-6,and 9-7 indicate the maximum length of wire (in feet)that can be used and have less than 2%voltage drop in one direction.Distances are provided for 12 V,24 V,and 48 V. Maximum One Way Wire Lengths for 5% Voltage Drop Tables 9-8,Table 9-9,and Table 9-10 indicate the maximum length of wire (in feet)that can be used for a 5%voltage drop in one direction. Distances are provided for 12 V,24 V,and 48 V. 30 Section &2 _PHOTOVOLTAIC SYSTEM WIRING Table 9-5 . Length (feet)of 12-V Wire for 2%Voltage Drop Amps #12 #10 #8 #6 #4 #2 #1/0 -#2/0 #3/0 -«#4/0 1 75.6 120.1 191.0 303.7 482.9 767.8 1221.1 1539.8 1941.7 2409.2 2 37.8 60.1 95.5 151.9 241.4 383.9 6106 769.9 970.9 1204.6 3 25.2 40.0 63.7 101.2 161.0 255.9 407.0 513.3 647.2 803.1 4 18.9 30.0 478 75.9 120.7 191.9 305.3 385.0 485.4 602.3 5 15.1 24.0 38.2 60.7 96.6 153.6 244.2 308.0 388.3 481.8 6 12.6 20.0 31.8 50.6 80.5 128.0 203.5 2566 323.6 401.5 7 10.8 17.2 27.3 43.4 69.0 109.7 1744 220.0 277.4 344.2 8 9.4 15.0 23.9 38.0 60.4 96.0 1526 192.5 242.7 301.1 9 8.4 13.3 212 33.7 53.7.85.3 135.7 171.1 215.7.267.7 10 7.6 12.0 19.1 30.4 48.3 76.8 1221 154.0 194.2 240.9 15 5.0 8.0 12.7 20.2 32.2 51.2 814 102.7 1294 160.6 20 3.8 6.0 9.6 15.2 24.1 38.4 61.1 77.0 97.1 120.5 25 3.0 4.8 7.6 12.1 19.3 30.7 48.8 61.6 77.7 96.4 30 2.5 4.0 6.4 10.1 16.1 25.6 40.7 51.3 64.7 80.3 35 2.2 34.5.5 8.7 13.8 21.9 34.9 44.0 55.5 68.8 40 3.0 4.8 7.6 12.1 19.2.30.5 38.5 48.5 60.2 45 2.7 4.2 6.7 10.7 17.1 27.1 34.2 43.1 53.5 50 2.4 3.8 6.1 9.7 15.4 244 30.8 38.8 48.2 55 2.2 3.5 5.5 8.8 14.0 22.2 28.0 35.3.43.8 60 2.0 3.2 5.1.8.0 12.8 20.4 25.7 32.4 40.2 65 1.8 2.9 47 7.4 11.8 18.8 23.7 29.9 37.1 70 1.7 27--43 6.9 11.0 17.4 22.0 27.7.34.4 75 160°(25 40 64 10.2 16.3 20.5 25.9.32.1 80 715.24..38 60.96 153 192 243 301 85 14-22-36.57 9.0 144 181 228 283 90 LB RL 34 54 BS 13.60 0 17.1 21.6 268 9 13 20 325"51.Bl 129 162 204 254 100 we ee B00 48 7.7 12.2 15.4 19.4 24.1 HO ee BS 4A ZO WA 14.0 17.7 21.9 20 5 AO GATS 10.2 °-«128) SC1G220.1 0 0 28 BT 5D 94 118 14.9 18.5 140 ee 2D BARS 5S oo 8.7- .11.0 13.9 17.2 000 SE BE 103d WO 08 AB 7G 86 CRTC WO AS TZ OT AS 14.2 190...43-68 86...108.134 90.cry ose?ar Cs)RO 27 200 0 we,BB OL TT 97 12.0 Values in shaded area may not meet NEC requirements. Saovon O32 91 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL ;Table 9-6 Length (feet)of 24-V Wire for 2%Voltage Drop Amps #12 #10 #8 #6 #4 #2 #1/0 #2/0 #3/0 #4/0 ]151.1 9 240.3 382.0 607.4 965.8 1535.5 2442.3 3079.7 3883.5 4818.3 2 75.6 120.1 191.0 303.7 482.9 767.8 1221.1 1539.8 1941.7 2409.2 3 50.4 80.1 127.3 202.5 321.9 511.8 814.1 1026.6 1294.5 1606.1 4 37.8 60.1 95.5 151.9 241.4 383.9 610.6 769.9 970.9 1204.6 5 30.2 48.1 76.4 121.5 193.2 =307.1 488.5 615.9 776.7,963.7 6 25.2 40.0 63.7 101.2 161.0 255.9 407.0 513.3 647.2 803.1 7 21.6 34.3 54.6 86.8 138.0 219.4 348.9 440.0 554.8 688.3 8 18.9 30.0 47.8 75.9 120.7 191.9 305.3 385.0 485.4 602.3 9 16.8 26.7 42.4 67.5 107.3 170.6 271.4 342.2 431.5 535.4 10°15.1 24.0 38.2 60.7 96.6 153.6 244.2 308.0 388.3 481.8 15 10.1 16.0 25.5 40.5 64.4 102.4 162.8 205.3 258.9 321.2 20 7.6 12.0 19.1 30.4 48.3 76.8 122.1 154.0 194.2 240.9 25 9.6 15.3 24.3 38.6 61.4 97.7 123.2 155.3 192.7 30 8.0 12.7 20.2 32.2 51.2 814 102.7 1294 160.6 35 6.9 10.9 17.4 27.6 43.9 69.8 88.0 111.0 137.7 40 6.0 9.6 15.2 24.1 38.4 61.1 77.0 97.1 120.5 45 5.3 8.5 13.5 21.5 34.1 54.3 68.4 86.3 107.1 50 4.8 7.6 12.1 19.3 30.7 48.8 61.6 77.7 96.4 55 4.4 6.9 .11.0 17.6 27.9 44.4 56.0 70.6 87.6 60 4.0 6A 10.1 16.1 25.6 40.7 51.3 64.7 80.3 _ 65 3.7 5.9 9.3 14.9 23.6 37.6 47.4 59.7 -74.1 70 3.4 5.5 8.7 13.8 21.9 34.9 44.0 55.5 68.8 75 3.2 5.1 8.1 12.9 20.5 32.6 41.1 51.8 64.2 80 3.0 4.8 7.6 12.1 19.2 30.5 38.5 48.5 60.2 85 2.8 4.5 7.1 11.4 18.1 28.7 36.2 45.7 56.7 90 2.7 4,2 6.7 10.7 17.1 27.1 34,2 43.1 53.5 95 25 4.0 -6.4 -10.2 16.2 25.7 32.4 40.9 50.7 100 2.4 3.8 6.1 9.7 15.4 24.4 30.8 38.8 48.2 110 2.2:3.5 5.5 8.8 14.0.22.2 28.0 35.3 43.8 120 2.0 32.S51 80 128 £204 25.7 32.4 402 130 1.8 2.9 47.74 118 -18.8 23.7 29.9 37.1 140 1.7 2.7 4.3 6.9 11.0 17.4°.22.0 27.7 34,4 150 1.6 -2.57 4.0 6.4 10.2 16.3 20.5 25.9 32.1 160 1.5 2.4 3.8 6.0 9.6 15.3 19.2 24.3 30.1 170 14 .2.2 3.6 5.7 9.0 -14.4 18.1 22.8 28.3 180 13°.21.3.4 5.4 8.5 13.6 17.1 21.6 26.8 190 1.3 2.0 3.2 5.1 8.1 12.9-16.2 20.4 25.4 200 "1.2 1.9 3.0 4.8 7.7 12.2 15.4 19.4 24.1 © Values in shaded area may not meet NEC requirements. 92 Section G3 PHOTOVOLTAIC SYSTEM WIRING Table 9-7 Length (feet)of 48-V Wire for 2%Voltage Drop Amps #12 #10 #8 #6 #4 #2 #1/0 #2/0 --#3/0 #4/0 1 302.3.480.5 764.1 1214.9 1931.6 3071.0 4884.5 6159.4 7767.0 9636.6 2 151.1 240.3 382.0 607.4 965.8 1535.5 2442.3 3079.7 3883.5 4818.3 3 100.8 160.2 254.7 405.0 643.9.1023.7 1628.2 2053.1 2589.0 3212.2 4 75.6 120.1 191.0 303.7.482.9 767.8 1221.1 1539.8 1941.7 2409.2 5 60.5 96.1 152.8 243.0 386.3 614.2 976.9 1231.9 1553.4 1927.3 6 50.4 80.1 127.3 202.5 321.9 511.8 814.1 10266 1294.5 1606.1 7 43.2 68.6 109.2 173.6 275.9 438.7.697.8 879.9 1109.6 1376.7 8 37.8 60.1 95.5 151.9 241.4 383.9 610.6 769.9 970.9 1204.6 9 33.6 53.4 84.9 135.0 2146 341.2 542.7 6844 863.0 1070.7 10 30.2 48.1 764 121.5 193.2 307.1 488.5 615.9 776.7 963.7 15 20.2 32.0 50.9 81.0 1288 2047 3256 4106 517.8 642.4 20 15.1 24.0 38.2 607 966 153.6 244.2 308.0 388.3 481.8 25 12.1 19.2 30.6 486 77.3 122.8 195.4 2464 310.7 385.5 30 16.0 25.5 40.5 644 1024 162.8 205.3 258.9 321.2 35 13.7 21.8 34.7 55.2 87.7 139.6 1760 221.9 275.3 40 12.0 19.1 30.4 .48.3 76.8 122.1 154.0 194.2 240.9 45 17.0 27.0 42.9 68.2 108.5 136.9 172.6 2141 50 15.3 24.3 38.6 61.4 97.7.123.2 155.3 192.7 55 13.9 22.1 35.1 55.8 88.8 112.0 141.2 175.2 60 12.7 20.2 322 51.2 81.4 102.7 129.4 160.6 65 11.8 18.7 29.7 47.2 75.1 94.8 119.5 148.3 70 10.9 17.4 27.6 43.9 69.8 88.0 -111.0 137.7 75 16.2 25.8 40.9 65.1 82.1 103.6 128.5 80 -15.2 24.1 38.4 61.1 77.0 97.1 120.5 85 3 14.30 22.7 36.1 57.5 72.5 91.4 113.4 90 2 135 QE 341 54.3 68.4 86.3.107.1 95 12.8 20.3 32.3 51.4 64.8 81.8 101.4 100 oe Ste 19.3 30.77.48.8 61.6 777 96.4 110 a Be ee ATG 27.9.444 56.0 70.6 87.6 120 Bee a AGL 25.6.40.7 51.3 64.7 80.3 00 ee 286 B76 47A 59.7 7A 140 a os ee O09 34.9 5 44.0 55.5 68.8 150 a 20,5.32.6 ALD 518 64.2 '160 19.2 305 38.5 2 48.5 60.2 170 a 18.1 °°28.7 36.2.45.7 -°56.7 180 )a Oe O71 34.2 43.1 0°453.5 190 oo -25.7..324 40.9 50.7 200 oo [-244 30.8 38.8 .48.2 Values in shaded area may not meet NEC requirements. Section 9.3 93 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Table 9-8 Length (feet)of 12-V Wire for 5%Voltage Drop Amps #12 #10 #8 #6 #4 #2 #1/0 #2/0 --#3/0 #4/0 1°188.9 3003 4776 759.3 1207.2 1919.4 3052.8 3849.6 4854.4 6022.9 2 945.150.2 238.8 379.7 603.6 959.7 1526.4 1924.8 2427.2 3011.4 3 630.1001 159.2 253.1 4024 639.8 1017.6 2183.2 1618.1 2007.6 4 47.2 75.1 1194.189.8 301.8 479.8 763.2 962.4 1213.6 1505.7 5 37.8 60.1 95.5.151.9 241.4 383.9 610.6 769.9 970.9 1204.6 6 31.5 50.1 796 1266 2012 319.9 5088 641.6 809.1 1003.8 7 27.0 42.9 68.2.108.5.172.5 274.2 436.1 549.9 693.5 860.4 8 23.6 37.5 59.7 949 150.9 239.9 381.6 481.2 606.8 752.9 9 21.0 33.4 53.1 84.4.134.1 213.3 339.2 427.7 539.4 669.2 10 18.9 30.0 47.8 75.9 120.7 191.9 305.3 385.0 485.4 602.3 15 12.6 20.0 31.8 50.6 80.5.128.0 203.5 2566 323.6 401.5 20 9,4 15.0 23.9 38.0 60.4 96.0 152.6 192.5 242.7 301.1 25 7.6 12.0 19.1 30.4 48.3 76.8 122.1 1540 194.2 240.9 30 6.3 10.0 15.9 25.3 40.2 64.0 101.8 128.3 161.8 200.8 35 5.4 8.6 13.6 21.7 34.5 54.8 87.2 110.0 138.7 172.1 40 7.5 11.9 19.0 30.2 48.0 76.3 96.2 121.4 150.6 45 6.7.10.6 16.9 26.8 42.7 67.8 85.5 107.9 133.8 50 6.0 9.6 15.2 24.1 38.4°61.1 77.0 .97.1 120.5 55 5.5 8.7 13.8 ©21.9 34.9 55.5 70.0 88.3 109.5 60 5.0 8.0 12.7 20.1 32.0 50.9 64.2 80.9 100.4 65 4.6 73 11.7 18.6 29.5 47.0 59.2 74.7 92.7 70 43.68 (108 ..17.2 27.4 43.6 55.0 69.3 86.0 75 40 (64°©101°."161 25.6 40.7 51.3 64,7 80.3 80 38 6.00 95 2 ISL 24.0 38.2 48.1 60.7 75.3 85 PBS OS 8 8.9 35.9 45.3 57.1 709° 90 oa 33.9 42.8 53.9 66.9 95 40.5 51.1 63.4 100 38.5 48.5 60.2 110 35.0 44.)54.8 120 32.1 40.5 50.2 130 29.6 37.3 46.3 140 <27.5 34.7 43.0 150 225.7 32.4 40.2 160 Ae 2445 30.3 37.6 170 )2 22.6.5-28.6...35.4 180 QV4 27.00)33.5 190 20.38 °25.5.317 200 19.2.)24.300 30.1. Values in shaded area may not meet NEC requirements. 94 Sectian O.3 PHOTOVOLTAIC SYSTEM WIRING Table 9-9 Length (feet)of 24-V Wire for 5%Voltage Drop Amps #12 #10 #8 #6 #4 #2 #1/0 #2/0 #3/0 #4/0 1 377.8 600.7 955.1 1518.6 2414.5 3838.8 6105.6 7699.2 9708.7 1204.5 2 188.9 300.3 477.6 759.3 1207.2 1919.4 3052.8 3849.6 4854.4 6022.9 3 125.9 200.2 318.4 506.2 8048 1279.6 2035.2 2566.4 3236.2 4015.3 4 94.5 150.2 238.8 379.7 603.6 959.7.15264 1924.8 2427.2 301 1.4 5 75.6 120.1 191.0 303.7 482.9 767.8 1221.1 1539.8 1941.7.2409.2 6 63.0 100.1 159.2 253.1 402.4 639.8 1017.6 1283.2 1618.1 2007.6 7 54.0 85.8 136.4 216.9 344.9 548.4 872.2 1099.9 1387.0 1720.8 8 47.2 75.1 119.4 189.8 301.8 479.8 763.2 962.4 1213.6 1505.7 9 42.0 66.7 106.1 168.7 268.3 426.5 678.4 855.5 1078.7 1338.4 10 37.8 60.1 95.5 151.9 241.4 383.9 610.6 769.9 970.9 1204.6 15 25.2 40.0 63.7 101.2 161.0 255.9 407.0 513.3 647.2 803.1 20 18.9 30.0 47.8 75.9 120.7 191.9 305.3 385.0 485.4 602.3 25 24.0 38.2 60.7 96.6 153.6 244.2 308.0 388.3 481.8 30 20.0 31.8 50.6 80.5 128.0 203.5 256.6 323.6 401.5 35 17.2 27.3 43.4 69.0 109.7.174.4 220.0 277.4 344.2 40 23.9 38.0 60.4 96.0 152.6 192.5 242.7 301.1 45 21.2 33.7 53.7 85.3 135.7 171.1 215.7.267.7 50 30.4 48.3 76.8 122.1 154.0 194.2 240.9 55 27.6 43.9 69.8 111.0 140.0 176.5 219.0 60 25.3 40.2 64.0 101.8 128.3 161.8 200.8 65 23.4 37.1 59.1 93.9 118.4 149.4 185.3 70 21.7 |34.5 54.8 87.2 110.0 138.7 172.1 75 20.2 32.2 51.2 81.4 102.7 129.4 160.6 80 19.0 30.2 48.0 76.3 96.2 121.4 150.6 85 17.9 28.4 45.2 71.8 90.6 114.2 141.7 90 16.9 26.8 42.7 67.8 85.5 107.9 133.8 95 16.0 25.4 40.4 64.3 81.0 102.2 126.8 100 15.2 24.1 38.4 61.1 77.0 97.1 120.5 110 13.8 21.9 34.9 55.5 70.0 88.3 109.5 120 ;12.7 20.1 32.0 50.9 64.2 80.9 100.4 130 11.7 18.6 29.5 47.0 59.2 74.7 92.7 140 10.8 17.2 27.4 43.6 55.0 69.3 86.0 150 25.6 40.7 51.3 64.7 80.3 160 24.0 38.2 48.1 60.7 75.3 170 22.6 35.9 45.3 57.1 70.9 180 21.3 33.9 42.8 53.9 66.9 190 20.2 32.1 40.5 51.1 63.4 200 19.2 30.5 38.5 48.5 60.2 Values in shaded area may not meet NEC requirements. Section 93 0 95 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Table 9-10 Length (feet)of 48-V Wire for 5%Voltage Drop Amps #12 #10 #8 #6 #4 #2 #1/0 =#2/0 =#3/0 #4/0 1 755.7 1201.3.1910.2 3037.2 4829.0 7677.5 12211 15398 19417 24091 2 377.8 600.7 955.1 1518.6 2414.5 3838.8 6105.6 7699.2 9708.7 12045 3 251.9 400.4 636.7 1012.4 1609.7 2559.2 4070.4 5132.8 6472.5 8030.5 4 188.9 300.3 477.6 759.3 1207.2 1919.4 3052.8 3849.6 4854.4 6022.9 5 151.1 240.3 382.0 607.4 965.8 1535.5 2442.3 3079.7 3883.5 4818.3 6 125.9 200.2.3184 506.2 804.8 1279.6 2035.2 2566.4 3236.2 4015.3 7 108.0 171.6 272.9 433.9 689.9 1096.8 1744.5 2199.8 2773.9 3441.6 8 94.5 150.2 238.8 379.7 603.6 959.7 1526.4 1924.8 2427.2 3011.4 9 84.0 133.5 .212.2 337.5 536.6 853.1 1356.8 1710.9 2157.5 2676.8 10 75.6 120.1 191.0 303.7 482.9 767.8 1221.1 1539.8 1941.7 2409.2 15 50.4 80.1 127.3 202.5 321.9 511.8 8141 10266 1294.5 1606.1 20 37.8 60.1 95.5 151.9 241.4 383.9 610.6 769.9 970.9 1204.6 25 30.2 48.1 76.4 121.5 193.2 307.1 488.5 615.9 776.7 963.7 30 40.0 63.7.101.2 161.0 255.9 407.0 513.3 647.2 803.4 35 343 546 868 138.0 219.4 348.9 440.0 5548 688.3 40 30.0 447.8 75.9 120.7 191.9 305.3 385.0 485.4 602.3 45 424 67.55 107.3 1706 2714 342.2 431.5 535.4 50 38.2 60.7 966 153.6 244.2 308.0 388.3 481.8 55 34.7 55.2 878°139.6 222.0 280.0 353.0 438.0 60 31.8 506 80.5 128.0 203.5 2566 323.6 401.5 65 29.4 467 ©74.3 1181 187.9 236.9 298.7 370.6- 70 273°434 69.0 109.7 1744 220.0 2774 344.2 75 40.5 -644 1024 162.8 205.3 258.9 321.2 80 38.0.604.96.0 152.6 192.5 242.7 301.1, 85 i BSZoc 568°90.3 143.7 181.2 228.4 283.4 90 a 33.7.93.7...85.3 135.7 171.1 215.7 267.7 95 2 32.00°°508°80.8 128.5 162.1 204.4 253.6 100 ee 48.3 76.8 122.1 154.0 194.2 240.9 110 Be 438s 69.8 111.0 140.0 176.5 219.0 120 2 40.260°°64.0 1018 128.3 161.8 200.8 130 eeees59D 93.9%118.4 149.4 185.3 140 54.8 9 87.2 110.0 138.7 172.1 150 DS SL26 9.81455 102.7:129.4 160.6 160 oe,48.0.76.3 2.96.2.121.4 -150.6 170 8 A520 0 718 90.6 --114.2.141.7 180 67.85;85.5.107.9 133.8 190 64.3.81.0 -102.2 +126.8 200 os .ao,61.1 77.0.97.1 120.5| Values in shaded area may not meet NEC requirements. 96 Section 9.3 Wire Sizing Exercise Problem:Using the sample PV system below, calculate the wire sizes needed for the various portions of the system by answering each of the questions.This system consists of the following specifications and equipment: *DC system voltage =24 volts. *Ten 100-watt modules,each with nominal module voltage of 12 volts.The short circuit current (Isc)of each is 7.2 amps and the maximum power current (Imp)of each is 6.2 amps. °Eight batteries,each is 6 volts and rated at 350 amp-hours. *One charge controller that is 24 volts and rated for 60 amps. *One 2500-wart inverter with an input DC voltage of 24 volts and an output AC voltage of 120 volts. ¢Total connected DC load is 500 watts at 24 volts. *Voltage drop requirement berween the PV and battery bank is 2%and the distance is 50 feet. *Voltage drop requirement between the battery and DC load is 2%and the distance is 15 feet. *Voltage drop requirement between the battery bank and inverter is 2%and the distance is 8 feet. Determine the wire size in various circuits on the DC side ofa PV system that powers both DC and AC loads. Note:In this example you will consider the PV to controller and the controller to battery as a single wire run. Step 1: Question:How must the 12-volt modules be wired to provide the correct DC system voltage? Answer:2 modules wired in series,then 5 series strings wired in parallel. If this is confusing to you,consider breaking the problem into parts.First,you need to determine the PHOTOVOLTAIC SYSTEM WIRING voltage.With 12-volt modules,wiring two panels in series will result in one "array”with a nominal voltage of 24 volts that delivers 6.2 amps under standard test conditions (STC).Now,if you do this with the remaining two modules,the result will be 5 sets of 24-volt arrays each providing 6.2 amps.To increase the amperage,take each set of 2 modules and wire them in parallel.The final result will be one large "array with 24 volts (nominal)that produces 31 amps (STC),wired into a combiner box. Step 2: Question:Now,calculate the minimum wire gauge that must be used between the PV array combiner box and battery bank.The wire must be able to safely pass the current provided by the array.Assume you are using type THWN wire in conduit.Disregard voltage drop considerations for the moment.Refer to Table 9-4:Ampacity of Copper Wire. Answer:#6 AWG wire How did you get this?From Step 1,you simplified the problem to 5 sets of modules in parallel.The short circuit current of the entire array will be 5-x 7.2 amps =36 amps.Now,using information from "Wire Size”on page 89,the NEC requires you to multiply the short circuit current by 125%to increase the wire's capacity to handle full current for long durations.Then,you must multiply by another 125%to account for potential excessive current produced by the PV array in conditions of high insolation caused by edge of cloud reflection or snow reflection. The NEC required ampacity calculation is 36 amps x 1.25 x 1.25 =56.25 amps If you look at Table 9-4,you see that for type THWN wire in conduit,you need to use #6 AWG wire to safely pass up to 65 amps. Step 3: Question:Consider voltage drop specifications.If you sized wire solely based on the calculations from Step 2,you may pass the NEC requirement for wire sizing,but you could potentially lose power due to voltage drop.Voltage drop considerations are used to promote efficiency in each circuit.Since PV modules are costly,you want to reduce any power loss due to voltage drop.These calculations must be done in addition to the minimum ampacity (wire gauge)calculations needed above.So,how do you "pass code”and meet the required voltage drop requirements?Using the voltage drop tables (Table 9-5 through Table 9-10),calculate the "normal” one 97 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL operating ampacity of the array.Realistically,youcouldusethemaximumpowercurrent(Imp),however using the short circuit current (Isc)is moreconservative.So,for this assignment use the Isc ofeachmoduleinyourcalculations.Note that you donotneedtomultiplyby1.56 for voltage dropcalculations.Calculate the appropriate array ampacity. Answer:36 amps Multiply the short circuit current of each modulebythenumberofsetsinparallel.7.2 amps x 5 (sets) =36 amps. Step 4: Question:With the appropriate array ampacity,what size wire do you need between the PV andbatterybankwirerunforthespecifiedvoltagedrop? Answer:#1/0 AWG Using Table 9-6:Length of 24-V wire for 2%voltage drop,for an ampacity of 36 amps,a distanceof50feet,and a voltage drop of 2%,you need a #1/0 AWG wire. Step 5: 'Question:Given that your answers in Step 2 andStep4differ,what wire size will satisfy both theNECrequirementsandthe2%voltage drop specification? Answer:#1/0 AWG #1/0 AWG type THWN in conduit can safely passupto150amps,which satisfies the NEC requiredampacityof56.25 amps.You also know that #1/0AWGwillcauseonlya2%voltage drop at thegivendistanceandthe"normal”ampacity (36 amps). Step 6: Question:Now that you have sized a wire from thePVtobatterybank,figure out the wire size for thebatterybanktoDCloadrun.Again,you need tofirstcalculatewirebasedonNECrequirements.What is the minimum ampacity for the wire willneedtoberatedtooperatetheloadsafely? Answer:27 amps Calculate this number by first figuring out the loadampacity.You know that Watts =Volts x Amps.Usealgebratorearrangethisequationtocalculateamps. Watts /Volts =Amps,so:500 watts /24 volts = 20.83 amps Now,multiply this number by 125%to give the wiresomeexcesscapacitytohandlefullcurrentforlong durations.This is 20.83 amps x 1.25 =26.04 amps. To be safe,always round up.Thus,use 27 amps asyournumber.You may ask,"Why don't I multiplyagainby125%like I did for the PV to batterycalculation?”Once the power has reached thebattery,excess amperage from the PV modules getsabsorbedintothebatterybankandisnotdirectly reflected into any other section of the wiring. Step 7: Question:Whar is the minimum wire gauge youmustusetosatisfyNECrequirements? Answer:#10 AWG Refer to Table 9-4:Ampacity of Copper Wire. Using THWN in conduit,#10 AWG wire cansafelypassupto30amps,therefore the 27-ampNECampacityrequirementissatisfied. Step 8: Question:Consider voltage drop specifications.Which wire will satisfy the desired voltage drop?Remember to calculate your "normal”load ampacity. Answer:#8 AWG - Use a "normal”ampacity of 20.83 amps and roundupto2}amps.This calculation 1s 500 watts/24volts=20.83 amps.(You do not need to multiplyby125%.)Table 9-6:Length of 24-V wire for 2%voltage drop indicates that for an ampacity of 21,adistanceof15feet,and a voltage drop of 2%,you need #8 AWG wire. Step 9: Question:Which wire will satisfy both the voltagedropspecificationsandminimumNECwiresize requirements? Answer:#8 AWG From Table 9-4:Ampacity of Copper Wire,#8AWGtypeTHWNwireinconduitcanhandle 50amps.The NEC requirement of 27 amps will bemorethansatisfied.An #8 AWG wire will meet thespecifiedvoltagedropof2%for a distance of 15feetandthe"normal”ampacity of 21 amps. Step 10: Question:Specify the wire between the batterybankandtheinverterthatwillsatisfybothNECrequirementsandvoltagedropspecifications.-Remember,you still are on the DC (24 volt)side of the system. Answer:#1/0 AWG So how did you get this?Take the inverter output of2500wattsanddivideby24volts(DC systemvoltage).The result is 104.17 amps.Then multiplyby125%for the NEC requirement to get 130.21amps.Round up to 131 amps to be safe.Refer toTable9-4:Ampacity of Copper Wire for thecorrespondingwiresize.A #1/0 AWG wire typeTHWNorRHWinconduitcansafelypass150amps.The NEC requirement is satisfied,but whataboutvoltagedrop?Take the "normal”ampacity of 104.17 amps androundupto105amps.Refer to Table 9-6:Lengthof24VWirefor2%Voltage Drop.To go 8 feetwitha2%voltage drop,you can use #4 AWG wire.Hmmm...#4 AWG is smaller than #1/0 AWG,something seems strange here.That is what the bolddiagonallineonthechartisfor.It tells you thatanythingbelowthislineissuspect.If you look at #4AWGwireinTable9-4:Ampacity of Copper Wire,you find out that it can only pass 85 amps.This is alotlessthanthe131ampsrequiredbytheNEC.So PHOTOVOLTAIC SYSTEM WIRING what would happen if you had a 2500-watt loadandused#4 AWG wire?It could burn up!So youwouldn't use #4 AWG wire here. Does the #1/0 wire pass the 2%voltage dropspecification?You bet it does!If you look at Table9-6 you'll see that #1/0 AWG for 110 amps (thenexthighernumbertoour"normal ampacity of105amps)can travel 22.2 feet and not exceed a 2%drop.So in reality,when you only have to go 8 feet,you have a lower voltage drop than 2%.And that is great!Note:This problem has been simplified to teachyouthebasicsofwiresizing.An actual PV designwouldrequiretheinverterefficiencyandthelowestoperatingvoltageoftheDCinputtotheinvertertobeconsidered.You should always check with theinvertermanufactureranduserecommendedwiresizes.Also the wire from the PV array wouldactuallybecomingfromacombinerboxas#6 wireistoolargetoconnectthemodules. 99 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL System Wire Sizing Worksheet Use the following worksheet to determine system wire Sizes. PV Combiner Box to BatteryYoucansizethissectionasone wire run from PV to Battery,due to the fact that the controller is basicallyapassthroughdevice.You can also break this wire run into two sections,PV to Controller and ControllertoBattery(see wire sizing worksheet below). A.NEC Requirement Isc of #of modules _-_ . modules in parallel Total Amps X 1.25 X 1.25 =NEC required amps X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements Total Amps: One Way Distance:Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10):Is this equal to or greater than the size wire needed for safety? System Voltage: *Lf yes,this is your answer.»Tf no,use the wire size from A. PV Combiner Box to ControllerAttimes,it can be advantageous to break up the PV to Battery wire run into two separate wire runs,PVtoControllerandControllertoBattery.Since the Controller is usually very close to the battery,you canusuallysizethissectionwithwiresmallerthanthePVtoControllersectionaslongasitpassestheNECrequiredampacityfromthePVarray. A.NEC Requirement Isc of #of modules __ modules *in parallel Total Amps X 1.25 X 1.25 =NEC required amps Xx =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements Total Amps:____ One Way Distance:_Voltage Drop(%):a Wire Size from voltage drop tables (Tables 9-5 through 9-10): Is this equal to or greater than the size wire needed for safety? System Voltage: °If yes,this is your answer.*If no,use the wire size from A. *Note:Circuits operating at less than 50 volts,which are most DC circuits in PV systems require #12 copperorequivalentconductorminimum.Conductors for appliance branch circuits supplying more than oneapplianceorappliancereceptacleshallnotbesmallerthan#10 copper or equivalent (NEC,Article 720). 100 PHOTOVOLTAIC SYSTEM WIRING Controller to Battery A.NEC Requirement Isc of #of modules modules in parallel X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= =Total Amps X 1.25 X 1.25 =NEC required amps B.Voltage Drop Requirements System Voltage: One Way Distance: Total Amps: Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10):Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.*Ifno,use the wire size from A. Battery to DC Load Center A.NEC RequirementDCloadwatts+DC voltage =DC total amps X 1.25 =NEC required amps +=X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements: System Voltage:Total Amps:; Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10):One Way Distance: Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.¢If no,use the wire size from A. Battery to Inverter A.NEC Requirement DC SystemInverter.Inverter a ___Inverter _ .Rated Watts >Efficiency”Tower pera)=Total Amps *1.25 =NEC required amps >>=X1.25= Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps: Voltage Drop(%):; -Wire Size from voltage drop tables (Tables 9-5 through 9-10):One Way Distance: Is this equal to or greater chan the size wire needed for safety? +If yes,this is your answer.*Tf no,use the wire size from A. *See note on previous pageTemperaturederationisnot included in the wire sizing worksheets.For information on temperature derationseeNECTables310.16 and 310.17.page 2 of 2 ection 2.3 101 DESIGN AND INSTALLATION MANUALPHOTOVOLTAICS. IVA021IQAP2 'sHem ov¢I90 00sejenay (yaks HY04€) Saeed 9QAg 1y619 S}[OAPZ10} pans (J0AbZ) SHeM 605 :Peo] Ja Yuanvsua ec (GA,AQZL) ssmanan speoy yo) 'SLINDHIQ Ssaasaes HONWHa whiarsancncieas Yy31N39avolov unuixeu sduegg JBUIWOU S}fOA$Z' W3LN3) (dA) Agzt) SMV O/l# avo1oda sunsets speo]900}*SLINDYID NVd@ Adslivd OMYO/L# *(_| YaVI"d Ld Japaaut 01yue Asaeg jaa}Gpue%Z Bears eati peo)Jq0} Asaneg 40)18a}G,pue%Z yueq Alaneg 0}Ad10}188)0Gpue%Z ASLSAS JHL40 SLNANOdIW09 NJ4AMLI9 SJINVLSIO AVM-JNO ONV SLNJINGYINOIY dowd JOVLIOA YaNVIN $0pz= afieyoqwaysAs 9q LDAY O/L# yoeaJo(dw]) Juang Jamog WNuIxe| 'sdiwe 7/7=yoeeJo(9S]) ALIN Wd. WOYS SYOAZ|= BHeYyoA ajNpow |BUILUON 'sajnpow Hemgotvay joSpem pajoauuag jejo] Figure 9-1 AC AND DC LOAD SCHEMATIC Saction 3.3102 PHOTOVOLTAIC SYSTEM WIRING Figure 9-1 on page 102 is a schematic of the Example 9-4 previous wire sizing exercise showing the principle components of a photovoltaic system that powers both alternating current and direct current loads. The conductors between each of the components should be sized to limit voltage drop to acceptable Calculating Voltage Drop with the VDI Chart Using the VDI equation,calculate the voltage drop index for the PV array to the battery for the previous wire sizing exercise,also shown inlosses.Figure 9-1.Use a 2%voltage drop and a one way distance of 50 feet.Then use the VDIVoltageDropIndexchartintable9-12 to determine the wire size Another way to size wires for a PV system uses an needed.Compare this answer to the answer you got when you used the voltage drop tablesequationtocalculatethevoltagedropindex(VDI).in Step 4 of the wire sizi :in Step 4 of the wire sizing exercise.With this equation and a VDI chart,you can calculate the wire size for any voltage drop and any nominal system voltage. VDI =Amps x feet %Voltage drop x voltage where: *amps =maximum number of amps through "clrcuit *feet =one way wire distance *%voltage drop =Percentage of voltage drop desired (use 2 for 2%), *voltage =nominal system voltage Table 9-12 Voltage Drop Index Chart Wire Size Copper Wire | Aluminum Wire AWG VDI Ampacity "VDI Ampacity 4/0 99 230 62 180 3/0 '78 200 49 155 2/0 62 175 39 135 1/0 49 150 31 120 2 31 115 20 94 4 20 85 12 65 6 12 65 8 8 50 10 5 30 12 -3 20 14 2 15 Section 23 1038 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Overcurrent Protection Every circuit must be protected from electrical current that exceeds the wire's ampacity.The National Electrical Code specifies the maximum overcurrent protection for each conductor size.Two types of overcurrent protection are: ¢Circuit breakers *Fuses When the current exceeds a fuse or circuit breaker's rated amperage,the circuit will open and stop all current flow.A fuse that has "blown”must be replaced,while a circuit breaker may simply be reset. Circuit Breakers:Circuit breakers must be Underwriters Laboratory (UL)listed and be DC rated if used in direct current circuits.Many circuit breakers commonly used in AC circuits are not suitable for DC systems unless rated specifically for that purpose,Direct current tends to "arc”across the contacts of a breaker as the switch opens the circuit.° Consequently,a breaker without an adequate DC rating will soon burn out its contact points.This affect applies to general use switches as well. Fuses:Fuses consist of a wire or metal strip that will burn through when a predetermined maximum current passes through the fuse.This opens the circuit and protects the wire.Fuses,like circuit breakers,must be UL listed and be DC rated if placed in DC circuits. When a fuse blows or circuit breaker trips, determine the cause before replacing the fuse or resetting the circuit breaker to avoid damaging the PV system wiring or starting a fire.Common causes of fuse failure from excess current are: *Overload:Operation of too many loads on the same circuit. *Short circuit or ground fault:Caused by faulty wiring or equipment. Overcurrent Protection Placement The NEC requires that every ungrounded conductor (refer to Grounding in this chapter for a definition) be protected by an overcurrent device (NEC 240.20). In a DC system,the ungrounded conductor is the positive conductor.In a PV system with multiple sources of power,such as PV panels,batteries,and generators,the overcurrent device must protect the conductor from overcurrent from any power source connected to that conductor.(See NEC,690.9A) Figure 9-1 on page 102 shows a PV system with proper overcurrent protection placement. Sizing Overcurrent Protection A common misconception is that breakers and fuses are to protect equipment from damage.Remember, their primary task is to protect the wire from overheating and potentially causing a fire.To achieve this,the rating of an overcurrent device must be less than or equal to the ampacity of the wire used.The wire ampacities shown in Table 9-4 also represent the maximum overcurrent protection that meets code. (Keep in mind that this is only a partial table.)When an overcurrent device is placed at the connection between two different wire sizes,you must protect the smaller wire. When sizing wires as you were doing earlier,for each run you usually came up with two different sizes of wire to use.The first was looking at the maximum current,and then multiplying it by a safety factor to satisfy NEC requirements.The next was looking at the Jength of the wire run and considering voltage drop to design an efficient system.Depending on the length of the wire run,sometimes the two sizes of wires are greatly varied.Using these two sizes,you can come up with an acceptable range of appropriately sized overcurrent protection devices.As a designer,you can then choose the one that fits your system best. Minimum overcurrent device:The amperage of the power source or power draw,including safety factors.This is the minimum amperage rating of a fuse or breaker that will not cause nuisance tripping. Maximum overcurrent device:The ampacity of the wire actually used -often based on wire chosen by voltage drop considerations. Overcurrent Protection Sizing Exercise The following example provides you with an opportunity to practice sizing overcurrent protection. In this exercise,you will use the PV system and the wire choices made for the Wire Sizing Exercise on page 97.Figure 9-1 shows the placement of the overcurrent protection devices you will size in this exercise. Pa 04 ce 4 'f } 4 Note:Not all circuit breakers in Figure 9-1 are sized in this example. PV Array Combiner Box to the Battery Bank The following list contains a review of the wire sized for the Wire Sizing Exercise is in the following list: *#6 AWG wire-Minimum size wire needed to meet NEC safety requirements;rated for a maximum of 65 amps. *1/0 AWG wire-Size wire needed for a 2% voltage drop at a one-way distance of 50 feet rated for a maximum of 150 amps. Question:What is the maximum size breaker needed to protect the #1/0 AWG wire used for a 2%voltage drop? Answer:150 Amps The rating of the overcurrent device must be less than or equal to the ampacity of the wire used.The rated ampacity for a 1/0 wire is 150 amps;therefore the maximum breaker would be rated at 150 amps. Question:What is the minimum size breaker or fuse we could use on the 1/0 AWG wire the PV panels to the batteries? Answer:60 Amps Remember,the 1/0 AWG wire is an oversized conductor and is used to make an efficient system. 1/0 AWG wire can safely carry 150 amps and the panels produce 56.25 amps.Refer back to the Wire Sizing Exercise,Step 2:for details.If you put a 55- amp breaker on this wire,you may encounter nuisance tripping if you actually see 56.25 amps coming from the array on a clear winter day.You need to use a 60-amp breaker to avoid this issue and still protect your 1/0 AWG wire. Note:As a designer,now you have the parameters to make a decision about what size breaker to choose.In this example,you may use any breaker between 60 amps and 150 amps. PHOTOVOLTAIC SYSTEM WIRING The following are factors that may influence your decision in choosing overcurrent devices: *Cost *Future system expansion *Local availability Continue specifying the overcurrent protection for the battery to DC load run. Batteries to the DC Loads The following list is a review of the wire sized for the Wire Sizing Exercise is in the following list: ¢#10 AWG:Minimum size wire needed to meet NEC safety requirements,rated for a maximum of 30 amps. °#8 AWG:Size wire needed for a 2%voltage drop at a one-way distance of 15 feet,rated for a maximum of 50 amps. Question:What is the maximum size breaker needed to protect the #8 wire used to meet both NEC and voltage drop requirements? Answer:50 amps Question:What is the minimum size breaker or fuse we could use on the #8 conductor from the batteries to the DC loads? Answer:30 amps. In the Wire Sizing Exercise you found the NEC required an ampacity of 26.04 amps from the batteries to the DC loads.Since breakers and fuses come in standard sizes,the next size breaker that would not cause nuisance tripping is 30 amps.The range for this example is 30 amps to 50 amps.The designer can now choose the size breaker that is appropriate according to the cost and availability of the breaker and expansion considerations. at |105 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL G &s)Disconnects Each piece of equipment in a PV system,such as inverters,batteries,and charge controllers,must be able to be disconnected from all sources of power (NEC 690.15).To comply with NEC code, disconnects must satisfy the following items: *They can be switches or circuit breakers. ¢They need to be accessible. ¢They must not have any exposed live parts. ¢They must plainly indicate whether they are in the opened or closed position. *They must be rated for the nominal system voltage and available current (NEC 690.17). Circuit breakers designed in the system for overcurrent protection can be used as disconnects. Fuses are not considered disconnects unless they are switched fuses. The total number of disconnecting devices a PV system can have must be six or fewer switches or circuit breakers to shut off all sources of power (NEC 690.14). These six disconnects must be grouped together (NEC 690.14)and grouped with other disconnecting means for the system (NEC 690.14 C5). +Grounding The following list contains the NEC definitions (NEC 100)for the grounding terms you should be familiar with. *Grounded.Connected to the earth or to some conducting body that serves as earth. *Grounded conductor.Current carrying conductor that is grounded at one point. Conventionally the white wire. *Grounding conductor.A conductor not normally carrying current used to connect the exposed metal portions of equipment or the grounded circuit to the grounding electrode system.Normally bare copper or green wire. *Grounding electrode conductor.Bare copper wire connecting grounded conductor and/or equipment grounding conductor to the grounding electrode. *Grounding electrode.Usually a ground rod or bare metal well casing. *Ungrounded conductor.Current carrying conductor not bonded with ground. Conventionally the red,positive wire on DC; conventionally black,any color besides white, gray,green,or bare copper on the AC side. Refer to Table 9-2 for color-coding. Why Ground? The following is a list of the reasons to ground: *To limit voltages due to lightning,line surges or unintentional contact with higher voltage lines. *To stabilize voltages and provide a common reference point being the earth. *To provide a path in order to facilitate the operation of overcurrent devices. There are two specific ways we ground a system: Equipment grounding and system grounding.It is important to know the difference between the two. Equipment grounding:Equipment grounding provides protection from shock caused by a ground fault and is required in all PV systems by the NEC.A ground fault occurs when a current-carrying conductor comes into contact with the frame or chassis of an appliance or an electrical box.A person who touches the frame or chassis of the faulty appliance will complete the circuit and receive a shock.See Figure 9- 4,The frame or chassis of an appliance is deliberately wired to a grounding electrode by an equipment grounding wire through the grounding electrode' conductor.The wire does not normally carry a current except in the event of a ground fault.The grounding wire must be continuous,connecting every non- current carrying metal part of the installation to ground.It must bond or connect to every metal electrical box,receptacle,equipment chassis,appliance frame,and photovoltaic panel mounting.The grounding wire is never fused,switched,or interrupted in any way. When metal conduit or armored cable is used,a separate equipment ground is not usually necessary since the conduit itself acts as the continuous conductor in lieu of the grounding wire.Grounding wires are still needed to connect appliance frames to the conduit. 106 PHOTOVOLTAIC SYSTEM WIRING ONE GROUNDING ELECTRODE aaeee Equipment grounding conductor_----Grounding electrode conductor CHARGE -j wseeeeeeeee'DC LOAD .CONTROLLER CENTER AC LOADINVERTER-so beeen ee eer erreess CENTER rT] , EARTH GROUND TWO GROUNDING ELECTRODES en es ae ee ee Equipment grounding conductor iF .-- -Grounding electrode conductor CHARGE DC LOAD CONTROLLER CENTER GROUND : AC LOAD INVERTER =evvecrscortttt CENTER BATTERY BANK EARTH GROUND Figure 9-2 EQUIPMENT GROUNDING SCHEMATIC Section 2.5 107 DESIGN AND INSTALLATION MANUALPHOTOVOLTAICS: GNNOYD Hluv4 Fray qqunooy & 7 4aVidd MNV@ AYILIVE INIOd DNIGNOGNIGNNOYD WIALSAS *) wayaua Y31N39avo1oa JOJINPUOID 8P01}34a/a HulpUNoIG a Joyonpuos BulpunosB yuawidinbRZ +*++- Joyonpuoed BulAuedjueung === eee ee ee ee ee oe yuanvaddS}[OApz10} palm Sajnpow Ad Figure 9-3 SYSTEM AND EQUIPMENT GROUNDING SCHEMATIC Section 9.6108 System grounding:System grounding is takingoneconductorfromatwo-wire system andconnectingittoground.The NEC requires this forallsystemsover50volts(NEC 690.41).In a DCsystem,this means bonding the negative conductortogroundatonesinglepointinthesystem(NEC690.42).Locating this grounding connection pointascloseaspracticabletothephotovoltaicsourcebetterprotectsthesystemfromvoltagesurgesduetolightning(NEC 690.42 FPN).In grounded systems,the negative becomes ourgroundedconductorandourpositivebecomestheungroundedconductor.If you choose not to system-ground a PV system under 50 volts,both conductorsneedtohaveovercurrentprotection(NEC 240.21), which is often more cumbersome and costly.MostPVinstallerssimplychoosetosystem-ground even if the system operates under 50 volts.Ground-Fault Protection:Roof-mounted,DC PV arrays located on dwellings must be providedwithDCground-fault protection (NEC 690.5).Many grid-tie inverters offer built-in ground faultprotection.If a system Is to be roof-mounted on adwellingandthesystemisnotusinganinverterpackagewithbuilt-in ground-fault protection,ground fault protection must be wired in separately.Ground-fault protection isolates the groundedconductor(in DC,this is the negative wire)fromgroundunderground-fault conditions,as well asdisconnectingtheungroundedconductor(the positive wire). Size of Equipment Grounding Conductor The size of the equipment grounding wire for the PVsourcecircuits,such as the PV to battery wire run;orforgrid-tie systems with no battery back up,the PVtoinverterwirerun,depends on whether or not thesystemhasground-faule protection.If the system has ground-fault protection,theequipmentgroundingconductorscanbeaslargeasthecurrentcarryingconductors,the positive andnegativewires,but not smaller than specified inNEC,Table 250.122 (page 359).This table is basedontheamperageratingoftheovercurrentdevice PHOTOVOLTAIC SYSTEM WIRING protecting that circuit.For example,if the circuitbreakerprotectingthecircuitisratedatorbetween30ampsand60amps,you can use a #10 AWGcopperequipmentgroundingwire.If the positiveandnegativeconductorshavebeenoversizedforvoltagedrop,the equipment grounding wire alsomustbeoversizedproportionally(NEC 250.122(b)). From the example in the Wire Sizing Exercise,youincreasethenecessarywiresizefrom#6 AWG to #1/0 AWG to satisfy a 2%voltage drop requirement. Here you would have to increase your equipmentgroundingwirefrom#10 AWG to #4 AWG.If the system does not have ground-faultprotection,the equipment grounding wire must besizedtocarrynolessthan125%of the PV array shortcircuitcurrent.For example,if your PV array has a short circuit current of 30 amps,the equipmentgroundingwirewouldhavetobesizedtohandleatleast37.5 amps (30 amps x 1.25).Similar to the PVsystemswitheround-fault protection,if the positiveandnegativeconductorshavebeenoversizedforvoltagedrop,the equipment grounding wire alsomustbeoversizedproportionally(NEC 250.122(b)).From example in the Wire Sizing Exercise,youincreasethenecessarywiresizefrom#6 AWG to #1/0 AWG to satisfy a 2%voltage drop requirement.Here you would have to also increase the equipmentgroundingwirefrom#10 AWG to #4 AWG. Size of Grounding Electrode Conductor The DC system grounding electrode conductor,which is the bare copper wire connecting grounded conductor (the negative wire)and/or equipmentgroundingconductortothegroundingelectrode(thegroundrod),cannot "be smaller than #6 AWGaluminumor#8 AWG copper or the largestconductorsuppliedbythesystem(NEC 250.166).Even though many PV systems have largerconductorsinthesystem(for example,#4/0 invertercables),they can use #6 AWG copper wire for thegroundingelectrodeconductorifthatistheonlyconnectiontothegroundingelectrode(NEC© 250.166(C)).PSPectBatRaw aeerarm OfwetAe PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Hot -/Blown fuseMotor 7; Windingin motor-*Grounded conductor.i Ground connection at- service equipment \hh Earth|, Hot heseendli>emBlown fuse, a, Grounded conductor hk Alt 1 -i gpa Grounded conductor\hI hr Hot FNY,use Hot L Fuse-\%,4 Ser Equipment Ground -.-------|Grounding Wire IGrouhded || conductor AN ov Figure 9-4 GROUNDING Grounding Electrodes Because all PV systems must have equipment grounding,regardless of operating voltage,PV systems must be connected to a grounding electrode. This is usually done by attaching the equipment grounding wire to a ground rod,via a grounding electrode conductor.PV systems often have AC and DC circuits where both sides of the system can use the same grounding electrode.Some PV systems may have two grounding electrodes,which is often the case for pole mounted PV arrays.One electrode for the AC system and one electrode for the DC system at the array.If this is the case,these two grounding electrodes must be bonded together (NEC 690.47). Miscellaneous Code Issues Stand-alone systems must have a plaque or directory permanently installed in a visible area on the exterior of the building or structure used.This sign must indicate that the structure contains a stand-alone electrical power system,and the location of the system's means of disconnecton (NEC 690.56).Alternating current and.direct current wiring may be used within the same system,although they may never be installed within the same conduit,or electrical enclosures without some type of physical barrier separating the AC conductors from the DC conductors.O410.yeeother omeOerer Chapter 10 Sizing Photovoltaic Systems Contents:10.1 Introduction to SizingPVSystems ..+-+++eer rrret ttt ..11210.2 Design Penalties...+.-0+0 eee er reer errs r tresses sss 11210.3 Sizing Worksheet eect rettressttttteeeetreeceees LIZ10.4 Sample System Exercise...0++-seeerrerrrerstst tess wee LYS 111 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL introduction to Sizing PV Systems Stand-alone photovoltaic power systems are low- maintenance,versatile solutions to the electric power needs of any off-grid application.They provide electric power for telecommunication stations and water pumping systems throughout the world. Twentieth-century comforts and conveniences can now be provided to remote homes and vacation cabins via photovoltaic systems.These self-contained power stations have proven to be a reliable,cost- effective alternative to conventional power,and frequently replace the noisy,unreliable generators that most remote homes currently use. Sizing a residential photovoltaic power system is not particularly complex.This chapter illustrates a six-step process to accurately size a system based on the user's projected needs,goals,and budget.Sizing a system includes the following steps: 1.Estimating the electric load 2.Sizing and specifying batteries 3.Sizing and specifying an array 4.Specifying a controller 5.Sizing and specifying an inverter 6.Sizing system wiring This method is not biased toward any product,but rather will result in generic product specifications for the system.The method uses climatic data specific to a location and energy data specific to the user's needs. Each phase may be broken into smaller,simpler steps.A calculator,sharp pencil,and a lot of common sense are all you're going to need to size a system! 1 O.2 Design Penalties More people would utilize photovoltaic power systems if it were not for the high initial cost.Since the photovoltaic system industry is competitive,system designers must try to minimize the initial system costs by maximizing the system's energy efficiency.Efficient energy use lowers initial system expenses.For example, reducing the electric lighting load by 75 percent, perhaps by shifting from incandescent to,fluorescent lights,will reduce the modules and batteries needed for the system.Eliminating module shading by relocating the mounting system doesn't cost any money and can increase the system's efficiency. Inefficiency caused by excessive voltage drop in the system's wiring can be reduced with proper wire sizing. Intelligent advance planning doesn't cost anything and can drastically reduce a system's initial cost. Some penalties,such as module efficiency,are out of the realm of system designers and should be left to research scientists.Other penalties are the responsibility of the designer to consider -for example,the fact that some modules perform better in certain climates. In general,designers should consider the following penalty areas when trying to optimize a system: *Siting.The site should be clear of shade to increase the system's efficiency. *Orientation.The array orientation with respect to true south and proper inclination is critical for maximizing annual photovoltaic output based on local climatic conditions. *Mounting options.The optimal mounting system can maximize insolation gain. *Modules.PV modules should be selected according to the system's parameters. *Wiring.System wiring should be designed to minimize voltage drop,meet safety codes,and provide protection from the environment. *Controllers.The controller must operate a system efficiently while meeting the needs of the user. *Battery Storage.The battery bank must be sized to the specific installation. *Loads.The system loads determine the size of the system and should be minimized by intelligent planning. Remember the six P's of photovoltaic system design: Proper Planning Prevents Poor Photovoltaic Performance Advance system planning gives the designer the opportunity to quantitatively address these potential areas and minimize their cumulative impact.It is 12 certainly more cost-effective to consider these issuesupfrontratherthantryingtoprovidesolutionsforapoorlyplannedsystemthatisalreadyinstalled.Most photovoltaic dealers can help designers sizesystems.Each module manufacturer has a design.method based on their product specifications, ranging from simple analysis to full-scale computersimulations.If continuous power is critical,for example with a life support system,an engineeringanalysisoftheproposedphotovoltaicsystemshouldbeperformed.If needs are not critical,a more general sizing method may be adequate. 10.3¥&aad Sizing Worksheet The Photovoltaic System Sizing Worksheet is dividedintosixstepsthatshouldbecompletedsequentially.This chapter contains one copy of the sizingworksheet.(For additional copies of the worksheet, refer to Appendix D.)You will need a calculator tocompletethecalculations.Each of the followingstepscorrespondstoasectionoftheworksheetandcontainsdetailedproceduresforcompletingthecalculations.Complete the worksheet by working through the following steps: _Step 1:Electric Load EstimationCompletetheElectricLoad Estimation byinputtingtheload,volts,amps,and usageinformationforeachoftheloadsinasystem.Upon completion,you will know the Total ConnectedWatts(alternating current and/or direct current)andtheAverageDailyLoad(alternating current and/ordirectcurrent).If the loads vary significantly on a seasonal or monthly basis or are of a critical nature,use the highest values in designing the system.Themethodofloadanalysisinthisportionoftheworksheetisthesamemethodasdescribedin Chapter 4.Now that you have determined theAverageWatt-Hour Per Day Load the next step isdesigninganadequatebatterybank. Step 2:Battery SizingBeginbyestablishing the inverter losses bydividingtheACAverageDailyLoadbythetypicalInverterEfficiency.The inverter efficiency varies withusepatterns;generally,0.9 can be used.Add.thisfiguretotheDCAverageDailyLoadanddividethe SIZING PHOTOVOLTAIC SYSTEMS sum by the DC System Voltage to arrive at theAverageAmp-Hour Per Day Load.To factor in autonomy,multiply the AverageAmp-Hour per Day Load by the desired Days ofAutonomytodeterminetherequiredbatterycapacity.Divide this total by the Discharge Limit,orthebattery's maximum depth of discharge,a numberlessthan1.0,to determine the total required battery capacity.At this point,you must select a particular batterytobeusedinthesystemandusethespecificationsforthatbattery.Specify the battery Make and Model atthebottomoftheBatterySizingWorksheet.If youhavetroublecompletingthissection,refer toChapter6whichlistsspecificbatteryinformation.Divide the total required battery capacity by the_Battery Amp-Hour Capacity supplied by themanufacturertodeterminethenumberofBatteries in Parallel needed.If the battery bank includes batteries connected in a series configuration,the required number of Batteries in Series is determined_by dividing the Direct Current System Voltage by theBatteryVoltageofthebacteryyouhavechosen.Multiply Batteries in Series by Batteries in Parallel toobtainTotalBatteriesRequired. Step 3:Array SizingTobeginsizing the array,you must modify theaveragedailyloadfortheinefficiencyofthebatteriesthathavebeenselected.Divide the Average Amp Hour Per Day Load from Step 2:Battery Sizing,bytheestimatedBatteryEnergyEfficiency,commonly 0.8.Then divide this number by the Peak Sun Hours Per Day available.The resulting figure is the ArrayPeakAmps.At this stage,you should consider the system's mounting scheme.Note:Monthly peak sun hours for locationsaroundtheworldareavailableinAppendixB.This contains seasonal peak sun hours for tile angles,azimuth,and tracking options.Also included areworldwidemapsthatshowsolarinsolationforthreetiltanglesandfourseasons.Peak sun hours may beadjustedtoaccountforothervariables,such as addedreflectanceorshading.You may also consult othersourcesofsolarradiationdataforyourparticular location.At this point,you must select a particular PVmoduleforthesystemandusethespecificationsforthatmoduletocompletefurthercalculations.Specify Section 10.3 113 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL the Make and Model of the selected modules at the bottom of the Array Sizing Worksheet.For more information on modules,refer to Chapter 5.From the module manufacturer's specifications,find the Peak Amps Per Module,which is a tested value at STC (not short circuit current). Note:From the manufacturer's specifications, also write down the Module Short Circuit Current, which will be usedin Step 4.Divide Array Peak Amps by Peak Amps Per Module.The resulting number is the required Modules in Parallel. To determine the required Modules in Series, divide DC System Voltage by the Nominal Module Voltage.Next,multiply Modules in Series by Modules in Parallel to determine the Total Modules required. Step 4:Controller Specification To begin,multiply Module Short Circuit Current by Modules in Parallel from Step 3.Then multiply this by a safety factor of 1.25.The resulting figure is the Array Short Circuit Amps that the controller must handle under a short circuit condition. At this point,you must select a controller for the system.Using the Array Short Circuit Amps from the worksheet and the manufacturer's specifications for the desired type of controller,find a controller with Controller Array Amps or Charging Current that meets the required Array Short Circuit Amps.Also consider the other controller features.After you have chosen a controller,specify the Make and Model at the bottom of the Controller Sizing Worksheet.If you choose a controller with LVD make sure it is able to handle the ampacity of the DC loads connected to it.For more information on controllers,refer toChapter7. Divide the DC Total Connected Watts from Step 1 to calculate the Maximum DC Load Amps the controller will be required to handle.Compare this figure to the manufacturer's specifications for load amperage and enter the load amperage in Controller Load Amps. Step 5:Inverter Specification Divide the Total Connected Watts that will be used simultaneously by the DC System Voltage to calculate the Maximum Direct Current Amps Continuous. Determine the Maximum Surge Watts required. Remember that electric motors can require from three to seven times their rated wattage during startup.Surge requirements for an appliance are available from the motor manufacturer or can be measured with an ammeter. Using these figures and the manufacturer's specifications for the desired type of inverter,find an inverter that meets the system's wattage specifications, budget,and other requirements,such as a sine-wave inverter for solid-state equipment.Specify the inverter Make and Model at the bottom of the Inverter Sizing Worksheet.For more information on inverters,refer to Chapter 8. Step 6:System Wire Sizing Refer to Chapter 9 for instructions on completing the system wire sizing section. 114 Section 10.3 sa,#|Sample System'|0.4 ExerciseThefollowingsamplesystem describes and illustratesasimple,stand-alone photovoltaic lighting applicationcommoninremotehomesandvacationcabins.Itincludesthebasiccomponentsofasafelyinstalled system.The sample system's load is described below.Review the worksheets on the following pages to see how we size the system.Electric Load Information:Winter is the peakuseperiod.The system contains the following 12-volt direct current lights.Each light is used fourhoursperdayandfourdaysperweek. ¢One 20-watt fluorescent light ¢One 10-watt incandescent light «Three 25-watt incandescent lights Inverter Specification: e No Inverter Battery Information: *Battery stored at room temperature *Five days of autonomy required ¢Maximum depth of discharge 50% *Model 12-100 AH,12 volt batteries rated at100amphours(over 16 hours)made by XYZ Battery Company +Battery energy efficiency estimated at 80% SIZING PHOTOVOLTAIC SYSTEMS Array Information:¢Panels to be pole mounted at a 55°tilt anglenearGrandJunction,Colorado (40°N Latitude) *Design for winter conditions ¢12-volt (nominal)direct current module with a current rating of 2.23 amps (at 1000watts/m?and 25 C)and a short circuit current of 2.4 amps *Module short circuit current ts 2.4 amps made by ABC,model 2A Controller Specification: +Controller charging capacity rated at 9 amps ©Controller load switching capacity rated at 10 amps *Automatic adjustable low-voltage disconnect with integrated voltage and amperage meter *PQR controller,Model C-12 Wiring Information:°2 feet from the array to controller +2 feet from the control to battery *10 feet from the controller to DC load center *wire type:THWN in conduit,2%voltage drop for all circuits 4 115 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Stand-Alone Electric Load Worksheet (abbreviated) Individual Loads Qty X Volts X Amps =Watts X Use X Use +7 =Watt HoursAC|{DC}hrs/day |days/wk |days |AC |DC fluorescent light I2v 1.47 20 4-4 7 4571 incandescent light I2V 83 10 4 4 7 22.86 incandescent light IZv |2.08 75 4 4 7 I71.4-3 7 7 7 7 7 7 *.AC Total Connected Watts:_O__AC Average Daily Load:_O oe DC Total Connected Watts:105 DC Average Daily Load:240 Inverter Sizing Worksheet MaximumACTotalDCSystem DC Estimated Listed Desired Connected Watts Voltage Amps Continuous Surge Watts Features O I2V =0 N/A N/A Inverter Specification'_Make:N/A Model:»N/A | Battery Sizing Worksheet AC Average Inverter DC Average DC System _Average Amp- Daily Load Efficiency Daily Load Voltage hours/Day(w-hr/day)__.(w-lir/day) [(9)+N/A +24-0 ]+I2V =20 Average x Days of Discharge + BatteryAH -Batteries in Amp-hours/day Autonomy Limit Capacity Parallel 20 X 5 +5 +{00 _2 DC System Battery _Batteries x Batteries in =Total Voltage Voltage in Series Parallel Batteries 2 2 =I X 2 =2 Battery Specification ;Make:XYZ Battery .ae Model:;10-100 AH 7 .a ” 116 SIZING PHOTOVOLTAIC SYSTEMS table 10-1 Array Sizing Worksheet Average .Battery .Peak Sun _Array Amp-hrs/day Efficiency Hrs/day Peak Amps 20 +0.80 +45 =5.56 Array . Peak Modules Module Short Peak Amps)*Amps/module in Parallel Circuit Current 5.54 +2.23 =3 2.4 DC System ,Nominal Module _Modules X Modules in __Total Voltage .Voltage " .in Series Parallel Modules 12.+12.=|X 3 =3 Panel Specification Make:ABC Model:|-2AL Controller Sizing Worksheet Module Shorty Modules 125 =Array Short Controller Listed Desired Circuit Current in Parallel ,Circuit Amps Array Amps Features 2.4 X 3 X 1.25 =9 q LVD,metering DC Total DC System Maximum DC Controller Connected Watts'Voltage Load Amps Load Amps lO5 +12.=875 10 Controller Specification Make:PQR Model:C-I2 117 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL System Wire Sizing Worksheet Use the following worksheet to determine system wire sizes. PV Combiner Box to Battery You can size this section as one wire run from PV to Battery,due to the fact that the controller is basically a pass through device.You can also break this wire run into two sections,PV to Controller and Controller to Battery (see wire sizing worksheet below). A.NEC Requirement N/A Isc of #of modules __ .modules in parallel -Total Amps X 1.25 X 1.25 =NEC required amps x '=X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps: One Way Distance:Voltage Drop(%):2. Wire Size from voltage drop tables (Tables 9-5 through 9-10): Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.*Ifno,use the wire size from A. PV Combiner Box to Controller At times,it can be advantageous to break up the PV to Battery wire run into two separate wire runs,PV to Controller and Controller to Battery.Since the Controller is usually very close to the battery,you can usually size this section with wire smaller than the PV to Controller section as long as it passes the NEC required ampacity from the PV array. A.NEC Requirement aot;"onal's =TotalAmps X 1.25 X 1.25 =NEC required amps 24A xX -3 =772A X1.25X 125 =__U25A _Amperage satisfying NEC =I25A Wire Size from Table 9-4*=#!4 AwG B.Voltage Drop Requirements System Voltage:lav .Total Amps:7.2A_ One Way Distance:28 t Voltage Drop(%):#4 AWG Wire Size from voltage drop tables (Tables 9-5 through 9-10):#6 AWG Is this equal to or greater than the size wire needed for safety?__yeS *If yes,this is your answer.#6 AWG *If no,use the wire size from A. *Note:Circuits operating at less than 50 volts,which are most DC circuits in PV systems require #12 copper or equivalent conductor minimum.Conductors for appliance branch circuits supplying more than one appliance or appliance receptacle shall not be smaller than #10 copper or equivalent (NEC,Article 720). page 1 of2 118 SIZING PHOTOVOLTAIC SYSTEMS Controller to Battery A.NEC Requirement Isc of #of modules __: , modules in parallel Total Amps X 1.25 X 1.25 =NEC required amps 24A_X 30 =_722A X 1.25 X 1.25 =__l25A | Amperage satisfying NEC =L25A Wire Size from Table 9-4*=(#l4)_#12,AWG* B.Voltage Drop Requirements ) System Voltage:_!2V Total Amps:7.2A One Way Distance:_2 ft Voltage Drop(%):_4 Wire Size from voltage drop tables (Tables 9-5 through 9-10):I2.Is this equal to or greater than the size wire needed for safety?yes °If yes,this is your answer.¢If no,use the wire size from A.#12 AWG Battery to DC Load Center A.NEC Requirement DC load watts +DC voltage =DC totalamps X 1.25 =NEC required amps lOSW +v=9A X 1.25 =__25A Amperage satisfying NEC =W.25 A Wire Size from Table 9-4*=(#14)#12,AWG* B.Voltage Drop Requirements: System Voltage:_!2V Total Amps:A One Way Distance:12.+t Voltage Drop(%):_2 Wire Size from voltage drop tables (Tables 9-5 through 9-10):#10 AWG Is this equal to or greater than the size wire needed for safety?_yes *If yes,this is your answer.#10 AwG *If no,use the wire size from A. Battery to Inverter W/A A.NEC Requirement DC SystemInverter..Inverter +:_Inverter _ .Rated Watts ”Efficiency ”(lowest operating)=Total Amps X 1.25 =NEC required ampsVoltage =+=X125= Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps: One Way Distance:Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10): Is this equal to or greater than the size wire needed for safety? °If yes,this is your answer.«If no,use the wire size from A. *See note on previous pageTemperaturederationisnot included in the wire sizing worksheets.For information on temperature deration see NEC Tables 310.16 and 310.17.page 2 of 2 Section 10.4 119 Chapter 11 Utility-Interactive Systems Contents:11.1 Introduction .......-ceeeeens Lae 11.2 Utility-Interactive Systems ..-.-++--- 11.3 System Sizing and Economics ...-++++-++++5 11.4 Net Metering ......--0s eee eee 11.5 Obtaining an Interconnection Agreement . /122 ..122 . .126 .127 .128 121 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Le b Introduction Utility-interactive systems,also called utility- connected,grid-tied,or line-tied systems,are solar- based energy systems installed on homes or commercial buildings connected to an electric utility. They are designed to displace all or a portion of the building's total electricity needs.Advances in solar 'power electronics make it relatively easy to connect a solar electric system to the utility.Energy generated by such a system is first used within the home,and surplus power is "pushed”onto the utility's wires.In most states of the US,local utilities are required by law to allow "spinning the meter backward”when the electricity being produced by the PV system is greater than what is being used in the home. The enactment of the Public Utility Regulatory Policies Act of 1978 (PURPA)eliminated the electric utilities'traditional monopoly over electricity generation for the utility grid.Among other things, PURPA required utilities to interconnect non-utility generators to their transmission and distribution networks,which allow small PV systems to be connected to the utility grid. Most of the non-utility generators developed under PURPA were utility-scale bulk power facilities designed and built to sell power at the wholesale or "avoided cost”price to their utilities who would resell the power to their customers.The most common PURPA facilities were industrial cogeneration facilities sized to produce hundreds of megawatts of power. Most other PURPA facilities,including biomass, geothermal,solar and wind-powered generators,were also megawatt-scale facilities.The interconnection of small-scale facilities sized to serve an individual home, small business,farm,or ranch was relatively unusual. One of the principal reasons for the scarcity of small-scale generating facilities was the burden of negotiating interconnection requirements with the local utility.Although PURPA established a federal mandate for interconnection of non-utility generation,much of the detailed implementation of PURPA was left to utilities and regulators at the state level.Because utilities historically had exercised primary responsibility for maintaining the safety and integrity of the transmission and distribution network,regulators were inclined to grant the utilities substantial deference and discretion with respect to interconnection requirements.Generally speaking, non-utility generators found utility requirements to be unreasonably and unduly burdensome,and they argued for more streamlined and simplified approaches to resolving interconnection issues. This chapter discusses the evolution of policymakers'response to interconnection issues, including both technical requirements and non- technical requirements. = Utility-Interactive[|:&x Systems There are two types of utility-connected systems, systems without battery backup and systems with battery backup.Utility-interactive systems without battery backup consist of just two main components,aPVarrayandautility-interactive inverter,and have no means of providing power when the utility grid fails. Utility-interactive systems with battery backup also have an array and utility-interactive inverter,but include the addition of a battery bank and charge controller.With these components,systems with battery backup can provide power during utility power outages. There are many advantages to a_utility- connected system,including: Improved Economics:It is expensive to get the last 5%of system availability with PV.In regions with variable climate,where average daily insolation in winter is two or three times less than in summer, relying on PV only requires a big system and can get very expensive.Thus,the use of a utility-connected system may be quite economical.Applications with large loads may also be more economically powered directly by the grid.A utiliry-connected system without batteries is also more efficient than a battery based system because the inverter can track the PV modules "maximum power curve”rather than having the module voltage pulled down to the battery voltage level. Lower Initial Cost:Meeting the full requirements of the load with PV may be too expensive for the homeowner.The start into a utility-connected system with just an inverter and a small PV array is possible for even small budgets.There is no battery,charge controller,control panel,or backup generator required.More PV modules and/or a battery can be added later on to decrease the grid dependence. 'Increased Reliability:Because there are tw independent power systems,there is inherent system redundancy and possibly greater overall reliability. 122 Section T1.4-11.2 Adding a battery to the system makes an uninterruptible power system (UPS). Design Flexibility:Since the utility provides a permanent power source,the PV system can be designed to the budget and desires of the homeowner.Utility:Interconnected systems have been made possible by advances in inverter technology that have been brought about by utilicy-interactive inverters. These inverters are capable of both converting the DC power from the PV array to standard AC power and synchronizing that power with the utility's electricity. A user-friendly uciliry-interactive inverter includes all components necessary to make a simple,and code compliant,utility-interconnected installation, Utility-interactive System without Battery Back-up The advantages and disadvantages of a utility- interactive system without battery backup include the following: *Cost-effective for net metering *Does not provide backup power *Simple to install *No power management opportunities High efficiency Figure 11-1 displays a utility-interactive system without battery backup. As long as the PV array produces more power than the house demands,solar power is fed back onto the utility grid.In times where the demands are higher or during the night,the grid helps powering the loads. Note:Local utilicy requirements may ask for a disconnect switch on the AC side and DC side. Utility-interactive Systems with Battery Backup: These systems which are equipped with a battery and charge controller can provide backup power during utility power failures.Some battery-based inverters also offer energy management opportunities.They reduce the electrical fees during the time of day when electricity is the most expensive.Peak load shaving is overcoming the utility time of use (TOU)metering by using a battery-based inverter to store 'energy during the low cost power hours and consume the battery energy during high cost power hours.One disadvantage is that adding batteries decreases the performance of the system 10 to 15 percent due to additional efficiency losses in charging the batteries. UTILITY-INTERACTIVE PHOTOVOLTAICS Also,the battery voltage dictates the system voltage, which is generally lower than the PV voltage,and thus reduces the power output of the PV array. The advantages and disadvantages of a battery- based utility-interactive system include the following: *Provides uninterruptible back-up power ¢Batteries are an additional cost Reduces energy costs for utility time of use (TOU)Metering Efficiency loss in charging batteries *Offers power management opportunities *More components to install Figure 11-2 displays a utiliry-interactive system with battery backup. As long as the utility grid is present,the AC disconnect/bypass box lets power through to the inverter and constantly floats the batteries.When the grid fails,che inverter allows the sub-panel to be powered by the batteries via the inverter. Uninterruptible Power Supply Rolling blackouts have become a regular occurrence for many electric utilities.In many places,the lack of both transmission and generation capacity may plagtie the residents with blackouts in the near future.An inverter/battery-based uninterruptible power supply (UPS),with or without PV,can provide blackout-proof power to the home.See Figure 11-3.A UPS will keep the electric appliances up and running during utility blackouts. An inverter-based grid backup system uses utility power,when it's available,to charge a battery bank. When a blackout occurs,selected loads are automatically transferred to the inverter.The inverter's main job is to convert a battery's linear DC waveform to a digital representation of an AC sine wave,which the household appliances are designed to run on.The inverter uses the energy stored in the batteries to power household loads. When the grid comes back online,the loads are automatically transferred back to the grid power.Then, the inverter's battery charger goes to work recharging the batteries to prepare the system for the next blackout.These systems are both modular and expandable;a larger capacity battery bank or renewable energy inputs can easily be added to the system. :123 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL yen ag To/From Utility: KWH Meter: energy out KWH Meter: :energy in ;PV Array :wired at 48 volts be oo bbe eee ph eS 0 0 2 |J'mee:Ground .e+| Duplex Outlet::ee outdoorrated =:gee ¥ _.: :Disconnect:G dUtility-Interactive Inverter DPST,lockable roun Ground Figure 11-1 GRID-TIE SYSTEM WITHOUT BATTERY BACKUP 124 Section 11.2 UTILITY-INTERACTIVE PHOTOVOLTAICS xog sauIquiay yosuuossig 30 IGSUOA gpieSalas Ul Pasim JOAg WHl3 'saueneg =! $19]j0U05abseyy UOWWOS ULM punoiy dd1Aas JVAOKC = 'feued Site OV: ajgessaaoe AWnn J9LBAUT BLAM cetiTee wares oo yauuessig jy sayealg tH|aS aaceaanane eo0 -le @ ttEs| RS H() ! sayeeig duegg aee -f.eu ABVSAUL 8191] OL'xog ssedAgfasuuoosiq JY ras : ' eeereeecaneee Se e-. LA - jeuonoanp-iq ietr ' oe KOGA sevenHA Sy HI feo f-Fal | speol j2INW9 01 QYAOZL :_$1942a59 [49 o 30 QVACL que 4. :: yaauuoasiq Ad ul QVAOPZ Joued-ans OV "AI Worg/O], Sasnj YIM [2 S]JOAOpye palinAewyAdHY yong oat xASS Om §:¢ sasny yum P ' xog sauIquio) 211-Figure GRID-TIE WITH BATTERY BACKUP 125 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL |1 o%System Sizing and As an example,look at a PV system designed toDobecEconomicsprovideone-third of the electricity needs.If the homeuses8000kWhperyear(number from the utility ;bill),the PV system would have to produce 2667connectedsystemdoesnothavetoprovide100ayy,per year (8000+3=2667).Assuming the annualpercentofthedailyenergyneeds.The system can be delivered energy at that location for a fixed tilt anglesizedaccordingtotheowner's desires and budget.ig 1400 kWh per 1000 W solar power,a 1900-wattWhensizingasystem,the following considerations system would be needed (2667+1400x1000=1900).are important:Using the rate of $10 per watt of installed PV,such a °Budget system would cost roughly $19,000. *Percentage of power from PV array Depending on the owner's finances,a 1000-watt Lap ;system might be bought this year and another 900 WAvailabilicyoftaxcreditscouldbeaddedinafewyears.This is possible because *Financing of the scalable nature of PV arrays.However,because +Net metering inverters come in discrete sizes,a 2000-watt inverter Unlike a stand-alone solar electric system,a utility- AC Disconnect/Bypass Box:60-amp breakers Power in from Utility Grid (CRAB E poh ade Lox Lian .i()t '()jie Lea Lhe 7b MeeAC]HERE TF of TERE HI as om res -$ out \_ran xf ot nsbereennnnscecerererenenceneccerns.Exsoswemmomaee,|...[ees es Inverter 1]a-$ /a Subpanel:oe "-<120VAC 60 Hz in/out from utility {6 ° 24VDC in from battery bank Opec iH ihe ;<e AC Mains Panel: 240VAC Ground Battery Bank:Eight6 volt,220 amp-hour batteries.Wired series/parallel for 24 volts,440 amp-hours. Figure 11-3 UNINTERRUPTIBLE POWER SUPPLY SYSTEM (Courtesy of Home Power Magazine) 126 section 11.3 zHi'pe Home Power Appliances UTILITY-INTERACTIVE PHOTOVOLTAICS Ze Solar Power -g ° Panels Utility i ;Power i 'Figure 11-4 NET METERING:UTILITY-INTERACTIVE SYSTEM could be bought initially in preparation for future expansion,rather than buying two 1000-watt unitsseparately.The same goes for installation costs;it's cheaper to do itall at once.Initially buying a 2000-watt system will likely cost less tume and money than buying in two increments.The larger the system or increment, the less it costs per unit of energy delivered.In addition to the owner's finances,tax credits and utility incentives might also play a role in system sizing.. Bs 3a4 ™?Net Metering Net metering allows exchanging any surplus energyproducedbythePVsystemforutilityenergycredit 'to be used during periods when the PV system is not producing enough energy to meet the needs.This means that the electric meter spins "backward”whenpowerisflowingfromthebuildingtotheutility,andspins"forward”when electricity is flowing from the utilicy into the building.At the end of the month, only the net consumption is billed.Ic is the amountofelectricityconsumed,less the amount of electricity produced.The utility acts much the same as abattery,crediting the energy "account”for later use if production exceeds consumption, For example,during the middle of the day,the system produces three kilowatt-hours but the building uses only one kilowatt-hour,Thus,the "account”will be credited for two kilowatt-hours. Later that evening,two additional kilowatt-hours might be used and the "account”ends up with a net zero balance,owing the utility nothing for that day. The net metering protocol is a boon to small renewable energy systems.There are three main reasons net metering is important.First,as increasing numbers of primarily residential customers install renewable energy systems in their homes,net metering provides a simple,standardized protocol for connecting their systems into the electricity grid that ensures safety and power quality.Second,as many residential customers are not at home using electricity during the day when their systems are producing power,net metering allows them to receive full value for the electricity they produce without installing expensive battery storage systems. Third,net metering provides a simple,inexpensive, and easily administered mechanism for encouraging the use of renewable energy systems,enabling important local,national,and global benefits. :127 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Benefits and'Costs:Net metering provides a -variety of benefits for both utilities and consumers. Utilities benefit by avoiding the administrative and accounting costs of metering and purchasing the small amounts of excess electricity produced by these small-scale renewable generating _facilities. Consumers benefit by getting greater value for some of the electricity they generate,being able to interconnect with the utility using their existing utility meter,and being able to interconnect using 'widely-accepted technical standards. The only cost associated with net metering is indirect;the customer buys less electricity from the utility,which means the utility collects less revenue from the customer.The reason is that any excess electricity that would have been sold to the utility at the wholesale or 'avoided cost'price is instead being used to offset electricity the customer would have purchased at the retail price. In most cases,the revenue loss is comparable to the customer reducing their electricity use by investing in energy efficiency measures,such as compact fluorescent lights and efficient appliances. The bill savings for the customer and correspondingrevenuelosstotheutilitydependsonavarietyof factors,particularly the difference between the 'avoided cost'and retail prices.-In general,the difference will be from $5 -$10 a month for a residential-scale PV system (2 kW),and from $25 - $50 a month for a farm scale wind turbine (10 kW). Moreover,any revenue losses associated with net metering are,at least partially,offset by the administrative and accounting savings,which are not included in the above figures. Using the Existing Meter:The standard kilowatt-hour meter used by the vast majority of residential and small commercial customers accurately registers the flow of electricity in either direction.This means the 'netting'process associated with net metering happens automatically.The meter spins forward in the normal direction when the consumer needs more electricity than is being produced and spins backward when the consumer is producing more electricity than they need in the house or building.Some utilities use a meter that records the number of time the meter spins,not registering if it is moving forward or backward.This type of meter will bill the homeowner for PV power produced! Current Worldwide Status:Currently,many U.S.states have some form of net metering. Germany,Japan,and Switzerland also have net metering.Many U.S.state net metering rules were enacted by state utility regulators pursuant to state implementation of the federal PURPA statute.In recent years many states have enacted net metering laws legislatively. For more information about states with net: metering legislation and incentives for renewable energy systems,refer to the Database of State Incentives for Renewable Energy (DSIRE)located at:www.dsireusa.org f 1 5 Obtaining an: E et?Interconnection Agreement Interconnecting a PV system with the utility grid will require entering into an interconnection agreement with the local utility.The interconnection agreement specifies the terms and conditions under which the PV system will be connected to the utility grid.It includes the technical requirements necessary to ensure safety and power quality and other issues, such as the obligation to obtain all necessary permits for the system and having the PV system insured. The key to obtaining an agreement is to involve the utility as early as possible in the installation. Recently,progress has been made in developing nationally recognized standards for the utility interconnection of PV systems.Although these standards are not necessarily binding on utilities, many utilities are adopting the standards rather than developing their own.The most important standards focus on inverters.Two of these standards are particularly relevant. Note:The homeowner does not necessarily need to know about these standards,but the PV provider and utility should. *Institute of Electrical and Electronic Engineers,Standard 929-2000:Recommended Practice for Utility Interface ofPhotovoltaic Systems.Institute of Electrical and Electric Engineers,Inc.,New York,NY. ¢Underwriters Laboratories,UL Subject 1741: .Standardfor static inverters and Charge Controllers for Use in Photovoltaic Power Systems (First Edition).Underwriters Laboratories,Inc.,Northbrook,IL 128 Section 17.5 OrePORRCEOKAaresgetonsgotsaeeeNicoEEADLOAOLOAOERETneeeet(December 1997).An inverter listed to UL1741withthewords"Utility-Interactive”printed on the listing mark indicates that theunitisfullycompliantwithIEEE929-2000. The Interstate Renewable Energy Council(IREC)recommends practices and guidelinesregardinggridinterconnectionissues.[REC is a non-profit organization committed to accelerating thesustainableutilizationofrenewableenergyresourcesandtechnologies.For more information,refer totheirwebsiteathetp://www.irecusa.org/connect.htmNECRequirements:Utility-connected systemspresentsomeuniqueissuesforthePVdesignerandinstallerinmeetingtheNEC.The following sectionsdescribetheNECissuesforutility-interactive systems. Inverters Inverters have to meet UL Standard 1741.Some oftheutility-interactive inverters that are available donotcurrentlymeetthisstandard.Some of theinverterscannothaveboththeDCcircuitsfromthePVarrayandtheACoutputcircuitsgroundedwithoutcausingparallelgroundcurrentpaths.Newer versions of these inverters may have solutions for this problem.Other inverters have the internal circuitry tied to the case and force the central system grounding point to be at the inverter input terminals.In someinstallations,this design is not compatible withground-fault equipment and does not provide theflexibilityneededformaximumsurgesuppression. Overcurrent Devices When UL tests and lists fuses for DC operation,thevoltageratingisfrequentlyone-half the AC voltagerating.This results in a 600 volt AC fuse rated for300voltDC.Finding fuses with high enough DCratingsforutility-interactive systems operating at1300volts(G00 volt system voltage)and above willposeproblems.There are a limited number of listed,DC-rated 600 volt fuses available.Circuit breakers (Heinemann)that are "back fed” for any application,but particularly for interactiveinverterconnectiontothegrid,must be identified inthelistingforsuchuseandmustbefastenedinplace -with a screw or other additional clamp. UTILITY-INTERACTIVE PHOTOVOLTAICS Disconnects In addition to the Heinemann circuit breakermentionedabove,manufacturers,such as GE,Siemens,and Square D,may certify their switches forhighervoltagewhenthepolesareconnectedinseries. Blocking Diodes Blocking diodes are not required by the NEC andtheiruseisrapidlydeclining.Blocking diodes are notovercurrentdevices.They block reverse direct-current 'circuits and help to control circulatingground-fault currents in both ends of high-voltagestrings.Lightning induced surges are tough ondiodes.If isolated case diodes are used,at least 3500yoltsofinsulationmustbeprovidedbetweentheactiveelementsandthenormallygroundedheatsink.Choosing a peak reverse voltage that is as high asavailable,but is at least twice the PV open-circuitvoltagewillresulcinlongerdiodelife.Substantialamountsofsurgesuppressionwillalsoimprovediode longevity.Note:Blocking diodes may not be substitutedfortheUL-1703 requirement for module protectiveFusesineachseries-connected string of modules. Surge Suppression Surge suppression is covered only lightly in the NECbecauseitaffectsperformancemorethansafety,anditismainlyautilicyproblematthetransmissionlinelevelinACsystems.PV arrays mounted in the open,on the tops of buildings,can act like lightning rods.The PV designer and installer should provideappropriatemeanstodealwithlightning-inducedsurgescomingintothesystem.Array frame grounding conductors should berouteddirectlytosupplementalgroundrodslocatedasnearaspossibletothearrays.Metal conduit willaddinductancetothearray-to-building conductorsandslowdownanyinducedsurgesaswellasprovide some electromagnetic shielding.Metal oxide varistors (MOVs)commonly used as surge suppression devices on electronic equipmenthaveseveraldeficiencies.They draw a smal{amountofcurrentcontinually.The clamping voltage lowersastheyageandmayreachtheopen-circuit voltage ofthesystem.When they fail,they fail in che shortedmode,heat up,and frequently catch fire.In manyinstallations,the MOVs are protected with fastactingfusestopreventfurtherdamagewhenthey "TS 129 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL fail,but this may limit their effectiveness as surge suppression devices.Other electronic devices are available that do not have these problems.| Silicon oxide surge arrestors do not draw current when they are off.They fail open circuited when overloaded.And while they may split open on overloads;they rarely catch fire.They are not normally protected by fuses and are rated for surge currents up to 100,000 amps.They are rated at voltages of 100 volts and higher and are available from electrical supply houses or Delta Lightning Arrestors.Inc. Several companies specialize in lightning protection equipment,but much of it is for AC systems.Electronic product directories,such as the Electronic Engineers Master Catalog should be consulted. 130 UTILITY-INTERACTIVE PHOTOVOLTAICS ceaeraneeremeetUtility-Interactive System Sizing Worksheet Electric Load Estimation 1.Figure out approximate monthly and daily average energy usage: Yearly average energy consumption:Kilowatt-hrs/yr Kilowatt-hrs/yr +12 months =average Kilowatt-hrs/month average Kilowatt-hrs/month +30 days =Kilowatt-hrs/day (This is your Average Daily Load.) %of power to be generated from PV system ______Kilowart-hrs/day X ______%of power to be from PV =____PV System Kilowatt-hrs/day Array Sizing 2.Find out your Average Sun Hours Per Day: 3.Figure out the PV system kilowatts needed (the initial size of the array): PV System Kilowatt-hrs/day +average peak sun hours per day =PV System Kilowatts 4,Factor in inverter inefficiency: PV System Kilowatts +inverter efficiency =PV array Kilowatts needed PV array Kilowatts X 1000 watts/Kilowatt =PV array watts 5.Choose a PV module: We will use the PTC ratings to pick a module because remember Standard Test Condition ratingswherecelltemperature=25°C (77°F)is not very realistic when solar panels are out in the sun.Formorerealistictestconditions(Ambient air temperature =20°C)and module ratings (PTC)see the following website:www.consumerenergycenter.org/erprebate/eligible_pvmodules.html Make:Model: STC watt rating:Voc:__-Vmax: PTC watt rating: PV array watts +PTC watt rating =#of modules needed continued Saction 17.5 | 131 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Utility-Interactive System Sizing Worksheet -Continued Inverter Sizing 6.Choose an inverter (or a combination of inverters)that has an appropriate continuous wattage rating (remember you can leave room for future system expansion when sizing your inverter): With utility-interactive PV systems we choose an inverter based on the amount of watts we are trying to pass through it at any one time (unlike stand-alone PV systems where the inverter size is based on our AC total connected load). #of PV modules needed X STC watt rating =max watts inverter(s)must pass. Make:Model: Watt rating (continuous power):DC input Voltage Range: 7.Calculate how many of these inverters the system will require,and how many modules will be wired into each inverter: max watts inverter must pass +inverter watt rating =#of inverters #of PV modules needed +#of inverters =#of modules per inverter 8.Find out how many of our modules the chosen inverter requires in series? Check with the inverter manufacture to see how many modules this inverter requires in series for it's DC input voltage window. (For SMA inverters use the string sizing program on their website: www.sma-america.com to figure out how many modules in series it needs ) Using our chosen PV modules,how many modules does the inverter need in series? Does this divide evenly into the #of panels that we need per inverter? Remember,if using more than one inverter,you will need to break up the PV array up into sub-arrays that will feed each inverter.Each inverter must have the appropriate number of modules in series to match it's DC input voltage range.If not,then our options are to either round the number of modules in our array up or down (which will affect our %of power to be generated by the PV system).Alternatively we can choose a different module or inverter to be used in our system. 132 Section 11.5 Chapter 12 Integrating Photovoltaics into Buildings Contents: 12.1 Introduction ......+-- 12.2 Retrofitted PV Systems . 12.3 BIPV Options ......--12.4 Costs/Benefits ...Leas ceceeeneeees134 Cove eee eee ee LBZ pee133 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 12.1 | |Lox ws I introduction Building integrated photovoltaic (BIPV)systems are electric generating systems that are part of the building shell.Examples of BIPV systems are roofing,atriums,and shade screens that integrate PV _ arrays into their design.In addition to generating electricity,integrated BIPV systems can also enhance a building's beauty,visibility,and value. _BIPV systems offer many advantages compared to adding a PV system onto an existing building: *No additional support structures are required - because they use the building's frame. *Limited additional construction expenses are incurred. *BIPV are easily designed to provide day lighting and heat control. *They can be designed aesthetically,to maximize visibility or educational impact. *They can be financed as part of the entire building. In addition,a BIPV system can be less expensive than a retrofitted system.This is because the PV replaces building materials,such as roofing,thus avoiding the cost of those materials and the associated labor costs. .Retrofitted PV Systems Most building PV systems are retrofitted.Typically, PV systems are attached to the roof or are mounted on ballasted structures.Retrofitted PV systems cost more than integrated PV.These additional costs include: *Wiring.All PV systems require additional wiring,but retrofitted systems must be integrated into an electrical system that was not designed for PV. ¢Mounting structures.This is equipment that "support and orient the modules,like roof mounts or ballasted pans. *Rooftop reinforcement.Some roofs are not designed to support the additional weight of a PV system and must be improved.The rooftop must be able to support the PV system,snow and ice accumulation,wind stress,and increased traffic due to maintenance. *Increased rooftop maintenance.Roofs have a life span of about 20 years,while PV systems may last 25 years or more.Replacing the roof would mean removing and then reinstalling the PV system,increasing the system's lifecycle cost.In addition,installing a retrofitted system can result in penetration of the building's shell.This can result in water leaks,which are a serious problem, particularly for buildings with flat roofs. 12.3|Govt?BIPV Options There are several ways to integrate PV into a building's design: *Roofing *Facades *Atriums,skylights,and greenhouses ¢Shade screens PV Roofing PV roofing systems can serve as fundamental roofing components,including water tight seals,drainage, and insulation,while also generating electricity.Roof tiles,slates,shingles,and standing seam roofing are the most common systems.PV slates,shingles and standing seam units are used on sloped roofs.In non- equitorial areas,PV on flat rooftops will generate less electricity than PV on sloped roofs. Some PV roofing modules use an amorphous solar cell that consists of a thin-film PV material.Other types use a mono-crystalline silicon,polycrystalline or amorphous silica cell. There have been technical concerns with PV roofing products: *Degradation of the amorphous silica material and PV output over time.(Not all PV roofing manufacturers use amorphous silicon). *Delamination of the flexible module substrate and cover used with PV shingles and standing seam PV roofing. 134 PNBAATSVacninentincenoeSrNeeema*Shorts at the electrical connections between the many modules. *Roof leakage caused by wiring penetrations. *Unfamiliarity of BIPV to architects, designers,and builders. ¢Amorphous silicon modules are less efficient and take up more roof space than single and polycrystalline. Capacity Degradation:The pre-1997 amorphous silicon modules used two,three-layer cells of PV material,which is also known as a dual- junction solar cell.These dual-junction cells experience a phenomenon known as photo- degradation.Typically,20%of their rated capacity for power output degraded over time.The output of all PV materials degrades gradually with time but the dual-junction amorphous cells degrade more rapidly than crystalline cells.For example,an eight-year-old dual-junction amorphous system being tested at the National Renewable Energy Laboratory (NREL)is now producing 20%less power than its rated capacity.This is,however,better than single junction amorphous cells from the 1980s,which exhibited output reductions of abour 30%. In 1997,a new PV product line fabricated with a new amorphous silica solar cell became available. The new cell has improved conversion efficiency and power output,long-term performance due to reduced photo-degradation,and greater durability. This new product uses a triple junction amorphous solar cell.The triple-junction cell uses three,three- layer cells of PV material,each tuned to a specific spectrum of sunlight.This has improved the modules'efficiency.In addition,each of the three amorphous silica layers is thinner than in the past; the thinner the amorphous silica layer the less photo- degradation is experienced.Thus,power-output degradation has been significantly reduced, improving long-term performance.The triple- junction module's degradation is anticipated to be about 10%over a 20-year period. To date,NREL has not seen any power degradation in their triple-junction test module.In cold climates output will decline slightly in the winter. But in general,the amorphous silica modules are slightly less temperature-sensitive over all temperature INTEGRATING PHOTOVOLTAICS INTO BUILDINGS ranges than crystalline silica modules.This product has a 20-year limited warranty and guarantying that output degradation will not exceed 20%of the module's rated capacity for 20 years.The rated power output of this module is based on an estimate of the module's stabilized long-term performance.Thus,it is common that this type of module's output will be somewhat higher than its rated capacity for the first several months of operation. Delamination of Module Materials:Older PV roofing had problems with moisture entering the module and causing delamination of the module. Newer modules have wider seals around the edges and sit on a substrate that does not wick moisture.To date,delamination has not been a problem with newer PV roofing modules.Today,delamination is covered under warranty.; Electrical Shorts and Open Circuits:Individual PV roof modules have the following peak outputs: °17 watts for a PV shingle *12.2 watts for a crystalline slate *64 or 128 warts for a standing seam panel To date,electrical shorts have not been a significant problem if the modules were properly installed.Installation of PV roofing products can be performed by conventional roofers using standard installation practices.Electrical installation is also straightforward,allowing a qualified electrician or PV system installer to install the system.Some manufacturers use plugs designed to provide quick and easy module interconnection and protect the connection from the elements.In all cases,with proper installation techniques,electrical shorts or open circuits between modules need not be a major concern. Roof Penetrations for Wiring:Roof penetrations are needed for some brands of PV shingles.Other brands run wires out the gable ends of the roof.With standing seam metal roofing,the wires are run either beneath the ridge cap or under the roof's overhang. To minimize the potential for leakage with the PV shingles,they are designed to form a double weatherproof layer upon installation,similar to conventional shingles.At the overlap between each shingle an adhesive seal forms a water and weather tight bond between the consecutive layers. Fearne 135 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL PV Facades PV facades offer a large area to place PV modules. Besides generating electricity,PV facades must protect the building from weather and look appealing.They can be integrated with windows,day . lighting,and shading schemes to provide multiple benefits.The typical BIPV facade is vertical and faces south (in northern latitudes).However,vertically oriented PV panels at the latitude of Wisconsin have a reduced electricity output compared to panels sloped toward the sun.The reduction is greatest in the summer when the sun is high in the sky;this 1s also when electricity can be most valuable.To overcome this issue,facades can be sloped using a saw _tooth design. Figure 12-6 shows an example of a sawtooth PV- facade consisting of an overhanging PV shade that screens windows.The overhang reduces direct sunlight in the summer,but allows solar heating in the winter. Opaque PV materials can be used to cover walls, building structural members,and mechanical infrastructure.Semi-translucent PV glazing applied directly to the glass can replace windows not used for viewing.Many off-the-shelf PV modules are suitable for this application. Facades can include: *Structural mullion/transom curtain wall systems.Curtain walls are non-load bearing external walls that provide a watertight building envelope.(Mullions and transoms are the vertical and horizontal framework on which the curtain wall is mounted.) *Pressure plate mullion/transom curtain wall systems. *Panel curtain wall systems. *Rain screen over cladding. PV Atria,Skylights,and Greenhouses These glazing systems,though best suited for small capacity PV systems,can be very visually appealing and provide great visibility.Because skylight,atrium and greenhouse glass is often heavily tinted to minimize glare,semi-transparent PV glazing can make a good substitute.The glazing panels consist of PV material attached to the glass.Semi-transparent PV units generate electricity while typically allowing about 20%day lighting through the modules.Open- air PV atriums are especially economical because the PV modules do not require extra ventilation. ea a a Figure 12-6 PV FACADE -SAWTOOTH DESIGN 136 Sect mn 12.3 pemeeneoeTerapenesamensePV Shade Screens PV shade screens provide a large area for generatingelectricityandreducesolarheatinginthesummer,which cuts cooling loads and glare.Shade screenscostlessthanotherBIPVsystemsbecauseextraventilationofthePVmodulesisnotneeded.Theycanberetrofittedontoexistingbuildingsorintegratedintoanewbuilding's design. 4:"2 ff4?JA Costs/Benefits Costs Though more economical than retrofitted systems,abuildingwithBIPVwillcostmorethanabuildingwithoutPV.Costs can vary significantly dependingonthesystemsdesign,the materials replaced by theBIPVmodulesandthecomplexityofinstallationandconstruction.Extra costs can include:+Additional design time.Time is needed tointegratethePVsystemintothebuilding. *PV modules.The cost of a BIPV moduleequalsthecostofthemodulelessthecost ofthebuildingmaterialitreplaces.For example,using an amorphous silicon PV glazingcosting$160/m?,rather than a windowcosting$65/m',has a net cost of $95/m'(Kiss and Kinkead,1995).This "materialscredit”reduces the panel's cost 40 percent. +Inverters.The inverter changes the directcurrentproducedbythecellsintothealternatingcurrent(compatible with the grid) used by building equipment. *Ventilation.PV modules heat up under thesun,resulting in both lower efficiency andheatingofwallsorroofs.For these reasonssomeBIPVsystemsneedextraventilation. *Balance of System (BOS).Controls,monitoring systems,and wiring. INTEGRATING PHOTOVOLTAICS INTO BUILDINGS BenefitsBIPVsystems also provide other benefits comparedtoretrofittedsystems.These include: +Additional energy savings.BIPV systems canprovideday-lighting,shading,and increasedrooftopinsulation.These benefits reducelightingandcoolingrequirements.+Public relations and education.Because BIPVsystemareintegratedintoabuilding,theycanbemorevisiblefromthestreetthanretrofittedsystems.Thus BIPV systems canhaveahighprofile,increasing opportunitiesforeducationandmarketing. ¢Lower maintenance.Some BIPV systems canincreasethelifeoftheroof. One analysis of BIPV atria,sloped glazing (such asskylights),and building facades found that BIPVatriumsarethemosteconomicaloption(Kiss andCompanyArchitects,1995).According to this study,BIPV atriums had a 70 percent shorter payback periodthanBIPVfacades.This is due primarily to the largematerialcreditthatreducesthePVatrium's first cost.Insulated PV tiles and slates seem to have goodeconomicsaswell.They are relatively simple andinexpensive,prolong roof life,and reduce heatingloads.Shade screens may also have promisingeconomicsbecausetheyreducecoolingloadsandglare.BIPV system design and installation specificsvarygreatlydependingonthebuildingdesignandmaterialsusedinconstruction.While the Balance ofSystemcomponentswilllikelybethesameaswithanyotherPVsystem,the array design and:installation will require an experienced professionalfamiliarwithstructuralengineeringaswellas photovoltaic installation. Section 12.4 137 7 ||Chapter 13 :Photovoltaic System Applications Contents: 13.1 Tools and Appliances ....--cece senee eee eee ence eeenenes 140 13.2 Lighting 0......seeeee sree esse renee e reese 141 13.3 Water Pumping ...---+-s+eererrretert Cece eee nena 145 13.4 Refrigeration ..-.-++++e e500 eee eee nee eee e een need 149 a 13.5 Hybrid Systems with Generators «++serererr eee 150 b || | 139 140 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL This chapter describes the common loads powered by PV stand-alone systems and discusses specific considerations for each. {3.1 Tools and Appliances An increasing number of people living in remote areas are using PV systems or PV-generator hybrid systems because these systems are clearly the best economical option.Some estimates for utility line extension are up to $30,000 per mile depending on terrain.In these situations,PV systems are the economic choice,even for homeowners who want to maintain a comfortable lifestyle.For the owner of a weekend cabin,recreational vehicle,or boat,the choice of PV is often based on the desire for serenity. PV systems make no noise,and fuel delivery is immediately available and free.Unlike other systems, the owner/operator has direct control over the use of the loads,and therefore,the power demand placed on the system. Motor Driven Tools:Many household appliances are driven by motors and often have a large electrical power requirement.Direct current motors are available in 12,24 and 48 volts for use in DC systems. Most power tools are designed to use alternating current.Alternating current motors can be powered by photovoltaic systems with a correctly sized inverter included in the system design.The system inverter must be able to meet the starting surge requirements of the motor.Table 13-1 lists the starting surge requirements of several common power tools. Many tools can be converted from alternating current to direct current.Alternating current drill motors can be replaced with direct current motors that match the original unit in size and have the necessary torque.Belt driven tools such as grinders, table saws,polishers,and sewing machines can easily be converted to direct current operation by replacing the motor with a lower voltage unit. Homeowners may choose to use cordless tools in lieu of converting alternating current tools.The batteries in these rechargeable tools can be recharged by the photovoltaic power systems,though it is important to check with your inverter manufacturer before using your recharger (some have been known to be incompatable).Evaporative cooler pumps and blower motors can be converted to direct current operation and would then constitute a direct current cooling system. A 120-volt alternating current washing machine can sometimes be a problem applianceif the incorrect type of size inverter is used.Older "wringer”style washers are easily converted to 12-volt direct current. Table 13-1 Surge Power Requirements for 120V AC Toois Full Load Measured MeasuredToolMakeAmpSurgeNoLoad Rating Amps Amps ”Jointer Milwaukee 7.8 28 7.4 7 '16 Circular Saw Skil 10 52 8 7 Va Circular Saw Milwaukee 13 40 Power Miter Saw Ryobi 12.5 46 6.3 7 '/4 Worm Drive Saw Milwaukee,15 44 8 Radial Arm Saw Sears 1];57 10 Reciprocating Saw _Milwaukee 4 16 2.5 Conractors Table Saw Rockwell NA 51 16 Jig Saw Black &Decker 13 2.2 Drill Press Orbit 8 34.6 6.1 Hole Hawg Drill Milwaukee 7.5 29 3.5 Bench Grinder Jet 6 14.8 3.4 Another option is to have a motor rewound to adifferentvoltageoruseadirectcurrentmotor.Somealternatingcurrentmotorswillnotconverttodirectcurrent.Others may not be rewound to a differentvoltage.In any case,check with a qualified motor repair shop.Electronic Devices:Electronic devices can be powered by photovoltaic systems without anyproblem.For example,many photovoltaic userssuccessfullyoperatecomputersusingaproperlysizedinverter.As a rule,the more "pure”the AC output oftheinverter,the better the electronic devices willoperate.In some cases,an improperly matched loadandinvertermayresultindamagetotheload.Linenoisesorinterferencegeneratedbyinvertersand slower operation of appliances,such as in microwaveovens,can also create problems for some people.AnalternativetousingACloadswithaninverteristouseappliancesdesignedforthe12-volt direct currentsystemsfoundinautomobiles,recreational vehicles,and boats.These products include CB radios,tapeplayers,televisions,and electronic ballasts used influorescentlighting.Most of these are relatively efficient,low wattage loads.An ever-increasing selection of small consumergoodsisavailablewithintegralphotovoltaiccells.Most common are solar calculators and watches,though portable radios,flashlights,and clocks arenowavailablewithintegratedPVcells.Often the photovoltaic cells eliminate the need for batteries. Resistance Loads Many common household appliances use electricresistancetoperformtheirfunction.Resistanceheatingisusedintoasters,coffee pots,hair dryers,ovens,clothes dryers,water heaters,and spaceheatingsystems.As a rule,these loads can be toolargeforresidentialphotovoltaicsystems,and youshouldfindanalternativewaytoheat.A water heater element may be rated at 2,500 watts and operate 25percentofthetime.Water heating and space heatingloadscanbebetteraccomplishedthroughothermeansincludinggas,propane,wood,and solar thermal heating.Small convenience items and tools,such as soldering irons or welders,can be powered byphotovoltaicsystems.If these tools are not usedfrequently,their overall energy consumption willgenerallybeinsignificant. PHOTOVOLTAIC SYSTEM APPLICATIONS :if”eybts!ade Lighting Lighting is an essential element in most lifestyles,andelectricityornaturaldaylightinggenerallyprovidesit.In some cases,kerosene or propane lamps are used. These lamps can be an appropriate option becausetheyeffectivelyreducetheelectricalloadrequirementsofaphotovoltaicsystem.Today,manydifferentlightsourcesareavailable,which makeschoosingthecorrectenergy-efficient light sourcemuchmoredifficult.A wide variety of attractive,economical lighting options are available in 12-voltand24-volt direct current and 120-volt alternating current types making photovoltaic powered lighting a feasible choice for many homeowners.New types of lamps with electrical and lightoutputcharacteristicsfarsuperiortothefamiliarincandescentandfluorescentlampsfurtherconfusea potential purchaser.The following sections describethecommonlamptypesandtheirapplications.Thisinformationwillhelpyoudeterminethetypeoflamptouseforspecificapplications.If you are still unsureoftherightchoice,expert advice is available fromlocalutilities,electrical equipment distributors andmanufacturers,electrical contractors,consulting engineers,and state and federal energy offices. Lamp Efficiency When selecting a lamp type,efficiency is animportantconsideration,but it should not be theonlycriteriaused.In most cases,a more efficientlightsourcecanbesubstitutedforalessefficientsourcewithlittleornolossinvisibilityorcolorrendition.The total annual cost savings help to decrease the size of the photovoltaic system. Lamp efficiency is measured in lumens per watt.Lumens are a measure of the light output from thelamp.If a lamp produces more lumens from eachwattofelectricalenergyinput,it is more efficient.Table 13-2 shows the typical efficiency ranges for the six main lamp categories. Lighting Controls Lighting control and operation is an importantconcernwhensizingaphotovoltaicsystemsincealowerloadwillreducethesizeofthephotovoltaicsystem,and therefore,its cost.Lighting controls include the following: 3.2 141 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Manual switches:These controls,typified by a wall switch or pull-chain mounted directly on a fixture,are the least expensive and most commonly used controls.Switching each light separately with a manual switch offers the greatest potential for minimizing energy use,but this method is effective only if people consistently use the switches.Switches must be conveniently located and easy to use.For example,stairway lights should be switched at the top and bottom of the stairs using three-way switches.Remember that the standard wall mounted light switches commonly used with 120V alternating current systems are usually inappropriate for use with 12V direct current lights and systems due to higher currents and arcing in a 12V system. Timers:These controls can be set to automatically turn lights on or off or to limit the time a light will be on.You should consider safety when using timers,for example lights should not turn off without warning the occupants first.Timers can require a small amount of additional power for their own operation. Photocells:Security or safety lighting can be controlled by photocells,which are devices that sense light levels.Photocells sense a loss of daylight at dusk and activate the light,and conversely,they sense daylight at dawn and turn the light off.Photocells are more dependable than manual switching and more accurate than timers.There is a wide selection of 120-volt alternating current photocells on the market.Twelve-volt direct current photocells are less common. Sensors:Sensors are used when precise control is desired.Sensors activate lights when they detect motion or infrared heat. Example 13-1 Problem:A 12-volt direct current,13-watt flourescent light is controlled by a photocell. The average daily on-time is 12 hours per day. How many watt-hours are consumed by the light on an average day? Solution:Multiply 13 watts by 12 hours, resulting in 156 watt-hours. Lighting Load Estimates Lighting loads can be accurately estimated when a control.strategy is implemented.For example,if a photocell control is used the light will operate from dusk to dawn.However,since an estimate of on-time usually has to be made,you should use the standard estimating procedure for electrical loads described in Chapter 4 Note that the on-time for the lighting loads is greatest in the winter when solar radiation is lowest. Lamp Types Lamps designed for indoor applications are generally divided into the following categories: *Incandescent *Fluorescent - *High intensity discharge mediums,including mercury vapor,metal halide,high-pressure sodium,and low-pressure sodium. Table 13-2 Lamp Characteristics Lamp Lumens Life (Hours)Initial CostperWatt Incandescent 20 750 Low Mercury Vapor 63 16-24,000 Medium Flourescent 83 12-20,000 Medium Metal Halide 115 8-15,000 High High Pressure Sodium 140 20-24,000 High Low Pressure Sodium 183 18,000 High 142 Section 13.2 The incandescent lamp is the least expensive,yet the least efficient when converting energy to light.Itsmainbenefitsarelowinitialcost,attractive color, cold weather operation,and simple installation.Attheotherextremeisthelow-pressure sodium lamp, which is the most efficient at converting electricity to light,although it is seldom used for indoorapplications.The basic characteristics of each lamptypeareshowninTable13-2.Incandescent Lamps:Incandescent lamps arethemostcommonlyusedeven:though they have the poorest efficiency or lowest lumens per watt ratings.In typical incandescent lamps,electricity isconductedthroughafilamentthatresiststheflowofelectricity,heats up,and glows.The popularity of theincandescentlampisduetothesimplicityofitsuseandthelowinitialcostofbothlampsandfixtures. Incandescent lamps use the familiar "Edison base”bulb and require no special equipment or ballasts tomodifythecharacteristicsofthepowersuppliedtothefixture.Incandescent lamps are available in manywattages,both in 120-volt alternating current and 12-volt direct current.Common incandescent lamp types include: *Arbitrary bulb-shaped lamp (A) *Pear-shaped lamp (PS) *Reflector lamp (R) Sealed-beam lamp (PAR) Quartz-halogen lamp *Tungsten-halogen lamp Tungsten-halogen lamps,like other incandescentlamps,use a tungsten filament as the light source.However,these lamps contain a "family of elements”known as halogens.The halogens prevent lamp wallsfromdarkeningasquicklyasthewallsofotherincandescentlamps,which keeps the light output oftungsten-halogen lamp higher for a longer period oftime.Halogen lamps are available in low wattages.The efficiency of 120-volt alternating current*incandescent lamps generally increases as the ampwattageincreases.Thus,one higher wattage lamp canbeusedinsteadoftwolowerwattagelamps,which saves on both energy and fixture costs.For example,one 100-watt general service (GS)lamp producesmorelight,1740 lumens,than two 60-watt GS lamps,860 lumens each for a total of 1720 lumens.This is PHOTOVOLTAIC SYSTEM A PPLICATIONS not necessarily true for 12-volt direct current lamps.The type of incandescent lamp and fixture usedalsoalterefficiency.For example,a 75-wattellipsoidalreflectorlampinstalledinastack-baffleddownlightwilldelivermorelightthana150-watt R- 40 reflector lamp.Note:When choosing or recommending a lamp,you should remember that shocks,vibrations,andvoltagevariationscouldshortenthelifeof incandescent bulbs. Fluorescent Lamps:Fluorescent lamps are thesecondmostwidelyusedlightsource.They are foundinhomes,stores,offices,and industrial plants.These lamps are easily distinguished by their tubular design,which can be circular,straight,or bent into an L shape.When operating,an electric arc is drawn alongthelengthofthetube.The ultraviolet light producedbythearcactivatesaphosphorescentcoatingontheinsidewallofthetube,causing light to be emitted. Fluorescent lamp sizes range from 4 to 215 watts.Generally,lamp efficiency increases with lamp length.Reduced wattage fluorescent lamps introduced in thelastfewyearsuse10to20percentlesswattagethanconventionalfluorescentlamps,yet provide almost as many lumens.The fluorescent lamp requires an electronic'ballast to initially strike the electric arc in the tubeandmaintainthepropervoltageandcurrentrequired:for the arc.Ballasts must be correctly paired with the lamp characteristics to optimize light output andlamplife.Fluorescent lamps generally work in eitheralternatingcurrentordirectcurrentsystems,thoughtheballastmustmatchasystem's voltage and currenttype.A large selection of alternating current anddirectcurrentballastswithawiderangeofwattages is available.The energy use of ballasts peal whentheystriketheinitialarctolightthelamp,typicallydrawingabout2ampsinaDCballast.In the past,the power required to start inefficientballastsoftenmadeitmoreeconomicaltoleave fluorescent lights on for short periods of time when aroomwasunoccupied,rather that turn the lights off. Today,energy efficient ballasts make it more cost-effective and energy efficient to turn the lights offwhenaspaceisunoccupied.This is especially true inPVsystemswherethecostofelectricityishigh.Poor color rendition that distorts the true color of objects is a common complaint from users ofstandardfluorescentlamps.A broad selection of 143 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL lamps that produce better color rendition are now available.Many of these bulbs produce a pleasing, warm light and are designed to replace standard incandescent bulbs.Some have a conventional screw base with a built-in electonic ballast.Although these bulbs are initially more expensive,they save energy and have a longer life than incandescent bulbs. Excellent 12-volt direct current and 24-volt direct current ballasts are now widely available.It can make sense to run lighting loads on direct current to avoid using of an inverter.This preserves the lighting circuit should an inverter fail.This also creates a more efficient system.In addition,lights operated from direct current are slightly more efficient and usually last longer than their alternating current counterparts. Homeowners should know that fluorescents may take a while to warm up in extremely cold environments.Many lighting fixtures may be retrofirced to operate more efficient fluorescent lamps while maintaining the appearance of an incandescent fixture. High Intensity Discharge (HID)Lamps:The term high intensity discharge (HID)often designates four distinct types of lamps that actually have little in common.These types of lamps include: ¢Mercury vapor *Metal halide *High-pressure sodium *Low-pressure sodium All of these lamps require a short period of time to become fully lit,generally from one to seven minutes.If a high intensity discharge lamp is turned off,the arc type must cool to a given temperature before the arc can be restruck and light produced. Mercury vapor lamps,for example,may require up to seven minutes to cool. Mercury Vapor Lamps:Mercury vapor lamps produce light when an electrical current passes through a small amount of mercury vapor.The lampconsistsofaninnerglassenvelopewherethearcis struck and an outer protective envelope.The mercury vapor lamp,like the fluorescent lamp, requires specially designed ballasts.Special ballasts are also required for dimming mercury vapor lamps. Mercury vapor lamps range in size from 40 to 1,000 watts and are most often used in industrial and outdoor lighting applications because of their 16,000-to 24,000-hour life expectancy. Because a significant portion of the radiated energy is ultravioler light,the color rendition of mercury vapor lamps is not as good as that of incandescent and fluorescent lamps.By using phosphor coatings on the inside of the outer envelope,some of this energy is converted to visible light,which produces better color rendition and lamp efficiency.Phosphor-coated mercury vapor lamps now enable lighting designers to use HID lighting for many indoor applications,including lobbies,hallways,and retail display areas. Metal Halide Lamps:Metal halide (MH)lamps are similar in construction to mercury vapor lamps. These lamps,however,contain metal halide in the mercury vapor that the electrical energy passes 'through.These lamps are 1.5 to 2 times more efficient than mercury vapor lamps.Almost all "white light”varieties of metal halide lamps produce a color rendition equal or superior to that of mercury vapor lamps;MH lamps range in size from 175 to 1,500 watts and require specially designed ballasts. High-Pressure Sodium.Lamps:.High-pressuresodium(HPS)lamps have the highest efficiency ofall common indoor lamps.They produce light when electricity passes through a sodium vapor.These lamps are constructed using two envelopes:an inner envelope made of a polycrystalline alumina where the arc is struck and a protective outer envelope that may be clear or coated.Since the sodium in the lamp is pressurized,the light produced is not the characteristic bright yellow associated with sodium, but a more "golden white”light. Although HPS lamps were first used in street and outdoor lighting,they are suitable for industrial, commercial,and institutional applications.HPS lamps range in size from 70 to 1000 watts,are available in 12-volt direct current and 120-volt alternating current versions,and require specially designed ballasts. Low-Pressure Sodium Lamps:Low-pressure sodium (LPS)lamps are the most efficient type of lamp,providing up to 183 lumens per watt. Unfortunately,their indoor use is restricted by their monochromatic light output.Reds,blues,and other colors illuminated by an LPS light source all appear as tones of gray. Low-pressure sodium lamps range in size from 144 Sacton JaceomespilettheaEEtsceeeecemensmmmaeachpennneinaneagaaplannerenenepnee35 to 180 watts,are available in 12-volt direct current and 120 volt alternating current versions, and require specially designed ballasts.LPS lamps areprimarilyusedforstreetandhighwaylightingaswellasoutdoorareaandsecuritylighting.They are also used for indoor applications,such as warehouses where color is not an important consideration.Though not yet commonly used in residentialapplications,the LED (light emitting diode)is worthmentioning.In a light emitting diode,the creationoflighthappensmuchmoreefficientlyatthemolecularlevel.As previously mentioned,a diode isanelectronicdevicewhichlimitsthedirectionthat electrons may flow in an electronic circuit.A LED isaspecialtypeofdiodethathasbeenoptimizedtoreleaseenergyintheformoflightinsteadofasheatasinatraditionaldiode.An unbreakable,crystal clear solid resin encases each LED and makes it nearly indestructible,contributing to the long life ofLEDs,which typically last 5 to 10 years of constantuseanddrawaslittleas1/10th to 1/20th the current of an incandescent light bulb producing equivalentlumens.The main drawback of LED lighting is the quality of the light tends to be a bit too bright andglaring.These lights are great for short term spacelighting,though not pleasing to read by for extendedperiodsoftime.Currently research is being done toreducecost,and to improve light quality.Worldwide,LEDs are starting to be used for low wattage PV lighting systems. }ate Water Pumping Photovoltaic power systems are used to pump waterthroughouttheworld.Compared to many of thealternatives,PV systems are reliable and cost- effective.The simplest method of water delivery, diversion of rain or surface water by gravity,is not possible in many locations.Manual'pumps are acommonmethodofwatertransferworldwide,but cannot move large volumes of water or pump fromdeepwells.Mechanical pumps powered by engines orelectricmotorsareexpensive,maintenance intensive, and use expensive fuel.Generally,these systems areonlyusedwhena'community or corporateinfrastructureexiststosupportthecostsassociated with a larger,more complex distribution mechanism. PHOTOVOLTAIC SYSTEM APPLICATIONS Pump Terminology The pressure a pump creates,called head,ismeasuredinfeet.A column of water 2.31 feet in height (or 2.31 feet of head)exerts a pressure of 1poundpersquareinch(psi)at its base.If a pumpmustdeliverwatertoapoint10feetabovethewatersource,it must create a minimum of 10 feetof head. Ten feet of head is equal to 4.3 psi (10 feet of head divided by 2.31 feet/psi equals 4.3 psi).The total head a pump must create is a function of the following parameters: *Head from the water source to the point of discharge or storage. *Head from the storage point to the delivery point when using one pump. ©Friction loss or the resistance of water flowing through pipes. When specifying a water pumping system,you will need to be familiar with the following terms. Suction head:The vertical distance from the surface of the free water source to the center of the pump when pump is located above water level.Discharge head:The vertical distance from thecenterofpumptothewatersurfaceorpointoffree discharge.Static head:The vertical distance from the water source to the water surface or point of free discharge. Static head is equal to the sum of the suction head and discharge head.Service pressure:The service pressure is the feet of head needed to supply the final discharge pressure. Ifa final discharge pressure is desired,the pump mustsupplytherequiredflowatthespecifiedpressure.Friction head (FH):The pressure the pump must provide to overcome the loss of energy due tofrictionaswatermovesthroughapipe.The smaller the pipe diameter and the faster the flow,the greaterthelosses.The exact amount of FH can be obtained from friction loss tables,which are out of the scope of this manual.At low flow rates,friction losses are small compared to static head.Service head:The vertical distance from the storage point to highest delivery point. 145 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Pressure:The measure of force exerted on the walls of piping,tanks,and other components by the liquid in a system.Pressure is measured in pounds per square inch where 2.31 feet of head is equal to 1 pound per square inch. Flooded section:The section of pipe between the water source and pump when the water source is higher than the pump.Water flows through this section of pipe to the pump by gravity. Flow:The rate of liquid volume capacity of the pump.Flow is measured as a unit volume per unit of time,such as gallons per minute (gpm)or liters per minute (Ipm). Pump Types Specific water pumping applications have dictated the design of water pumps,resulting in a wide range of pumps that serve specific needs.Pumps can be divided into one or both of the following major categories: . Self-priming:The ability for a pump to initially run dry and create sufficient suction pressure to draw water from the source to the pump.Pumps that are not self-priming must 'either be primed prior to operation or installed below the level of the water source. Positive displacement:Any type of pump that moves a liquid by the action of a chamber,plunger, or rotary gear and when discharged,moves another volume of liquid into place that displaces the volume before it.Many positive displacement pumps are self- priming. Pumps are further divided into one of the following categories: Centrifugal:Any type of pump that moves a liquid by the action of an impeller.The impeller draws the liquid to an intake at the impeller's center and then discharges centrifugally at an outlet at the impeller's perimeter.Centrifugal pumps generally require priming prior to operation or must be installed below the water source level. . Self-priming centrifugal:Same as standard - centrifugal pumps but with a chamber above the .rig ,”.impeller that keeps the pump "primed”for'easy restarting. Jet pump:A centrifugal pump that allows some flow to return into a venturi on the input side.This can increase the suction head to as much as 150 feet but results in a decreased flow rate because water is used to move water.-Submersible:A pump with a series of centrifugal impellers or diaphragms and a motor in a water tight housing.The entire assembly is submerged near the bottom of the well.These pumps can deliver water from great depths. Jack pump:A positive displacement type pump in which the motor operates a reciprocating jack above the ground.The jack pulls a long drive shaft with a plunger at the end to move water in steps. These pumps can deliver water from great depths at low flow rates. Rotary vane:A pump containing two gear-like vanes that rotates within a tight-fitting housing to create positive displacement flow.These pumps are capable of several hundred feet of head and used for shallow well,low volume applications. Pump Curves A pump's performance is measured in terms of flow rate and head.The greater the head a pump must overcome,the lower the flow rate.The relationship of flow rate and head for a particular pump is graphically illustrated by a pump curve.Figure 13-1] shows three sample pump curves similar to the curves supplied by pump manufacturers. The horizontal axis of the graph represents the pump's flow rate in gallons per minute (gpm).The vertical axis represents feet of head or psi,which 1s the pressure the pump must overcome.Any point on the curve is a flow rate corresponding to the head that the pump must overcome., Example 13-2 Problem:A pump manufacturer supplies you with pump #2 from Figure 13-1,stating that it is the most appropriate for your specific application.The application requires that the pump overcome 9 feet of head.At what flow rate will the pump perform? Solution:To determine the flow rate of this pump's output,locate 9 feet of head on the vertical scale and move horizontally until you intersect the pump curve.Move straight down from this point to read the flow rate listed on the horizontal scale.The flow rate is 11.5 gallons per minute (gpm). 146 Section 13.3 Pump Selection Criteria:To specify a pump,you must define several parameters,including:Total head:This is equal to the sum of suction head,discharge head,friction'head,and service or pressure head.Suction head:For shallow wells,suction head may be a maximum of 20 feet.Required quantity of water:This is usuallyspecifiedingallonsperday(gpd)or liters per day (Ipd). Example 13-3 Problem:You are using pump #3 from Figure13-1 in an application where a minimum flowof3gallonsperminuteisneeded.What is themaximumheadthispumpcanprovideandstill meet the minimum flow rate? Solution:To determine the head,locate 3 gpmonthehorizontalscaleandreadstraightupuntilyouintersectthepumpcurve.Then from thispointmovehorizontallytofindtheheadlisted ontheverticalscale.The maximum head is 34 feet. For shallow wells,maximum suction head is reduced by 1 foot of suction lift per 1,000 feetelevationabovesealevel.A shallow well pump systemmayuseacentrifugalpumpwhenthesuctionliftdoesnotexceed25feet(at sea level).. PHOTOVOLTAIC SYSTEM APPLICATIONS Storage and Delivery In photovoltaic powered water pumping systems,energy can be stored in batteries so that the waterthathasbeenpumpedfromthewatersourceintoastoragetankcanbedistributedduringtimesofnosunlight.In some cases,batteries can also be desirabletoprovidesufficientsurgepowerforstartingthe pump.; Some photovoltaic system pump controllers areavailablethatallowthepumptobepowereddirectlyfromaphotovoltaicpanelorarray.These controllersmonitorthephotovoltaicsystem's output and turnthepumpononlywhenthereissufficientsunlighttopowerthepump.As the sunlight's intensity increasesandthephotovoltaicsystem's output increases,thepump's performance increases proportionally.Elevated or pressurized tanks can provide waterstorageanddelivery.Elevated tanks should be fittedwithafloatswitchchatturnsthepumponoroff according to a preset water level.Water from the tankisdeliveredtousepointsbelowthetanklevelby gravity pressure.For every 2.31 feet of elevation,1psiwillbedeliveredatthedischargepoint.Forexample,for the tank to provide 40 psi,it wouldneedtobe92feethigh(40 x 2.31 =92).Pressure tanks,such as those commonly used in many well systems,can supply water to points of useaboveorbelowthetank.A flexible neoprene bladder 70 60 50 40 30 PumpingHead(ft)20 10 0 5 10 15 Flow Rate (gpm) 20 25 30 35 Figure 13-1 PUMP CURVES anes 147 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL within the tank is charged on one side with air pressure.Water is pumped into the tank under pressure against the bladder until a pressure switch turns the pump off at a preset pressure.Water is delivered to the use points by air pressure within the tank.The tank is refilled when the pressure switch activates the pump belowa preset pressure setting. Sample Water Pumping Systems You must evaluate every water pumping application individually.The examples in this section contain the calculated electrical load for various pumping applications based on flow and head requirements and the pump manufacturer's specifications.To determine the PV panel and battery requirements for your location,refer to Chapter 10. Application 1:Shallow Well Water Requirements:200 gallons/day Required Lift: 15 feet suction head 23 feet discharge head 38 feet total head Pump Specifications: Type:12-volt centrifugal Maximum suction head (at sea level):25 feet Maximum discharge head:32 feet Flow rate at 38 feet of head:0.3 gpm Power requirements:300 watts Hours of operation (at 200 gpd):0.4 hours Total daily load (at 200 gpd): 120 watt-hrs/day at 12 volts Application 2:Shallow Well Water Requirements:400 gallons/day Required Lift:, 5 feet suction head 35 feet discharge head 40 feet total head Pump Specification: Type:12-volt centrifugal Maximum suction head (at sea level):25 feet Maximum discharge head:44 feet , Flow rate at 40 feet head:6.7 gpm © Power requirements:300 watts Hours of operation (at 400 gpd):1.0 hours Total daily load (at 400 gpd): 300 watt-hours/day at 12 volts Application 3:Deep Well Water Requirements:200 gallons/day Required Lift: 30 feet suction head 35 feet discharge head 65 feet total head Pump Specification: Type:12-volt jet pump Maximum suction head:60 feet Maximum discharge head:67 feet Flow rate at 65 feet of head:2.2 gpm Power requirements:270 watts Hours ofoperation (at 200 gpd):1.5 hours Total daily load (at 200 gpd): 405 watt-hrs/day at 12 volts Application 4:Deep Well Water requirements:600 gallons/day Required Lift: 0 feet suction head 100 feet discharge head 100 feet total head Pump Specifications: Type:12-volt submersible Maximum discharge head:125 feet Flow rate at 100 feet of head:2 gpm Power requirements:325 watts Hours of operation (at 600 gpd):5 hours Total daily load (at 600 gpd): 1625 watt-hrs/day at 12 volts Application 5:Deep Well Water requirements:200 gallons/day Required Lift: 0 feet suction head 150 feet discharge head 150 feet total head Pump Specifications: Type:24-volt submersible Maximum discharge head:175 feet Flow rate at 150 feet head:1.3 gpm Power requirements:580 watts Number hours of operations (at 200 gpd) 2.6 hours Total daily load (at 200 gpd) 1508 watt-hours/day at 24 volts 148 esertioye,(2 2sectonPoa.a%x eastMeteeesnetngeMEMITETEIekmeee'Refrigeration Refrigeration plays a vital role in our lives byextendingtheusefullifeofperishablefoodproducts.Virulent diseases cannot be contained in many partsoftheworldsincerefrigerationisnotavailabletomaintaintheeffectivenessofmedicinesandvaccines.The World Health Organization estimates that overfivemillionchildrendieeachyearfromdiseasesthatcanbepreventedbyimmunization.Photovoltaicrefrigeratorshaveproventobeeffectiveandreliablemethodforrefrigeratingmedicinesandvaccinesinremoteandruralareasthroughouttheworld.However,homeowners must recognize thatrefrigerationwillconstituteamajorenergyloadthatsignificantlyaddstothecostofaphotovoltaicsystem.It is important to ask the following questions:*Is mechanical refrigeration really necessary? *Would cool storage work sufficiently? *Would another fuel source be more cost- effective?(i.e.propane) Obviously,the ultimate energy conserving,costeffectivemeasureisdoingwithout,although gettingbywithlessmaybethemorereasonablesolution.If a refrigerator is an essential load that cannotfail,for example a vaccine refrigerator,you must incorporate design elements to prevent systemfailure.Two handbooks available from the WorldHealthOrganization,Users Handbook and FaultFindingandRepairofSolarRefrigerators,are usefulreferencemanualsforusersofcriticalloadrefrigeratorspoweredbyphotovoltaicpowered. Refrigeration Operating Principles Refrigeration is generally accomplished using a vaporcompressioncycle,During the vapor compression orsimplecompressioncycle,a gaseous refrigerant iscirculatedthroughthesystemproducingheatwhenitiscompressedandcoolingwhenitexpands.Refrigerators work by using a condenser,anevaporator,a compressol,and an expansion valve.Cool low-pressure freon enters the evaporator andevaporates.As it evaporates,it absorbs heat from PHOTOVOLTAIC SYSTEM APPLICATIONS another substance,such as air or water,and cools theinterioroftherefrigerationunit.The refrigerantleavestheevaporatorasacoollow-pressure gas andproceedstothecompressor.In the compressor,itspressureandtemperatureareincreased,and itdischargesasahothigh-pressure gas into thecondenserwhereitiscondensedintoaliquid.Thecondensingagentisatalowertemperaturethantherefrigerantgas.The hot high-pressure liquid flowsfromthecondenserthroughtheexpansionvalvetotheevaporatorthatmeterstheliquidflowand-reduces the hot high-pressure liquid to a cool low-pressure liquid as it reenters the evaporator tocompleteitscycle.Typically,most modernmechanicalrefrigeratorcompressorsarepoweredbyelectricity,although propane or kerosene units are available. Refrigeration Options You should only consider energy efficientrefrigerationunitsforphotovoltaicpoweredresidentialsystems.If a mechanically-operatedrefrigeratorisrequiredbyahomeowner,four optionsatecommerciallyavailable,including: *Propane powered *Kerosene powered ¢Alternating current powered (standard 110 volts) ¢Direct current powered (12,24,or 48 volts) Propane Refrigerators:Propane refrigeratorshavebeenusedintheUnitedStatesforover70yearstorefrigeratefoodstuffsinremotelocations.Modernpropanerefrigeratorsarewidelyavailableandusedthroughouttherecreationalvehicleandmarineindustry.They are more dependable and require lessmaintenancethantheearliermodels.Modernpropanerefrigeratorscanbeasafe,cost-effectivesolutionforremoterefrigerationapplications.However,while the initial cost of these refrigeratorsmakesthemanattractivepurchaseformanyusers,they do have some limitations.They require periodicrefueling,making them less "independent”thanrefrigeratorspoweredbyaphotovoltaicsystem.Youshouldconsiderareftigerator's life-cycle cost when deciding which unit to purchase. afom meinn 73 4Sacion13.4 149 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Alternating Current Refrigerators:Alternatingcurrentrefrigeratorsarenormallyusedinhomeswithutility-supplied electricity.They require an inverter iftheyaretobepoweredbyaphotovoltaicsystem.Ifthesystemdesigndictatesusinganinverter,analternatingcurrentrefrigeratorcanbeanappropriatechoice.However,most conventional alternatingcurrentunitsarerelativelyinefficientandimposeasubstantialpenaltyonaphotovoltaicsystem.Forexample,a 12 cubic foot alternating currentrefrigeratordrawing240wattswouldrequiretwenty-two 30-watt photovoltaic modules just to power therefrigerator!There are many commercially availableenergyefficientrefrigeratorsonthemarketthatcanbefoundinalternatingcurrentanddirectcurrentvarieties.If an alternating current model is needed,only energy efficient models are recommended for use with a photovoltaic system.Direct Current Refrigerators:Direct current refrigerators are available and,like alternating currentrefrigerators,only some are energy efficient.Whiletheyhaveahigherinitialcostthanalternatingcurrentunits,direct current units operate directly off battery power and do not require an inverter.Advances are currently being made in reducing boththeenergyconsumptionandinitialcostoftheseunits.Conversion kits are available for changing alternating current refrigerators to direct currentrefrigerators.Separate direct current compressor andcondenserpackagesarealsocommerciallyavailable for constructing homemade units. Design Criteria When deciding which mechanical refrigerator topurchase,you should choose a unit with thefollowingspecifications: *Superior insulation with a high R value °Small current draw when operating *Compartmentalized storage/separate freezer *Efficient compressor waste heat removal Refrigeration Load Estimating:Refrigerationloadscanbeaccuratelyestimatedfromthemanufacturer's specifications and a thoroughknowledgeofusepatterns.The manufacturer shouldbeabletosupplyvoltage,amperage draw,and actualon-time under given conditions.Refrigerator on- time is seasonal because the load is affected byambienttemperature.Routine maintenance,such as cleaning or defrosting,can reduce unnecessary on- time and improve performance. Example 13-4 Problem:A 120-volt alternating current,22cubicfoot,540 watt,4.5 amp refrigerator sitsonashaded,exterior porch in Missouri.On an August day,how many watt-hours areconsumed?To calculate the answer,refer toChapter4andusetheElectricLoadEstimationsheetinAppendixD. Solution:A 540 watt refrigerators running for 14 hours consumes 7560 watt-hours. Remember that manufacturer's literaturegenerallyusesroomtemperaturefortheirspecifications.Since the outdoor temperature inMissouriissignificantlywarmerthanroomtemperatureandtheusageinAugustismuchgreaterthanaverage,we can assume 18 hourson-time as the peak summer load.Therefore,the refrigerator consumes 9720 watt-hours. Refrigeration loads are often the highest duringthewarmestmonths.Fortunately,these months usually coincide with the periods having the most abundant solar radiation.if155 =Hybrid Systems withLwetGenerators Most residential PV systems cannot satisfy a home'sentireelectricalneeds.A large part of the cost for PVstand-alone systems is due to sizing the array andbatteriestosupporttheentireloadunderworst-caseweatherconditions.In some instances,this fractional power requirement can be more economically provided by another power source.A stand-alone PV system with another integrated power source is called a PV hybrid system.The mostcommonauxiliarypowersourceisagasOrdiesel-powered engine generator,called a PV-generatorsystem.Although there are many types of hybridsystems,this is the only hybrid system covered in this manual._The most common configuration for a PV- generator system is one in which both the PV arrayandthegeneratorchargethesamebatteries.(SeeFigure13-2.)The PV array is a slow rate battery 150 Section 13.5 charger,and the generator is used primarily as a high- rate battery charger.Generators run more efficiently when operating close to their maximum load, typically at 80 to 90 percent of their rated power. When generators are operating in this range,they can quickly charge batteries to nearly 70 percent state of | charge.This allows the generator to operate for a short time at or near its most efficient operating point.As a result,generator maintenance and fuel costs are reduced and its lifetime is prolonged. The photovoltaic array is designed to complement the generator by supplying the power totheloadandcompletingthebatterycharging. The advantages to a hybrid system include: Improved economics:Using the PV array to produce the last 5 percent of system availability is expensive.In regions with a variable climate,where average daily insolation in the winter is two or three times less than in the summer,the use of a hybrid system can be quite economical.For applications with large loads,a generator may also be more economical to provide some power.However, maintenance,logistics,and fuel costs can be quite expensive for generators in remote areas.These PHOTOVOLTAIC SYSTEM APPLICATIONS factors must be considered in any cost comparisons. Lower initial cost:Meeting the full requirements of the load with photovoltaics may be too expensive for the homeowner.By combining a generator with the PV array,the designer can trade off the high initial cost and low operating cost of PV modules against the generators low initial cost and high operating cost of a generator. Increased reliability:Because there are two independent charging systems for the battery,there is inherent system redundancy.If the hybrid system is properly'maintained and controlled,the overall system reliability is also greater. Design flexibility:The generator backs up the photovoltaic system during periods of cloudyweatherand/or heavier than normal electrical use. This is best illustrated in residential systems where the generator is not only used to charge the batteries but also to power large loads,such as washing machines,dryers,and power tools.In a typical home, the owner may use the generator a few hours a week to wash,dry,iron clothes,vacuum the house,and pump water.While the generator is running,it can also be charging the batteries. 3.5 151 DESIGN AND INSTALLATION MANUALPHOTOVOLTAICS $avo1 DVOL SLINDYID HONVYIor q Y31NI9qvo1ovYI LY3ANIERT:aoe dod GNndYdes 4ASYVHI9099 o™ ©6 asn ee ed YOLVYINAD OV e ) suanwaud fh NVAA HIV AWUYY Ad Figure 13-2 HYBRID SYSTEM WITH GENERATOR 152 LeEREETBIOETContents: 14.1 Preparing for the Installation ... 14.2 Tools and Materials .........- 14.3 Photovoltaic Array Installation .. 14.4 Battery Installation'........... 14.5 Controller &Inverter Installation 14.6 Photovoltaic System Wiring ....14.7 PV System Installations Final Checklist Chapter 14 Photovoltaic Installation 154 154 157 159 160 161 163 153 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 14 1 Preparing for the;"S'e E Installation Designers or installers of remote photovoltaic systems encounter unique challenges in planning the logistics of transporting tools and materials to the system installation site.You should plan to bring all tools and materials to the remote site during the installation.There may not be many electrical supply stores nearby so proper planning is required.Since each remote site has unique installation characteristics,you should visit the site prior to the installation.During this initial site visit,you should list all tools and materials that will be required to install the system. During 30 remote system installations,the Solar Energy International staff compiled the checklists included in this chapter.These checklists contain a combination of the tools and materials required for photovoltaic installations. Site Visit:Before planning the installation,you should visit the job site to obtain detailed site-specific information needed to design and install the system in one trip.Topographic maps or detailed directions to the site location must be obtained prior to departure.The required personal and safety gear will depend on the length of stay and conditions to be encountered.Usually,a small daypack is suitable for the gear and siting tools required during an initial visit.Overnight trips may require larger backpacks and camping gear. You should bring paper and pencil to record all observations and measurements.A 50-foot tape measure is adequate for most measuring tasks.An inclinometer is useful for leveling and quickly measuring sloped surfaces.A solar siting device or Solar Pathfinder™is very helpful for assessing site shading.The Solar Pathfinder's™compass doubles as an orienting compass if needed.A lightweight camera is also invaluable. Initial site visits must be thorough enough to provide accurate information needed to completely design and plan the installation.Anything less will result in extra trips,added time,improper equipment choices,installation delays,and less profit. 1 42 Tools and Materials All of the installations that were used to generate the following checklists required at least one mile of additional travel from a motor vehicle or boat.The sites had no available electrical power before the photovoltaic installation.The checklists have been developed assuming the installation will be a 12-volt, direct current,stand-alone photovoltaic power system requiring a pole mount,battery storage,and controller.The lists also assume the system will power incandescent and fluorescent lighting in a previously constructed shelter.An additional checklist of tools for sites that are accessible by motor vehicle is also included in this chapter. Even though the following guidelines have beendevelopedthroughexperiencewithactual photovoltaic power system installations,you must use them with the understanding that each job is unique and may require modification of the checklists.The six P's adage certainly applies to remote system installations:Proper Planning Prevents Poor Photovoltaic Performance.Planning with intelligent foresight is the only sure method to insure a successful photovoltaic power system installation. You should check certain installation tools to ensure they are in operational condition and have no missing parts prior to departure.Some tools are also more fragile than others are.You should have a backup tool for these tools.You should check the following tools prior to departure and also determine if backups are needed. Many power tools that would be helpful during an installation are inappropriate for remote system installations.System installers often.prefabricate items,especially metal components,prior to going into the field.All alternating current tools are eliminated unless the installation power system has an inverter.The added space and weight requirements of an inverter that would be used only during the installation is usually unwarranted for sites that are inaccessible to motor vehicles.Most power tools can be replaced with hand tools.A variety of direct current power tools are available that 154,Section 14.1 -14.2 segaeeeneeAEMcerealeFeInstallation -Tools and Materials Lists PHOTOVOLTAIC INSTALLATION Basic Tools: D pencil Ovolt-ohm meter with spare battery O sockets and wrench O drill bits (hand operated drill O screwdriver(s)(1 slotted and 1 #2 O tape measure C hacksaw blade - O knife O wire cutter 1 wire strippers slip joint pliers ©torpedo level nealicbiniepenetratiennenmaeeenicnmin!income*wntienasPhillips head) Initial Site Visit Tools: O pencil CO compass 050-foot tape measure 3 personal gear Cmaps O first aid kit O solar siting device 1 inclinometer 1 paper DO camera Non-Motor Transported Installation Tools: O pencils C rope Oc-clamps O wood chisel O drill bits O Phillips driver bit O drill bit extender C expansionbit C level O prick punch O slip joint O pliers CO slotted screwdrivers O tape measure O string line Chole saw D utility knife CO torque wrench D collapsible shovel O volt-ohm meter O wire cutter (8” handle) O soldering iron O flashlight C system operations literature O carabiners O tool belt O drill 0 nut driver bits paddle bits C brace and bit D uni bit DO socket set with extender O Phillips screwdrivers O file D adjustable wrench Chand saw O hack saw O caulk gun O hammer O combination square Ol wire stripper/crimper C needle-nose pliers . 0 black polyethylene CO component product literature O resealable plastic bags Motor Transported Installation Tools: oO pencils OB 1000-watt inverter 0 4-gang outlet withextensioncord D reciprocating saw with blades O full drill bit index O jig saw blades O chain saw Ol extension ladder 0 shovel O pry bar C pipe wrenches O aviation snips O carpenters 6'6”level 1 open end wrenches O extension cord O circular saw with blades 0)1/2”electric drill O hole saw bits DC hole punches O step ladder O sledge hammer O pick D nail puller O vise grip 0 rasp O framing square 155 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL qty component/item/material Array/Mounting photovoltaic modules split bolt connectors #8 x %bolts,nuts,washers,lock washers photovoltaic panel interconnect cables ole mounting structure cable ties 2 4”weatherhead 12 ¥galvanized steel pipe 24>x 2%x2 #galvanized tee 2 4”x 90 degree galvanized elbow 2 ¥&close nipples 2%”floor flanges #x 6”lag bolts and washers wood shims 25°#10-2 Romex with gd. 3'#10-uf tubes silicon caulk fused disconnect switch and enclosure 30-amp fuses Grounding 15'#6 bare copper ground wire copper ground rod ' ground clamp 4”x 1”bolt,nut,washer,lock washer terminal¥%”strain relief connector box Romex staples attery "No Smoking”sign "Danger”sign batteries prefabricated insulated battery box battery interconnect cables (#2 AWG) #8 THHN (black) #8 THHN (red) terminal lugs 10-amp fuses 4%”x 1”bolts,nuts,washers,lock washers 1”polyethylene pipe 1”tankwall flange 1”MPT slip fitting adapter 1”slip fitting elbows 2”x 2”screen 1”hose clamps %bushingsBoNeRRNtBDOOOONNYOoboY”x 3%bolts,nuts,washers,lock washers Table 14-1 Sample Installation Materials This following checklist contains the materials and components needed for installing a 12-volt,direct current,stand-alone PV system with a pole mount,battery storage,and controller. 1 %x2”nipple 4 1”conduit clamps 8 #10 x %”screws Controller/Load Center 1 DPST 30-amp safety switch 1 controller with low voltage disconnect,voltmeter,and ammeter 20 #10 spade crimp connectors12”x 12”NEMA Type J electrical enclosure"10 4”x 10 %”enclosure panel #10 x 1%”sheet metal screws with washers #”chase nipple with nut and bushing ¥strain relief connector fuse block (6 circuit) boxes 20A glass fuses terminal bus bars (6 circuit) Type T disconnect switches 2-gang junction boxes 2-gang switch plates 2 #10 x %”bolts,nuts,washers,lock washers ¥%”Romex connectors Lighting Load 7 'Romex connectors 50°#10-2 Romex with gd. 24 #10 x 1%”sheet metal screws with washers 1 round junction box 4 pull chain light fixtures 1 socket adapter #593 3 -#1141-21 12V direct current incandescent lights 12 25-watt 12V direct current incandescent bulbs slip-on bulb lampshades swag lamp fixture direct current ballast 20-watt fluorescent tubes fluorescent fixture 2-junction box Type T switch switchplate cover Miscellaneous Wiring Materials wire ties solder anti-oxidizing compound small bottle dish soap or pulling grease duct tape red and black electrical tape assorted wire nuts assorted nails and screws assorted electrical fittings and screwsAeNONNNDNHSeRRRSeeeheeOD 156 . Section 14.2 can be powered on-site by rechargeable batteries or photovoltaic panels.You should charge all batteries before going into the field.These direct current tools include: *lights ¢drills *circular saws *flashlights '©soldering irons *jigsaws Designers have developed a variety of methods to reduce weight and bulk in gear.You should consider replacing heavier metal tools with lightweight wooden or alloy tools.You should also eliminate single-use tools wich multi-use tools where possible. Before going into the field,you should verify thar all components are operating properly,'especially components with movable parts. Note:The following are only installation guidelines.Always refer to the National Electrical Code (NEC)for specific component requirements. _™Photovoltaic Array2.Installation The major aspects of installing the photovoltaic array are choosing the most applicable mounting systems and making a proper installation.Once you have installed the array,you should verify that the array 1s functioning as expected by measuring the output and comparing this figure to the manufacturer's specifications.This section describes the specific applications,basic components,and installation considerations for the various mounting systems.This section also discusses how to measure the array output. Mounting System Considerations:The first step in completing a safe system installation is carefully selecting the photovoltaic array's location.Electrical ° equipment should be protected from unnecessary environmental exposure and mounted to facilitate convenient,regular system maintenance.The photovoltaic array should be located as near as possible to the power conditioning equipment to minimize power loss from long wire runs. Photovoltaic modules are expensive,lightweight and compact,making them vulnerable to theft. PHOTOVOLTAIC INSTALLATION Protection systems can be installed to improve the security of photovoltaic arrays.Using specialized screws with unique heads to mount the panels can prevent speedy removal.Padlocking the interconnecting mounting channel to the permanently mounted support frames increases security while allowing access with a key.Commercial padlocking hardware for support structures is also available. Photovoltaic module support structures should provide a simple,strong and durable mounting system.Most commercially available photovoltaic modules are manufactured with extruded aluminum frames.These frames are strong,durable,corrosion' resistant,and provide adequate support for the module to be incorporated into an array. Weather-resistant,corrosion-free should be used when fabricating a photovoltaic array mounting system.Anodized extruded aluminum, galvanized steel,and stainless steel are the optimal choices.The support structures need to be lightweight so they can be easily transported and installed. Wooden racks and trusses have been successfully used in many mounting applications.Wood, however,requires more maintenance over the life of the system,making other mounting system materials materials more desirable. Bracket Mounting Systems:A simple bracket system can be used to mount a single solar module. Two galvanized steel angle brackets are bolted to a building's exterior walls or roof structure.A second pair of compatible brackets is attached to the end frames of the solar module.When the two sets of brackets are mated,they form a simple,durable,cost- effective mounting:system for a one module photovoltaic system.Bracket systems can be constructed to pivot and tilt to seasonally optimize the photovoltaic system's performance. Pole Mounting Systems:Arrays can also be mounted on a hardware system that bolts directly to a vertical pole placed permanently and securely in the ground.Generally,24 inch steel pipe works well for the base support.Pole mounting hardware can be bought or fabricated out of 19-gauge stainless steel. This popular mounting technique can be seasonally © adjusted to optimize the system's performance. Ground Mounting Systems:A ground mounted array support structure uses a frame that is bolted directly to prepared footings.Standard support 157 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL structure for four,eight,and twelve modules are commercially available or may be site fabricated. A mounting frame often consists of two parallel channel bars that form a simple rack.Cross supports 'are bolted to the frame to increase lateral structural support and to prevent wind damage.Non- adjustable,extruded aluminum legs bolt to the frame to hold the array at a predetermined tilt angle. Adjustable tilting support legs can also be fabricated or purchased to allow manual seasonal tilt adjustments. Metal that is mounted directly to a concrete footing should be galvanized steel since the lime content in the concrete can corrode aluminum over time.In addition,nuts,bolts,and washers should be made of stainless steel to provide durable,corrosion- resistant connections. You should carefully evaluate local weather characteristics as well as soil load bearing capacity before selecting a final site for a photovoltaic array. Ground mounting systems require level foundations with a sufficient structural integrity to avoid load- bearing failure.The foundation must resist wind uplifting and wind shear (lateral movement). Consult local building codes to help determine specific foundation requirements and to ensure that you meet these standards before installing the mounting system. Roof Mounting Systems:Four types of systems are commonly used when roof mounting a photovoltaic array: ¢Rack mounts ¢Stand-off mounts ¢Direct mounts *Integrated mounts Rack Mounts:In a rack mount,the photovoltaic modules are supported by a metal framework and are set at a predetermined angle.The rack-mounted array is placed above the roof with the rack's members bolted to the roofs'structural members.A rack mount does increase the bearing weight of the system on the home's roof and can pose wind-loading problems.However,since air circulates completely around the modules,they are kept at a cooler,more efficient operating temperature.The array's electrical connections are easier to access since the rear surfaces of the modules are exposed. Some rack mounting systems are adjustable, which can increase the photovoltaic system's efficiency throughout the seasons.Many manufacturers have precut,predrilled rack-mounting systems for their modules.Both adjustable and fixed generic rack mounting systems are available from third-party suppliers. Stand-Off Mount:In a stand-off system,a framework that is constructed above the finished roof,such that no roofing materials are replaced, supports the photovoltaic modules.The framework is four to ten inches high and parallel to the roof's pitch.Support rails are fastened to the stand-off framework,and the modules are fastened to the support rails.While the stand-off mounting system allows for a free flow of air around the array,limited access to electrical connections makes maintenance more difficult. Direct Mount:In direct mounting systems,the photovoltaic modules mount directly to the conventional roof covering materials,eliminating the need for a supporting framework and mounting rails. The modules must maintain the roof covering's weather tight integrity and be adequately sealed using appropriate sealants. The direct mounting system does not allow for air circulation around the array's modules,which results in operating temperaturesas much as 20 degrees C higher than other mounting systems. Access to the array electrical connections is limited, making diagnosis,repair and maintenance difficult. Integral Mount:With integral photovoltaic atray mounting systems,the photovoltaic modules attach directly to the roof's rafters and replace the conventional roof covering.The array is sealed using butyl rubber glazing tape or EPDM gasket material that is capped with a meta]batten.These systems are designed for use in new construction where the building's roof is appropriately oriented and sloped. These systems are easy to ventilate,resulting in a more efficient array operating temperature.An adequate ventilation scheme can be designed into the system that incorporates vents normally found in residential construction.Access to the system's electrical connections can often be made in the attic space., Tracking Mounting Systems:Solar photovoltaic array mounts that track the sun in its daily path across the sky are a cost-effective,alternative 158 weereeSERmeSNLerleetineenshgedemounting system for some installations.Passive tracking units have no motors,controls,or gears and use the changing weight of a gaseous refrigerant within a sealed frame to track the sun.Sunlight activates the refrigerant,and the frame assembly moves by gravity or is driven by a piston.They can also be seasonally adjusted to optimize altitude angle. Active trackers use motors powered by small, integrated photovoltaic panels to move the array. Tracking mounts that follow the sun's azimuth but not its altitude are called single-axis crackers. Trackers that follow both the sun's azimuth and altitude are called dual-axis trackers.These sophisticated trackers are also commercially available, although they are not cost effective for small-scale residential systems. Tracking mounts require firm foundations because of their weight and wind loading characteristics.Four to six inch outside diameter pipe 'is commonly set in reinforced concrete footings to insure long term,safe operation.The tracker stem is then placed over the pipe.The tracking unit needs to be mounted at an adequate height above ground level to allow unobstructed movement above snow or debris. Tracking units generally enhance a system's annual performance by approximately 25%to 30%but can add a significant cost to a system.The economics of tracking mounts should be carefully evaluated in the initial design phase.Trackers offer different performance gains throughout the year, increasing system performance by 15 percent in the winter and by 40 percent in the summer.Systems requiring larger loads during the summer months are ideal candidates for tracking systems.Longer hours of effective insolation are available in the summer and increase the photovoltaic system's collection potential.In contrast,winter dominated loads are less likely to benefit significantly from trackers.Each system must be carefully evaluated to determine the economic viability of trackers versus fixed mounts. Measuring Array Output:When the entire installation is complete,you should measure the array output when connected to the load (battery). You can judge or measure the intensity of the sunlight as it strikes the array and decide if array performance is operating as expected from manufacturer's specification. Note:You must know how to measure open PHOTOVOLTAIC INSTALLATION circuit voltage and short circuit current.For more information,refer to Chapter 5. You should take the open circuit voltage measurements before the module warms up from the sun.As the module temperature increases,the voltage will drop.Short circuit current measurements are directly affected by sunlight intensity.Unless you can measure sunlight intensity,you can only make an educated guess as to the module's currence output performance.Few installers have equipment for measuring sunlight,so it is best to measure modules under full sun conditions at noon.Face the module directly into the sun for this measurement.Most modules will measure within 10 percent of their specification. Battery Installation Installing a battery system starts with shipping. Remember that batteries are heavy and prone to leakage.Consequently,some carriers will not ship liquid batteries.Even certain sealed batteries contain some liquid called reserve electrolyte that can spill. Upon arrival check the batteries for any damage that may have occurred during shipping. Caution!Remember to think "safety first”when working with batteries. Batteries must be protected from theft, children,temperature extremes,corrosion,and accidental short circuit from falling objects. They also must be protected from open flames and sparks that can cause explosion. You should protect batteries at all times, including during transport and while boost charging before departure for the site.A boost charge is needed if the batteries are not fully charged;you should charge the batteries before leaving the shop. When boost charging with an AC powered battery charger,make sure you do not exceed the charge termination voltage or charge at a faster rate than the manufacturer specifies.As a general rule,the boost charge rate in amps equals the number of positive plates in one cell.When charging batteries,keep them away from open flames and sparks and open the vent caps to allow explosive hydrogen gas to escape.Keep batteries away from children, tae 159 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL unauthorized personnel,dust and oil.When transporting batteries,pack them to avoid spillage and short circuits.You should cover both battery terminals with an electrical insulator such as wood, tape or insulated connectors. Building a Battery Enclosure:The battery bank must be safely located to prevent accidents,yet provide for periodic maintenance.Batteries are often housed in a ventilated battery box that is corrosion resistant and sometimes insulated.Smaller systems can use an insulated,plastic food cooler for a battery box.Larger battery banks can be set on racks that are corrosion resistant,extremely stable,and provide access for maintenance.When building a battery enclosure,you should use the following guidelines: *Protect batteries from items that can accidentally fall from above and cause a dangerous short circuit. *Protect batteries from freezing temperatures by insulating the enclosure or locating the enclosure in a heated area. *Vent to the battery enclosure to provide free airflow and prevent the buildup of explosive hydrogen gas.If vents are used,they must be located high enough to properly vent hydrogen gas,which is lighter than air.Vents should be directed outdoors and screenedto prevent insects and animals from blocking them.Note that with free airflow the battery temperature will be about the same as the average ambient air temperature. *Build the enclosure,box,or compartment so that it can be locked,yet is easily accessible for maintenance.Size the access to the enclosure to allow for easy removal and replacement of batteries.When placed in the enclosure,the batteries or cells should have air space between them. *Store the maintenance equipment and manufacturer's information in re-sealable plastic bag or container inside the enclosure. *Build a strong level floor. ¢Build the enclosure with material that will not be damaged by the corrosion from the electrolyte.Use wood,plastic,or painted metal. When installing batteries,keep in mind the following installation guidelines: *Use the connector bolt torque specified by the battery manufacturer. ¢Adequately size all battery wiring and fuses. *Use #2 AWG battery interconnect cables for small systems.Refer to Chapter 6. *For wire entries,use connectors that protect the wire from tension and damage. *Place fuses on the positive wires leaving the battery box. *Use stainless steel nuts,bolts,and washers on battery terminals. *Protect all battery terminals and terminal connections from corrosion by coating them with battery terminal coating,petroleum jelly, oxidation protection material,or high témperature grease. *Provide a one-quarter inch space between batteries. f.Controller &inverter Photovoltaic charge controllers are intended for specific solar applications,and they should not be used for other system regulation unless specified by the manufacturer.You should read and follow the exact installation procedure specified in the manufacturers instructions.When installing controllers and inverters,you should use the following guidelines: *Protect control hardware from excess dust, dirt,overheating,and rough handling.Remember that electrical equipment is sensitive and requires careful handling.Some controllers require ventilation to prevent components from overheating.Use common sense in locating and mounting controller units;install all system components away from potential hazards,such as overhanging tree limbs,heat sources,snowdrift,and debris build-up areas. *Cover the array with an opaque material when installing the controller.Also turn off all load: to protect the installer and equipment. 160 Section 14.5 oecaerneARetianmaetel-peteeeeeldeeeeinnyenneepmeenteenegiennememeEo«Use correct wire size and proper terminal fasteners. *Choose a controller with field adjustable setpoints because each different battery typehasslightlydifferentvoltagerequirements.Suggested setpoints for each battery type are listed in Chapter 6. , ©Use an enclosure or metal box made especially for electrical wiring.Controls aremountedinsideanenclosuretoprotectthem from dust,moisture,sunlight,insects, tampering,and abuse.Also,other electricalwiringisoftencompletedinsidetheenclosure.The cover of the enclosure protects people from shock and is a good place tomountelectricalmetering. «Use some form of overcurrent protection and switching in or near the control enclosure toprotectthecontrolandprovideameansofdisconnectionbetweenthearrayandbattery. Fusing or circuit breakers protect the controlfromtoomuchchargingcurrentandprotectthewiringfromtoomuchcurrentintheeventofashortcircuit.Too much current will overheat the wiring and may cause a fire if not protected with fusing or circuitbreakers.Disconnect switching is used to open the circuit between the array,control,and battery.Disconnect switching also turnsofftheload.This switching is necessary for servicing the system and in case of emergency.A double pole,single throw fused safetyswitchactsasbothdisconnectand overcurrent protection for the entire system. See Chapter 9. Note:Fusing is subject to corrosion frommoistureandrequiresthatsparefusesbeavailable.Circuit breakers are less likely to corrode and more convenient.In addition,breakers have more concealed wiring. PHOTOVOLTAIC INSTALLATION A fi c Photovoltaic Systemaedae.4fy.Wiring When wiring a PV system,it is very important to usethecorrectelectricalboxes,wiring connections,and switches for each specific application.This sectiondescribesthevariouselectricalcomponentsandtheir applications. Electrical Boxes All wiring connections must be made within anaccessibleelectricalbox.The box must be securely fastened in place and have a removable cover.Electrical boxes can be either surface mounted orrecessedintoawall,ceiling or floor.Surface mountedboxes,called handy boxes or utility boxes,haveroundedcorners.Recessed boxes come with a varietyofmeansforfasteningtointeriorframingorsurfacecoverings,such as wallboard and paneling.Electrical boxes that are exposed to weather must be weather resistant and have weather resistantconnectors.Electrical boxes must be an adequate sizeforthenumberandsizeofwirescontainedwithinthe box.Boxes used for switches and receptacles are often referred to as switch boxes and receptacle boxes. These boxes are rectangular in shape and use a coverplate.Utility boxes normally use an extension ring tofastentheswitchorreceptacle.Electrical boxes usedonlyformakingwireconnectionsarecalledajunctionbox.They are usually rectangular oroctagonalinshapeandcoveredwithablankcoverplate,making them accessible when construction iscomplete.Boxes used for light fixtures are usuallyroundoroctagonalandcoveredbythelightfixture itself. Wiring Connections. Electrical connectors perform one of the following connecting functions:Wire to wire:Connections between wire and wire are ustially made with either a wire nut,splitbolt,reducer or crimped connector.Wire nuts aresizedandcolor-coded.Crimp-type connectors mustbecrimpedusingaspecialtoolrecommendedbythemanufacturerandarebestusedwithstrandedwire.Wire to terminal:Connections berween a wireandterminalareusuallymadewitharingorspadetypeconnector.These connectors are commonly ToamtinarwekeLt 48 161 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL used when connections are frequently removed and reconnected or where large wire would be difficult to connect. Wire,cable,cord,or conduit to electrical box: Connections between electrical boxes and wires, cables,cords,or conduit must be secure enough to prevent wires from pulling loose.When exposed to weather,these connections must thread into the box and make a watertight seal.A "drip loop”should be used for outdoor wire connections to electrical boxes to prevent water from running down a wire and into the box.Outdoor wire'connections are made only from the underside of an electrical box. Common Electrical Connectors Wire nuts:Connectors used to connect two or more wires.Twist the wires together and screw wire nut on until tight. Ring terminals:Crimp-on connectors that maintain a connection even if the screw loosens. Spade terminals:Crimp-on connectors for use in non-vibrating applications.They allow for quick disconnection. Screw lugs:Bolt-on connectors used to connect large or multiple wires to one terminal. Flag terminals:Connectors used for securing wires where no electrical connection is made. Cable connectors: Connectors used for connecting non-metallic sheathed cable to a box., Conduit connectors:Connectors used for connecting conduit to a box for interior or dry applications. Conduit couplings:Connectors used for connecting lengths of conduit for interior or dry applications. Compression couplings:Connectors used for making watertight connections between lengths of conduit. Armored cable connectors:Connectors used for connecting flexible armored cable to a box. Strain relief connectors:Connectors used with round cord,such as SO,SJ,or TC,where resistance to pulling or weather is necessary. connectors or Romex Switches Switches must be rated for a given voltage and for the amount and type of current that will flow through them.Type "T”switches are rated for direct current use.They have a snap-action compatible with direct current characteristics.A switch rated for alternating current does not have an adequate "interrupt rating” for direct current.Using alternating current rated switches or "quiet switches”for direct current systems will result in a shortened switch life because the contacts burn out from repeated electrical arcing. Under higher current conditions,the switch contacts may become permanently fused,rendering the switch inoperable. Disconnect switches are required for safe direct current system operation.The National Electrical Code requires a means for disconnecting each voltage source.Photovoltaic panels and batteries are voltage sources that need a disconnect switch.Safety switches or circuit breakers are the most appropriate switches to use for disconnecting photovoltaic panels, batteries,and generators.A safety switch is fused, thus providing overcurrent protection between major photovoltaic system components.Circuit breaker used here functions as a switch on over current protection. Receptacles:Receptacles for direct current wiring are not the same as those commonly used for alternating current wiring.The correct receptacle should be used to prevent damage to appliances, eliminate fire and reduce shock hazards.The National Electrical Code requires direct current receptacles to be a twist lock type.More common "bayonet”or "cigarette lighter”type receptacles are unsafe because children can easily insert their fingers or other objects into the outlets.These receptacles should be avoided.. 162-Ci«;8 op3))ction 14.3rtO Wiring Installation Checklist You should ask the following questions when installing a system to ensure a safe,correct wiring installation.You should be able to answer 'yes'to each question.*Is the ampacity of the wire adequate for the total of all-loads in each circuit? Does the voltage drop not exceed 2%in any branch circuit or 5%of the total from the battery to the load? Does the overcurrent protection not exceed the wire's ampacity? e Are the wires properly coded? *Are the types of wires,cables,cords,and conduits correct for each application? Are all conduits the correct size for the number and type of wires that they contain? *Are all electrical boxes adequately rated,sized, * covered,and accessible? Do all electrical boxes that are subject to moisture include a "drip loop”? Are all electrical connections accessible? Are all electrical connections protected from moisture if necessary? Are all switches rated for the voltage and current they will switch? Are the correct direct current receptacles used? Are all receptacles clearly labeled with their correct voltage and current? Are all equipment grounds made with green or bare wire or metal conduit? Are any grounded conductors switched, fused,or interrupted in some way? Note:Grounded conductors should never be switched,fused,or interrupted in any way. Are all equipment grounds and ground conductors grounded at only one point in the system? Is conduit supported every 5 feet and within 12 feet of each electrical box? Is all cable fastened every 4%feet and within 12 inches of each electrical box? PHOTOVOLTAIC INSTALLATION x jl 7 PV System Installations"fs #Final Checklist This section contains a system installation checklist that can be used as a final check for a newly installed system or as a maintenance assessment for an existing system. PV Array *Pre-test module voltage and current to verify proper operation. *Make sure all modules are attached securely to their mounting brackets._ *Visually inspect the array for cracked modules, damaged junction boxes,and loose wires. ¢Open each combiner box and test open circuit voltage and short circuit current,if possible.Recheck torque on any screw terminals. *Before powering up the system,at final array breakers,repeat open circuit voltage and short circuit current tests,if possible,to ensure that all array wiring is properly connected. *Perform dry insulation test,at test voltage of 500 V,on array and array wiring. Note:Disconnect all SOVs and MOVs BEFORE doing insulation test. *Check for NEC-type marking/label on the modules.NEC 690-51:"Modules shall be marked with identification of terminals or leads as to polarity,maximum overcurrent device rating for protection,and with rated 1) open-circuit voltage,2)operating voltage,3) maximum permissible system voltage,4) operating current,5)short-circuit current, and 6)maximum power.See NEC 690-52 for AC module requirements.” Wiring *Check exposed array wiring for correct rating and sunlight resistant insulation. *Check that all wiring and conduit is neat and well supported. *Check thar strain reliefs/cable clamps are properly installed on all cables and cords by pulling on cables to verify (NEC 300-4,400-10). Section 14.7 163 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Make sure that all grounded conductors are white and equipment grounding conductors are green or bare (NEC 200-6(a),Ex 5). Disconnect all MOVs and SOVs,if any,then perform insulation test on system wiring.Use a test voltage of 500 V for all wiring 600 V and below. Verify that all field wiring is tagged at both ends with permanent wire markers. Wiring Methods Check that conduit supports are no more than 54 inches apart and no more than 12 inches from boxes,such as junction boxes, cabinets or conduit fittings (NEC 350). In general,use Liquidtight Flexible Non- Metallic Conduit for installation in wet and dry locations.Check that supports are no more than 36 inches apart and no more than 12 inches from boxes such as junction boxes, cabinets or conduit fittings (NEC 351). Check that long,straight,rigid,nonmetallic (PVC)conduit runs of 100 feet or more have expansion fittings. Verify that expansion fittings are used on conduit runs that go underground. Use schedule 80 conduit above ground if using PVC, Overcurrent Protection Verify that the overcurrent device rating of the PV circuit is at least 156%of the rated short circuit current (125%X 125%= 156%).Not larger than the ampacity of the wire used in that circuit. Make sure DC voltage and current ratings are clearly marked on overcurrent protection. Post the overcurrent protection documentation for inspector to see at the final inspection. Charge Controllers e Torque all terminations again. Check that all voltage settings are properly set for the appropriate battery type and proper voltage. If the system is connected to a utility- interactive inverter,make sure that the settings of the charge controller(s)do not interfere with the proper operation and dispatch of the inverter system. Verify that charge controller operation matches the programmed settings by forcing the system to the set points and making sure that the unit performs the proper control function.You should test the following points: -Low voltage disconnect (LVD). -Low voltage reconnect (LVD). -High voltage disconnect (HVD). -High voltage reconnect (HVD). Disconnects Retorque all terminals on disconnect switches. Check voltage drop across switches while operating. Check the continuity of fuses and circuit breakers with power off. Batteries Retorque all battery connections. Coat each terminal with anticorrosive gel. Make sure that access co terminals is limited (NEC Art.690-71(b)). Make sure that location provides adequate natural ventilation.Well-vented areas include garages,basements,and outbuildings,but not living areas. If battery contains flooded cells,top off cells with distilled water according to the manufacturers instructions. If battery contains flooded cells,be sure an eyewash station is accessible, 164 seereywee*Once inverter is operational,"equalize charge” the battery to ensure that the battery isproperlyconnectedandfunctioningcorrectly. °Ideally,run the battery through a few heavycharge-discharge cycles to exercise the battery. *Check individual cell or battery voltages after equalization. *Check the specific gravity of all questionable cells with a hydrometer.: *Store safety gear near-by.(eye protection,rubber gloves,baking soda and distilled water) Inverters in Utility-Connected Systems *Verify in the inverter manual that the arrayopencircuitvoltageisacceptabletothe inverter. *Check utility line voltage to verify that it iswithinthepropercolerancesforinverter.Iflinevoltageisabove124voltsACbeforestartinginverter,verify that the maximumvoltagedropfortheinverteroutputcircuit is less than two volts. Note:ANSI C84 requires that the inverter not raise the service voltage at the branch serviceboxabove127voltsAC.Inverters are therefore required to shut down above this voltage. ¢If the inverter measures and reports utility orinverterACvoltageonadisplay,verify thatthisvoltageagreeswithameasurementfromahighquality,true-RMS AC voltmeter. Retorque all electrical terminal connections ontheinvertertotightenanyconnectionsthatmayhaveloosenedsincetheinitialinstallation. Follow inverter-starting procedure from the owner's manual. has started and is operational,check that themaximumpowerpointtracking(MPPT)circuit is operating.This should be doneduringclearskyconditionsifpossiblebymonitoringarrayvoltagefromtheopencircuitconditionuntilitreachesapoint where system power peaks and then starts todropagain.Keep monitoring voltage untilyounotethatthesystemvoltagehasbeenadjustedupanddownseveraltimes. For non-battery-based inverters,once inverter PHOTOVOLTAIC INSTALLATION Verify that the operating voltage is near theexpectedpeakpowervoltagefortheconditionsofthetest,this can be found in most manufacturers'literature.If the inverter has manual voltage control,move the inverter voltage through expected maximum powerpointvoltagetoverifyactualmaximumpowervoltageandproperoperationofMPPTcircuit. For battery-based inverters,use the programming features of the inverter tochargethebatteryandthendispatchthebatterytotheutilirygridtoensurethatthesefunctionsareoperatingproperly. Check the programming of the inverter toensureoperationatthepropervoltagesforthechosenbattery.The inverter should beprogrammedtoperformtheconstantvoltagechargecontrolratherthanthecharge controller. Properly connect the temperaturecompensationprobetocontrolbattery voltage. Instruct the homeowner on what to do in the event of an inverter failure. Grounding Verify that only one connection to DCcircuits(grounded conductor)and oneconnectiontoACcircuitsisbeingused for system grounding referenced to the samepoint(NEC Art.250-21). Check to see that equipment groundingconductorsandsystemgroundingconductorshaveasshortadistanceaspossibletoground. Check that non-current carrying metal parts are grounded properly. For roof mounted systems on dwellings, incorporate ground fault protection.Note:Terminal lugs bolted on an enclosure's finished surface may be insulated becausepaint/finish at point of contact has not been properly removed. Check resistance of grounding system toearthground.NEC allows 25 ohms or less. 7 165 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Safety Signs *Post a "No Smoking”sign near the batteries. *Label any fuse or circuit breaker that can be *Place a sign at the point of PV system energized in either direction (NEC 690-17)._disconnect listing:;Operating current, operating voltage,maximum system voltage"::a ar*Post an "Interactive Point of Connection”sign .OSandshort-circuit current.for interactive PV systems (NEC 690-54). *Place a sign at the equipment service-entrance that states the type and location of on-site optional standby power sources (NEC 702-8). *Provide any additional documentation that would be helpful to the homeowner, inspector,or fire officials. 166 Section 14.7 a Chapter 15 Maintenance and Troubleshooting Contents: 15.1 MaterialsandToolsList Docc cence tte entene terete scee es 16815.2 Maintaining PV Components PI CS)15.3 Maintaining Appliances Lecce alee nee eteeteeeedeeeeeenes 16915.4 Troubleshooting Common System Faults .....-..+++++++ss 170 _15.5 Troubleshooting Wiring Problems Using a Multimeter weeeeeeee IZ] -15.6 Troubleshooting Specific Problems ......-++.seers eee cece 174BaeninanatesginSeammeneTen 167 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL .weé e -£Materials and Tools List You should bring the following materials and tools on any maintenance trip: ©first aid kit *soldering iron and solder *torque wrench *paper *pencil ¢mild detergent *rags *screwdrivers (1 Phillips and 2 slotted) *hydrometers (2). *safety gogeles,rubber gloves and rubber apron *baking soda (vinegar if you are working with alkaline batteries) *distilled water *volt-ohm meter (2) *adjustable power supply *anti-oxidizing compound *spare fuses,batteries,wire nuts,wire *wire strippers *lineman's pliers *manufacturer's literature and troubleshooting guides *personal gear with pack ae &e Maintaining PV|tle <z Components Although photovoltaic power systems require little maintenance compared to other power systems,you should periodically perform a few simple maintenance tasks. Photovoltaic Array:The PV array needs very little maintenance.If the system is in a dusty climate with little rain,the array may need to be cleaned off periodically.Clean the modules with water and milddetergent.Avoid solvents or strong detergents.The junction boxes should be checked periodically for weather protection.And if there are _any questions about solar access,check for shading problems caused by new plant growth. Batteries:If you are responsible for producing power,then youre responsible for maintenance. Battery maintenance depends largely on battery type, though all batteries require periodic inspections to verify system operation. To estimate a battery's state of charge,you can measure battery voltage measured with a multi- meter.(Refer to "Troubleshooting Wiring Problems Using a Multimeter”on page 171)Operating a loadforseveralminuteswillstabilizethebatteryvoltage and remove any inaccurate surface charges.Do not measure voltage when the battery is charging or discharging.Disconnect the battery from both thearrayandloadbeforetakingavoltagereading.Table 6-4 on page 66 compares general state of charge to voltage readings.More precise values may be obtained from the battery manufacturer's data. °Nicad and Sealed Liquid Electrolyte (VRLA) Batteries.Nicads and sealed liquid electrolyte batteries require the least amount of annual maintenance.Terminal connections,casing, venting and wiring should be checked semi- annually,Even so-called "maintenance-free” batteries require inspections of the case, terminal connections,wiring,voltage and any venting strategies. Vented Liquid Lead-Acid Batteries.The deep- cycling,liquid electrolyte lead-acid batteries, such as those used in electric vehicles,require the most maintenance.These batteries have a higher amount of gassing than other batteries and require the addition of distilled water. Furthermore,they are prone to acid stratification at the bottom of a cell when continually under-charged.A slight amount of overcharge will assist in de-stratification. This excess charging can also "equalize”all cells in series and/or parallel strings. Equalization is the process of restoring all cells in a battery to an equal state of charge, 100 percent for lead-acid batteries.You can reduce maintenance requirements by using recombinators or catalytic converter battery vent caps thar capture hydrogen gas and recombine it with oxygen to form water.This water is automatically returned to the electrolyte. 168 Determining State-of Charge By MeasuringSpecificGravity:Liquid electrolyte,non-sealed lead-acid batteries can be precisely tested for state ofchargebymeasuringtheelectrolyte's specific gravitywithahydrometer.A hydrometer is a bulb-typesytingethatwilldrawelectrolytefromthecell.Aglassfloatinthehydrometerbarreliscalibratedtoreadintermsofspecificgravity.The lower the floatsinksintheelectrolyte,the lower its specific gravity. Never take a hydrometer reading immediatelyafterwaterisaddedtothecell.The water mustbethoroughlymixedwichtheunderlyingelectrolytebychargingthebatterybeforehydrometerreadingsarereliable. 1.Wear safety glasses,rubber gloves,and arubberapron.Have some baking soda handy toneutralizeanyacidspillageandhavefreshwateravailableforflushingpurposes.If you get acidintoyoureyes,flush with water immediately foratleast10minutesandobtainprofessional medical assistance. 2.Draw the electrolyte in and out of thehydrometerthreetimestobringthetemperatureofthehydrometerfloatandbarreltothatoftheelectrolyteinthecell.Hold the barrel verticallysothefloatdoesnotrubagainstthesideofit. 3.Draw an amount of electrolyte into the -barrel.With the bulb fully expanded,the floatshouldbeliftedfree,not touching the side,top,or bottom stopper of the barrel. 4,Read the hydrometer with your eye levelwiththesurfaceoftheliquidinthehydrometerbarrel.Disregard the curvature of the liquidwherethesurfacerisesagainstthefloatstemandthebarrelduetosurfacetension.Note:Keep the float clean.Make certain thehydrometerisnotcracked.5.Adjust the reading for the temperature of theelectrolyte.Use the thermometer and directionsfortemperaturecompensationthatcomewith the hydrometer. Hydrometer floats are calibrated to give a truereadingatonefixedtemperatureonly,commonly 80degreesF.A correction factor must be used if thetemperaturedoesnotmatchthespecifictemperature MAINTENANCE AND TROUBLESHOOTING for the thermometer.At increased temperatures,theelectrolyteexpandsandbecomeslessdense;thus,thefloatwillsinklowerinthelessdensesolutions,resulting in a lower specific gravity reading.Conversely,at lower temperatures the electrolyteshrinksandbecomesdenser;thus,the float will notsinkasdeep,resulting in a higher specific gravity.Note:Remember that some new batteries do notgiveafullspecificgravityreadinguntiltheyhaveundergonenumerouscycles.Adding Water:The only water to use whenpreparingelectrolyteisdistilledwater.This is alsotrueforroutinewateradditionstothebattery.Besurenottousemineralwaterorspringwater.USEDISTILLEDWATERONLY!Avoid using metalliccontainers.Metal impurities in the water will lower the performance of the battery.Wiring:Check all wiring connections yearly.Tighten any loose wires immediately. 4432 Maintaining Appliances To ensure that your PV power system operatesefficiently,you need to wisely choose,operate,andmaintaintheappliancesonthesystem.The followingsectionsoutlinetheoperationsandmaintenanceissuesfortwocommonlargeloads,lighting and refrigeration.. Lighting A systematic maintenance schedule allows thephotovoltaicsystemusertokeeplightinglevelsashighaspossiblewithoutaddingtotheelectricload.The following is a list of recommended design,maintenance,and operations procedures for lighting systems: : °Use a single incandescent lamp of higherwattageratherthantwoormoresmallerlampswhosecombined.wattages equal the higher wattage lamp. *Use extended service lamps only wheredifficultmaintenanceorotherfactorsare ofoverridingimportance.These lamps providefewerlumensperwattthanstandardlamps. *Discontinue using multi-level lamps wherepossible.The efficiency of single wattagélampsishigherperwattthanthatofamulti- level lamp. Section 15.3 169 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Replace non-decorative incandescent lamps with more energy conserving types of lighting,such as fluorescent in general purpose areas and metal halide in large group areas. Replace conventional spotlights with lower wattage elliptical reflector spotlights. When re-lamping,replace fluorescent lamps with more efficient,lower wattage lamps,such as a 34-watt lamp insteadof a 40-wate lamp. Consider de-lamping where it is possible,for example in four-lamp fixtures disconnect two of the lamps. Lower fixtures to increase illumination levels on task areas.The increased illumination enables a reduction in the number of fixtures or the required lamp wattage. Regularly inspect and clean lamps and fixtures.Dust and dirt build-up can reduce unit effectiveness by as much as 20 percent. Replace fixture lenses that have turned yellow with acrylic or plastic lenses that do not discolor. Replace outdated or damaged fixtures with modern,energy efficient types. Reduce outdoor lighting levels. Eliminate outdoor lighting where practical. Install a control device,such as timer or photocell,to automatically turn off lights when not needed.Use timers in seldom used areas where there will be sporadic occupancy. Replace exterior incandescent lamps with more efficient types,such as high-pressure sodium or metal halide. Consider using low-pressure sodium lighting if color rendition is not a concern. Provide signs instructing occupants to turn off lights when leaving the room. Consolidate task areas to eliminate unnecessary illumination. Eliminate single switches that control all the fixtures in multiple workspaces. Utilize natural lighting whenever possible. *Clean walls and ceilings.Paint or decorate walls with light colors to reflect light. *Install light sensors and dimming equipment that automatically compensates for varying natural lighting conditions. Refrigeration The following is a list of recommended design, maintenance,and refrigerators: operations procedures for *Load refrigerator neatly.Jumbled loading results in inefficient use of space and causes heavier frost deposits,more frequent defrosting,and loss of refrigerated air. *Rapidly transfer food products out of the refrigerator and back in.Allowing products to warm outside the refrigerator will cause unnecessary energy use for re-cooling and can cause the food to degrade. *Obrain and follow manufacturer's cleaning recommendations and maintenance schedules.Dirty fixtures and condensers increase compressor operating time and raise condensing temperatures,which decreases cooling capacity *Check all door seals and gaskets for cracks and other damage.To test the gaskets,place a dollar bill between the gasket and doorframe and close the refrigerator door.Try to pull the dollar bill out;it should resist withdrawal. *Defrost units as often as necessary to keep the evaporator free of frost build-up. *Thaw frozen food in the refrigerator.Food will thaw easily and help reduce the power required by the refrigerator. |>)Kie .Troubleshooting*Common System Faults: The best method for avoiding system failures is to initially install a high quality,properly designed system.Regular maintenance is the second line of defense against failures.The first step in troubleshooting photovoltaic power system problems is to save all of the manufacturer's product literature that comes with each component.This literature should be kept in a handy location that is protected 170 rieemngerweMeetSeeeenfrom weather,chemicals,and rodents.The most common system failures are usuallythesimplesttofix.You should check the system forfundamental.problems first to save a great deal oftime.The most common system failures are blownfuses,tripped breakers,or bad connections.Theothercommonproblemisaloworemptybatterybank.The following general troubleshootingchecklistforsystemoperationcanbecompletedvisually,with the possible exception of the last two items. *Has the weather been cloudy for several days? If so,system may need recharging. ©Check the array for partial shading or dirt. ©Check all fuses and circuit breakers. *Check system wiring for loose connections and/or corrosion. ¢Check system wiring for proper polarity. ¢Check system for proper system voltage and current. *Check modules and batteries for proper series-parallel configuration. Troubleshooting Wiring -.,.Problems Using a Multimeter The volt-ohm-milliamp (VOM)meter is essential fortroubleshootingwiringproblems.You should befamiliarwiththismeter's proper operation to insureyourpersonalsafetyandprotectthemeterandsystemequipment.To acquaint yourself with a meter,refer to the operator's manual for proper use of the meter.The most useful tasks performed with a VOM meter include: *Checking for continuity *Measuring AC and DC voltage °Measuring AC and DC current *Checking the polarity of DC voltage General Safety Precautions These precautions are reminders of specific hazardschatshouldbeavoidedwhenusingaVOMmeter. MAINTENANCE AND TROUBLESHOOTING Always refer to the equipment manual and heed themanufacturer's specific warnings and instructions. °Always wear safety glasses when working with electrical circuitry ©Do not work alone on electrical circuits. Make certain that someone capable of rendering medical aid is nearby , ©Do not handle the instrument,its test leads, or the circuitry while high voltage is being applied. *Operate the VOM meter only if you arequalifiedtorecognizeshockhazardsandtrainedinthesafetyprecautionsrequired to avoid possible injury. ¢Turn off the power and discharge anycapacitorsinthecircuittobemeasuredbeforeconnectingtoordisconnectingfrom the circuit. , *Dry your hands,shoes,floor,and workbenchbeforeworkingwithelectricity. *Do not change switch settings or test leadconnectionswhilethecircuitisenergized. This could result in damage to the instrument and possible personal injury. ©Locate all voltage sources and accessiblecurrentpathsbeforemakingconnections to circuitry. ©Check and double check switch positions and jack connections before applying power to the instrument. ¢Make certain that the equipment you areworkingwithisproperlygroundedandfusesareofthepropertypeandrating. *Whenever measuring a current or voltage of unknown magnitude,begin measurements atthehighestscaleavailable.Proceed to a lowerscalewhenyouaresatisfiedthatthevalueiswithinthelimitsofalowerscale. Checking For Continuity Checking for continuity indicates whether a circuit isopenorclosed,which is useful when checking forbrokenwires,short circuits,fuse,or switchoperation.Checking for continuity involves circuit S 171 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL resistance.Short circuits have very low resistance. Closed circuits have some resistance depending upon circuit wire and loads.Open circuits exhibit infinite resistance.Use the following procedure for checking continuity: Caution!Resistance and/or continuity measurements should.be made with the power off.Review the safety precautions in "Safety and PV installation”,Chapter 16. To check the continuity of a circuit: ¢Turn the power off and discharge all capacitors. ¢Disconnect at least one conductor in the Circuit. *Choose the Rx100 resistance scale or another resistance scale if more appropriate for your application. *Plug the black test lead into the common (-) jack.Plug the red test lead into the positive (+)jack. *Connect the ends of the test leads together to short the VOM resistance circuit. ¢Turn the zero ohms control until the needle indicates zero ohms. *Disconnect the test leads.You are now ready to check for continuity. *Connect one test lead to the disconnected point on the circuit you want to test and the other lead at the opposite end of the circuit. An open circuit has no continuity and will read 'infinite resistance.The pointer will not move.A closed circuit has continuity and will read little or no resistance.The needle will move to the right hand side of the scale. Measuring Voltage Measuring voltage is similar to measuring for continuity,with the exception that you are measuring the energy potential in the circuit;the voltage.The following steps are a procedure to measure the voltage in a circuit. To measure the voltage of a circuit: *Review the safety precautions in "General Safety Precautions”on page 171. *Select the proper type of voltage being measured,alternating current or direct current.To help in measuring direct current voltage some meters have a direct current positive (+)and direct current negative (-) position.When in the direct current positive (+)position,the meter will read correctly if the wiring is correct and the meter leads are correctly connected.If the meter leads are inadvertently placed on the wrong wires,the polarity may be corrected at the meter by switching to the direct current negative (-) position. *Set the range indicator to the appropriate scale.If the voltage scale is unknown,start at the highest scale and work your way down to prevent meter damage or personal injury *Plug the black test lead into common (-)jack. Plug the red test lead into the positive (+) jack. ¢Turn the power off and discharge any capacitors in the circuit. ¢For direct current circuits,connect the black test lead to the negative side of the circuit. Connect the red lead to the positive side. *For alternating current circuits,connect the black test lead to the common or neutral side of the circuit.Connect the red lead to the hot side of the circuit. ¢Turn the power on. *Read the voltage on the proper scale.If the needle deflects or moves backwards,the polarity of the wiring or the meter may be reversed, Measuring Current Measuring current is similar to measuring for voltage,with the exception that you are measuring the energy passing through the circuit;the current. The following steps are a procedure to measure the voltage in a circuit.Review the safety precautions in "General Safcty Precautions”in Chapter 16. 172 Section 15.5 a7 akea4\ 4 To measure the curent of a curcuit:*On the VOM meter,select the type ofcurrentbeingmeasured,alternating currentordirectcurrent.Diréct current positive (+)position will indicate proper polarity whenredisconnectedtopositive(+)side of thecircuitandblackisconnectedtonegative (-)side of the circuit.Polarity may be reversed byswitchingtothedirectcurrentnegative(-) position. Set the range indicator to the appropriatescale.If the current scale is unknown,start at the highest scale.Plug the black test lead into the common (-)jack.Plug the red test lead into the positive (+)jack. °Turn the power off and discharge all the capacitors in the circuit.Open the ground side of the circuit where thecurrentisbeingmeasured. *Connect the meter in series (the circuit mustbebrokenthenthemeterinsertedinline with the circuit). Caution!Never connect the meter across avoltagesource.Doing so can result indamagetoyourmeterorthedevicebeing tested. e Turn power on and read the current on the proper scale. MAINTENANCE AND TROUBLESHOOTING Some technicians like to use clamp onammeters.They easily measure current withoutneedingtoopenthecircuit.The meter simplyclampsonasingleconductorandreadscurrent via inductance. Checking Polarity Polarity of a circuit refers only to direct currentcircuits.Alternating current circuits don't havepolarityperse,because polarity in an alternatingcurrentcircuitisreversedsixtytimespersecond.When polarity in a direct current circuit 1sreversed,direct current motors will run backwardsandoftenoverheat.Some direct current appliancessimplywillnotworkatall.Others will be destroyed by reverse polarity.Follow the steps for measuring the current ofvoltageofadirectcurrentcircuit.*Polarity is correct when the selector is ondirectcurrentpositive(+)position,the testleadsareconnectedwithredtothepositive(+)side of the circuit and black to negative (-)side,and the pointer reads a positive value on the meter scale. *Polarity is reversed when the selector is ondirectcurrentpositive(+)position,the testleadsareconnectedwithredtothepositive(+)side of the circuit and black to negative (-)-side,and the pointer deflects to below zero on the meter scale. Section 15.5 173 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 2)Troubleshooting Specific Problems This section contains troubleshooting information for common issues in photovoltaic power systems.The remedies listed may not apply to the equipment supplied with your system.You should familiarize yourself with the manufacturer's specifications for your equipment prior to using this guide. Sympt om:Load is inoperative :_ogame segs, Possible Cause: *Fuse is blown or circuit breaker tripped.*Investigate for possible short circuit,overload or excessive surge.Replace fuse or reset circuit breaker. *Circuit is open due to break in wire or loose *Check circuit continuity.Check continuityconnection.through load. *Appliance has overheat protection.¢Wait for appliance to cool.Reset thermal protection. *Inverter surge capacity is inadequate.*Install larger inverter or reduce !oad. Symptom:Battery is undercharged Possible Cause:Remedy: *Period of cloudy weather has not charged *Increase system autonomy or reduce electricalbatteries.energy consumption. *Actual energy consumption has exceeded the *Reduce electrical energy consumption or re- estimated load.;evaluate load and increase system output accordingly. *Battery fluid is low.*Check fluid level of each cell.Fill with distilled water as needed. *Specific gravity of battery cells is not within 1.1 to *Perform load test.Replace battery if old. 1.4, *Battery capacity and ability to accept charge has *Replace battery bank. been reduced by age or abuse. *Excessive voltage drop to battery caused by high *Check and/or calculate possible excessive voltage current,small wire,and/or long wire runs.drop. *Batteries are too cold and require higher voltage *Insulate battery box or replace controller with atoachievefullcharge.unit with temperature compensation. *If the controller has temperature compensation,*Inspect for temperature sensor or wire damagedamagetothesensororthesensorwirewillcauseandrepair. undercharging. *Controller not allowed full charge current with *Defective control.Return unit for repair or check charging light on.setting of high voltage disconnect. 174 Section 15.6 MAINTENANCE AND TROUBLESHOOTING -Symptom:Battery is overcharging /has excessive water loss_2caertmperneePossible Cause:Remedy: ¢Controller is not receiving proper battery voltage *For controllers with temperature compensation, sensing.check connection.Adjust high voltage disconnects. *Inspect for temperature sensor or wire damage ¢If the controller has temperature compensation,and repair. damage to the sensor or the wire will cause overcharging. ¢Batteries are too hot.Gassing voltage is lower *Insulate battery bank or replace controller with a than normal.unit with temperature compensation. *Controller always allows full charge causing *Check voltage at battery terminals to see when batteries to reach too high voltage.regulator switches.Compare with specs and adjust. Symptom:Relays are buzzing Possible Cause:Remedy: *Incorrect battery voltage.'*Check series-parallel wiring of batteries.Check voltage of controllers for proper match. *Improper battery connection.¢Check for proper connections. *Broken wire(s)from battery.*Check wiring. *Relay contacts are obstructed.*Clean contacts. *Batteries are dead.*Measure battery state-of-charge.If voltage is very low,connect array directly to batteries until charged.Then reconnect controller. Symptom:Erratic operation of controller Possible Cause:Remedy: *First day of operation or the array was *Check operation next day.Proper cycle is disconnected that day..°reinitiated for controllers with timer circuitry. Disconnect array,wait10 seconds,then reconnecttoresetcycle. *Loads,such as inverters,can generate electronic *Wire inverters directly to battery.Add filtering to noise.loads. *Battery is defective and may be deteriorating,*Replace battery. which results in unusual voltage swings. 175 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Symptom:Loads are disconnecting improperly Possible Cause: *Controller not receiving proper battery voltage. Remedy: *Check connection at battery voltage and temperature compensation sensor terminals. *Inverters can cause this problem.*Wire inverters directly to battery.Add filtering to load. *Load has high surge.*Check load specification for battery voltage to drop surge rating.Use larger wire or shorter wire run.Consider larger battery or generator. *Lightning strike.¢Check voltage. ¢Faulty controller.*Measure when load control switches,compare with spec sheet.Return unit for repair if incorrect. *Adjustable low voltage disconnect is set too high.*Reset adjustable low voltage disconnect using variable power supply. Symptom:Loads not disconnecting Possible Cause: *Load contro]disabled by switch. Remedy: *Check position of manual load switch. ¢Unit not equipped with low voltage disconnect.*Controller does not have load control. *Lightning strike or other high voltage source damaged controller. *Check voltage when load control switches, compare with specifications.Return unit for repair if incorrect. Symptom:Array fuse blows Possible Cause: *Array short circuit test performed with battery connected. Remedy: *Disconnect battery from controller to perform test. *Array exceeds rating of controller.¢Add another controller in parallel if appropriate or replace with controller of greater capacity. .Symptom:Load fuse /circuit breaker blows Possible Cause: *Load exceeds rating of controller,fusing,or circuit - breaker. Remedy: *Check surge rating on controller.Check for shorts in the load circuit.Check for maximum load amps exceeding over-current protection. *Surge current of load exceeds fuse rating.*Replace fuse with "slow-blow”type fuse. 176 .Section 16.6 MAINTENANCE AND TROUBLESHOOTING "Symptom:Charge light on atnight Possible Cause:Remedy: *Normal operation for some controllers with timer *Check later. circuitry if less than two hours after sunset. *First day of system installation or array *For controllers with timer circuitry,check disconnected that day.operation next day. +Faulty controller.*Return unit for repair. ©gymiptom:Pump eyeles on and off| Possible Cause:Remedy: e Air in plumbing.°Vent air. ¢Restricted pump delivery.*Check that discharge lines,fittings and valves are not clogged or undersized.. Symptom:Pump fails to prime /motor operates but no pump discharge Possible Cause:Remedy: ¢Yield of water source is inadequate.+Increase water volume. . *Pump has inadequate suction lift.*Check pump specifications.Replace or plumbanotherpumpinseriesifnecessary. *Direct current pump is running backwards.*Check polarity and reverse wiring. *Restricted intake or discharge line.*Open all fixtures,clean clogged lines. ¢Air leak in intake line.*Seal air leak. *Punctured pump diaphragm.*Replace diaphragm. *Defective pump check valve.*Replace check valve. *Cracked pump housing.*Replace housing. symptom:Pump motor fails to turnon Possible Cause:Remedy: *Pump switch is off..«Turn pump on. *Loose or corroded wiring connection.*Clean connection.Tighten connection. *Pressure switch failure.*Replace pressure switch. *Replace pump motor. 1.6 177 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL -yimptoin:Pup tlle to tro after al ures are closed, Possible Cause:Remedy: *Tank not full yet.*Normal operation. *Punctured pump diaphragm.*Replace diaphragm. *Discharge line leak.*Repair leak. *Defective pressure switch.*Replace pressure switch. *Insufficient voltage to pump.*Check for loose or corroded wiring connections. *Check for excessive line losses. "Symptom:Fluorescentlightsoperateerratically. Possible Cause:Remedy: *Cold temperature affects ballasts.*Warm rooms before use or relocate. *Open circuit.*Check all wiring as per previous remedies. *Bad ballast.*Replace ballast. *Install safety tubes,if available for lamp size. Symptom:Incandescent lamps fail prematurely Possible Cause:Remedy: *Lamp subject to vibrations or shock.*Remount or relocate fixtures. ¢Lamp receiving improper voltage.*Verify and repair. *Incorrect lamp being used.*Verify and replace. ':"|Symptom:Photocontrol malfunctions. -Possible Cause:Remedy: *Line voltage exceptionally high or low.*Check voltage at photocontrol and take steps to correct condition. *Photocontrol not rated at voltage being used.*Replace photocontrol with unit of correct voltage rating, *Contacts welded due to excessive load.*Replace photocontrol and connect only the permissible load and voltage. *Not enough light strikes photocontrol in daytime.*Reposition photocontrol in the direction of the greatest amount of natural light. *Light from the load is directly or indirectly *Reposition photocontrol to avoid artificial light | shining on photocontrol.sources. *Incorrect wiring.*Refer to wiring diagram and correct. 178 Section 15.6 Chapter 16 Safety and PV Installation Contents:16.1 Introduction obec b ec eebevneensseeeeetnnereceeees 18016.2 Basic Safety ccc bbb eter rtentttnttetteeeeeeeeeere es 18016.3 Hazards rr 6-7716.4 Safety Equipment Cnc ee eveee eset eteetet eens ences ss 18316.5 Site Safety ESS Co16.6 First Aid rene CP.siecabennbpegertsast:EioriyCREVetaTe"apBaanetnsomataclearea179 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 1 6.1 Introduction As with any activity,safety is a full-time job and the responsibility of everyone working with PV equipment,whether in the design,installation,maintenance,or use of the systems.The following items constitute good,safe practice for any type of job and reduce the potential for accidents and injuries.To work safely,you must have the following: *Good work habits *A clean and orderly work area *Proper equipment and training in its use e An awareness of potential hazards and how to avoid them *Periodic reviews of safety procedures *Instruction in basic first aid and cardiopulmonary resuscitation (CPR) Photovoltaic devices generate electricity,and they should always be considered electrically "hot.” Because they generate electricity any time light falls on them,even attempting to cover them,for example with a blanket,is not a safe practice,as light could still reach the PV or the covering could come off. Similarly,batteries are always "hot”and cannot be turned off. When working with PV modules and systems, you need to be familiar with the basics of safety: *You are your own best safety system -be alert,check everything,and work carefully. *Never work on a PV system alone. Study and understand the system before you start to work on it. *Review the safety,testing,and installation steps with everyone involved before starting work. *Make sure that your tools and test equipment are in proper working order. *Check your test equipment before going to the job site. *Wear appropriate clothing,including a safety helmet,eye protection,and dry leather gloves. Also,remove all jewelry that might come in contact with electrical components. *Measure everything electrical with a digital multi-meter.Measure the conductivity from exposed metal frames and junction boxes to ground.Measure voltage from all conductors (on the PV output circuit)to ground. Measure the operating voltage and current. *Expect the unexpected.Do not assume that switches always work,that the actual configuration agrees with the electrical .diagrams,that current is not flowing in the grounding circuit,etc. *Working with any size PV system involves a number of potential hazards,both non-electrical and electrical.Consequently,safety must be foremost in the mind of anyone working on a PV system.This chapter provides important and necessary safety information for PV practitioners and others working on or near PV systems. ;uf efx Basic Safety Regardless of whether or not the location of the PV system is covered by a local or national electrical safety code,it is important to follow guidelines that ensure safe electrical systems.Examples of codes and standards that provide recommendations and guidelines for electrical safety include: *National Electrical Code (NEC) ¢Underwriters Laboratories (UL)equipment safety testing and certification You can find hardware standards from the following organizations: *Global Approval Program for PV (PV GAP) ¢Institute for Electrical and Electronics Engineers (IEEE) International Electrotechnical Commission (IEC) American Society for Testing and Materials (ASTM) -¢International Standards Organization (ISO) 180 Section 16.1 --16.2 canalautiSinenetaedapaipeeriefeeneaereerinneereenteecgavermemetardecmtCaaabeawedsaewySystem Current and VoltageWhendesigningaPVsystem,you should consider the following:»The rated voltage in any PV source circuit should be the open-circuit voltage. *Voltages should be less than 600 volts. ©Conductors and overcurrent devices shouldbeabletocarryatleast125percentoftheshort-circuit current of the source circuit. *PV source circuit,inverter,and batteryconductorsshouldhaveovercurrentprotection. *A sign indicating PV system operating voltageandtheshort-circuit current should be placed near the system disconnect point. Wiring and Disconnect Requirements You should be consistent with electrical wiring.There are certain conventions for the color ofconductorsandspecificrequirementsfordisconnectingthepowersource,including the following:*The grounded conductor must be white.TheconventionstatesthatthefirstungroundedconductorofaPVsystemmustberedandthesecondungroundedconductormustbeblack(negative in a center-tapped PV system). *Single-conductor cable is allowed for moduleconnectionsonly.Sunlight-or ultra violet(UV)-resistant cable should be used if the * cable is exposed. *Modules must be wired so that they can beremovedwithoutinterruptingthegrounded conductor of another source circuit. *Any wiring junction boxes must be accessible. ¢Connectors must be polarized and guarded to prevent shock. *Means to disconnect and isolate all PV source circuits must be provided. *Means to disconnect all ungroundedconductorsfromtheinvertermustbe provided. *If fuses are used,means to disconnect thepowerfrombothendsmustbeprovided. *Switches must be accessible and clearly labeled. SAFETY AND PV INSTALLATION Grounding The purpose of grounding any electrical system is topreventunwantedcurrentsfromflowingthroughequipmentofpeopleandpossiblycausingequipmentdamage,personal injury,or death.Lightning,natural,and man-made ground faults andlinesurgescancausehighvoltagesinotherwiselow-voltage systems.Proper grounding,along withovercurrentprotection,limits the possible damage that a ground fault can cause.You should be familiar with the following andrecognizethedifferencebetweentheequipmentgroundingconductorandthegroundedsystem conductor: *One conductor of a PV system (>50 V)mustbegrounded,and the neutral wire of acenter-tapped,three-wire system must also begrounded,If these provisions are met,this isconsideredsufficientforthebatteryground, if batteries are included in the system.Agroundisachievedbymakingasolidlow-resistance connection to a permanent earth ground,which can be created by driving ametallicrodintotheearth,preferably in a moist location. *A single ground point should be made.Thisprovisionwillpreventthepossibilityofpotentiallydangerousgroundfaultcurrentflowingbetweenseparategrounds.In somePVsystemswherethePVarrayislocatedfarfromtheload,a separate ground can be usedateachlocation.This will better protect thePVarrayfromlightningsurges.If multiplegroundpointsareused,they must be bondedtogetherwithagroundingconductor. +All exposed metal parts must be grounded (equipment ground). ¢The equipment grounding conductor mustbebarewireorgreenwireandbelargeenoughtohandlethehighestcurrentthatcouldflowinthecircuit. PV System Output Before the PV array is connected to the load,battery,or inverter,there are certain requirements you need to address,including: ¢If an inverter is used to interconnect the PV 16.2 181 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL system to a utility,it must disconnect automatically if the utility power goes off.If the inverter is operating in a stand-alone hybrid system,it can supply power to the load continuously. *The output of a single-phase inverter should not be connected to a three-phase service. ¢The AC output from a PV system inverter must be grounded in accordance with requirements for AC systems. *A circuit breaker or fuse/switch mechanism must be included so that the PV system output can be disconnected. *The interconnection should be made so that all ground fault interrupters remain active. °If batteries are used in a system,they must be guarded to prevent unauthorized access if the voltage is greater than 50 Vdc.Otherwise,the voltage must remain below 50 Vdc. *If batteries are used in a system,charge controllers must be installed in the system. Hazards When installing or working with PV systems,you should be aware of the many potential physical, electrical,and chemical hazards. Physical Hazards (non-electrical,non-chemical): When working on a PV system,you will be workingoutdoors,possibly in remote areas,and using hand and power tools on metal and wire equipment.In. many systems,you will also be working with batteries, which pose their own sets of burn,shock,and physical hazards.Take the necessary precautions to use these tools safely and appropriately. Exposure:When designed properly,PV systems are installed where the sun is brightest and no shade _exists.When working on a PV system,you should wear a hat,keep yourself covered,and use plenty of sunscreen to-protect yourself from the sun.In hot -weather,drink plenty of fluids,preferably water,and never alcohol.Take regular breaks in the shade for a few minutes each hour.In the wintertime,dress warmly,and wear gloves whenever possible. Insects,Snakes,and Other Creatures:Spiders and many insects,including wasps,will often move in and inhabit junction boxes,array framing,and other enclosures of a PV system.Snakes use the shade provided by the array.Also,ants are commonly found under arrays or near battery boxes.Always be prepared for the unexpected when you open junction boxes and other enclosures.Look carefully before you crawl under or move behind the array. Cuts and Bumps:Most PV systems consist of components that have sharp edges and can cause injury if you are not careful.These include metal framing, junction boxes,bolts,nuts,guy wires,and anchor bolts. Wear gloves when handling metal,particularly if you are drilling or sawing.Metal slivers from a drill bit often remain around a hole,and these can cause severe cuts to a bare hand.Wear a dielectric hard hat any time you are working under an array or on a system with hardware higher than your head. Falls,Sprains,and Strains:Many PV systems are installed in remote areas and in rough terrain.Walking to the site and around it,particularly carrying systems components and test equipment,can result in falls and sprains.Wear comfortable shoes,preferably with soft soles.Steel toe reinforced shoes should not be worn around PV systems because they lower the resistance of a potential current path,increasing your risk of becoming a conductor.Be careful when lifting and carrying heavy equipment,particularly batteries.To avoid back strains,lift with your legs and not with your back.If climbing is required,have a partner hold the ladder firmly anchored and assist with handling equipment.Also,remember that a PV module can act as a wind sail and knock you off a ladder on windy days. Thermal Burns:Metal exposed to the sun can reach temperatures of 80°C (176°F).This is too hot to handle but unlikely to cause burns if you break contact quickly.To be safe,wear gloves at all times when working on PV systems in the summertime. 'Survey the system to be aware of elements that might get hot. Electrical Hazards:Common electrical accidents result in shocks and burns,which can cause muscle contractions and traumatic injuries resulting from falls.These injuries can occur any time electric current flows through the human body.The amount of current that will flow is determined by the difference in potential (voltage)and the resistance in the current path.At low frequencies (60 Hz or less), the human body acts like a resistor,but the value of resistance varies with conditions.It is difficult to 182 Section 16.3 Py'f1d 4 al { estimate when current will flow through the body ortheseverityoftheinjurythatmightoccurbecausetheresistivityofhumanskinvariesfromjustunderathousandohmstoseveralhundredthousandohms,depending primarily on skin moisture.If a current greater than 0.02 amperes (only 20milliamperes)flows through your body,you are inseriousjeopardybecauseyoumaynotbeabletoletgoofthecurrent-carrying wire.This small amount ofcurrentcanbeforcedthroughsweatyhandswithavoltageaslowas20volts,and the higher the voltage,the higher the probabiliry that current will flow.High voltage shock (greater than 400 volts)mayburnawaytheprotectivelayerofouterskinattheentryandexitpoints.When this occurs,the bodyresistanceisloweredandlethalcurrentscancause instant death.Flectrical shock is painful,and potentially minorinjuriesareoftenaperavatedbythereflexreactionofjumpingbackawayfromthesourceoftheshock.The best way to avoid shock is to always measurethevoltageofawiretoothersitesandtoground.Use.a clamp-on ammeter to measure the current flowinginthewiresandneverdisconnectawirebeforeyou have checked the voltage and current.Do notpresumethateverythingisconnectedandworkingasdesigned.Do not trust switches to operate perfectlyanddonot"believe”schematics.A digital multi-meter is a wonderful instrument and using it could save your life.AC.Power Hazards:If alternating current power is to be supplied,a power conditioning unit isrequiredtoconvertthedirectcurrentpowerfromthePVsystemtoACpower.This equipment may havehighvoltageatbothinputandoutputwhenitisoperating.The output is nominally 120 Vac or 240Vac,which is enough currentto kill a person.All oftheprecautionsforACcircuitsgiveninthisdocumentshouldbefollowed.Chemical Hazards:You should be aware ofpotentialchemicalhazardswhenworkingwithPV systems.Acid Burns:Most stand-alone PV systems use batteries,which are typically the most dangerous component in PV systems.The most common typeofbatteryisthelead-acid battery that uses sulfuricacidastheelectrolyte.Sulfuric acid is extremelyhazardous;it can spill when handling a battery andsprayasafinemistwhenabatteryischarging.If acid SAFETY AND PV INSTALLATION makes contact with an unprotected part of your body,you will receive a chemical burn;your eyes areparticularlyvulnerable.It will also burn holes in yourclothing.Any time you are working around lead-acidbatteries,you should wear non-absorbent gloves,protective eyewear,and a neoprene-coated apron.Gas Explosion or Fire:Most types of batteriesusedinPVsystemsreleasehydrogengasasaresultofthechargingprocess.This flammable gas is a hazard,and flames,sparks,and any equipment that couldcreateaspark,such as controllers with relays,shouldbekeptawayfromthebatteries.Batteries should also -be located in a well-ventilated area to prevent a buildup of hydrogen gas. :0 me Safety Equipment This section lists the recommended safety equipmentthatyoushouldhaveavailable.You should make surethatthisequipmentisinworkingorderbefore beginning a job. Personal Safety Resources: *Work partner (Never work alone!) Understanding of safety practices,equipment, and emergency procedures *Safety checkdist Safety helmet +Eye protection *Dry leather gloves for installation *Rubber gloves for working with batteries *Apron for working with batteries Appropriate harnesses,if working on roofs or other elevated sites Proper measuring equipment,electrical and dimensional *Tape and wire nuts (Never leave wire ends exposed!) Job-Site Safety Resources: *Safety plan °First-aid kit ¢Fire extinguisher Distilled water -¢Baking soda Ve 4 183 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL *Appropriate ladders ¢Appropriate lifting equipment *Proper labels on all components,such as boxes and wiring Note:Safety equipment standards can also refer to what you should not wear.Remove all jewelry that might come in contact with electrical components! 1 6.5 Site Safety Sometimes,you will need to troubleshoot a PV system that is not working correctly.Safety should be your main concern,both in planning to go to the site and during the actual testing.Before working with any PV system,you should become familiar with the electrical configuration. Before traveling to the site,you should be able to answer the following questions: ¢Who will assist you?(Always work with a trained partner or team.) *How many modules make up a source circuit? '©What are the system voltages? ¢What are the system currents? *How many circuits are there? *How can the system be disconnected? *What safety equipment is available? ¢What equipment will you need to bring? At the PV system site,you should take the following safety precautions: *Remove jewelry. *Walk around the PV system and record any apparent hazards in the system logbook or a notebook.Take photographs of the system and any hazards. *Locate the safety equipment,such as a fire extinguisher and check the condition of all equipment before starting work.Locate the nearest telephone. Check the actual system configuration against the electrical schematics. Locate and inspect all subsystems,such as the batteries,inverter,and the load. Determine if,how,and where the system is grounded.Check to see if the AC and DC grounds are common. Locate and inspect all disconnect switches and fuses.Determine if the switches are designed to interrupt both positive and negative conductors. Disconnect the source circuits and measure the open-circuit voltage to verify the proper operation of the disconnected switch. Measure the voltage from each conductor to ground and from line to line. Note:Only when you are sure that you understand the circuit should you proceed with testing. Keep the work area clear of obstacles, particularly the area behind where you are working. Never disconnect a wire before measuring voltages. Keep your hands dry and/or wear gloves. Work with only one hand,if possible. Have your partner or team member stationed near the disconnect switches. Once a wire is disconnected,don't leave the end exposed -tape it or use a wire nut for temporary covering. Reconnect the wires from one source circuit before disconnecting a second source circuit. 184 CentionNateeLek selontnernenisiinguneprmmeeeetiesancettenogeeeeanereratecaeeneeetCPR. 1 6.5 First AidThefollowingisareviewof the first-aid proceduresthateveryoneworkingonPVsystemsshouldbe .familiar with.Each person working on theinstallationormaintenanceofPVsystemsshouldalsocompleteacardiopulmonaryresuscitation(CPR)course or equivalent training.The followinginformationisasummaryofthefirst-aid you shouldunderstandandbecapableofperforming,but it isnotintendedtoreplaceformaltraininginfirst-aid or Note:Both electrical and non-electrical injuriescanoccurwhenworkingaround/with PV systems.If you witness an accident or are the first persontoarriveatthescene,perform the following first-aid actions:¢Survey the scene for potential hazards.Thefirstruleispersonalsafety.The worst thingthatcouldhappenisthatyou,the rescuer,getinjuredorkilledinanattemptprovideassistancetothevictim.Try to determine if ahazardstillexists.Is a live conductor stilllyingonornearthevictim's body?Is thevictimstillholdingaliveconductor?Arethereotherhazards,such as fire or spilledcausticmaterialthatwouldputyouinjeopardy?You will be safer in assisting avictimifyouarewithsomeoneelse,but do not delay to wait for a partner.Note:Also,be aware that some otherwisecompetentpeoplemaynotreactwellorasexpectedinanemergencysituation,everyonereactsdifferently.You are on your own toprotectyourselfandhelpthevictim.©Check the victim for an open airway,adequate breathing,and adequate pulse.Determine the victim's condition. *Call for help and give the victim's conditionandvitalinformation.During an emergency,do anything you can to quickly attractattentiontothescene.Call an ambulance,getsomeoneelsetodoit,or even pull a firealarm,but get qualified emergency personneltothesceneasquicklyaspossible,thenattendtothevictimusingacceptedfirst aidandCPRtechniques.Although in remote SAFETY AND PV INSTALLATION areas,you may need to provide the necessaryinitialcare.Again,call for emergency help.They can meet you half way to the hospital if necessary.-' Non-Electrical Injuries:These injuries includecuts,sprains,broken bones,exposure,and insect andsnakebites.Most of the time,these situations are notlifethreatening,but in some cases if care is notprovidedimmediately,the victim may go into shockandpotentiallydie.Respond quickly. CutsIfsomeone receives a cut,you should stop thebleedingbyusingthefollowingmethods,in this order:¢Direct pressure -Apply direct pressure withasteriledressing(gauze pad)between thewoundandyourhand.Use a clean cloth if asteriledressingisnotavailable. ¢Elevation -Elevate the wound if it continues to bleed. *Pressure points -Apply direct pressure to anearbypressurepointifthewoundcontinuestobleed.For example,if the lower arm Is cut,apply pressure with the fingers on the middleinsideoftheupperarmwherethepulsecan be felt. ©Pressure bandage -Wrap the wound with arollerbandageusingoverlappingturnstocompletelycoverthewound.Applyadditionalsteriledressingbeforewrapping 1 necessary. , Sprains,Strains,Dislocations,and Fractures These injuries are sometimes hard to differentiate,sotreatthemallasyouwouldafracture.Help thevictimmoveintotheshadeandtoacomfortablepositionwithaslittlemovementtotheinjuredareaaspossible.The injury,usually to an arm of leg,willneedtobesplintedtolessenthepainandpreventfurtherinjury.Splints can be made from rolled-upnewspaper,magazines,pieces of wood,blankets,orpillows.The splint can be tied up with bandages orcloth,such as a shirt torn into strips.The following ion 18.8 188 TaererPHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL principles should be followed when splinting: *Splint only if you can do it without causing more pain. *Splint an injury in the position you find it. *Immobilize the limb and joints above and below the injury. Check the blood circulation by pinching nail beds of the fingers or toes.Red color should return within two seconds,if not,loosen the splint. *If the injury is a closed fracture,no bone extruding,apply a cold pack to it. Note:Do not apply a cold pack to an open or compound fracture. Heat Exposure Heat exposure is a common hazard to system installation and maintenance personnel because of the location of the systems.If you or your partner has cramps,heavy sweating,cool and pale skin,dilated pupils,headaches,nausea,or dizziness,you may be nearing heat exhaustion.You should perform the following first-aid: *Get the victim to the shade. *Give them one half of a glass of water every 15 minutes (if they can tolerate it). *If heavy sweating occurs,have the victim lie down and raise their feet,loosen clothing, and put wet towels or sheets over them. *If the victim has red,dry skin,they may have. heat stroke,which is life-threatening. Immerse them in cool water,if possible,or wrap their body with wet sheets,and fanthem.Do not give them anythingto drink. Call an ambulance. Cold Exposure Persons exposed to extended periods of cold may . 'suffer from hypothermia.Possible symptoms are shivering,feeling dizzy,confusion,or numbness.You should perform the following first-aid: *Take the victim to a warm place. °Remove wet clothing. ¢Warm the body slowly. *Call an ambulance. *If fully conscious,give them a warm drink a little at a time.Check the temperature of the liquid.(Don't add a scalded tongue to their injuries.) -Insect and Snake Bites A small number of people may have an allergic reaction to an insect bite or sting.If so,this situation could be life threatening,Signs of an allergic reaction include pain,swelling of the throat,redness or discoloration, itching,hives,decreased consciousness,and difficulty in breathing.If these symptoms occur,perform the following first-aid: *Call an ambulance immediately. ¢If a stinger from an insect is embedded into the flesh,remove it (do not squeeze it)with tweezers or scrape it away with a credit card, rigid strip of plastic,or a playing card. ¢Wash the area. *Put on a cold pack with a cloth between the skin and the ice. *Arrange the victim so the affected area is below the heart. *If it is a snake bite,immediately call for medical help.Keep the victim still and the affected area below the heart-to slow absorption of the snake venom.A splint can be used if the bite is on an arm or leg.Try to remember what the snake looked like.Do not cut a snake bite and try to suck the venom out.This only increases the chances of infection.Few people die from snake bites. Electrical,Chemical,and Thermal Injuries The number one priority in assisting injured people should always be your (the rescuer's)safety.This is especially important in situations involving electrical hazards.Avoid becoming a second victim.Electrical injuries consist mainly of shocks,burns,muscle contractions,and traumatic injuries associated with falls after electrical shocks.Burns can result from electrical,chemical,and thermal exposure. 186 Section waeohelanagehanett,saaneetelemenntDienSnapeanSoeeT0mElectrical InjuriesElectricshock is a general term indicating anysituationwhereelectriccurrentflowsthroughthebody.The intensity of a shock can vary from a barelyperceptibletingletoastrongshocktonear-instantdeath.A stabbing pain or intense tingling andburningisusuallyassociatedwithelectricshock.Thepointsofentryandexitareoftenbadlyburned.Frequently,a shock involves involuntary musclecontraction.If the strong muscles of the back andlegscontract,this can lead to falls,broken bones,orworse.The large muscles of the chest,throat,anddiaphragmcancontract,causing respiratory arrest.When electric current passes through the heart,it can cause a spasmodic contraction and relaxationoftheventricles,called ventricular fibrillation.This isoneofthemajorcausesofdeathassociatedwithshocks.Once a person's heart has begun fibrillating,'¢is difficult to stop.Sometimes,another electricshock,administered by a trained technician using adefibrillacorcanrestorethehearttoitsnormalbeatingcycle.Victims of fibrillation need qualifiedparamedichelpwithinminutestosurvive.If you are at the scene of a suspected electricalaccident,you must survey the scene for hazards beforeyourushintohelpthevictim.If che victim is holding ©a live conductor,chances are that they may be.physically unable to let go.You must find some waytodisconnectthepowersothatyoucanhelpthem.This is one more reason that familiarity with thesystemisveryimportant.If there is no way to switchoffthepower,you have to find a way to remove theconductorfromthevictim's body or vice versa.AproperlyequippedPVsiteshouldhaveagroundingstickornon-conducting wooden cane near possibleelectricalhazards.Use one of these to move theconductorfromthevictim.You can use a rope or belt to drag the victim away from the live wire or even cutthelivewirewithawoodenhandledax.Be creativewithwhatyouhaveavailable.Remember that thevictim's life is in danger and time is of the essence.In the case of spinal injuries,possibly resultingfromafallafterbeingshocked,you may possibly SAFETY AND PV INSTALLATION cause more injury to the victim by moving them.Donotmoveavictimunlessitisabsolutelynecessary.However,if the person is likely to die unless you domovethem,possible spinal injury may be a smallpricetopayforalife.You have to decide.Once you and the victim are free from the shockhazard,you can begin assessing injuries and treatingthevictim.Remember the ABCs of CPR:Airway,Breathing,and Circulation.Determine if the victimisconsciousorunconscious.If they are unconscious,open the airway and check for breathing.Put yourcheekclosetotheirmouthandfeelforbreathasyouwatchforthechesttoriseandfall.You should take5-10 seconds to check for a neck pulse at this time aswell,Check closely,it may be faint.If they are notbreathing,using mouth-to-mouth,with a cleansterilemouthshieldifavailable,give two breaths.Iftheairdoesn't go in,check to be sure the victim'sairwayisclear.It could be blocked by their tongue.Once you've cleared the airway,if they are stillnotbreathing,begin artificial respiration.Inaddition,if there is no pulse,begin CPR.Artificial respiration and CPR should beperformedinaccordancewithcurrentfirst-aid standards.Hopefully,the victim will begin to breathe andtheirheartwillbeat.Only when this happenedshouldyoustopCPR.If you stop sooner,they maydie.If they do breathe and their heart beats,watchthemcloselyuntilcheambulancearrives,as they may need your help again.If the victim is breathing,has a pulse,and isconscious,the victim should be treated for ordinaryshock,which is the body's attempt to correct a failingcirculatorysystem.To treat for shock perform the following first-aid: ©Have the victim lie down. *Raise the feet to help keep the blood flowing to the vital organs. *If they are cool,cover the victim to keep them warm. 16.4 187 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Chemical,Electrical,and Thermal Burns Minor burns or red skin with no blistering should be flushed with cool water and a loose dressing and bandage should be applied.This will protect the burn from possible infection.Deep burns with blistering and charred skin are life threatening and an ambulance must be called immediately.The biggest problem is contamination,which causes infection.Do not put water on a deep burn,unless it is a chemical burn,such as from battery electrolyte, which should be flushed with clean water.Use the following first-aid for deep burns: ©Carefully remove any large pieces of debris. ¢Prevent further contamination,if possible,by covering with a dry,loose dressing (gauze -pad)and then bandage.Apply as little pressure as possible.If possible,use sterile dressings. ¢Treat for shock. *Call for help and stay with the victim until medical professionals arrive to take charge. The batteries typically used in PV systems are some variant of a lead-acid design.These batteries are filled with highly concentrated sulfuric acid and give off hydrogen gas,which could explode if concentrated and exposed to a spark or flame.In addition to the potential for explosion,the acid could splash on your skin,clothing,in your eyes,or in your mouth. Consequently,always wear proper clothing and protective gear,and be prepared with the proper first aid materials to treat victims involved in accidents with acids. For chemical burns,including in the eyes,you should perform the following first-aid actions: ¢Flush immediately with large amounts of water for fifteen to thirty minutes. *Remove any affected clothing or jewelry. *Call an ambulance. *If the chemical burn is from acid,such as battery acid,flush with water and apply baking soda to neutralize the acid.Cover with a loose,dry,sterile dressing and bandage as loosely as possible. *If the burn is in an eye,cover both eyes. Then,creat for shock. *If acid is somehow taken internally,drink large quantities of water or milk,followed with milk of magnesia,beaten egg,or vegetable oil,and seek immediate medica]attention. 188 fa] chemerennyh,<premraredniceAReemsbtenoniat2aeAppendix A:Glossary -A- absorbed glass mat (AGM):A fibrous silica glassmattosuspendtheelectrolyteinbatteries.This matprovidespocketsthatassistintherecombinationgassesgeneratedduringchargingbackintowater. alternating current (AC):Electric current in whichthedirectionofflowisreversedatfrequentintervals, usually 100 or 120 times per second (50 or 60 cycles per second or 50//60 Hz). altitude:The angle between the horizon (a horizontal plane)and the sun's position in the sky, 'measured in degrees. amorphous silicon:A non-crystalline semiconductormaterialthathasnolong-range order,often used in thin film photovoltaic modules. ampere (A)or amp:The unit for the electric current;the flow of electrons.One amp is 1 coulomb passing in one second.One amp is produced by an electric force of 1 volt acting acrossaresistanceof1ohm.Sometimes this is abbreviated as I for intensity. ampere-hour (Ah):Quantity of electrical energyequaltotheflowofoneampereofcurrentforonehour.Typically used to quantify battery bank capacity. angle of incidence:Angle which references the sun'sradiationstrikingasurface.A "normal”angle of incidence refers to the sun striking a surface at a 90- degree angle. array:Any number of photovoltaic modules connected together to provide a single electrical output at a specified voltage.Arrays are oftendesignedtoproducesignificantamountsof electricity. autonomous system:A stand-alone PV system that has no back-up generating source.May or may not include storage batteries. avoided cost:The minimum amount an electric utility is required to pay an independent powerproducer,under the PURPA regulations of 1978,equal to the costs the utility calculates it avoids innothavingtoproducethatpower(usuallysubstantiallylessthantheretailpricecharged by the utility for power it sells to customers). azimuth:Angle between true south and the point directly below the location of the sun.Measured in degrees east or west of true south in northern latitudes. -B- balance of system (BOS):All system components and costs other than the PV modules.It includes design costs,land,site preparation,systeminstallation,support structures,power conditioning, operation and maintenance costs,indirect storage, and related costs. barrier energy:The energy given up by an electroninpenetratingthecellbarrier,a measure of the electrostatic potential of the barrier. base power:Power generated by a utility unit that operates at a very high capacity factor. baseline performance value:Initial values of Isc, Voc,Pmp,Imp measured by the accredited laboratory and corrected to Standard Test Conditions,used to validate the manufacturer's performance measurements provided with thequalificationmodulesperIEEE1262. battery:Two or more "cells”electrically connected for storing electrical energy.Common usage permitsthisdesignationtobeappliedalsotoasinglecellusedindependently,as in a flashlight battery. battery capacity:The total number of ampere-hoursthatcanbewithdrawnfromafullychargedcellor battery. battery cell:A galvanic cell for storage of electrical energy.This cell,after being discharged,may berestoredtoafullychargedconditionbyanelectric current. 189 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL battery cycle life:The number of cycles,to a specified depth of discharge,that a cell or battery can undergo before failing to meet its specified capacity or efficiency performance criteria. battery self-discharge:The rate at which a battery,without a load,will lose its charge. battery state of charge:Percentage of full charge or 100 percent minus the depth of discharge. building-integrated photovoltaics (BIPV):A term for the design and integration of PV into the building envelope,typically replacing conventional building materials.This integration may be in vertical facades,replacing view glass,spandrel glass, or other facade material;into semitransparent skylight systems;into roofing systems,replacing traditional roofing materials;into shading "eyebrows”over windows;or other building envelope systems. blocking diode:A semi-conductor device connectedinserieswithaPVmoduleandastoragebatteryto prevent a reverse current discharge of the batterythroughthemodulewhenthereisnooutput,or low output from the cells.When connected in series to a PV string;it protects its modules from a reversepowerflowpreventingagainstthetiskofthermal destruction of solar cells. boron (B):A chemical element,atomic number 5, semi-metallic in nature,used as a dopant to make p- semiconductor layers. British thermal unit (Btu):The amount of heat energy required to raise the temperature of onepoundofwaterfrom60degreesFto61degrees F atoneatmospherepressure.Roughly equivalent to the amount of energy released by burning one stick match. bypass diode:A diode connected across one or moresolarcellsinaphotovoltaicmodulesuchthatthe diode will conduct if the cell(s)become reverse biased.Alternatively,a diode connected anti-parallel across a part of the solar cells of a PV module.Itprotectsthesesolarcellsfromthermaldestruction incaseoftotalorpartialshadingofindividualsolar cells while other cells are exposed to full light. 190 -C- cadmium (Cd):A chemical element,atomic number 48,used in making certain types of solar cells and batteries. cadmium telluride (CdTe):A polycrystalline,thin- film photovoltaic material. capacity factor:The amount of energy that the system produces at a particular site as a percentage of the total amount that it would produce if it operated.at rated capacity during the entire year.For example,the capacity factor for a wind farm ranges from 20%to 35%. cathodic protection:A method of preventing oxidation (rusting)of exposed metal structures,such as bridges and pipelines,by imposing between the structure and the ground a small electrical voltage that opposes the flow of electrons and that is greater than the voltage present during oxidation. cell:The basic unit of a photovoltaic module.This word is also commonly used to describe the basic unit of batteries (ie.a 6-volt battery has 3 2-volr cells). cell barrier:A very thin region of static electric charge along the interface of the positive and negative layers in a photovoltaic cell.The barrier inhibits the movement of electrons from one layer to the other,so that higher-energysidediffusepreferentiallythrough iit in onedirection,creating a current and thus a voltage across the cell.Also called depletion zone,cell junction,or space charge. »electrons from one cell junction:The area of immediate contact between two layers (positive and negative)of a photovoltaic cell.The junction lies at the center of the cell barrier or depletion zone. _central power:The generation of electricity in largepowerplantswithdistributionthroughanetworkoftransmissionlines(grid)for sale to a number of users.Opposite of distributed power. charge controller:A device that controls the charging rate and/or state of charge for batteries. charge rate:The current applied to a cell or battery to restore its available capacity. chemical vapor deposition (CVD):A method of depositing thin semiconductor films.With thismethod,a substrate is exposed to one or more vaporized compounds,one or more of whichcontaindesirableconstituents.A chemical reaction is initiated,at or near the substrate surface,to produce the desired material chat will condense on the substrate. cleavage of lateral epitaxial films for transfer (CLEFT):A process for making inexpensive GaAs photovoltaic cells in which a thin film of GaAs is grown atop a thick,single-crystal GaAs (or other suitable material)substrate and then is cleaved from the substrate and incorporated into a cell,allowing the substrate to be reused to grow more thin-film GaAs. coal:A black,solid fossil fuel,usually found underground.Coal is often burned to make electricity in utility scale production. combined collector:A photovoltaic device or module that provides useful heat energy in addition to electricity. compact fluorescent lights:Lights that use a lot less energy than regular light bulbs.We can use compact fluorescent lights for reading lights and ceiling lights. concentrator:A PV module that uses optical elements to increase the amount of sunlight incident ona PV cell.Concentrating arrays must track the sun and use only the direct sunlight because the diffuse portion cannot be focused onto the PV cells. conversion efficiency:The ratio of the electric energy produced by a photovoltaic device (under full sun conditions)to the energy from sunlight incident upon the cell. copper indium diselenide (CuInSe2,or CIS):A polycrystalline thin-film photovoltaic material (sometimes incorporating gallium (CIGS)and/or sulfur). crystalline silicon:A type of PV cell made from a single crystal or polycrystalline slice of silicon. current:The flow of electric charge in a conductor between two points having a difference in potential (voltage). current at maximum power (Imp):The current at which maximum power is available from a module. (UL 1703] APPENDIX A -GLOSSARY cycle life:Number of discharge-charge cycles that a battery can tolerate under specified conditions before it fails to meet specified criteria as to performance (e.g.,capacity decreases to 80-percent of the nominal capacity). Czochralski process:A method of growing large size, high quality semiconductor crystal by slowly lifting a seed crystal from a molten bath of the material under careful cooling conditions. -D- days of autonomy:The number of consecutive days a stand-alone system battery bank will meet a defined load without solar energy input. DC to DC converter:Electronic circuit to convert DC voltages (e.g.,PV module voltage)into other levels (e.g.,load voltage):Can be part ofamaximum power point tracker (MPPT). deep cycle battery:Type of battery that can be discharged to a large fraction of capacity many times without damaging the battery. deep discharge:Discharging a battery to 50 percent or less ofits full charge. depth of discharge (DOD):The amount of ampere- 'hours removed from a fully charged cell or battery, expressed as a percentage of rated capacity. design month:The month having the combination of insolation and load that requires the maximum energy from the array. diffuse insolation:Sunlight received indirectly as a result of scattering due to clouds,fog,haze,dust,or other obstructions in the atmosphere.Opposite of direct insolation. diode:Electronic component that allows current flow in one direction only. direct current (DC):Electric current in which electrons flow in one direction only.Opposite of alternating current. direct insolation:Full sunlight falling directly upon a collector.Opposite of diffuse insolation. discharge rate:The rate,usually expressed in amperes over time,at which electrical current is taken from the battery. 191 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL disconnect:Switch gear used to connect or disconnect components of a PV system for safety or service. distributed power:Generic term for any power supply located near the point where the power is used.Opposite of central power.See 'stand-alone'; 'remote site.” dopant:A chemical element (impurity)added in small amounts to an otherwise pure semiconductor material to modify the electrical properties of the material,An n-dopant introduces more electrons.A p-dopant creates electron vacancies (holes). doping:The addition of dopants to a semi- conductor. duty cycle:The ratio of active time to total time. Used to describe the operating regime of appliances or loads. -E- edge-defined film-fed growth (EFG):A method formakingsheetsofpolycrystallinesiliconinwhich molten silicon is drawn upward by capillary action through a mold. efficiency:The ratio of output power to input power.Expressed as a percent, electric circuit:Path followed by electrons from a "power source (generator or battery)through an external line (including devices that use the electricity)and returning through another line to the source. electric current:A flow of electrons;electricity. electrical grid:An integrated system of electricity distribution,usually covering a large area. electrodeposition:Electrolytic process in which ametalisdepositedatthecathodefromasolution of its 1ons. electrolyte:A liquid conductor of electricity in which flow of current takes place by migration of ions.The electrolyte for a lead-acid storage cell is an aqueous solution of sulfuric acid. electron volt:An energy unit equal to the energy an electron acquires when it passes through a potential difference of one volt;it is equal to 1.602 x 10” volt. 192 energy:The ability to do work.Stored energy becomes working energy when we use it. energy audit:A survey that shows how much energy you use in your house,apartment,or business.It can indicate your most intensive energy consuming appliances and even identify heating and cooling leaks that will help you find ways to use less energy. energy density:The ratio of energy available from a battery to its volume (Wh/1)or mass (Wh/kg). energy pay back time:The time required for any energy producing system or device to produce as much energy as was required in its manufacture. equalization:The process of mixing the electrolyteinbatteriesbyperiodicallyoverchargingthebatteries for a short period to "refresh”cell capacity. -F- fill factor:The ratio of a photovoltaic cell's actual power to its power if both current and voltage wereattheirmaxima.A key characteristic in evaluating cell performance. flat-plate PV:Refers to a PV array or module that consists of nonconcentrating elements.Flat-plate arrays and modules use direct and diffuse sunlight,but if the array is fixed in position,some portion of the direct sunlight is lost because of oblique sun- angles in relation to the array. float charge:Float charge is the voltage required to counteract the self-discharge of the battery at a certain temperature. float life:Number of years that a battery can keep its stated capacity when it is kept at float charge (see float charge). fossil fuels:Fuels formed in the ground from the remains of dead plants and animals.It takes millions of years to form fossil fuels.Oil,natural gas,and coal are fossil fuels. fuel:Any material that can be burned to make energy. iiadelreeeaeBam-G- gassing current:Portion of charge current that goesintoelectrolyticalproductionofhydrogenandoxygenfromtheelectrolyticliquidinthebattery.This current increases with increasing voltage and temperature. gel-type battery:Lead-acid battery in which theelectrolyteiscomposedofasilicagelmatrix. gigawatt (GW):One billion watts.One millionkilowatts.One thousand megawatts. glazings:Clear materials (such as glass or plastic)that allow sunlight to pass into solar collectors and solar buildings,trapping heat inside. grain boundaries:The boundaries where crystallitesinamulticrystallinematerialmeet. grid:See 'Electrical grid.' grid-connected:A PV system in which the PV arrayactslikeacentralgeneratingplant,supplying power to the grid.” grid-interactive:See 'Grid-connected (PV system). -H- hybrid system:A PV system that includes othersourcesofelectricitygeneration,such as wind or fossil fuel generators. incident light:Light chat shines onto the surface of a solar cell or module. infrared radiation:Electromagnetic radiation whose wavelengths lie in the range from 0.75 micrometer to 1000 micrometers. insolation:Sunlight,direct or diffuse;from 'incident solar radiation.'Usually expressed in watts per .square meter.Not to be confused with 'insulation.' insulation:Materials that reduce the rate or slow down the movement of heat. interconnect:A conductor within a module or other means of connection which provides an electrical interconnection between the solar cells. inverters:Devices that convert DC electricity into AC electricity (single or multiphase),either forstand-alone systems (not connected to the grid)or for utility-interactive systems. APPENDIX A -GLOSSARY 1-V curve:A graphical presentation of the currentversusthevoltagefromaphotovoltaicdeviceastheloadisincreasedfromtheshortcircuit(no load) condition to the open circuit (maximum voltage) condition.Typically measured at 1000 watts persquaremeterofsolarinsolationataspecificcelltemperature.The shape of the curve characterizes cell performance. -J- junction box:An electrical box designed to be a safeenclosureinwhichtomakeproperelectrical connections.On PV modules this is where PV strings are electrically connected, -K- kilowatt (KW):1000 watts. kilowatt-hour (kWh):One thousand watt hours. The kWh is a unit of energy.1 kWh=3600 kJ. -L- life cycle cost:An estimate of the cost of owningandoperatingasystemfortheperiodofitsusefullife;usually expressed in terms of the present value of all lifetime costs. line-commutated inverter:An inverter that is tied to a power grid or line.The commutation of power(conversion from DC to AC)is controlled by the power line,so that,if there is a failure in the powergrid,the PV system cannot feed power into the line. load:Anything in an electrical circuit that,when thecircuitisturnedon,draws power from that circuit. -M- maximum power point (MPP):The point on thecurrent-voltage (I-V)curve of a module underillumination,where the product of current and voltage is maximum.For a typical silicon cell,this is at about 0.45 V. maximum power point tracker (MPPT):Means ofapowerconditioningunitthatautomaticallyoperatesthePVgeneratoratitsMPPunderall conditions. megawatt (MW):One million watts;1000 kilowatts. module:See 'Photovoltaic Module.' 193 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL multicrystalline:Material that is solidified at such as rate that many small crystals (crystallites)form.The atoms within a single crystallite are symmetrically arranged,whereas crystallites are jumbled together. These numerous grain boundaries reduce the device efficiency.A material composed of variously. oriented,small individual crystals.(Sometimes referred to as polycrystalline of semicrystalline). -N- NEC:An abbreviation for the National Electrical Code®which contains safety guidelines and required practices for all types of electrical installations. Article 690 pertains to solar photovoltaic systems. nominal operating cell temperature (NOCT):The reference cell (module)operating temperature presented on manufacturer's literature.Generally the NOCT is referenced at 25°C,77°F. nominal voltage:A reference voltage used to describe batteries,modules,or systems (ie.a 12-,24- ,or 48-volt battery,module or system). nonrenewable fuels:Fuels that cannot be easily made or "renewed.”We can use up nonrenewable fuels.Oil,natural gas,and coal are nonrenewable fuels. n-type semiconductor:A semiconductor producedbydopinganintrinsicsemiconductorwithan electron-donor impurity,for example phosphorous in silicon. -O- ohm:The unit of resistance to the flow of an electric current. one-axis tracking:A system capable of rotating about one axis,also referred to as single axis.These tracking systems usually follow the sun from east to west throughout the day. open-circuit voltage (Voc):The maximum possible voltage across a photovoltaic cell or module;the voltage across the cell in sunlight when no current is flowing. orientation:Placement according to the compass directions,north,south,east,west. -P- panel:See 'photovoltaic panel.' parallel connection:A way of joining two or more electricity-producing devices such as PV cells or modules,or batteries by connecting positive leads together and negative leads together;such a configuration increases the current but the voltage is constant. passive solar building:A building that utilizes non- mechanical,non-electrical methods for heating , cooling and/or lighting. peak load;peak demand:The maximum load,or usage,of electrical power occurring in a given period of time,typically a day. peak power:Power generated by a utility unit that operates at a very low capacity factor;generally used to meet short-lived and variable high demand periods. peak sun hours:The equivalent number of hours per day when solar irradiance averages 1000 w/m? (full sun). phosphorous (P):A chemical element,atomic number 15,used as a dopant in making n- semiconductor layers. photon:A particle of light that acts as an individual unit of energy. photovoltaic (PV):Pertaining to the direct conversion of photons of sunlight into electricity. photovoltaic array:An interconnected system of PV modules that function as a single electricity- producing unit.The modules are assembled as adiscretestructure,with common support or mounting.In smaller systems,an array can consist of a single module. photovoltaic cell:The smallest semiconductor element within a PV module to perform the immediate conversion of light into electrical energy (DC voltage and current). photovoltaic conversion efficiency:The ratio of the electric power produced by a photovoltaic device to the power of the sunlight incident on the device. criesponeitedyahweneeRacepemertneeteaeoehotovoltaic module:The smallest environmentallyrotected,essentially planar assembly of solar cellsandancillaryparts,such as interconnections,terminals,{and protective devices such as diodes]intended to generate DC power underunconcentratedsunlight.The structural (load Pp carrying)member of a module can either be the toplayer(superstrate)or the back layer (substrate).photovoltaic panel:Often used interchangeably withPVmodule(especially in one-module systems),butmoreaccuratelyusedtorefertoaphysicallyconnectedcollectionofmodules(i.e.,a laminatestringofmodulesusedtoachievearequiredvoltage and current). hotovoltaic peak watt:Maximum "rated”output ofa.cell,module,or system.Typical rating conditions are 0.645 watts per square inch (1000 watts persquaremeter)of sunlight,68 degrees F (20 degreesC)ambient air temperature and 6.2 x 10°mi/s (1 m/s)wind speed. photovoltaic system:A complete set of componentsforconvertingsunlightintoelectricitybythephotovoltaicprocess,including the array and balance of system components. physical vapor deposition:A method of depositingthinsemiconductorfilms.With this method, physical processes,such as thermal evaporation orbombardmentofions,are used to deposit elementalP semiconductor material on a substrate. p/n:A semiconductor device structure in which thejunctionisformedbetweenap-type layer and an n- type layer. polycrystalline:See 'Multicrystalline.' power conditioning equipment:Electricalequipment,or power electronics,used to convertpowerfromaphotovoltaicarrayintoaformsuitableforsubsequentuse.A collective term for inverter,converter,battery charge regulator,and blocking diode. power factor:The ratio of the average power and the apparent volt-amperes. pulse-width-modulated wave inverter (PWM):PWM inverters are the most expensive,but produce a high quality of output signal at minimum currentharmonics.The output voltage is very close to sinusoidal. APPENDIX A -GLOSSARY PV:Abbreviation for photovoltaic. P-Type silicon:Semi-conductor grade silicon dopedwiththeelementborongivingitapositivebias. -Q- quad:A measure of energy equal to one trillionBTUs;an energy equivalent to approximately 172 million barrels of oil. qualification test:A procedure applied to a selectedsetofPVmodulesinvolvingtheapplicationof| defined electrical,mechanical,or thermal stress in a prescribed manner and amount.Test results aresubjecttoalistofdefinedrequirements. -R- rectifier:A device that converts AC to DC.See "inverter.” remote site:Site which is not located near the utility grid. remote systems:Systems located away from the utility grid. resistance (R):The property of a conductor whichopposestheflowofanelectriccurrentresultinginthegenerationofheatintheconductingmaterial.The unit of resistance is ohms. -S- satellite power system (SPS):Concept for providinglargeamountsofelectricityforuseontheEarthfromoneormoresatellitesingeosynchronousEarth orbit,A very large array of solar cells on eachsatellitewouldprovideelectricity,which would beconvertedtomicrowaveenergyandbeamedtoareceivingantennaontheground.There,it would bereconvertedintoelectricityanddistributedthesameasanyothercentrallygeneratedpower,through a grid. semiconductor:Any material that has a limited.capacity for conducting an electric current.Certainsemiconductors,including silicon,gallium arsenide,copper indium dislenide,and cadmium telluride,areuniquelysuitedtothephotovoltaicconversion process. semicrystalline:See 'Multicrystalline.' 195 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL series connection:A way of joining electrical equipment by connecting positive leads to negative leads;such a configuration increases the voltage while current remains the same. series regulator:Type of battery charge regulator where the charging current is controlled by a switch connected in series with the PV module or array. shelf life of batteries:The length of time,under specified conditions,that a battery can be stored so that it keeps its guaranteed capacity. short-circuit current (Isc):The current flowing freely from a photovoltaic cell through an external circuit that has no load or resistance;the maximum current possible. shunt regulator:Type of a battery charge regulator where the charging current is controlled by a switch connected in parallel with the PV generator. Overcharging of the battery is prevented by shorting the PV generator. silicon (Si):A chemical element,atomic number 14, semimetallic in nature,dark gray,an excellent semiconductor material.A common constituent of © sand and quartz (as the oxide).Crystallizes in face- centered cubic latrice-like a diamond.The most common semiconductor material used in making photovoltaic devices. sine wave inverter:An inverter that produces utility- quality,sine wave power forms. single-crystal material:A material that is composed of a single crystal or a few large crystals. solar cell:See 'Photovoltaic cell.' solar constant:The strength of sunlight;1353 watts per square meter in space and about 1000 watts per square meter at sea level atthe equator at solar noon. solar energy:Energy from the sun.For example,the heat that builds up in your car when the windows are closed is solar energy. solar-grade silicon:Intermediate-grade silicon used in the manufacture of solar cells.Less expensive than electronic-grade silicon. 196 solar noon:That moment of the day that divides the daylight hours for that day exactly in half.To determine solar noon,calculate the length of the day from the time of sunset and sunrise and divide by two.The moment the sun is highest in the sky. solar spectrum:The total distribution of electromagnetic radiation emanating from the sun. solar thermal electric:Method of producing electricity from solar energy by using focused sunlight to heat a working fluid,which in turn drives a turbogenerator. _square wave inverter:The inverter consists of a DC source,four switches,and the load.The switches are power semiconductors that can carry a large current and withstand a high voltage rating.The switches are turned on and off at a correct sequence,at a certain frequency.The square wave inverter is the simplest and the least expensive to purchase,but it produces the lowest quality of power. Staebler-Wronski effect:The tendency of amorphous silicon photovoltaic devices to lose efficiency upon initial exposure to light;named for Dr.David Staebler and Dr.Christopher Wronski; work performed at RCA. stand-alone:An autonomous or hybrid photovoltaic system not connected to a grid.Some stand-alone systems require batteries or some other form of storage.Also,"stand-alone PV system.” stand-off mounting:Technique for mounting a PV array on a sloped roof,which involves mounting the modules a short distance above the pitched roof and tilting them to the optimum angle.This promotes air flow to cool the modules. standard reporting conditions (SRC):A fixed set of conditions (including meteorological)to which the electrical performance data of a photovoltaic module is translated from the set of actual test conditions [ASTM E 1036]. standard test conditions (STC):Conditions under which a module is typically tested in a laboratory:(1) Irradiance intensity of 1000 W/square meter (0.645 watts per square inch),AM1.5 solar reference spectrum,and (3)a cell (module)temperature of 25 °C,plus or minus 2 °C (77 °F,plus or minus 3.6 °F). state of charge (SOC):The available capacityremaininginacellorbattery,expressed as apercentageoftheratedcapacity.For example,if 25amp-hours have been removed from a fully charged100amp-hour cell,the state of charge ts 75 percent. substrate:The physical material upon which aphotovoltaiccellismade.sulfation:A condition that afflicts unused anddischargedbatteries;large crystals of lead sulfategrowontheplate,instead of the usual tiny crystals,making the battery extremely difficult to recharge. superconductivity:The pairing of electrons incertainmaterialsthat,when cooled below a criticaltemperature,cause the material to lose all resistancetoelectricityflow.Superconductors can carry electriccurrentwithoutanyenergylosses. superstrate:The covering on the sun side of a PVmodule,providing protection for the PV materialsfromimpactandenvironmentaldegradationwhileallowingmaximumtransmissionoftheappropriate wavelengths of the solar spectrum. surge:The momentary start-up condition of amotorrequiringalargeamountofelectricalcurrent. surge capacity:The ability of an inverter orgeneratortodeliverhighcurrentsmomentarily required when starting a motor. -T- temperature compensation:An allowance made inchargecontrollersetpointsforchangingbattery temperatures. thermal electric:Electric energy derived from heatenergy,usually by heating a working fluid,which_drives a turbogenerator See 'solar thermal electric.' thermal mass:Materials,typically masonry,that store heat in a passive solar home. thin film:A layer of semiconductor material,such ascopperindiumdiselenide,cadmium telluride,gallium arsenide,or amorphous silicon,a fewmicronsorlessinthickness,used to make photovoltaic cells. tilt angle:Angle of inclination of collector asmeasuredindegreesfromthehorizontal.Formaximumperformancesolarcollectors/modulesshouldbesetataperpendiculartothesun. APPENDIX A -GLOSSARY total harmonic distortion (thd):The measure ofclosenessinshapebetweenawaveformandits fundamental component. tracking PV array:PV array that follows the path ofthesuntomaximizethesolarradiationincidentonthePVsurface.The two most common orientationsare(1)one axis where the array tracks the sun east towestand(2)two-axis tracking where the arraypointsdirectlyatthesunatalltimes.Tracking arraysuseboththedirectanddiffusesunlight.Two-axistrackingarrayscapturethemaximumpossibledaily energy. transformer:An electromagnetic device used toconvertACelectricity,either to increase or decrease the voltage. transmission lines:Conductors used to transmithigh-voltage electricity from the transformer to the electric distribution system. trickle charge:A charge at a low rate,balancingthroughself-discharge losses,to maintain a cell orbatteryinafullychargedcondition. two-axis tracking:A system capable of rotatingindependentlyabouttwoaxesandfollowingthesun's orientation and height in the sky (e.g.,vertical and horizontal). -U- ultraviolet (UV):Electromagnetic radiation in the wavelength range of 4 to 400 nanometers. uninterruptible power supply (UPS):Thedesignationofapowersupplyprovidingcontinuousuninterruptibleservicewhenamainpowersourceis lost. _utility-interactive inverter:An inverter that canfunctiononlywhentiedtotheutilitygrid,and usestheprevailingline-voltage frequency on the utilitylineasacontrolparametertoensurethatthePVsystem's output is fully synchronized with the utility power. -V- Vac:Volts AC. Vde:Volts DC. Voc:Open-circuit voltage. 197 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL vacuum deposition:Method of depositing thin coatings of a substance by heating it in a vacuum system. _vacuum evaporation:The deposition of thin films of semiconductor material by the evaporation of elemental sources in a vacuum. volt (V):A unit of measure of the force,or 'push,' given the electrons in an electric circuit.One volt produces one ampere of current when acting against a resistance of one ohm. voltage at maximum power (Vmp):The voltage at which maximum power is available from a module. 198 -W- wafer:A thin sheet of semiconductor material made by mechanically sawing it from a single-crystal or multicrystal ingot or casting. watt (W):The unit of electric power,or amount of work.One ampere of current flowing at a potential of one volt produces one watt of power. watt-hour (Wh):A quantity of electrical energy when one watt is used for one hour. waveform:The shape of the curve graphically representing the change in the AC signal voltage and current amplitude,with respect to time. |Appendix B:Solar Data The U.S.solar data contained in this appendix is from the Solar RadiationDataManualforFlat-Plate and Concentrating Collectors and was provided bytheNationalRenewableEnergyLaboratory(NREL).The data was compiledfromtheNationalSolarRadiationDatabase,a database of hourly solarradiationdatacollectedbytheNationalWeatherServicefrom1961to1990. There are 239 sites recorded.The international solar data was provided by Vern Risser of Daystar,Inc.and was compiled for Sandia National Laboratories.There are 46 sites.The solar radiation data is displayed as monthly and yearly averages,expressed as kWh/m"/day.Each site has data for seven configurations:*Modules facing south with a tilt equal to latitude *Modules facing south with a tilt equal to latitude +15° *Modules facing south with a tilt equal to latitude -15° °Single axis tracker with a tilt equal to latitude *Single axis tracker with a tilt equal to latitude +15° *Single axis tracker with a tilt equal to latitude -15° ¢Dual axis tracker _Single axis trackers pivot on one axis to track the sun,facing east in themorningandwestintheafternoon.The data presented assumes continuoustrackingofthesunthroughouttheday.Data for dual axis trackers represents the maximum solar radiation at a siteavailabletoaPVmodule.Tracking the sun in both azimuth and elevation;thetrackerskeepthesun's rays normal to the module surface.The website portal to NREUs Solar Resource information is: http://rredc.nrel.gov/solar 199 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL United States Daily Insolation Data (KWh/m') ANCHORAGE AK Latitude:61.17 degrees Elevation:35 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 0.9 2.1 3.8 4.7 4.9 5.0 4.8 4.1 3.1 2.0 1.1 0.5 3.1 Latitude 1.0 2.2 3.9 4.6 4.6 45 44 3.8 3.1 2.1 1.2 0.6 3.0 Lat+15 1.0 2.3 3.9 4.3 4.0 3.9 3.8 3.4 2.9 2.0 1.3 0.6 2.8 Single axis trackerLatr-15 0.9 2.4 4.6 6.1 6.6 6.6 ,6.3 5.2 3.8 2.2 1.2 0.5 3.9 Latitude 1.0 2.5 4.8 6.1 6.4 6.3 6.1 5.1 3.8 2.3 13 0.6 3.9 Lat+15 1.1 2.6 4.7 5.8 6 5.9 3.7 4.8 3.6 2.3 1.4 0.6 3.7 Dual axis tracker 1.1 16 48)COGLCTti'(KSC BOK TO ANNETTE ©AK Latitude:55.03 degrees Elevation:34 meters jan Feb «=Mar=Apr-«=s May =sJun Ss Jul,«=Aug,«Sep «=Oct,«Nov Dec Aug Fixed array Lat-15°1.2 2.1 3.1 4 Latitude 1.4 2.2 3.1 4 Lat+15 14 2.2 3.0 3 Single axis tracker Lat-15 14 2.4 3.7 5.3 6.4 6.5 6.4 5.7 4.3 2.3 1.5 1.0 3.9 Latitude 1.5 2.5 .3.7 5.2 6.2 6.2 6.2 5.6 4.3 2.4 1.6 1d 3.9 Lat+15 1.6 2.5 3.6 4.9 5.9 5.8 5.8 5.3 4.2 2.4 1.6 1.2 3.7 _Dual axis tracker . 16 (25 «(38 53)6G GSB KA 2A TD 40 ASX 4.9 4.9 4.4 3.5 2.1 1.3 0.3.1 4.5 4.5 4.5 4.2 3.5 2.1 1,5 1.1 3.0 1.54.0 3.9 3.9 3.7 3.2 2.1 2.8 Single axis tracker . Lat-15 0.0 1.2 Latitude 0.0 1.2 5.0 Lar+15 0 1.3 5 Dual axis tracker 0.0 1.3 5.0 8.3 7A 7.3 6.9 3.6 1.9 1.1 0.1 0.0 3.6 BARROW AK Latitude:71.30 degrees.Elevation:4 meters an:Feb Mar Apr May Jun Jul'Aug Sep Oct Nov Dec Avg Fixed array Lat-15 0.0 1.1 3.8 5.2 4.8 4.6 2.8 7 0.9 0.1 0.0 2.6 Latitude 0.0 1.1 4.0 4.9 44 42 2.6 1.6 1.0 0.1 0.0 2.5 Lat+15 0.0 1.2 4.0.1.5 1.0 01°0.0 2.3 49 7.0 6.9 6.6 3.5 1.9 1.0 0.1 0.0 3.5 6.9 6.7 6.4 3.4 1.9 11 0.1 0.0 3.4 1.1 Apr 5.8 8 5.6 4.6 3.8 3.6 2.3 8.2 8.2 8 6.7 6.4 6.1 3.2 1.8 0.1 0 3.3 BETHEL AK.Latitude:60.78 degrees Elevation:46 meters Jan Feb Mar May Jun .Jul Aug Sep Oct Nov Dec Avg 0.8aFixedarray pe.lat-15 12 27 43 Ps Latitude 1.4 3.0 4.5 Lat+15 1.5 3.1 -44 Single axis tracker Lar-15 1.3 3.3 5.5 Latitude 1.5 3.5 5.6 Lat+15 1.6 3.6 5.6 Dual axis-tracker 1.6 3.6 5.6 6.9 6.7 6.5 5.7 4.3 3.7 2.5 1.6 Ld 4.2 Apr 51 48 47 #42 34 30 21 13 3.1 50 45 42 38 32 29 22 14 10 3.1 47.460 36 33 29 28 2 15 10 29 6.9 6.9 6.7 66 63 «55 43 37 24 14 09 40 6.4 6.0 5.3 4.]3.7 2.5 1.6 1.0 4.0 6 56 49 1.63.9 3.5 2.5 1.1 3. 200° APPENDIX B -SOLAR DATA BETTLES )AK Latitude:66.92 degrees Elevation:205 meters Jan eb Mar Apr May Jun jul Aug Sep Occ Nov Dec Avg 5.8ixedarrayes15 6.2 5.2 4.2 3.3 1.9 0.7 0.1 3.3 . 2.0 . 5.8 [otinde 050«=«O22 4 re ee ee ©ee0 08 Ol 32 Lat +15 73 44585 SS 35 30 20 08 O01 38 Single axis trackerlat-15 0.5 2.3 5.4 8.1 9.4 9.0 77 5.8 4.2 2.1 0.8 0.1 4.6 Latitude 0.5 2.5 5.5 8.1 9.2 8.8 7.5 5.6 4.2 2.2 0.8 0.1 4.6 Lat +15 0.6 2.6 5.5 7.9 8.8 8.3 7A 5.3 4 2.2 0.9 0.1 4.5 Dual axis tracker 2.6 5.5 8.1 9.5 9.4 8.0 5.8 4.2 2.3 0.9 0.1 4.8 BIG DELTA AK Latitude:64.00 degrees Elevation:388 meters Jan Feb Mar Ape May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 1.0 2.4 44 5.5 5.7 5.6 5.4 47 3.6 2.1 1.2 0.5 3.5 Latitude 1.1 2.6 4.6 5.4 5.3 5.1 5.0 4.4 3.6 2.2 1.3 0.6 3.4 Larc+15 1.2 2.7 4.6 5.1 47 44 43 4.0 3.4 2.2 1.4 0.6 3.2 Single axis trackerLat-15 1.1 2.8 5.7 7.6 8.3 8.1 7.8 6.4 4.6 2.4 13 . Latitude 1.2 3.0 5.9 7.6 8.1 7.8 7.5 6.3 4.6 2.5 1.5 0.6 47 Lar+15 1.3 3.9 5.9 7.3 77 7.4 7.1 5.9 4.5 2.5 1.5 Dual axis cracker 1.3 3.1 5.9 7.6 8.5 8.4 8.0 6.5 47 2.5 1.5 0.6 4.9 COLD BAY AK Latitude:55.20 degrees.Elevation:29 meters Fixed array Lat-15 1.2 2.0 3.0 3.3 3.6 3.7.3.5 3.0 2.5 1.9 1.2 0.9 2.5 Latitude 1.4 2.1 3.0 3.2 3.3 3.4 3.2 2.8 2.4 2.0 1.3 1.0 2.4 Lat+15 14 2.1 2.9 2.9 2.9 2.9 2.8 2.5 2.2 1.9 1.4 Ll 2.3 Single axis trackerLat-15 1.4 2.2 3.5 3.9 4.2 4.3 4.0 3.4 2.8 2.1 13 1.0 2.9 Latitude 1.5 2.3 3.6 3.8 4.1 4.1 3.8 3.2 2.8 2.2 1.4 1.1 2.8 Lat+15 1.6 2.4 3.5 3.7 3.8 3.8 3.5 3 2.7 2.2 1.5 1.1 2.7 Dual axis tracker 1.6 2.4 3.6 4.0 4.4 45 42 3.4 2.9 2.2 1.5 1.1 3.0 FAIRBANKS AK Latitude:64.82 degrees Elevation:138 meters Fixed array Lat-15 0.7 2.2 4.5 5.6 5.7 5.7 5.4 4.5 3.4 1.9 1.0 0.2 3.4 Latitude 0.7 2.4 47 5.6 5.3 5.2 49 4.2 3.4 2.0 1.1 0.3 3.3 Lac+15 0.8 2.5 47 5.3 4.6 4.5 4.3 3.8 3.2 2.0 1.1 0.3 3.1 Single axis tracker Lat-15 0.7 2.6 5.7 77 8.2 8.3 7.6 6.0 4.4 2.2 1.1 0.2 4.6 Latitude 0.8 2.7 5.9 77 8.0 8.0 7.4 5.8 4.4 2.3 1.2 0.3.45 Latc+15 0.8 2.8 5.8 7A 7.6 7.6 6.9 5.5 4.2 2.3 1.2 0.3 4.4 Dual axis tracker 0.8 2.8 5.8 77 8.4 8.7 7.9 6.0 4.4 2.3 1.2 0.3.47 201 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL GULKANA Jan Fixed array Lat-15 1.1 Latitude 1.2 Lat+15 1.3 Single axis tracker Lat-15 1.2 Latitude 1.3 Lar+15 1.4 Dual axis tracker 1.4 KING SALMON Jan Fixed array Lat-15 1.4 Latitude 1.5 Lat+15 1.6 Single axis tracker Lar-15 1.5 Latitude 1.7 Lat+15 1.8 Dual axis tracker 1.8 KODIAK Jan Fixed array Lat-15 1.2 Latitude 1.4 Lat+15 1.5 Single axis tracker Lat-15 14 Latitude 1.5 Lat+15 1.6 *Dual axis tracker 1.6 KOTZEBUE Jan Fixed array Lat-15 0.4 Latitude 0.5 Lat+15 0.5 Single axis trackerLat-15 .04 Latitude 0.5 Lat+15 0.5 Dual axis tracker 0.5 202 Feb AK Mar 4.5 4,7 4.7 Apr 6.0 6.0 5.7. 8.4 8.4 8.2 8.4 Latitude:62.15 degrees May Jun 5.6 5.5 5.2 5.0 4.6 43 8.1 8.1 7.9 7.8 7.5 7.4 8.3 8.4 lul 8.1 Aug 6.9 Latitude:58.68 degrees May Jun 45 45 42.4) 37 3.6 6.0 5.8 58 5.6 54 5.2 61 6.0 Latitude:57.75 degrees 44.45 41 41 36 3.5 59 «5.9 5.7.57 53 5.3 6.0 6.2 Jul 4.3 3.9 5.6 lul 4.5 4.1 3.6 6.1 Aug 3.6 3.4 3.0 4.5 Aug 4.2 4.0 3.6 5.6 Latitude:66.87 degrees May Jun 64 +57 6.1 5.2 5.6 4.4 9.5 8.7 9.4 8.4 9 8 9.6 9.0 jul Aug Elevation:481 meters Oct Nov Dec Avg 2.4 1.3 0.6 3.6 2.5 1.4 0.7 3.6 2.5 1.5 0.8 3.3 28 14 O07 49 29 15 O08 49 29 16 O08 47 29 16 O08 51 Elevation:15 meters Oct Nov Dec Avg 24 15 10 31 25 16 12 3.0 25°17 13 28 28 17 11 38 29 19 13 37 2.9 1.9 1.3 4.0 Elevation:34 meters Oct Nov Dec AvgIm 2.6 1.6 1.0 3.1 2.8 1.8 1.2 3.1 2.8 1.8 1.2 2.9 3.2 1.8 1 4.0 33 40 12 40 3.3 2 1.3 3.8 3.3 2.0 1.3 4.1 Elevation:5 meters Oct Noy Dec Avg 2.1 0.7 0.1 3.3 2.2 0.7 °0.1 3.2 2.2 0.8 0.1 3.0 2.4 0.7 0.1 4.6 2.5 0.8 0.1 4.5 2.5 0.8 0.1 4.4 2.5 0.8 0.1 47 MCGRATH Jan Fixed array Lat-15 1.0 Latitude 1.2 Lat+15 1.2 Single axis trackerLar-15 J. Latitude 1.2 Lac+15 1.3 Dual axis tracker 1.3 NOME Jan Fixed array Lat-15 0.8 Latitude 0.9 Lat+15 0.9 Single axis tracker Lat-15 0.8 Latitude 0.9 Lat+15 1 Dual axis tracker 1.0 ST PAUL IS. an Fixed array Lar-15 1.0 Latitude 1.1 Lat+15 1.1 Single axis tracker Lat-15 1.1 Latitude 1.2 Lat+15 1.2 Dual axis tracker 1.2 TALKEETNA Jan Fixed array Lat-15 1.2 Latitude 1.3 Lar+15 1.4 Single axis tracker Lac-15 1.3 Latitude 1.4 Lat+15 1.5 -Dual axis tracker 1.5 Mar Ape 3.7 Latitude:62.97 degrees 5.3 5.1 4.9 4.6 4.4 4.0 7.5 7.2 7.3 7.0 7 6.6 7.7 7.5 Jul 4.7 4.3 3.7 6.6 6.3 5.9 6.8 Aug 4.0 3.7 3.3 5.3 Latitude:64.50 degrees 5.9 5.5 5.6 5.0 5.0 43 8.7 8.3 8.5 8.0 8.1 7.6 8.8 8.6 Jul 4.7 4.3 3.7 6.7 6.4 6.1 6.9 Aug Latitude:57.15 degrees 3.9 3.8 3.6 3.4 3.2 3.0 4.6 43° 4.4 4.) |41 3.8 4.7 4.5 Jul 3.3 3.0 2.6 3.6 3.4 3.1 3.8 Aug 2.8 2.6 2.3 3.1 Latitude:62.30 degrees 5.2 5.0 4.9 4,5 4.4 3.9 73 6.8 7.1 6.6 6.8 6.2 7.5 7.1 Jul 4.8 4.4 3.8 6.6 6.3 5.9 6.8 Aug 4.2 3.9 3.5 APPENDIX B -SOLAR DATA Elevation:103 meters Oct Nov Dec Avg 2.0 1.1 0.6 3.3 2.1.13.0.6 3.2 2.1 1,3 0.7 3.0 2.3 1.3 0.6 4.3 2.4 1.4 0.7 4.3 2.4 1.4 0.7 4.2 2.4 1.4 0.7 4.5 Elevation:7 meters Oct Nov .Dec =Avg 2.2 1.0 0.4 3.4 2.4 1.1 0.5 3.3 2.4 1.2 0.5 3.1 2.7 Ll 0.4 4.6 2.8 1.2 0.5 4.6 2.8 1.3 0.5 4.4 2.8 1.3 0.5 4,7 Elevation:7 meters Oct Nov Dec Avg 1.8 1.1 0.7 2.5 1.9 1.1 0.8 2.5 1.8 1.2 0.8 2.3 2.0 1.1 0.8 2.9 2.1 1.2 0.8 2.9 2.1 1.2 0.9 2.8 2.1 1.3 0.9 3.0 Elevation:105 meters Oct Nov ec =Avg 2.3 1.4 0.7 3.3 2.4 1.6 0.8 3.3 2.4 1.7 0.9 3.1. 2.7 1.6 0.8 4.4 2.8 1.8 0.9 4.4 2.8 1.8 0.9 4.2 2.8 1.8 0.9 4.5 203 nbnReeePARBiaotaaaciate PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL YAKUTAT Jan Fixed array Lat-15 1.0 Latitude ©1.2 Lat+15 1.2 Single axis tracker Lat-15+1.1 Latitude 1.2 Lar+15 1.3 Dual axis tracker 1.3 BIRMINGHAM Jan Fixed array Lat-15 3.3 Latitude 3.7 Lat+15 3.9 Single axis tracker Lat-15 4.1 Latitude 4.4 Lat+15 4.6 Dual axis tracker 4.6 HUNTSVILLE an Fixed array Lat-15 3.1 Latitude 3.5 Lat+15 3.7 Single axis tracker Lat-15 3.8 Latitude 4.1 Lat+15 4.3 Dual axis tracker 4.3 MOBILE Jan Fixed array Lat-15 3,3 Latitude 3.7 Lat+15 4.0 Single axis tracker Lat-15 4.1 Latitude 4.4 Lat+15 4.6 Dual axis tracker 4.6 204 Latitude:59.52 degrees 4.2 4.2 3.9 3.8 3.5 3.3 5.5 5.4 5.3 5.1 5 4.8 5.7 5.6 Jul 4) 3.7 3.2 5.3 Aug 3.7 3.5 3.1 47 45 4.3 4.7 Latitude:33.57 degrees 6.0 6.1 5.6 5.6 5.0 4.9 7.6 7.7 74 74 6.9 6.9 7.7 7.8 Jul 7.3 Aug 7.2 Latitude:34.65 degrees May -Jun 5.9 6.2 5.6 57 5.0 49 76 79 74 7.6 6.9 7.1 7.7 8.1 Latitude:30.68 degrees. May Jun 58 °°5.8 5.5 5.4 49 4.7 7.4 7.3 7.2 7.0 6.7 6.5 7.5 74 Jul 6.0 5.6 4.9 7.6 7.3 6.8 7.7 Jul Aug 5.9 5.7 5.2 7.5 7.3 7 75 Aug 5.3 5.2 47 6.6 6.5 6.2 6.6 Elevation:9 meters Oct Dec 1.7 1.8 1.7 2.0 Nov 1.4 0.7 0.8 0.8 0.8 0.8 0.9 0.9 Avg 2.8 2.7 2.5 3.4 3.4 3.3 3.5 Elevation:192 meters Oct 6.4 Noy 5.0 Dec 4.4 Avg 6.4 Elevation:190 meters Oct 6.3 Noy 4,7 Dec 4.0 Av g 6.3 Elevation:67 meters _Oct 4.9 5.2 3.3 6.2 6.5 6.6 6.6 Nov 3.8 .43 4.5 4,7 5.1 5.3 5.3 Ayg 4.8, 4.9 4.7 6.0 6.1 5.9 6.2 MONTGOMERY AL Latitude:32.30 degrees Jan Feb Mar Apr May Jun Jul Aug i rraFined6”34 4.2 5.0 5.9 6.2 6.3 6.0 5.9 Latitude 3.8 4.6 5.2 5.8 58 5.8 5.6 5.7 Lat+15 4.0 4.7 5.1 5.4 5.2 5.1 4.9 5.2 Single axis trackerLat-15 42 5.3 6.3 7.6 7.8 7.8 7.3 7.2 Latitude 4.5 5.5 6.5,75 7.6 75 7.0 7.1 Lat+15 4.7 5.6 6.4 7.2 7A 7 6.5 6.7 Dual axis tracker 4.7 5.6 6.5 7.6 79 8.0 7.4 7.2 LITTLE ROCK AR Fixed array Lat-15 3.4 4.1 4.9 5.6 6.1 Latitude 3.8 4.5 5.1 5.5 5.7 Lat+15 4.1 4.6 5.0 5.1 5.1 Single axis trackerLat-15 4.1!5.1 6.2 7.2 7.8 Latitude 4.5 5.4 6.4 7.2 7.6 Lat+15 4.7 5.5 6.3 6.9 7.1 Dual axis tracker 4.7 5.5 64 7.3 79 FORT SMITH AR Jan Feb Mar Apr May Fixed arrayLat-15 3.6 42 -5.0 5.7 6.0 Latitude 4.1 4.6 5.2 5.6 5.7 Lat+15 4.3 4.8 5.1 5.2 5.0 Single axis tracker Lat-15 4.4 5.3 6.3 73 7.8 'Latitude 4.8 5.6 6.4 7.2 7.6 Lat+15 5 5.7 64.7 7.1 Dual axis tracker 1 5.7 6.5 7.3 7.9 FLAGSTAFF AZ an eb Mar Apr May Fixed array Lat-15 4.4 52 59 6.8 7.2 Latitude 5.2 5.8 6.2 6.7 6.7 Lat+15 5.6 6.1 6.2 6.2 5.9 Single axis tracker Lat-15 5.8 6.9 8.0 9.5 10.2 Latitude 6.4 74 8.3 9.4 9.9 Lat+15 6.5 7.6 8.2 9.1 9.4 Dual axis tracker 6.8 7.6 8.3 9.5 10.3 Jun 6.4 ° 5.9 5.1 8.3 8.0 7.4 8.5 Jun 6.3 5.8 5.0 8.3 8.0 75 8.5 Jun 7.4 6.7 5.7 Jul 8.4 Jul 6.5 6.0 5.3 8.7 8.4 78 8.8 Jul 6.2 5.8 5.0 8.6 8.3 7.8 8.7 Latitude:34.73 degrees Aug 6.1 5.9 5.4 8.0 7.8 75 8.0 Latitude:35.33 degrees Aug 8.2 Latitude:35.13 degrees Aug 6.1 5.9 5.4 8.4 8.3 7.9 8.5 wunfpbhAR&6.6" 6.7 6.5 6.7 Sep 5.3 5.4 5.2 6.8 6.8 6.7 6.9 Sep 5.3 5.4 5.2 6.8 6.9 6.7 6.9 Sep 6.1 6.3 6.0 8.5 8.6 8.4 8.6 APPENDIX B -SOLAR DATA Elevation:62 meters Oct 4.9 5.3 5.4 6.2 6.5 6.6 6.6 Nov 5.3 Dec 3.3 Avg 5.0 5.1 4.9 6.3 6.3 6.2 6.5 Elevation:81 meters Oct 6.4 6.4 Nov 4.9 5.0 Dec 4.6 Elevation:2135 Oct 5.6 6.1 6.3 7.6 8.0 8.1 8.1 Nov 47 5.4 5.8 6.2 6.7 7 7.1 Dec 4.2 4.9 5.4 5.4 6.0 6.4 6.5 Avg 6.6 Av $ 6.8 meters Avg 5.8 6.0 5.8 205 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL PHOENIX AZ Latitude:33.43 degrees Elevation:339 meters Jan Feb Mar Apr May =Jun jul Aug Sep Oct Nov Dec AvgFixedarray; Lat-15 4.4 5.4 -6.4 7.5 8.0 8.1 7.5 7.3 6.8 6.0 4.9 4.2 6.4 Latitude 5.1 6.0 6.7 7.4 7.5 7.3 6.9 7.1 7.0 6.5 5.6 49 6.5 Lat+15 5.5 6.2 6.6 6.9 6.6 6.3 6.0 6.4 6.7 6.7 5.9 5.3 6.3 Single axis tracker Lar-15 5.6 7 8.5 10.3 11.1 11.3 10.0 9.8 9.2 8.0 6.3 5.3 8.5 Latitude 6.2 75 8.7 10.3 10.7 10.8 9.6 9.6 9.3 8.4 6.8 5.8 8.6 Lar+15 6.6 7.4 8.2 9.4 9.7 10.1 8.4 8.4 8.9 8.5 7.2 6.3 8.3 Dual axis tracker 6.6 7.7 8.7 10.4 11.2 11.6 10.1 9.8 93 8.5 7.1 6.3 8.9 PRESCOTT ©AZ Latitude:34.65 degrees Elevation:1531 meters Jan Feb Mar Apr May Jun Jul Ang Sep Oct Nov Dec Avg Fixed array Lat-15 4.4 5.1 5.9 7.0 7.5 7.7 6.7 6.5 6.5 5.8 4.8 4.1 6.0 Latitude 5.1 5.7 6.2 6.9 7.0 |7.0 6.2 6.3 6.6 6.4 5.5 4.9 6.1 Lat+15 5.5 5.9 6.1 6.4 6.1 6.0 5.4 5.7 6.4 6.5 5.9 5.4 5.9 Single axis tracker Lar-15 5.7 6.8 8.1 9.8 10.6 11.2 9.3 9.0 9.0 8.0 6.3 5.4 8.3 Latitude 6.3 7.2 8.3 9.8 10.3.10.7 8.9 8.8 9.1 8.4 6.9 6.0 8.4 Lat+15 6.6 7.4 8.2 9.4 9.7 10.1 8.4 8.4 8.9 8.5 7.2 6.3 8.3 Dual axis tracker 6.7 74 8.3 9.9 10.8 11.5 9.4 9.0 9.1 8.5 7.2 6.5 8.7 TUCSON -AZ Latitude:32.12 degrees Elevation:779 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array . Lat-15 4.6 5.5 6.4 7.5 7.8 7.8 6.9 6.9 6.6 6.1 5.0 4.3 6.3 Latitude 5.4 6.2 6.7 7.3 7.3 7.1 6.4 6.6 6.8 6.6 5.8 5.1 6.5 Lat+15 5.9 6.4 6.6 6.8 6.4 6.1 5.6 6.0 6.6 6.8 6.2 5.6 6.3 Single axis tracker Lat-15 6.1 7.4 8.7 10.4 11.1 11.1 9.1 9.2 9.0 8.2 6.7 5.6 8.6 Latitude 6.7 7.8 9.0 10.4 10.7 10.6 8.8 9.1 9.1 8.6 7.3 6.2 8.7 Lat+15 7 8 8.9 10 10.1 99 8.2 8.6 9 8.7 7.6 6.6 8.6 Dual axis tracker 7.1 8.1 9.0 105 12 113 9.3 9.2 9.2 8.7 7.6 6.7 9.0 ARCATA CA Latitude:40.98 degrees Elevation:69 meters an Feb Mar Apr May un Jul Aug Sep Oct Nov Dec Avg Fixed array a)5.8 5.3 5.1 5.1 4.9 Lat-15 2.7 3.3 4.3 5.4 5.9 5 3.9 2.9 2.5 4.4 Latitude 3.0 3.5 4.4 5.3 5.9 5.4 5.4 5.0 4.1 3.2 2.8 4.4 Lat+15 3.2 3.6 4.3 4.9 4.9 47 4.7 4.6 4.1 3.3 3.0 4.2 Single axis tracker / Lat-15 3.2 3.9 5.3 6.8 7.5 7.5 7.4 6.5.6.4 4.8 3.4 2.9 5.5 Latitude 3.5 4.1 5.3 6.7 7.2 7.2 71 6.4 6.4 5.0 3.7 3,2 5.5 Lat+15 3.6 4.2 5.2 6.4 6.8 6.7 6.6 6 63.5 3.8 3.4 5.3 Dual axis tracker 3.6 4.2 5.4 6.8 75°77 7.5 6.5 6.5.5.0 3.8 3.4 5.7 206 APPENDIX B -SOLAR DATA BAKERSFIELD CA Latitude:35.42 degrees Elevation:1 50 meters Jan eh Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array . Lat-15 3.0 4.2 5.4 6.6 7.4 7.8 7.8 75 6.8 5.5 3.8 2.8 5.7 -Latitude 3.3 4.5 5.6 65 69 7A 72 7.3 6.9 6.0 4.3 3.2 5.7 Lat+15 3.5 4.7 5.5 6.0 6.1 6.1 6.2 6.6 6.7 6.1 45 3.4 5.4 Single axis crackerLat-15 3.5 5.1 6.8 8.7 10.2 11.0 11.1 10.5 9.1 7.2 47 3.3 7.6 Latitude 3.8 5.4 7.0 8.7 9.9 10.5 10.7.103 9.2 7.5 5.0 3.6.7.6 Lat+15 3.9 5.5 6.9 8.3 9.3 9.8 10 9.8 9 7.6 5.2 3.8 7A Dual axis trackerBases 5.5 7.0 8.8 10.3 11.2 11.3 10.5 9.2 7.6 5.2 3.8 7.9 Bos 'DAGGETT CA Latitude:34.87 degrees Elevation:588 meters on Jan Feb Mar Apr May =Jun Jul Aug Sep Oct Nov Dec Avg eh 'Fixed array :Lat-15 4.6 5.4 '75 7.9 8.1 78 7.6 7.1 6.2 5.0 4.4 6.5 Latitude 5.3 6.0 7A 7.4 74 7.20 73 7.3 6.8 5.8 5.2 6.6 Lar+15 5.7 6.2 6.8 6.5 6.3 6.2 6.6 7.0 6.9 6.2 5.6 6.4 Single axis trackerLat-15 5.9 7A 10.4 11.2 11.7 111 10.8 10.0 8.4 6.6 5.6 9.0 Latitude 6.5 75 10.3 10.9 11.2 10.7,10.6 10.1 8.8 7.2 6.3 9.1 Lat+15 68 77 8.9 10 10.3 10.5 10.1 10.1 9.9 89 =7.5 6.6 8.9 Dual axis wacker 6.9 7.7 9.0 10.4 113 12.0 11.4 108 10.1 9.0 7.5 6.8 9.4 FRESNO CA Latitude:36.77 degrees _Elevation:100 meters Jan Feb Mar Apr May =Jun jul Aug Sep Oct Noy Dec Avg Fixed array 6.8 7.6 7.8 7.9 75 6.8 5.5 -3.6 2.5 5.7 Lat-15 2.8 4.1 5.5 Latitude 3.1 4.4 5.7 6.7 7.1 7.2 73 73 6.9 6.0 4.1 2.8 5.7 Lar+15 3.2 4.5 5.6 6.2 6.3 6.1 6.3 6.6 6.7 6.1 4.2 3.0 5.4 Single axis tracker Lar-15 3.2 5.0 7.0 9.0 10.4 10.9 11.2 10.4 9.1 7A 4.4 2.9 75 Latitude 3.4 5.2 7.2 8.9 10.1 10.5 10.8 10.3 9.2 7.4 47 3.1 7.6 Lar+15 3.5 5.3 7A 8.6 9.5 9.8 10.1 9.8 9 7.5 4.9 3.2 74 Dual axis tracker 3.6 5.3 7.2 9.0 10.5 11.2 11.4 10.5 9.2 7.5 4.9 3.3 7.8 LONG BEACH CA Latitude:33.82 degrees Elevation:17 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Mec Avg . Fixed array Lat-15 3.8 4.5 5.4 6.4 6.4 6.5 7.2 6.9 6.0 5.0 4l 3.6 5.5 Latitude 4.3 4.9 5.6 6.3 6.1 6.0 6.7 6.7 6.1 5.4 4.7 4.2 5.6 Lat+15 4.6 5.1 5.5 5.8 5.4 5.2 5.8 6.1 5.8 5.5 5.0 4.5 5.4 Single axis tracker Lat-15 4.7 5.6 6.8 8.2 8.1 8.3 9.3 8.9 7.6 6.3 5.1 4.4 6.9 Latitude 5.1 5.9 7.0 8.1 7.9 7.9 8.9 8.8 7.6 6.6 5.6 4.9 7.0 Lat+15 5.3 6 6.9 7.8 7A 74 8.3 8.3 7.5 6.7 5.8 5.1 6.9 Dual axis tracker 5.4 6.0 7.0 8.2 8.2 8.4 9.4 8.9 77 6.7 5.8 5.2 7.3secwlognmepeidSoibevepeeyetateIpsisrartbennaipainaerectavilNyHenminteetyieBie00hcorre 207 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL LOS ANGELES an Feb Fixed array Latr-15 3.8 45 Latitude 4.4 5.0 Lar+15 4.7 5.1 Single axis tracker Lat-15 4.7 5.6 Latitude 5.1 6.0 Lat+15 5.4 6.1 Dual axis tracker 5.4 6.1 SACRAMENTO Jan Feb Fixed array Lat-15 2.6 3.9 Latitude 2.9 4.2 Latr+15 3.1 4.3 Single axis tracker Latr-15 3.0 47 Latitude 3.3 4.9 Lat+15 3.4 5 Dual axis tracker 3.4 5.0 ioSAN DIEGO Jan Feb Fixed array Lar-15 4.1 4.8 Latitude 4.7 5.3 Lat+15 5.1 5.5 Single axis tracker Lat-15 5.2 6.1 Latitude 5.7 6.5 Lat+15 6 6.6 Dual axis tracker6.0 66 SAN FRANCISCO Jan =FebFixedarray Lat-15 3.1 3.9 Latitude 3.5 4.2 Latc+15 3.7 4.4 Single axis tracker Lat-15 3.7 47 Latitude 4.0 5.0 Lat+15 4.2 5.1 Dual axis tracker 4.2 d.1 208 CA Apr 6.4 6.3 5.9 8.2 8.2 7.8 8.3 _Apr 6.5 6.3 5.9 8.6 8.5 8.2 8.6 Apr 6.4 6.3 5.9 8.3 8.2 7.9 8.3 Apr 6.2 6.1 5.6 8.0 8.0 7.7 8.1 Latitude:33.93 degrees May 6.4 6.1 5.4 8.0 7.8 7.3 8.1 Jun 6.4 6.0 5.2 8.2 9.1 Aug 6.8 6.6 6.0 8.6 8.4 8 8.6 Latitude:38.52 degrees May 7.3 6.8 6.0 10.1 9.8 9.2 10.2 Jun 7.6 7.0 6.0 Jul 7.8 7.2 6.3 11.2 10.8 10.1 11.4 Aug 7.5 7.2 6.5 10.4 10.2 9.8 10.4 Latitude:32.73 degrees May 6.3 5.9 5.2 7.7 75 7 7.8 Jun 6.3 5.8 5.1 7.8 7.4 6.9 7.9 Jul 6.8 6.4 5.6 8.7 8.4 7.8 8.9 Aug 6.7 6.5 5.9 8.6 8.4 8 8.6 Latitude:37.62 degrees May 6.8 6.4 5.7 8.9 8.7 8.1 9.0 Jun 7.0 6.5 5.6 9.2 8.9 8.2 9.4 Jul 7.3 6.8 5.9 9.7 9.4 8.7 9.9 Aug 6.9 6.7 6.1 9.0 8.8 8.4 9.0 Elevation:32 meters Oct Nov 5.0 4.2 5.4 4,7 5.5 5.0 6.3 5.2 6.6 5.6 6.6 5.8 6.7 5.8 Elevation:8 Oct Nov 5.3 3.3 5.7 3.7 5.8 3.9 6.8 4.0 7.1 4.3 7.2 "4.5 7.2 4.5 Dec Avg 3.6 5.5 4.2 5.6 4.5 5.4 4.4 6.9 4.9 7.0 5.2 6.8 5.3 7.2 meters Dec Ayg 2.4 5.5 2.7 5.5 2.9 5.2 2.8 7.3 3.0 7.4 3.2 7.2 3.2 7.6 Elevation:9 meters Oct 7.2 Nov 4.5 5.1 5.4 5.7 6.2 6.5 6.5 Dec Avgoe 3.9 5.6 4.6 5.7 5.0 5.5 5.0 7.1 5.5 7.2 5.8 7 5.9 7.4 Elevation:5 meters Oct Noy Dec =Avg 2.9 5.3 3.4 5.4 3.6 5.1 3.5 6.8 3.9 6.9 4.1 6.7 4.1 7.1 "o>Pixed array .Lat-15_Latitude 4.6 Lat +15Singleaxis trackerLat-15 5.0Latitude5.9-Lat +15 5.7Dualaxistracker ALAMOSA Jan Fixed array Lat-15 4.7 Latitude 5.5 Lat+15 6.0 Single axis trackerLat-15 6.1 Latitude 6.8 Lar+15 7.2 Dual axis tracker 7.2 BOULDER Jan Fixed array Lat-15 3.8 Latitude 4.4 Lac+15 48 Single axis tracker Lat-15 4.8 Latitude 5.2 Lat+15 5.5 Dual axis tracker 5.6 COLORADO SPRINGS CO .Feban Fixed array Lat-15 4.0 Latitude 4.6 Lat+15 5.0 Single axis cracker Lat-15 5.1 Latitude 5.6 Lat+15 5.9 Dual axis tracker 5.9 6.4 47 5.2 -5.4 6.1 6.5 6.6 6.7 7.2 Mar Apr 6.6 6.5 6.0 8.7 8.6 8.3 8.7 Apr 6.9 6.8 6.3 9.6 9.6 9.2 9.7 Apt 6.1 6.0 5.6 8.1 8.0 77 8.1 Apt 6.2 6.1 5.6 8.3 8.3 7.9 8.4 Latitude:34.90 degrees May Jun 7.0 7.2 6.6 6.6 5.8 5.7 91 9.4 8.8 9.0 8.3 8.3 9.2 9.6 Jul 7.4 6.9 6.0 9.6 9.2 8.6 9.7 Aug 9.1 Latitude:37.45 degrees May =Jun 71 74 6.6 6.8 5.8 5.7 10.1 10.7 9.8 10.3 9.3 9.6 10.2 11.0 Latitude:40.02 degrees May =Jun 6.2 6.6 5.9 6.1 5.2 5.2 8.4 9.1 8.1 8.8 77 8.2 8.5 9.4 Jul 7.0 6.5 5.6 9.8 9.5 8.9 10.0 jul 6.6 6.1 5.3 9.1 8.7 8.2 9.2 Aug 9.4 Aug 6.3 6.1 5.5 8.6 8.4 8 8.6 Latitude:38.82 degrees May =Jun 6.2 6.7 59 6.2 5.2 5.3 8.5 9.3 8.2 9.0 7.7 8.4 - 8.6 9.6 Jul 6.6 6.1 5.3 9.0 8.7 8.1 9.2 Aug 6.4 6.1 5.6 APPENDIX B -SOLAR DATA Elevation:72 meters Oct 6.9 7.3 7.3 7.4 Nov 4.4 5.0 5.3 5.6 6.0 6.3 6.3 5.8 Elevation:2297 meters Oct 8.5 Nov 4.9 5.6 6.0 6.4 7.0 7.3 7.3 Dec 4.4 5.2 5.7 5.7 6.3 6.7 6.8 Avg 6.1 6.3 6.1 8.4 8.5 8.4 8.8 Elevation:1634 meters Oct 7.1 Nov 5.7 Dec Elevation:1881 Oct |5.4 5.8 5.9 7.1 7A 75 75 Nov Avg 209 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL EAGLE Jan Feb Fixed array Lat-15 3.7 4.6 Latitude .4.3 5.2 Lat+15 4.6 5.4 Single axis tracker Lar-15 4.6 5.9 Latitude 5.1 6.3 Lar+15 5.3 6.5 Dual axis tracker 5.4 6.5 7.1 GRAND JUNCTION CO Jan FebFixedarray Lar-15 3.8 4.7 Latitude 4.4 5.2 Lat+15 4.7 5.4 Single axis tracker Lat-15 4.7 6.0 Latitude 5.2 6.4 Lat+15 5.4 6.6 Dual axis tracker 5.5 6.6 PUEBLO an Feb Fixed array Lat-15 4.1 4.9 Latitude 4.8 5.4 Lat+15 5.2 5.6 Single axis tracker Lat-15 5.3 6.3 Latitude 5.8 6.7 Lat+15 6.1 6.9 Dual axis tracker 6.2 6.9 BRIDGEPORT Jan FebFixedarray Lat-15 2.9 3.7 Latitude 3.3 4.0 Lat+15 3.5 4.1 Single axis trackerLat-15 35 45° Latitude 3.8 4.8 Lat+15 4 "49 Dual axis tracker 4.0 4.9 210 Mar Apr 6.1 6.0 5.6 8.2 8.] 7.8 8.2 Latitude:39.65 degrees May Jun Jul Aug 6.4 7.0 6.9 6.5 6.0 6.4 6.3 6.3 | 53 55 5S CST 89 99 96 9.0 86 95 93 8&8 81 89 87 8&4 9.0 10.2 9.8 9.0 Latitude:39.12 degrees May -Jun Jul =Aug 70 #75 73 7.0 6.6 6.8 6.7 6.7 5.8 5.8 5.8 6.1 9.6 10.6 10.1 9.5 9.3 10.1 9.8 9.4 8.8 9.5 9.2 8.9 97 108 103 96 Latitude:38.28 degrees May Jun Jul Aug 6.7 7.2 7.1 |6.9 6.3 6.6 6.6 °6.6 5.6 5.6 5.7 6.0 9.1 9.9 9.7 9.3 8.8 9.5 9.4 9.1 8.3 8.9 8.8 8.7 9.2 10.2 9.9 9.3 Latitude:41.17 degrees May Jun Jul =Aug 5.5 5.8 5.8 5.5 5.2 5.3 5.4 5.3 4.6 4.6 47 4.8 6.9 7.3 7.4 7.0 6.7 7.0 7.1 6.8 (63°65 66 65 7.0 75 7.5 7.0 Elevation:1985 meter. Oct 7.3 Nov 3.8 43 45 4.7 5.1 5.3 5.4 Dec 3.4 3.9 4.3 4.2 4.6 4.9 5.0 Elevation:1475 Oct 7.6 Nov 5.8 Dec 3.6 4.1 4.5 4.4 4.9 5.2 5.2 Elevation:1439 Oct 5.6 6.0 6.2 7.4 7.7 7.8 7.8 Nov 4.4 5.0 5.3 5.6 6.1 6.3 6.4 Dec 3.9 4.6 5.0 4.9 5.5 5.8 5.9 Avg 5.4 3.5 5.3 7.3 7.3 7.2 7.6 meters Avg 5.7 5.8 5.6 7.7 7.8 7.6 8.0 meters "Avg 5.8 5.9 5.7 77 7.8 7.7 8.1 Elevation:2 meters | Oct 4.0 4.3 4.3 5.0 5.2 5.2 5.3 Nov 2.8 3.1 3.3 3.4 3.6 3.7 3.8 Dec 2.4 2.8 2.9 2.8 3.1 3.3 3.3 APPENDIX B -SOLAR DATA HARTFORD cT Latitude:41.93 degrees Elevation:55 meters Jan Feb Mar May Jun Jul Aug Sep Oct Noy Dec Avg Fixed array Apr ec [at-15 2.9 9 37 5.1 5.5 5.8 5.4 4.8 3.9 2.7 2.3 Latitude 3.3 4.1 4.6 49 5.2 5.3 5.4 5.2 4.8 41 2.9 2.7 pare15 3.5 4.2 4.6 46 4.8 47 4.6 4,2 3.0 2.8 4.2 6.3 2.7 6.2 3.0 3.1 'Single axis trackerLat-15 34 4.5 5.5 Latitude 3.7 4.8 5.6 Lat+15 3.9 4.9 5.5 Dual axis tracker 4 49 56 63 70 75 75 69 60 50 34 (32 5.6 WILMINGTON _DE Latitude:39.67 degrees Elevation:24 meters .Jan Feb Mar Apr May =Jun Jul Aug Sep Oct Nov Dec Avg Fixed arrayLat-15 3.0 3.8 4.6 5.3 5.7 6.1 6.0 5.8 .3.1 . Latitude 3.4 4.2 4.8 5.2 5.4 5.6 5.6 5.5 5.1 4.5 3.5 3.0 4.6 Lat+15 3.6 4.3 47 4.8 47 4.9 49 5.0 .3.6 Single axis trackerLat-15 36 °47 5.9 6.7 7.2 7.8 7.7 7.3 6.3 5.3 . . Latitude 4.0 5.0 6.0 6.7 7.0 7.5 74 7.2 6.3 5.5 4.0 3.4 5.8 Lat+15 4.1 5.1 5.9 6.4 6.6 7 6.9 6.8 6.2 5.5 . . Dual axis tracker 4.2 5.1 6.0 6.8 7.3 8.0 7.8 7.3 6.4 5.6 4.2 3.6 6.0 es :ve aama3oY' DAYTONA BEACH FL Latitude:29.18 degrees Elevation:12 meters -Fixed array Lat-15 3.8 4.5 5.5 6.4 6.4 6.0 5.9 5.8 5.2 47 41 3.6 5.2 Latitude 4.3 4.9 5.7 6.3 6.0 5.5 5.5 5.6 5.3 5.0 4.6 4.1 5.2 Lat+15 4.6 5.1 5.6 5.9 5.4 4.8 4.9 5.1 5.1 5.1 4.8 4.4 5.1 Single axis trackerLat-15 4.8 5.7 7.0 8.3 8.2 7.4 7.4 7.2 6.5 5.9 5.1 44 6.5 Latitude 5.2 6.0 7.2 8.3 79 7.1 7.1 7.0 6.5 6.1 5.5 4.9 6.6 Lat+15 5.4 6.1 7A 8 74 6.6 6.6 6.7 6.4 6.2 5.7 5.1 6.4 Dual axis tracker 5.5 6.1 7.2 8.4 8.2 75 75 7.2 6.5 6.2 5.7 5.2 -68 4 JACKSONVILLE FL .Latitude:30.50 degrees Elevation:9 meters bo .jan =Feb «=Mar =Apr,May =Jun ul Aug Sep Oct Nov Dec Avg ae Fixed arraytoLa-15 36 43 61 61 58 57 50 450288 AD5.2 5.5 Latitude 4.2 4.7 5.5 6.0 5.7 5.4 5.4 5.3 5.0 49 44 3.9 5.0 Lat+15 44 4.9 54 5.6 5.1 47 4.7 4.9 4.8 4.9 4.7 4.2 49 Bo Single axis tracker : Lat-15 4.6 5.5 6.7 8.0:7.8 7.3 7.2 6.9 6.2 5.7 49 42 >63 i latitude 5.0 58 69 80 76 7.0 69 682i 4G 3 :Lat+15 5.2 5.9 6.8 7.6 7.1 6.5 6.5 6.4 6.1 6 5.5 4.9 6.2 Dual axis wacker 5.2 5.9 6.9 8.0 7.9 75 7.3 6.9 6.3 6.0 5.5 4.9 6.5 211 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL 212 KEY WEST an Feb Fixed array Lat-15 4.2 4.9 Laticude .4.9 5.5 Lat+15 5.3 5.7 Single axis tracker Lat-15 5.5 6.5 Latitude 6.0 6.9 Lat+15 6.3 7.1 Dual axis tracker 6.4 7.1 MIAMI Jan FebFixedarray Lat-15 4.1 4.7 Latitude 4.7 5.2 Lat+15 5.0 5.4 Single axis tracker Lat-15 5.2 6.1 Latitude 5.7 6.4 Lat+15 5.9 6.5 Dual axis tracker 6.0 6.6 TALLAHASSEE an Feb Fixed array Lat-15 3.6 4.3 Latitude 4.0 4.7 Lat+15 4.3 4.9 Single axis tracker Lat-15 44 5.5 Latitude 4.8 5.8 Latr+15 5 5.9 Dual axis tracker 5.1 5.9 TAMPA Jan =FebFixedarray Lat-15 3.9 4.6 Latitude 4.5 5.1 Lat+15 4.8 5.3 Single axis tracker Lat-15 5.0 5.9 Latitude 5.4 6.3 Lat+15 5.6 6.4 Dual axis tracker 5.7 6.4 FL Apr 6.2 6.1 5.7 7.9 7.8 75 7.9 Apr 6.1 6.0 5.6 7.9 7.8 7.5 7.9 Apr 6.4 6.3 5.9 8.4 8.4 8.1 8.5 Latitude:24.55 degrees May 6.3 6.0 5.3 8.1 7.8 7.3 8.1 Jun 6.0 5.5 4.8 7.5 7.1 6.6 7.6 Jul 6.0 5.6 | 5.0 7.5 7.2 6.7 7.6 Aug 5.9 5.7 5.2 7.3 7.2 6.8 7.3 Latitude:25.80 degrees May 74 Jun 6.7 Jul 7.1 Aug 5.6 5.5 5.0 6.9 6.7 6.4 6.9 Latitude:30.38 degrees May 6.2 5.9 5.2 7.9 7.7 7.2 8.0 Jun 6.0 5.6 4.9 7.4 7.1 6.6 7.6 Jul 7.2 Aug 6.9 Latitude:27.97 degrees May 6.4 6.0 5.3 8.2 8.0 7.5 8.3 Jun mucw\OANCNet7.6 Jul 5.7 5.3 4.7 7.1 6.8 6.3 7.2 Aug . Elevation:1 meters Oct 5.0 5.4 5.5 6.4 6.7 6.7 6.7 Elevation:3 Oct 5.0 5.4 5.5 6.4 6.7 6.8 6.8 Oct Nov 5.0 44 5.4 5.0 5.5 5.3 6.3 5.6 6.6 6.1 67 63 67 64 Elevation:2 Qc Nov 47 4.2 5.1 47 5.1 4.9 5.9 5.2 6.1 5.6 6.2 5.8 6.2 5.9 Nov Noy Dec Avg 4.0 5.4 4.7 5.5 5.1 5.4 5.2 6.9 5.7 7.0 6 6.9 6.2 7.2 meters Dec Avg 3.9 5:1 4.5 5.2 4.9 5.1 4.9 6.4 5.4 6.5 5.7 6.3 5.8 6.7 Dec Avg 3.4 5.0 4.0 5.1 42 -5.0 4.2 6.3 4.6 6.4 4.9 6.3 5.0 6.6 meters Dec =Avg 3.8 5.2 44 5.3 4.7 5.1 4.8 6.6 5.2 6.7 5.5 6.6 5.6 6.9 APPENDIX B -SOLAR DATA -WEST PALM BEACHFL Latitude:26.68 degrees Elevation:6 meters os Jan Feb Mat Apr May Jun Jul Aug Sep Oct Nov Dec Avg ixed arra'roe 15 "38 4.5 5.3 6.1 5.9 5.6 58 °5.6 5.1 4.6 4.0 3.7 5.0 Latitude 44 5.0 56 60 56 5.2 54 54 5.1 49 45 43 5.1 yee ls 470 51 9 5605S (BO CS ne ©ee Single axis trackerLar-15 4.9 5.8 6.9 7.9 75 6.8 7.2 7.0 6.2 5.8 5.0 47 6.3 atitude 5.3 6.2 7.1 7.9 7.3 6.6 6.9 6.8 6.3 6.0 5.4 5.2 6.4 Lat+15 5.6 6.3 7 7.6 6.9 6.1 6.4 6.5 6.1 6.1 5.6 5.4 6.3 -Dual axis tracker ,6 63.7.1 8.0 7.6 7.0 7.3 7.0 6.3 6.1 5.6 5.5 6.6 ATHENS ; GA Latitude:33.95 degrees Elevation:244 meters Jan Feb Mar Apr May Jun Jul Aus Sep Oct Nov Dec Avg 'Fixed array Lat-15 3.5 4.2 5.1 5.9 6.1 6.2 6.0 5.8 4.8 3.8 3.2 5.05.3 Latitude 3.9 4.6 5.2 5.8 5.7 5.7 5.6 5.6 5.4 5.2 43 3.7 5.1 Lat+15 4.2 4.8 5.2 5.4 5.1 5.0 4.9 5.1 5.1 5.3 45 3.9 4.9 Single axis trackerLar-15 4.3 5.4 6.5 77 7.8 7.9 7.5 73 6.6 6.1 4.7 3.9 6.3 Latitude 4.7 5.7 6.6 77 7.6 7.6 73 7A 6.7 .6.4 5.1 4.3 6.4 Lat+15 4.9 5.8 6.5 °74 71 7 6.8 6.8 6.5 6.5 5.3 4.5 6.3 Dual axis tracker 4.9 5.8 6.6 7.8 7.9 8.1 7.6 7.3 6.7 6.5 5.3 4.6 6.6 ATLANTA GA Latitude:33.65 degrees Elevation:315 meters Jan Feo «=Mar Apr May Jun ul -s Aug Oct Nov Dec Avg Fixed array Lat-15 3.4 4.2 6.0 5.2 4.2 3.7 5.1 Sep Pe ee 5.0 5.4ne nr Co eo5.1 ; Latitude 3.8 4.6 5.3 5.8 5.8 5.8 5.7 5.7 La+15 41 47 5.1 5.4 5.2 5.1 5.0 5.2 :Single axis tracker , %Latr-15 4.2 5.3 6.5 77 7.9 8.0 7.6 7.4 6.6 6.2 47 3.9 6.3 Latitude 4.5 5.5 6.6 7.6 7.7 7.6 7.3 7.2 6.7 6.4 5.0 4.3 6.4 *Latt 15)4.7 5.6 6.5 7.3 7.2 7.1 6.8 6.9 6.5 6.5 5.2 4.5 6.2 Dual axis tracker 4.8 5.7 6.6 77 8.0 8.1 7.7 7.4 6.7 6.5 5.3 4.5 6.6 4 oe _AUGUSTA GA Latitude:33.37 degrees _Elevation:45 meters 4 a a Feb Mat Apr May)Jun Jul Aug Se Oct Nov Dec Avg yO Fixed array Lat-15 3.4 5.1 6.0 6.1 6.2 6.0 5.7 5.2 49 3.8 5.0 4.3 3.3 Latitude 3.9 4,7 5.3 5.9 5.8 5.7 5.6 5.5 5.3 5.3 43 3.8 5.1 Lac+15 4.1 4.8 5.2 5.5 5.1 5.0 4.9 5.0 5.1 5.3 4.6 41 4.9 Single axis trackerLat-15 4.2 5.4 6.5 7.8 7.8 7.8 75 7A 6.5 6.2 4.8 4.0 6.3. Latitude 4.6 5.7 6.7 7.8 7.6 7.5 7.2 7.0 6.6 6.5 5.2 4.4 6.4 Lat+15 4.8 5.8 6.6 75 7A 7 6.7 6.6 6.4 6.5 5.3 4,7 6.3 Dual axis tracker 4.9 5.9 6.7 79 7.9 8.0 7.6 7A 6.6 6.6 5.4 4.8 6.6peheansclepentpenmemetistodee 213 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL COLUMBUS Jan Fixed array Lat-15 3.5 Latitude 3.9 Lat+15 4.2 Single axis tracker Lat-15 4.3 Latitude 4.7 Lat+15 4.8 Dual axis tracker 4.9 MACON Jan Fixed array Lat-15 3.4 Latitude 3.9 Lat+15 4.1 Single axis tracker Lat-15 4.2 Latitude 4.6 Lar+15 4.8 Dual axis tracker 4.8 SAVANNAH Jan Fixed array Lat-15 3.5 Latitude 4.0 Lat+15 43 Single axis tracker Lat-15 4.4 Latitude 4.8 Lat+15 5 Dual axis tracker 5.0 HILO .Tan Fixed array Lat-15 4.0 Latitude 4.5 Lat+15 4.9 Single axis tracker Lat-15 5.1 Latitude 5.5 Lat+15 5.7 Dual axis tracker 5.8 214 GA Apr 6.0 5.9 5.5 7.8 7.8 7.5 7.9 Apr Latitude:32.52 degrees May =Jun 6.2 6.2 5.8 5.7 5.2 5.0 8.0 7.8 7.7 7.5 7.3 7 8.1 8.0 jul 5.9 5.5 4.9 7.3 7] 6.6 74 Aug 5:8 5.6 5.1 7.2 7.1 6.7 7.3 Latitude:32.70 degrees May =Jun 62 62 5.8 5.7 5.2 5.0 79 7.8 77 75 72 69 8.0 8.0 jul 5.9 5.9 4.9 7.3 7.0 6.6 7.4 Aug 5.8 5.6 5.1 Latitude:32.13 degrees May -Jun 6.2 6.1 5.8 5.7 5.2 4.9 7.9 7.7 7.7 74 7.2 6.8 8.0 7.8 Jul 6.0 5.6 4.9 7.4 7.1 6.6 7.5 Aug 5.6 5.4 5.0 6.9 6.8 6.5 7.0 Latitude:19.72 degrees May Jun 5.1 5.3 4.8 4.9 4.3 4.3 6.2 6.5 6.0 6.2 5.6 5.8 6.2 6.6 Jul Aug 5.3 5.1 4.7 6.6 6.5 6.7 6.6 Elevation:136 meters Ocr 4.9 5.3 5.4 6.3 6.6 6.6 6.7 Nov 3.9 4.4 4.6 4.8 5.2 5.7 5.4 Dec 4.8 Avg 5.0 5.1 4.9 6.4 6.4 6.3 6.6 Elevation:110 meters Oct 6.6 Nov 3.9 4.4 4.6 4.8 5.2 5.4 5.5 Dec Ave 6.6 Elevation:16 meters Oct 48 5.] 5.2 6.0 6.3 6.3 6.4 Nov 5.5 Ave 6.6 Elevation:11 meters Oct 4.5 4.8 4.8 5.6 5.8 5.9 5.9 'Nov 3.9 4.3 4.5 4.8 5.1 5.3 5.3 Avg APPENDIX B -SOLAR DATA :HONOLULU HI Latitude:21.33 degrees Elevation:5 meters Jan Feb Mar Apr May =Jun Jul Aug Sep Oct Nov Dec Avg -Fixed arraFoes 0 56)(59)O63 OA OS SL 5B .5 4.5 . -Latitude 4.9 5.5 5.8 5.9 5.9 5.9 6.0 6.2 6.2 5.7 5.1 4.8 5.7 Tare 15 5.3 5.8 5.8 5.5 5.3 5.1 5.3 5.7 6.0 5.8 5.4 . Single axis trackerLat-15 5.6 6.6 7.3 77 8.3 8.5 8.6 8.7 8.1 7.0 5.8 5.3 7.3 Latitude 6.1 7.0 7.5 77 8.0 8.1 8.3 8.5 8.2 7.3 6.2 5.9 7.4 Lat+15 6.3 7.2 75 74 7.5 7.5 7.7 8.1 8 7A 6.5 6.2 7.3 Dual axis tracker 72 75 78 8.3 8.6 8.8 8&7 82 74°65 63 77 KAHULUI HI Latitude:20.90 degrees Elevation:15 meters an Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array : Lat-15 4.4 5.0 5.6 5.9 6.4 6.6 6.6 6.5 6.2 5.4 4.6 4.2 5.6 Latitude 5.1 5.6 5.9 5.9 5.9 6.0 6.0 6.3 6.3 5.9 5.3 5.0 5.8 Lat+15 5.5 5.8 5.8 5.5 5.30 5.1 5.2 5.7.61 6.0 5.6 5.5 5.6 Single axis tracker Lat-15 5.9 6.8 75 7.9 °8.5 8.9 8.9 8.9 8.5 73 6.2 5.7 7.6 Latitude 6.4 7.2 77 7.8 8.3 8.5 8.6 8.7 8.6 7.6 6.7 6.2 7.7 Lar+15 6.7 7.3 7.6 7.5 7.8 7.9 8 8.3 8.4 7.7 6.9 6.6 7.6 Dual axis tracker 6.8 7.4 77 7.9 8.7 91 °91 9.0 8.6 7.7 7.0 6.7 8.0 LIHUE HI Latitude:21.98 degrees 'Elevation:45 meters an Feb =Mar”Apr:«Ss May =s Jun-sJul «=Aug.)Sep,«=Oct,«Nov Dec Aug Fixed array Lat-15 4.0 4.6 5.0 5.4 5.8 5.9 5.9 5.9 5.8 4.9 4.1 3.8 5.1 Latitude 4.6 5.1 5.2 5.3 5.5 5.5 5.5 5.7 5.9 5.3 4.6 4.4 5.2 Lat+15 5.0 5.3 5.2 4.9 4.9 4.8 4.8 5.2 5.7 5.4 4.8 4.8 5.1. Single axis tracker Lat-15 5.2 6.0 6.4 6.7 74 7.6 75 77 7.6 6.3 5.1 4.9 6.5 Latitude 5.6 6.4 6.5 6.7 7.2 7.3 7.2 75 7.7 6.6 5.5 5.4 6.6 Lat+15 5.9 6.5 6.5 6.4 6.7 6.7 6.7 7.2 7.5 6.7 5.7 5.6 6.5 Dual axis tracker ' 60.65 65 67 75 78 76 77°77 67 57 6«45.7-t-C«CB e Fs i % Ff :4 Ke 5 i DES MOINES 1A Latitude:41.53 degrees Elevation:294 meters a .an Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec Avg}Fixed array |Lat-15 3.2 3.9 4.6 5.3 5.9 6.4 6.5 6.0 5.2 44 3.1 2.6 4.8 ;Latitude 3.6 4.3 4.7 5.2 5.5 5.8 6.0 5.8 5.3 4.7 3.4 3.0 4.8 Ad Lat+15 3.9 44 4.7 4.8 4.9 5.1 5.2 5.3 5.1 4.7 3.6 3.2 4.6 Single axis tracker Lat-15 3.8 4.9 5.8 6.9 77 8.6 8.7 8.0°6.8 5.5 3.7 3.1 6.1 Latitude 4.2 5.2 5.9 6.8 7.5 8.2 8.4 7.9 6.8 5.8 4.0 3.4 6.2 Lat+15 4.4 5.3 5.8 6.5 7 77 7.9 7.5 6.7 5.8 4.1 3.6 6 Dual axis tracker , . 4.5 5.3 5.9 6.9 7.8 8.8 8.9 8.1 6.9 5.8 4.1 37 6.4 215 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL MASON CITY Jan Fixed array Lat-15 3.1 Latirude 3.5 Llar+15 3.8 Single axis tracker Lat-15 3.7 Latitude 4.1 Lat+15 4.3 Dual axis tracker 4.3 SIOUX CITY Jan Fixed array Lat-15 3.1 Latitude 3.6 Lat+15 3.9 Single axis tracker Lar-15 3.8 Latitude 4.2 Lat+15 4.4 Dual axis tracker 4.4 WATERLOO 'Jan Fixed array Latr-15 3.0 Latitude 3.4 Lat+15 3.7 Single axis tracker Lat-15 3.6 Latitude 4.0 Lat+15 4.2 Dual axis tracker 4.2 BOISE Jan Fixed array Lat-15 2.5 Latitude 2.8 Lat+15 2.9 Single axis tracker Lat-15 2.9 Latitude 3.1 Lat+15 3.2 Dual axis tracker 3.3 216 Apr Latitude:43.15 degrees May 7.8 Jun 6.2 5.7 4.9 8.3 8.0 75 8.5 Jul 6.3 5.8 5.1 8.5 8.2 77 8.6 Aug 7.8 Latitude:42.40 degrees May 5.9 5.5 4.9 7.8 7.6 7.1 7.9 Jun 6.4 5.9 5.1 8.7 8.5 7.8 8.9 jul 6.5 6.0 5.3 8.9 8.5 § 9.0 Aug 6.1 5.8 5.3 8.1 8.0 7.6 8.] Latitude:42.55 degrees May 7.6 Jun 6.2 5.7 5.0 8.3 7.9 74 8.5 Jul 6.3 5.8 5.1 8.4 8.1 7.6 8.6 7.8 Latitude:43.57 degrees May =Jun 67 71 62 65 5.5 5.5 9.2 10.0 9.0 96 8.5 9 94 103 Jul 7.6 7.0 6.0 11.0 10.7 10 11.3 Aug 7.1 6.8 6.2 10.1 9.9 9.5 10.1 Elevation:373 metc.s Oct 5.4 Noy 2.8 3.1 3.2 3.3 3.5 3.6 3.6 Dec 2.5 2.8 3.0 2.9 3.2 3.3 3.4 Avg 4.6 4.6 4.4 6.2 Elevation:336 meters Oct Nov 3.0 3.4 3.5 4] Dec Avg 4.8 4.8 4.6 6.2 6.2 6.1 6.4 Elevation:265 meters Oct Nov 2.7 3.0 3.1 3.2 3.4 3.5 3.6 Dec 3.4 Avg 4.6 4.6 4.4 6.1 Elevation:874 meters Oct 4.9 5.2 5.3 6.3 3.7 6.7 6.7 Nov 2.9 3.2 3.3 3.4 2.9 3.8 3.8 Dec 2.3 2.6 2.8 2.7 6.9 3.1 3.1 Avg 5.1 - 5.1 4.8 6.9 8.1 6.7 71 POCATELLO Jan Feb Fixed arrayLat-15 2.6 3.6 "Latitude 2.9 3.9 Lar+15 3.0 4.0 Single axis trackerLat-15 3.0 4.4 Latitude 3.3 4.6 Lat +15 3.4 47Dualaxistracker3447° CHICAGO Jan Eeb Fixed array Lat-15 2.7 3.5 Latitude 3.1 3.8 Lat+15 3.3 3.9 Single axis tracker Lat-15 3.2 4.2 Latitude 3.5 4 Lat+15 3.7 4.5 Dual axis tracker 3.7 4.6 ROCKFORD an Feb Fixed array Lat-15 2.9 3.8 Latitude 3.3 4.1 Lat+15 3.6 4.2 Single axis tracker Lat-15 3.5 4.6 Latitude 3.8 49 Lat+15 4 5 Dual axis tracker 4.]5.0 SPRINGFIELD Jan Feb Fixed array Lat-15 3.1 3.9 Latitude 3.5 4.2 Lat+15 3.8 4.4 Single axis cracker Lat-15 3.8 4.8 Latitude 4.1 5.1 Lac+15 43 5.2 Dual axis tracker 4.4 5.2 6.9 6.5 Latitude:42.92 degrees May -Jun 63 6.8 5.9 6.2 5.2 5.4 86 9.6 83 93 78 87 8.7 9.9 Jul 7.3 6.7 5.8 10.4 10.1 9.5 10.7 Aug Latitude:41.78 degrees May Jun 58 61 54 57 48 49 74 8.0 7.20 «77 68 7.2 7.5 8.2 Jul 8.1 Aug 7.4 Latitude:42.20 degrees May =Jun 5.7 6.1 5.4 5.6 48 49 74 81 7.20 7.7 6.8 7.2 7.5 83 Jul 6.1 5.7 4.9 8.1 7.8 7.3 8.2 Aug 7.5 Latitude:39.83 degrees May -Jun 6.0 64 56 5.9 50 5.1 79 8.5 76 82 72°7.6 8.0 87 Jul 6.4 5.9 5.4 8.5 8.2 7.7 8.7 Aug 6.0 5.8 5.3 8.0 7.8 795 8.0 6.8 APPENDIX B -SOLAR DATA Elevation:1365 meters Oct Nov Dec Avg 4.9 2.9 2.3 5.0 5.3 3.2 2.6 5.0 5.3 3.4 2.8 4.7 6.3 3.5 2.7 6.7 6.6 3.8 3.0 6.7 6.7 3.9 3.1 6.5 6.7 3.9 3.2 6.9 Elevation:190 meters Oct Nov ec -Avg 3.9 2.5 2.2 44 4.2 2.8 2.4 4.4 4.2 2.9 2.6 4.1 4.8 2.9 2.5 5.5 5.0 3.1 2.7 5.5 5 3.2 2.9 5.3 5.0 3.2 2.9 3.7 Elevation:221 meters | Oct Nov Dec Avg 4.0 2.6 2.3 4.5 4.2 2.9 2.6 4.5 4.3 3.0 2.8 4.3 4.9 3.1 2.7 5.7 5.1 3.3 3.0 5.7 5.1 3.4 3.1 5.5 5.2 3.4 3.2 5.9 Elevation:187 meters Oct Nov Dec Avg 4.5 3.1 2.6 4.8 4.8 3.4 2.9 4.8 4.8 3.5 3.1 4.5 5.6°3.7 3.0 6.1 5.9 3.9 3.3 6.1 5.9 4.1 3.5 6 5.9 4.1 3.5 6.3 217 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL EVANSVILLE an Fixed array Lat-15 2.9 Latitude 3.3 Latr+15 3.5 Single axis tracker Lat-15 3.5 Latitude 3.8 Lar+15 3.9 Dual axis tracker 4.0 MOLINE Jan Fixed array Lat-15 2.9 Latitude 3.3 Lat+15 3.5 Single axis tracker. Lat-15 3.5 Latitude 3.8 Lat+15.4 Dual axis tracker 4.1 PEORIA Jan Fixed array Lat-15 2.9 Latitude 3.3 Latr+15 3.5 Single axis tracker Lat-15 3.5 Latitude 3.8 Latr+15 4 Dual axis tracker 4.0 FORT WAYNE Jan -Fixed array Lar-15 2.5 Latitude 2.8 Lat+15 3.0 Single axis tracker Lat-15 2.9 Latitude 3.2 Lat+15 3.3 Dual axis tracker 3.4 218 Latitude:38.05 degrees May Jun 5.9 6.3 5.6 5.8 4.9 5.0 7.7 8.4 7.5 8.1 7.1 7.5 7.8 8.6 Latitude:41.45 degrees May -Jun 5.8 6.2 5.4 5.7 4.8 4.9 7.6 8.3 7.3 7.9 5.9 7A 7.7 8.5 Jul 6.2 5.8 5.1 8.2 7.9 7.4 8.4 Jul 6.2 5.8 5.1 8.3 8.0 7.5 8.5 Aug 6.0 5.8 5.3 7.8 77 7.3 7.9 Aug 5.9 5.6 5.1 7.7 7.6 7.2. 77 Latitude:40.67 degrees May =Jun 5.8 6.3 5.5 5.8 4.8 5.0 7.6 8.3 74 8.0 6.9 7.4 7.7 8.5 jul 6.2 5.8 5.1 8.3 8.0 7.5 8.4 Aug 7.7 Latitude:41.00 degrees 57 6.1 54.5.6 48 49 73.«729 71 76 67 7A 74 81 Jul 6.0 5.6 4.9 7.8 7.6 7.4 8.0 Aug Elevation:118 mete.- Oct Nov 45 3.1 48 3.4 49 3.6 5.7 3.7 5.9 4.0 5.9 .41 6.0 41 Dec 3.5 Avg 4.7 47 4.5 6.0 6.0 5.9 6.2 Elevation:181 meters Oct Nov -42 2.8 45 3.1 4.5 3,3 5.2 3.4 5.5 3.6 5.5 3,7 5.5 3.7 Elevation:199 me Occ Nov 4.3 2.9 4.6 3.2 4.6 33 5.3 3.4 5.6 3.6 5.6 3.7 5.6 3.8 3.3 3.3 6.1 Elevation:252 meters Oct Nov 3.9 2.5 4.1 2.7 4]2.8 4.8 2.9 4.9 3.1 5 3.1 5.0 3.2 Dec 2.0 2.2 2.3 2.3 2.4 2.5 2.6 Avg 4.3 4.3 4.1 5.4 5.4 5.2 56 APPENDIX B -SOLAR DATA 'INDIANAPOLIS IN Latitude:39.73 degrees Elevation:246 meters oo eb ar Apr May fun Jul Aug Sep Oct Nov Dec Avg Fat-15 2:36 43 52 59 63 62 59 52 42 28 23 46 Latitude 3.1 3?44 51 56 58 yn ee ©4.6 :0 «430 «TAD SS 8A 5.1 45 32 27 43 "Lat -15 3.3 43.5.2 6.5 7.6 8.2 8.1 77 6.6 5.2 3.3 2.7 5.7 Latitude 3.6 4.6 5.3 6.5 74 7.9 7.8 7.5 6.7 5.5 3.5 2.9 5.8 "-Yat+15 3.7 47 5.2 6.2 6.9 73 73 7.3 6.5 5.5 3.6 3 5.6. -Dual axis tracker 3.7 47 5.3 6.6 77 8.4 8.3 77 6.7 5.5 3.6 3.1 5.9 "SOUTH BEND IN Latitude:41.70 degrees Elevation:236 meters nee Mat=s Apr May «Jun Jul,ug Sep Ost Nez De S Fixed array Lat-15 2.4 3.3 4.0 5.0 5.7 6.1 6.0 5.6 48 3.7 2.3 1.9 42 Latitude 2.7 3.5 4.1 48 5.4 5.6 5.6 5.4 4.8 3.9 2.5 2.0 42 Lat+15 2.8 3.6 4.0 45 47 48 49 49 4.6 3.9 2.6 2.1 4.0 4.8 4.9 4.8 Single axis trackerLat-15 2.7 3.9 6.2 7.3 7.9 7.8 7.2 6.0 4.5 2.6 2.1 5.3 Latitude ©3.0 4.1 6.1 7A 7.6 7.5 7A 6.0 47 2.8 2.2 5.3 Lat+15 3.1 4.1 5.8 6.6 7 7 6.7 5.9 47 2.9 2.3 5.1 Dual axis tracker 3.1 4.2 4.9 6.2 74 8.1 7.9 7.3 6.1 47 2.9 2.3 5.4 DODGE CITY KS Latitude:37.77 degrees Elevation:787 meters ee,Fixed array -Lat-15 4.0 48 Latitude 4.6 5.3 5.8 6.2 6.1 6.4 6.5 6.4 Lat+15 5.0 5.5 5.7 5.8 5.4 5.5 5.7 5.8 Single axis tracker ; Latr-15 5.1 6.1 7.2 8.4 8.7 9.4 9.6 8.8 77 6.7 5.0 4.5 7.3 Latitude 5.6 6.5 7A 8.3 8.4 9.0 9.2 8.7 7.8 7.0 5.5 5.0 74 Lac+15 5.8 6.6 7.3 8 7.9 8.4 8.6 8.2 7.6 7.1 5.7 5.3 7.2 Dual axis tracker 5.9 6.6 7.4 8.4 8.8 9.7 9.7 8.9 78 97.1 5.7 5.4 7.6 5.6 4.6 4.2 5.6 Sep 565 63.(657 TAL 6G 5D 8B 40 36 5.5 6.0a ee<< GOODLAND ,KS Latitude:39.37 degrees Elevation:1124 meters Jan 'Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.9 4.6 5.4 6.2 6:4 7.0 7.0 6.7 6.0 5.3 4.0 3.6 5.5 Latitude 4.5 5.1 5.7 6.1 6.0 6.4 6.5 6.4 6.1 5.7 4.6 4.2 5.6 Lat+15 4.9 5.3 5.6 57 =5.3 5.5 5.6 5.8 5.8 5.8 4.8 4.6 5.4 Single axis tracker Lat-15 4.9 5.9 7.1 8.3 8.6 9.6 97°9h 8.0 6.9 5.0 4.5 7.3 on Latitude 5.4 6.3 7.3 8.3 8.3 9.2 9.4 8.9 8.0 7.2 5.5 49.74 te Lat+15 5.7 6.4 7.2 8 7.8 8.6 8.8 8.5 7.9 7.3 5.7 5.3 7.3cuantosinnerpeunaiapid_sccmlassleeslgeinsc...1.ot:Dual axis cracker *57 64 73 84 87 99 9.9.91 8.1 73°57 53 77° 219 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL TOPEKA Jan Fixed array Lat-15 3.4 Latitude 3.9 Lar+15 4.2 Single axis tracker Lar-15 4.2 Latitude 4.6 Lat+15 4.8 Dual axis tracker 4.9 WICHITA Jan Fixed array Lat-15 3.6 Latitude 4.2 Lat+15 4.5 Single axis tracker Lat-15 4.5 Latitude 5.0 Lat+15 5.2 Dual axis tracker 5.3 COVINGTON Jan Fixed array Lat-15 2.7 Latitude 3.0 Lat+15 3.2 Single axis tracker Lat-15 3.2 Latitude 3.5 Lat+15 3.6 Dual axis tracker 3.6 LEXINGTON Jan Fixed array Lat-15 2.8 Latitude 3.1 Lat+15 3.3 Single axis tracker Lat-15 3.3 Latitude 3.5 Lat+15 3.7 Dual axis tracker 3.7" 220 KS Apr 5.5 5.4 5.0 7.1 7.0 6.7 7.1 Latitude:39.07 degrees May 7.8 Jun 6.3 5.8 5.0 8.4 8.0 7.5 8.5 Jul 6.5 6.0 5.3 8.8 8.5 7.9 8.9 Aug 6.1 5.9 5.3 8.1 8.0 7.6 8.2 Latitude:37.65 degrees May 6.1 5.7 5.1 8.0 7.8 7.3 8.1 jun 8.9 Jul 6.8 6.3 5.5 9.1 8.8 8.3 9.3 Aug 8.6 Latitude:39.07 degrees May 7.4 Jun 6.1 5.6 4.9 7.9 7.6 71 8.1 Jul 7.9 Aug 5.8 5.6 5.1 7.5 Latitude:38.03 degrees May fun 57 6.0 54 5.6 48 48 7.3 7.8 710 7.5 6.7 7 74 8.0 Jul Aug Elevation:270 meters Oct 4.6 4.9 49 6.1 Oct 4.8 5.2 5.3 6.2 6.5 6.5 6.6 Nov 5.2 Dec 4.2 Dec 3.3 3.8 4.) 4.0 4.4 4.7 4.7 Avg 4.9 4.9 4.7 6.3 6.4 6.2 6.6 Elevation:408 meters Nov Avg 5.2 5.2 5.0 6.7 6.8 6.6 7.0 Elevation:271 meters Oct 5.5 Nov 2.8 3.1 3.2 3.3 3.5 3.6 3.6, Dec 2.3 2.5 2.7 2.6 2.8 2.9 3.0 Avg 4.5 4.5 4.2 5.6 5.6 5.4 5.8 Elevation:301 meters Oct Nov Dec 2.4 2.7 2.9 2.8 3.1 3.2 3.2 APPENDIX 8 -SOLAR DATA KY Latitude:38.18 degrees Elevation:149 meters eh =Mar «=Apr_-«-May =Jun jul Aug Sep Oct Nov Dec Avg 4.4 5.3 5.8 6.2 6.0 5.9 5.1 4.4 3.0 2.4.4.6 3.6 3.9 4.5 5.2 5.5 5.7 5.6 5.7 5.2 4.7 3.3 2.7 4.6 4.0 44 4.8 4.9 4.9 4.9 5.1 5.0"4.7 3.4 2.9 4.40 Lat +15Singleaxis trackerTar1533044 54 67 75 80 78 75 65 54 35 28 5.7 "Tatimde 3.6 46 55 66 72 77 75 74 66 57 3.8 3.1 5.8 Tat+15 37 47 54 63 68 72 71 7 64.57 39 3.2 5.6 *-Dual axis 'tracker . 3 47.- C«'(DCT 7H 82 8.076 GST 89 3.2 6.0 a |BATON ROUGE LA Latitude:30.53 degrees Elevation:23 meters jon Feb «|Mac«=Apt May Jun Jul Ang sep Oct Nov Dec Ag Fixed array Lat-15 3.2 4.0 4.8 5.6 5.9 5.9 5.6 5.6 5.2 5.0 3.7 3.1 4.8 "Latitude 3.6 4.4 5.0 5.5 5.5 5.5 5.3 5.4 5.2 5.3 4.1 3.6 4.9 Lat+15 3.8 45 4.9 5.1 4.9 47 4.6 4.9 5.0 5.4 4.4 3.8 47 Single axis trackerLat-15 3.9 5.0 6.1 7.1 7.4 75 7.0 6.9 6.5 6.3 4.6 3.8 6.0 Latitude 4.2 5.3 6.2 7.0 7.2 7.2 6.7 6.8 6.5 6.6 4.9 4.2 6.1 Lat+15 44 54 6.1 6.7 6.8 6.7 6.3 6.4 6.4 6.7 5.1 4.4 5.9 Dual axis tracker 5.4 6.2 7A 7.5 7.6 .7.4 6.9 6.6 6.7 5.1 4.5 6.3 LAKE CHARLES LA Latitude:30.12 degrees Elevation:3 meters hn Fee «=Mar «Apr May «un Jul,Aug Sep SS Nov Dec Ag Fixed array Lat-15 3.3 4.1 49 5.5 6.0 6.2 5.9 5.7 5.4 5.0 3.9 3.2 4.9 Latitude 3.7 45 5.1 5.4 5.6 5.7 5.5 5.6 5.4 5.4 4.3 3.7 5.0 Lat+15 3.9 4.6 4.9 5.1 4.9 5.1 5.2 5.4 4.6 3.9 4.8 ; 5.0 5.0 a4 Single axis tracker - :Lat-15 4.0 5.2 6.1 6.9 7.5 7.8 73 7.2 6.7 6.3 4.8 3.9 6.1 Latitude 4.3 5.4 6.2 6.9 7.2 7.5 7.0 7.0 6.8 6.6 5.2 4.3 6.2 Lat+15 4.5 5.5 6.1 6.6 6.8 6.9 6.6 6.7 6.6 6.6 5.3 4.5 6.1 Dual axis tracker , 4.5 5.5 6.2 7.0 7.5 79.7.4 7.2 6.8 6.7 5.4 4.5 6.4 i NEW ORLEANS'LA Latitude:29.98 degrees Elevation:3 meters ence Mars Apr:May=sdun sul ug Sep Qt Nex Ps Fixed array Lat-15 3.3 4.2 49 5.7 6.0 6.0 5.7 5.6 53 5.0 3.8 3.2 4.9 Latitude'3.7 4.5 5.0 5.6 5.7 5.5 5.3 5.4 5.3 5.3 43.37 5.0 Lat+15 3.9 4.6 4.9 5.3 5.1 4.8 4.7 4.9 5.1 5.4 4.5 3.9 4.8 Single axis trackerLat-15 4.0 5.2 6.1 73 77 7.5 6.9 6.9 6.6 6.3 4.7 3.9 6.1 Latitude 4.3 5.5 6.3 73 7A 72 6.7 6.7 6.6 6.6 5.1 4.3 6.2 Lar+15 4.5 5.6 6.2 7 7 6.7 6.2 6.4 6.5 6.7 5.3 4.5 6 Dual axis tracker 4.5 5.6 6.3 7.3 7.8 77 7.0 6.9 6.6 6.7 5.3 4.5 6.4neskjartgceremrnasetehdeteetoweredeem ametatevangeatias221 aed PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL SHREVEPORT Jan Feb Fixed array Lat-15 3.4 4.1 Latitude 3.8 4.5 Lat+15 4.0 4.6 Single axis tracker Lat-15 4.1 5.2 Latitude 4.4 5.4 Lat+15 4.6 55 Dual axis tracker 47 5.5 BOSTON Jan Feb Fixed array Lat-15 3.0 3.8 Latitude 3.4 4.2 Lat+15 3.6 4.3 Single axis tracker Lac-15 3.6 4.7 Latitude 3.9 5.0 Lat+15 4.1 5.1 Dual axis tracker 4.1 5.1 WORCHESTER an eb Fixed array Lat-15 3.0 3.8 Latitude 3.4 4.2 Lat+15 3.6 4.4 Single axis tracker Lat-15 3.5 47 Latitude 3.9 5.0 Lat+15 4.1 5.1 Dual axis tracker 4.1 5.1 BALTIMORE an eb Fixed array Lat-15 3.1 3.8 Latitude 3.5 4.2 Lat+15 3.7 4.3 Single axis tracker Lat-15 3.7 4.7 Latitude 4.1 5.0 Lat+15 43 5.1 Dual axis tracker 4.3 5.1 222 LA Latitude:32.47 degrees May 6.0 5.7 5.0 7.6 7.4 7 7.7 Jun 6.3 5.8 5.0 8.1 7.7 7.2 8.2 Jul 6.3 5.9 5.2 8.2 7.9 7.3 8.3 8.0 Latitude:42.37 degrees May 5.7 5.3 4.7 7.3 7.1 6.6 7.4 Jun 7.9 Jul 7.9 Aug 7.3 Latitude:42.27 degrees May 7.1 May 5.7 5.3 4.7 Jun 7.7 Jun 6.0 5.6 4.8 7.8 7.5 7 8.0 jul 7.7 jul 6.0 5.5 4.9 7.7 7.4 6.9 7.8 Aug 5.6 5.3 4.8 71 6.9 6.6 7.1 Latitude:39.18 degrees Aug 5.6 5.4. 4.9 Sep Elevation:79 meters Oct 4.9 5.2 5.3 6.2 6.5 6.7 6.6 Elevation:5 meters Oct Nov 4.1 4.3 4.4 5.0 5.2 4ae 5.3 Nov 3.7 4.2 4.4 4.6 5.0 5.3 5.2 2.8 3.1 3.3 3.4 3.6 3.7 3.8 4.6 Dec 3.4 Avg 5.0 5.1 4.9 6.3 6.4 6 6.6 5.9 Elevation:301 meters Oct 4.0 4.3 4.3 4.9 5.1 5.1 5.2 Nov 2.8 3.0 3.2 3.2 3.5 3.6 3.6 Dec 2.4 2.8 3.0 Avg 4.5 4.5 4.3 5.8 Elevation:47 meters Oct 4.3 4.6 4.6 Nov 3.2 3.6 3.7 3.9 4.2 43 4.3 Avg 4.6 4.6 4.4 APPENDIX B -SOLAR DATA ME Latitude:46.87 degrees Elevation:190 meters Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg FS 29 50 51 53 56 56 52 43 31 22 22 423.933)43 52)5049S 5 4B KS 4DLae3s454744454G45483252740 Cingle axis trackersneee34 48 (63)66)7.0 74 74 67 55 BBS 265 fede 37 «51 650 (65 GT OTL 72 66 563.927 BS ae 3983 SCS OB KH CT 638 5489 288 SD Dual axis tracker -4.0 5.2 6.5 6.6 71 7.6 7.6 6.8 5.6 4.0 2.8 3.0 5.6 'PORTLAND ME Latitude:43.65 degrees Elevation:19 meters 'Fixed array Lat-15 °3.1 4.1 4.8 5.2 5.7 6.0 6.0 5.8 5.1 4.0 2.8 2.6 4.6 'Latitude 3.6 4.5 5.0 5.1 5.3 5.5 5.6 5.5 5.1 4.3 3.1 3.0 4.6 Lat+15 3.9 47 5.0 4.7 47 47 4.9 5.0 4.9 4.3 3.2 3.2 44 Single axis tracker Lat-15 3.8 5.1 6.1 6.7 7.4 7.9 7.9 7.5 6.5 5.0 3.3 3.1 5.9 Latitude 4.2 54 +63 6.6 7.1 7.5 7.6 °7A 6.6 5.2 3.6 3.4 5.9 "Lar+15 4.4 5.6 6.2 6.3 6.7 7 7.1 7 6.4 5.2 3.7 3.6 5.8 Dual axis tracker 4.5 5.6 6.3 6.7 75 8.1 8.1 7.6 6.6 5.3 3.7 3.6 6.1 ALPENA _Mi .Latitude:45.07 degrees Elevation:210 meters Fixed array Lat-15 2.5 3.6 4.7 5.2 5.8 6.1 6.1 5.5 4.5 3,3 2.1 1.8 43 Latitude 2.8 3.9 49 5.1 5.4 5.5 5.7 5.3 4.5 3.5 2.3 2.0 4.2 Lat+15 2.9 4.0 4.9 4.7 4.8 4.8 4.9 4.8 43 3.5 2.3 2.1 4.0 Single axis tracker Lat-15 2.9 4.3 6.0 6.8 7.8 8.2 8.4 74 5.7 4.0 2.4 2.1 .5.5 Latitude 3.1 4.6 6.1 6.7 75 79 8.1 7.2 58 42 2.5 2.2 5.5 Lat+15 3.3 47 6.1 6.4 7.1 74 7.6 6.9 5.6 4.2 2.6 2.3 5.4 -Dual axis tracker33 47 #61 68 #79 85 86 74 58 42 26 24 «257 7 DETROIT MI Latitude:42.42 degrees Elevation:191 meters Jan Feb Mar Apt May Jun Jul Aug Sep Oct Nov Dec Axg Fixed array : Lat-15 2.4 3.3 4.1 5.0 5.7 6.1 6.1 5.6 .48 3.7 2.4 1.9 4.3 Latitude 2.7 3.6 4.2 4.9 5.4 5.6 5.6 5.4 4.8 3.9 2.6 2.1 4,2 Lat+15 2.8 3.7 4.1 4.5 4.8 4.9 4.9 49 4.6 3.9 2.6 2.2 4.0 Single axis tracker Lat-15 2.8 4.0 5.0 6.3 74 8.0 8.0 7.3 6.0 45 2.7 2.1 5.3 Latitude 3.0 4.2 5.1 6.2 7.1 7.7 7.7 7.1 6.1 4.7 2.9 2.3 5.3 Lat+15 3.)4,3 5 5.9 6.7 7.1 7.2 6.8 5.9 4.7 2.9 2.4 5.2 Dual axis tracker © 3.1 4.3 5.1 63»7.5 8.2 8.2 7.3 6.1 4.7 3.0 2.4 9.9 223 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL FLINT Fixed array Lat-15 2.3 Latitude 2.6 Lar+15 2.7 Single axis tracker Lat-15 2.7 Latitude 2.9 Lat+15 3 'Dual axis tracker 3.1 Jan 4.3 GRAND RAPIDS Jan Fixed array. Lat-15 2.3 Latitude 2.5 Lat+15 2.6 . Single axis tracker Lat-15 2.6 Latitude 2.8 Lat+15 2.9 Dual axis tracker 2.9 HOUGHTON Jan Fixed array Lat-15 2.1 Latitude 2.3 Lat+15 2.5 Single axis tracker Lat-15 2.4 Latitude 2.6 Lat+15 2.7 Dual axis tracker 2.7 LANSING Jan Fixed array Lat-15 2.4 Latitude 2.6 Lat+15 2.8 Single axis tracker Lat-15 2.7 Latitude 2.9 Lat+15 3.1 Dual axis tracker 3.1 224 Feb Latitude:42.97 degrees May Jun 5.7 6.0 5.3 5.5 47 47 7.3 7.8 710 7.5 6.6 7 74 8.0 Jul 6.0 5.5 4.8 7.9 7.6 7.2 8.1 Aug 7.2 Latitude:42.88 degrees May =Jun 5.8 6.2 5.4 5.7 4.8 4.9 7.6 8.2 7.3 7.9 6.9 74 7.7 8.4 Jul 6.1 5.7 5.0 8.2 7.9 7.4 8.3 Aug 7.5 Latitude:47.17 degrees May =Jun 5.6 5.9 5.3 5.4 47 4.7 76 82 74 7.8 7 7.3 7.7 8.4 Jul 6.0 5.6 4.8 8.3 8.0 7.5 8.4 Aug 7.4 Latitude:42.78 degrees 5.7 6.0 5.3 5.6 47 4,8 74 7.9 7.1 7.6 6.7 7.1 7.5 8.1 Jul 6.1 5.6 4.9 8.0 7.7 7.2 8.1 Aug Elevation:233 meters Oct 4.5 Nov 2.2 2.4 2.5 25 2.7 2.8 2.8 Dec 1.8 2.0 2.1 2.0 2.2 2.3 2.3 Avg 4.2 4.1 3.9 5.4 Elevation:245 meters Oct 4.5 Nov 2.2 2.4 2.5 2.5 2.7 2.7 2.8 Dec 2.2 Avg 5.5 Elevation:329 meters Oct 4.1 Nov '19 2.1 2.1 2.4 Dec 1.6 1.8 1.9 1.8 2.0 2.1 2.1 Ave 4.1 4.1 3.8 5.3 5.3 5.2 5.5 Elevation:256 meters Oct Nov 2.3 2.4 2.5 2.6 2.7 2.8 2.8 Dec 1.8 2.0 2.1 2.1 2.2 2.3 2.3 Avg 4.2 4.2 4.0 APPENDIX B -SOLAR DATA -MUSKEGON MI Latitude:43.17 degrees Elevation:191 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg peernen 3.1 52 60 63 64 48 35 24 16 43425.8 cla 33 48 SL 5G OBO 5G DBT DB 4pas234424750505SLGBT23BD”Single axis trackerets2300 BTL GB 83 8S 7H GL 4 23 1B SAToiude24«238 «45.2 «4660 76060 (80 8275 G1 455 fel 25 39 52 7S OTT OL GBS SD -.Dual axis tracker 2.5 3.9 5.3 6.7 7.9 8.5 8.7 77 6.2 44 2.5 2.0 5.5 SAULT STE.MARIE MI Latitude:46.47 degrees Elevation:221 meters Jan Feb Mar Apr May Jun Jul Aug Sep Qc Noy Dec AvgFixedarray la-15 25 38 S51 54 58 59 60 54 42 30 19 #419 43 ee Latitude 2.8 4.2 5.3 5.3 5.4 5.4 5.6 5.2 4.2 3.1 2.1 2.2 4.2 on Iat+15 29 43 53 50 48 47 49 47 40 31 21 23 40. 3 Single axis tracker Lat-15 2.9 4.6 6.4 7.1 7.9 8.1 8.3 7.2 5.3 3.6 2.2 2.2 5.5 Latitude 3.1 4.9 6.6 7.1 7.6 7.8 8.0 7.0 5.3 3.7 2.3 2.4 5.5 Lat+15 3.2 5 6.6 6.8 7.2 7.3 7.5 6.7 5.2 3.7 2.4 2.5 5.3 Dual axis tracker 3.3 5.0 6.6 7.1 8.9 8.3 8.5 7.2 5.4 3.7 2.4 2.5 5.7 TRAVERSE CITY Ml Latitude:44.73 degrees Elevation:192 meters Fixed array ; Lat-15 2.1 3.3 4.4 5.0 5.8 6.1"6.1 5.4 4.4 3.2 2.0 1.6 4.4 Latitude 2.3 3.5 4.6 4,9 5.4 5.6 5.6 5.2 4.4 3.4 2.1 1.8 4] Lat+15 2.4 3.6 4.5 4.6 4.8 4.8 4,9 4.7 4.2 3.3 2.1 1.8 3.8 Single axis tracker Lat-15 2.3 3.8 5.4 6.5 7.6 8.1 82.7.1 5.6 3.8 2.2 1.8 5.2 Latitude 2.5 4.0 5.6 6.4 7.4 7.8 7.9 7.0 |5.6 3.9 2.3 19°(5.2 Lat+15 2.6 4.1 5.5 6.2 7 7.3 7.4 6.6 5.4 3.9 2.4 2 5 Dual axis tracker 2.6 4.1 5.6 6.5 77 8.3 8.3 7.2 5.6 4.0 2.4 2.0 5.4 DULUTH MN Latitude:46.83 degrees Elevation:432 meters Fixed array Lat-15 28 4.0 5.0 5.5 5.7 5.9 6.1 5.5 4.5 3.4 2.4 2.2 4.4 Latitude 3.2 4,4 5.2 5.4 54°5.4 5.6 5.3 °4.5 3.6 2.6 2.5 4.4 Lat+15 3.4 4.5 5.2 5.1 4.7 47 4,9 4.8 4.3 3.6 2.7 2.7 |4.2 Single axis tracker Lat-15 3.3 4.9 6.3 7.2 7.6 7.9 8.3 7.3 5.7 4.2 2.7 2.6 5.7 Latitude 3.7 5.2 6.5 7.1 7.4 7.6 8.0 7.2 5.7 4,3 2.9 2.9 5.7 :Lat+15 3.8 5.3 6.5 6.9 7 71 75 6.8 5.5 4.3 3 3 5.6 ,Dual axis tracker . 3.9 5.3 6.5 7.2 7.8 8.1 8.5 7.4 5.7 '44 3.1 31 5.9 225 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL INTERNATIONAL FALLS MN Jan FebFixedarray Lat-15 2.6 3.9 'Latitude 3.0 4.3 Lat+15 3.2 4.5 Single axis tracker Lat-15 3.1 4.8 Latitude 3.4 5.1 Latr+15 3.6 5.2 Dual axis tracker 3.6 5.2 MINNEAPOLIS Jan Feb Fixed array Lat-15 3.1 4.1 Latitude 3.5 45 Lac+15 3.8 4.7 Single axis tracker Lar-15 3.7 5.0 Latitude 4.0 5.4 Lat+15 43 5.5 Dual axis tracker 4.3 5.5 ROCHESTER Jan FebFixedarray Lat-15 2.9 3.9 Latitude 3.3 4.2 Lat+15 3.6 44 Single axis tracker Lat-15 3.5 4.8 Latitude 3.8 5.1 Lat+15 4 5.2 Dual axis tracker 4.1 5.2 SAINT CLOUD Jan Feb Fixed array Lat-15 3.0 41 Latitude 3.4.4.5 Lat+15 3.7 47 Single axis tracker Lat-15 3.6 5.0 Latitude 3.9 5.4 Lat+15 4.1 5.5 Dual axis tracker 4.2 5.5 226 Mar 4.9 5.1 5.1 6.3 6.4 6.4 6.4 Apr Latitude:48.57 degrees May 5.6 5.2 4.6 7.6 7.4 7 7.7 Jun 5.7 5.2 4.5 7.7 74 7 8.0 Jul 5.9 5.4 4.7 8.1 7.8 7.4 8.3 Aug 5.4 5.1 4.6 7.3 7.1 6.8 7.3 Latitude:44.88 degrees May 7.9 Jun 6.1 5.6 4.9 8.3 8.0 7.4 8.5 Jul 6.4 5.9 5.1 8.7 8.4 7.9 8.9 Aug 7.9 Latitude:43.82 degrees May 5.7 5.3 47. 7.5 7.2 6.8 7.6 Jun 8.2 Jul 6.2 5.7 5.0 8.3 8.0 7.5 8.5 Aug 5.7 5.5 4.9 75 7.4 7 7.6 Latitude:45.55 degrees May Jun 6.1 5.6 4.8 8.2 7.9 7.4 8.5 Jul 6.3 5.8 5.1 8.7 8.4 7.9 8.9 Aug 5.8 5.6 5.0 7.8 7.7 7.3 7.9 Elevation:361 meters Oct 3.9 Nov 2.7 Dec 2.1 2.4 2.6 2.4 2.7 2.9 2.9 Avg Elevation:255 meters Oct 5.1 Nov Dec 2.3 2.7 2.9 2.7 3.0 3.2 3.2 Avg 6.2 Elevation:402 meters Oct 5.0 Nov 2.6 2.8 2.9 3.0 3.2 3.3 3.3 Dec 3.1 Avg 5.9 Elevation:313 meters Oct Nov Dec 2.3 2.6 2.8 2.7 2.9 3.1 3.1 Avg APPENDIX B -SOLAR DATA MO Latitude:38.82 degrees Elevation:270 meters Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Axg Fined 0 5 3 4.0 4.7 5.6 53 Latitude 3.8 44 4.9 5.5 5.6 5.9 6.1 5.9 5.4 4.9 3.6 3.2 49 }>5.1 6.0 6.4 6.6 6.2 4.5 3.2 2.8 4.9 5.0 5.1 5.3 5.4 4.9 3.8 3.4 4.7Tt+is 40 45 48Singleaxistrackeres40049597278,84 87 80 6B 87 39 33 62Fide4452607176B81847.9 69 60 42 37 63 eis 46 «453 «5.9 «68 «=7.1 760 78 75 (67 44 39 G61 Dual axis tracker 5.3 6.0 7.2 7.9 8.6 8.8 8.1 6.9 6.0 4.4 3.9 6.5 KANSAS CITY MO Latitude:39.30 degrees Elevation:315 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.4 4.0 4,7 5.5 5.9 63°6.5 6.1 5.3 4.6 3.4 2.9 4.9 Latitude 3.8 43 48 5.4 5.6 5.8 6.0 5.9 5.4 5.0 3.8 3.3 4.9 Lat+15 4.1 44 4.7 5.0 4.9 5.0 5.3 5.3 5.2 5.0 4.0 3.5 4.7 Single axis trackerLat-15 4.1 4.9 5.9 71 7.8 8.4 8.8 8.1 6.9 5.9 4.1 3.5 6.3 Latitude 4.5 5.2 6.0 7.0 7.5 8.1 8.5 8.0 7.0 6.2 45 3.8 6.4 Lat+15 4.7 5.3 5.9 6.7 7.1 7.5 7.9 7.6 6.8 6.2 4.6 4 6.2 Dual axis tracker48.4«530 C« CtC'(CT (tTCGC(<C WDC'i OT ST.LOUIS MO Latitude:38.75 degrees Elevation:172 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array . Lat-15 3.2 3.8 5.4 5.9 6.3 6.3 6.0 5.3 4,5 3.2 2.7 4.8 Latitude 3.6 4.2 4.7 5.3 5.6 58 5.9 5.7 5.3 4.8 35 3.1 4.8 Lat+15 3.8 4.3 4.6 4.9 4.9 5.0 5.1 5.2 5.1 4.8 3.7 3.3 4.6 Single axis tracker Lac-15 3.8 4,7 5.7 6.9 7.7 8.3 8.4 7.8 6.8 5.6 3.8 3.2 6.1 Latitude 4.2 5.0 5.8 6.8 75 7.9 8.1 77 6.8 5.9 4.1 3.5 6.1 Lat+15 4.4 5.1 5.7 6.5 7 7.4 7.6 °7.3 6.7 5.9 4.2 3.7 6 Dual axis tracker 4.4 5.1 58 69 #78 85 85 79 69 59 43 37 6.3 SPRINGFIELD MO Latitude:37.23 degrees Elevation:387 meters Jan Feb Mar Ape May ==Jun Jul Aug Sep Oct Nov Dec Avg Fixed array : Lat-15 3.4 3.9 4.7 5.6 5.9 6.2 6.5 6.2 5.3 4.6 3.4 2.9 4.9 Latitude 3.8 4.3 4.9 54 -5.6 5.7 6.0 5.9 5.4 4.9 3.8 3.3 4.9 Lat+15 4.1 44 4.8 5.0 4.9 5.0 5.2 5.4 5.1 5.0 3.9 3.5 4.7 Single axis tracker Latr-15 41 49 6.0 7A 77 8.2 8.7 8.2 6.8 5.9 4.1 3.5 6.3 Latitude 4.5 5.1 6.1 7.1 7.5 7.9 8.4 8.0 6.9 6.1 4.4 3.8 6.3 Lat+15 4.2 5.7 6 6.8 7 74 7.9 7.6 6.7 6.2 4.6 4 6.2 Dual axis tracker 47 52 «61)O72stCi«T72C("<i'a KSC CD DG 48S 22/7 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL JACKSON Jan Fixed array Lar-15 3.3 Latitude 3.7 Lat+15 4.0 Single axis tracker Lat-15 4.1 Latitude 4.4 Lat+15 4.6 Dual axis tracker 4.6 MERIDIAN Jan Lat-15 3.2 Latitude 3.6 Lar+15 3.8 'Fixed array Single axis tracker Lat-15 4.0 Latitude 4.3 Lat+15 4.4 Dual axis tracker 4.5 BILLINGS Jan Fixed array Lat-15 2.9 Latitude 3.3 Lat+15 3.5 Single axis tracker Lat-15 3.5 Latitude 3.8 Lat+15 4 Dual axis tracker 4.0 CUT BANK Jan Lat-15 2.6 Latitude 3.0 Lat+15 3.2 'Fixed array Single axis tracker Lat-15 3.1 Latitude 3.4 Lat+15 3.6 Dual axis tracker 3.6 . 228 MS Mar 5.0 5.2 5.1 6.4 6.5 6.4 Apr 5.8 5.7 5.3 7.4 7.3 7.1 7.4 Latitude:32.32 degrees May 6.1 5.8 5.1 7.8 7.6 7.1 7.9 Jun 6.3 5.8 5.0 8.0 7.7 7.1 8.2 Jul 6.1 5.7 5.0 7.7 74 6.9 7.8 Aug 6.0 5.8 5.3 7.6 Latitude:32.33 degrees May 5.9 5.6 5.0 7.5 7.2 6.8 7.6 un 6.0 5.6 4.9 7.6 7.3 6.8 7.8 Jul 7.3 Aug 7.1 Latitude:45.80 degrees May 6.0 5.6 8.3 Jun 6.6 6.0 5.2 9.2 8.8 8.3 9.4 Jul 7.1 6.5 5.7 10.1 9.7 9.1 10.3 Aug 6.7 6.5 5.9 9.4 9.2 8.8 9.4 Latitude:48.60 degrees May 6.1 5.7 5.1 8.4 8.2 7.7 8.6 Jun 6.5 5.9 5.1 9.1 8.7 8.2 9.3 Jul 7.0 6.5 5.6 10.1 9.8 9.2 10.3 Aug . 6.5 6.2 - 5.6 9.0 8.9 8.4 9.1 Elevation:101 metet Oct 5.0 5.3 5.4 6.3 6.6 6.6 6.7 Nov 3.7 4.2 4,4 4.6 5.0 5.2 5.2 Dec Avg 5.0 5.1 4.9 6.3 6.4 6.2 6.6 Elevation:94 meters Oct 4.8 5.2 5.2 6.1 6.4 6.4 6.4 Nov 5.1 Dec 4.4 Elevation:1088 Oct 4.5 4.8 4.9 5.7 6.0 - 6 6.1 Nov 4.3 Dec 2.7 3.1 3.3. 3.2 3.5 3.7 3.8 Elevation:1170 Oct 4.3 4.6 4.6 5.4 5.7 5.7 5.7 Nov 2.9 3.3 3.5 Dec 2.4 2.7 2.9 2.8 3.1 3.2 3.3 Avg 4.8 4.9 4.7 6.0 6.1 6 6.3 6.9 meters Avg 4.8 4.8 4.6 6.4 6.5 6.3 47 APPENDIX B -SOLAR DATA GLASGOW MT Latitude:48.22 degrees Elevation:700 meters Fixed arrayLge15 27 BT 58 64 68 64 52 41 28 23°47 Taide 31)41 50 53 555.9 638 GL 53 43 BL 26 47 [a+15 3.3 42 48 50 55 55 50 44 33 28 45 i is tracker 4 Single =32 OAS CBO OOsiOB BD DST 6D:Saude 35480 (63)7200-770 8G OA BT 6D 5.38 3G 8.63 :Ite 1s 37 49 «62 6D 7B BL BD 838 6B 5B 87 BL OG é ;Dual axis tracker fe 37 §0 63 7.3 811 92 100 89 7.0 54 3.7 3.2 6.5 :_GREAT FALLS MT Latitude:47.48 degrees Elevation:1116 meters 4 Jan Feb Mar Apr May Jun Jul Ang Sep Oct Nov Dec Avg E Fixed array 4 lat-15 26 37 48 55 60 66 72 #65 #%54 43 #29 23 48 a latitude 3.0 40 50 54 56 60 66 63 55 46 33 27 48 4 Lat+15 32 42 50 50 49 5.2 57 57 53 46 34 29 4.6 Lat-15 3.1 4.5 6.1 7.2 8.1 9.1 10.2 9.0 7.2 5.3 3.5 2.7 6.3 Latitude 3.4 4.8 6.3 7.2 7.8 8.7 9.8 8.9 7.3 5.6 3.7 3.0 6.4 Lat+15 3.5 4.9 6.2 6.9 7.4 8.2 9.2 8.4 7.1 5.6 3.9 3.2 6.2 :Dual axis tracker . :3.6 4.9 6.3 73 8.2 9.3 10.4 9.1 7.3 5.6 3.9 3.2 6.6 i Single axis tracker i HELENA MT Latitude:46.60 degrees Elevation:1188 meters Fixed array Lat-15 2.5 3.6 4.6 5.4 5.9 6.4 7A 6.5 5.5 4.3 2.8 2.2 4.7 Latitude 2.8 3.9 4.8 5.3 5.5 5.8 6.5 6.2 5.6 Lat+15 3.0 4.0 4.7 4.9 4.9 5.0 5.7 5.7 5.4 Single axis tracker Lac-15 3.0 4.3 5.8 7.1 8.1 8.9 10.2 9.2 7.4 5.5 3.4 2.6 6.3 Latitude 3.2 4.6 6.0 7.0 7.8 8.6 9.9 9.0 7.5 5.7 3.6 2.9 6.3" Lat+15 3.4 4.7 5.9 6.7 7.4 8 9.3 8.6 7.3 5.7 3.8 3 6.2 Dual axis tracker 3.4 4.7 6.0 7.1 8.2 9.2 10.4 9.2 7.5 5.8 3.8 3.1 6.5 4.6 3.1 2.6 47 4.7 3.3 2.8 4.5 KALISPELL MT Latitude:48.30 degrees Elevation:904 meters Jan Feb =Mar Apr =May =Jun Jul «=Aug.«Sep «=Oct,«=Nov Dec AvgFixedarray Lar-15 1.9 2.9 4.0 4.9 5.5 6.0 6.7 6.2 5.1 3.6 1.9 1.5 Latitude 2.1 3.1 4.1 4.8 5.1 5.5 6.2 5.9 5.2 3.8 2.0 1.7 4.1 Latc+15 2.2 3.2 4.0 4.4 4.6 4.7 5.4 5.4 5.0 3.8 2.1 1.7 Single axis tracker Lat-15 2.1 3.5 4.9 6.4 7.5 8.3 9.7 8.7 6.8 4.5 2.1 17°5.5 Latitude 2.3 3.6 5.0 6.3 7.2 8.0 9.4 8.5 6.9 -4.7 2.3 1.8 5.5 5 Lat+15 3.4 3,7 8 6 6.8 7.5 8.9 8.1 6.7 4,7 2.3 1.9 5.3 i Dual axis tracker . i 14 37 51 64 76 86 100 87 69 47 23 1.9 5.7TeTLVTSLNatealtaabertasetineaCenthinta,sikeietneRamySoapmperesaaMeNey229 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL LEWISTOWN Jan | Fixed array Lat-15 2.6 Latitude °3.0 Lat+15 3.2 Single axis tracker Lat-15 3.1 Latitude 3.4 Lat+15 3.5 Dual axis tracker 3.6 MILES CITY Jan Fixed array Lat-15 3.0 Latitude 3.4 Lat+15 3.6 Single axis tracker Lat-15 3.5 Latitude 3.9 Lat+15 4.1 Dual axis tracker 4.1 MISSOULA Jan Fixed array Lat-15 2.0 Latitude 2.2 Lat+15 2.3 Single axis tracker Latr-15 2.3 Latitude 2.4 Lat+15 2.5 Dual axis tracker 2.6 ASHEVILLE Jan Fixed array Lat-15 3.5 Latitude 3.9 Lat+15 4.2 Single axis tracker Lat-15 4.3 Latitude 4.7 Lat+15 49 Dual axis tracker 4.9 230 Apr 5.4 5.3 4.9 7.2 7.1 6.8 7.2 Latitude:47.05 degrees May 8.0 Jun 6.3 5.8 5.0 8.8 8.5 7.9 9.0 Jul 10.0 Aug 6.4 6.1 5.5 8.9 8.7 8.3 8.9 Latitude:46.43 degrees May 6.0 5.7 5.0 8.3 8.0 7.6 8.4 jun 6.7 6.1 5.3 9.4 9.1 8.5 9.7 Jul 10.3 Aug 6.7 6.5 5.8 9.4 9.2 8.8 9.4 Latitude:46.92 degrees May 5.6 5.2 4.6 7.5 7.3 6.9 7.6 Jun 8.7 jul 10.4 Aug 6.4 6.1 5.5 9.0 8.9 5.8 9.1 Latitude:35.43 degrees May Jul Aug Elevation:1264 mete Oct 5.6 Nov 2.9 3.2 3.4 3.4 3.7 3.8 3.9 Dec 2.3 2.7 2.8 2.7 3.0 3.2 3.2 Avg 6.5 Elevation:803 meters Oct 5.9 Nov 4.1 Dec 3.6 Avg 5.0 5.0 4.8 6.6 6.7 6.5 6.9 Elevation:972 meters Oct 5.1 Nov 2.7 Dec 1.7 1.9 2.0 1.9 2.0 2.1 2.1 Avg 4.4 4,3 4.0 5.9 Elevation:661 meters Oct Nov 3.6 4.1 4.3 Dec Avg 4.8 4.9 4.7 6.0 6.1 6 -6.3 APPENDIX B -SOLAR DATA CAPE HATTERAS NC Latitude:35.27 degrees Elevation:2 meters 'xed array SLat-15 3.3'Latitude 3.8 "3 Lat +15 4.0"Single axis trackereS.4.1 6.5 7.8 7.9 7.9 7.7 7.3 6.6 5.7 4.6 3.9 6.35.1 "Latitude 45 5-4 66 77 76 76 74 72 67 60 5.0 4.3 6.3 Tat+15 47 55 65 74 7.2 7 69 68 65 6 5.2 45 62 Dual axis tracker 4.7 5.5 6.6 7.8 7.9 8.1 7.8 7.4 6.7 6.0 5.2 4.6 6.5 5.3 4.6 3.7 3.2 5.0 5.4 4.9 4.2 3.6 5.0 5.1 4.9 4.5 3.9 4.8 5.1 6.0 6.1 6.2 6.1 5..5.8 5.7 5.7 5.2 5.5 5.1 5.0 5.0LRAnewatNWA\oaw-Aw"CHARLOTTE ---.....NC Latitude:35.22 degrees Elevation:234 meters ae Jan Feb Mar Apr May Jun Jul Aug Sep Oct Noy Dec Avg "”Bixed array Lat-15 34 50 59 60 61 6.0 52 47 37 31 494.1 .5.8 Latitude 3.8 45 5.2 5.7 5.7 5.7 5.6 5.6 5.3 5.1 4.2 3.6 5.0 Lat+15 4.1 4.6 5.1 5.3 5.0 4.9 4.9 5.1 5.0 5.2-4.4 3.9 4.8 Single axis trackerLat-15 4.2 5.2 6.4 7.6 7.7 7.8 75 7.3 6.5 6.0 4.6 3.8 6.2 :; Latitude 4.5 5.5 6.6 75 7.4 7.5 73 7.1 6.6 63 5.0 4.2 6.3 Pe Lat+15 4.7 5.6 6.5 7.2 7 6.6 6.8 6.8 64 63 5.2 4.5 6.2 "Dual axis tracker 4.8 5.6 6.6 7.6 7.7 8.0 77 7.3 6.6 6.3 5.2 4.5 6.5 RALEIGH NC Latitude:35.87 degrees Elevation:134 meters Jan Feb Mar Apr May un ul Aug Sep Qc Nov Dec Ag bo Fixed array i Lat-15 3.4 4.1 5.0 5.8 6.0 6.2 6.0.5.7 5.1 4.6 3.7 3.1:49 a.Latitude 3.8 4.5 5.2 5.7 5.7 5.7 5.6 5.5 5.2 4.9 4.1 3.6 5.0 Lat+15 4.1 4.6 5.1 5.3 5.0 4.9 4.9 5.0 5.0 5.0 4.3 3.8 4.8 Single axis tracker Lat-15 4.1 5.2 6.4 7.5 7.6 7.8 7.5 7.0 6.4 5.8 =4.5 3.8 6.1 ..Latitude 4.5 5.5 6.5 75 7.4 7.5 7.2 6.9 6.4 6.0 4.9 4.2 6.2 Lat+15 47 -5.6 6.5 7.2 7 7 6.7 6.5 6.3 6.2 5 4.4 6.1 Dual axis tracker 47 5.6 6.6 7.5 7.7 8.0 7.6 7.1 6.5 6.1 5.1 4.4 6.4 GREENSBORO NC Latitude:36.08 degrees Elevation:270 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.3 4.1 5.0 5.8 6.0 6.1 6.0 5.7 5.2 4.6 3.6 3.1 4.9 Latitude 3.8 4.5 5.2 5.7 5.6 5.6 5.6 5.5 5.2 5.0 4.1 3.6 5.0 Lat+15 4.1 4.6 5.1 5.2 5.0 '4,9 4.9 5.1 5.0 5.0 4.3 3.8 4.8 Single axis tracker Lat-15 4.1 5.2.64 7.5 7.6 78 7.46 73 6.5 5.9 4.5 3.8 6.2 Latitude 4.5 5.5 6.6 7.4 74 75 7.3 7.1 .... Lat+15 4.7 5.6 6.5 7.1 7 7 6.8 6.8 6.4 6.2 5 4.4 6.1 Dual axis tracker 4.8 5.6 6.6 75 7.7 8.0 7.7 7.3 6.6 6.2 5.0 8645 6.5 231 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL WILMINGTON NC :Latitude:34.27 degrees Elevation:9 meters Jan Feb Mar Apr May =Jun Jul Aug Sep Oct Nov Dec Avg Fixed array ; Lat-15 3.5 4.2 5.2 6.0 6.1 6.1 5.9 5.6 5.1 4.7 3.9 3.3 5.0 Latitude 4.0 4.6 5.4 5.9 5.8 5.6 5.5 5.4 5.2 5.0 44 3.8 5.0 Lat+15 4.2 4.7 5.3 5.5 5.1 4.9 4.8 4.9 5.0 5.1 4.6 4.1 4.9 Single axis tracker Lar-15 43 5.3 6.6 7.8 7.8 7.8 74 7.0 6.4 5.9 4.8 4.0 6.3 Latitude 4.7 5.6 6.7 7.8 7.6 74 7.2 6.9 6.4 6.2 5.2 4.5 6.3 Lat+15 4.9 5.7 6.6 7.5 7.1 6.9 6.7 6.5 6.3 6.2 54 47 6.2 Dual axis tracker 4.9 5.7 6.7 7.9 7.9 7.9 7.6 7.0 6.5.6.3 5.4 4.8 6.6 BISMARCK ND Latitude:46.77 degrees Elevation:502 meters: Jan Feb Mar Apr May Jun Jul Aug)Sep =Oct =Nov =Dec AvgFixedarray Lat-15 3.1 4.0 5.0 5.6 6.1 6.5 6.8 6.4 5.3 4.2 2.9 2.6 4.9 Latitude 3.5 4.4 5.2 5.5 5.7 5.9 6.3 G1.5.4 45 3.2 3.0 4.9 Lat+15 3.7 4.5 5.1 5.1 5.1 4.5 3.4 3.2 4.7 Single axis tracker Lat-15 3.6 4.9 6.3 7.3 8.3 8.9 9.5 8.7 7.0 5.3 3,4 3.0 6.4 Latitude 4.0 5.2 6.4 7.3 8.0 8.6 9.2 8.5 7.0 5.5 3.7 3.3 6.4 Lat+15 4.2 53 6.4 7 7.6 8 8.6 8.1 6.8 5.5 3.9 3.5 6.3 Dual axis tracker 4.2 5.3 6.5 7.4 8.4 9.2 9.7 8.7 7.0 5.5 3.9 3.6 6.6 5.]5.1 5.5 5.5 FARGO ND Latitude:46.90 degrees Elevation:274 meters an Feb Mar Apr.May Jun Jul Aug Sep Oct Nov Dec =AvgFixedarray Lat-15 2.9 3.9 5.3 5.9 6.1 6.5 6.1 4.9 9 2.6 2.3 4.64.8 .3 Latitude 3.4 43 5.0 5.2 5.5 5.6 6.0 5.8 5.0 4.1 2.9 2.7 46 Lar+15 3.6 45 5.0 4.8 4.9 4.8 5.2 5.3 47 4.1 3.0 2.9 4.4 Single axis tracker Lat-15 3.5 4.8 6.1 7.0 7.9 8.4 9.1 8.3 6.4 4.8 3.1 2.7 6.0 Latitude 3.8 5.1 6.2 6.9 7.7 8.1 8.8 8.1 6.5 5.0 3.3 3.0 6.1 Lat+15 4.1 5.2 6.2 6.7 7.2 7.6 8.2 77 6.3 5 3.4 3.2 5.9 Dual axis tracker 41 5.2 6.3 7.0 8.0 8.7 9.3 8.3 6.5 5.1 3.5 3.2 6.3 MINOT ND Latitude:48.27 degrees Elevation:522 meters oy Jan Feb =Mar May Jun Jul Aug Sep Oct Nov Dec AygFixedarray Lar-15 2.9 .3.8 BS) Latitude 3.3 4.]5.1 Lat+15 3.5 43 5.0 Single axis tracker Lat-15 3.4 4.6 6.2 Latitude 3.8 49 6.4 Lat+15 4 5 6.3 Dual axis tracker 40 50 64 #75 84 #O1 97 87 67 +54 37 34 8 Apr 56 60 63 66:62 50 41 28 24 47 55 56 .58 61 60 51 £44 31 28 47 5.1 7.4 7.4 7.1 5.0 5.0 5.3.5.4 4.8 4.4 3.3 3.0 4.5 83 -89 9.5 8.6 °66 5.1 3.3 2.8 6.2 8.1 8.5 9.2 8.5 6.7 5.3 3.6 3.1 6.3 7.6 8 8.6 8.1 6.5 5.4 3.7 3.3 6.1 232 APPENDIX 8 -SOLAR DATA GRAND ISLAND NE Latitude:40.97 degrees Elevation:566 meters Jan Feb «=Mar =Apr =Mays Jun Ss Jul'«Aug.«Sep,«=Oct «=Noy Dec Ag Fixed array Lat-15 3.6 4.2 5.0 5.8 6.1 67 6.8 6.4 5.5 ... latitude 41 46 52 57 57 62 63 61 56 51 40 36 5.2 Lat+15 44 4.8 5.2 5.3 5.1 5.3 5.5 5.6 5.4 ... Single axis trackerLac-15 4.4 5.3 6.5 7.7 8.2 92 9.3 8.6 7.3 6.1 4.3 3.8 6.7 Latitude 4.9-5.6 6.6 7.6 7.9 8.8 9.0 8.5 74 6.4 4.7 4.2 6.8 Lat+15 5.1 5.8 6.6 73 7.4 8.2 8.4 8 7.2 6.4 49 45 6.7 Dual axis tracker ' 5.2 5.8 6.6 7.7 8.3 9.4 9.5 8.6 -74 6.4 4.9 4.5 7.0 NORFOLK NE Latitude:41.98 degrees Elevation:471 meters Jan Feb Mar May Jun Jul Aug Sep Oct Nov Dec AvgMar=AprFixedarray Lat-15 3.3 4.0 4.9 5.6 6.1 6.6 6.7 6.2 5.4 4.5 3.3 2.9 -5.0 Latitude 3.8 4.4 5.1 5.5 5.7 6.0 6.2 6.0 5.4 4.9 3.7 3.3 5.0 Lat+15 41 4.6 5.0 5.1 5.1 5.2 5.4 5.4 5.2 4.9 3.9 3.6 4.8 Single axis tracker Lac-15 4.1 5.0 6.2 7.3 8.1 8.9 9.1 8.3 7.0 5.8 4.0 3.4 6.5 Latitude 4.5 5.3 6.4 7.3 7.9 8.6 8.8 8.2 7.1 6.0 43 3.8 6.5 Lat+15 4.7 5.4 63 7 7.4 8 8.2 7.8 6.9 6 4.5 4 6.4 Dual axis tracker 48 54 64 #74 82 92 #93 484 71 61 45 41°67 NORTH PLATTE NE Latitude:41.13 degrees Elevation:349 meters an Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.6 4.3 5.1 5.8 6.1 6.7 6.8 6.4 5.7 4.9 3.6 3.3 5.2 Latitude 4.1 4.7 5.3 5.7 5.7 6.1 6.3 6.1 5.7 5.3 4)3.8 5.3 Lat+15 4.4 4.9 5.2 5.3 5.1 5.3 5.5 5.6 5.5 5.3 4.3 4.]5.0 Single axis tracker Lac-15 4.4 5.4 6.5 7.8 8.1 9.1 9.3 8.6 7.5 6.3 4.5 4.0 6.8 Latitude 4.9 5.7 6.7 77 7.8 8.8 9.0 8.5 7.5 6.6 4.8 4.4 6.9 Lat+15 5.1 5.9 6.6 74 74 8.2 8.4 8.1 74 6.6 5 4,7 6.7 Dual axis tracker 5.2 5.9 6.7 7.8 8.2 9.4 9.5 8.7 7.6 6.7 5.0 4.7 7.1 OMAHA NE Latitude:41.37 degrees Elevation:404 meters Fixed array . Lat-15 3.3 4.0 47 5.5 6.0 6.5 6.5 6.1 5.2 4.4 3.2 2.7 4.9 Latitude 3.8 4.4 4.9 5.3 5.6 6.0 6.0 5.8 5.3 4.7 3.5 3.2 4.9 Lat+15 4.1 4.6 4.8 5.0 5.0 5.2 5.3 5.3 5.1 47 3.7 3.4 4.7 Single axis trackerLac-15 9 4.1 5.0 6.0 7.0 7.8 8.7 8.6 8.0 6.7 5.5 3.8 3.3 6.2 Latitude 4.5 5.3 6.1 7.0 7.5 8.3 8.3 7.8 6.7 5.7 4.1 3.6 6.3 Lat+15 47 5.4 6 6.7 7.1 7.8 7.8 7.4 6.6 5.8 4.2 3.8 6.1 Dual axis tracker , 47 54 6]7400 7.9 8.9 8.8 8.0 6.8 5.8 4.3 3.9 6.5 233 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL SCOTTSBLUFF NE Latitude:41.87 degrees Elevation:1206 mete. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec AvgFixedarray Lat-15°3.5 4.3 5.1 5.8 6.0 6.7 7.0 6.7 5.9 4.9 3.6 3.2 5.2 Latitude 4.0 4.8 5.3 5.7 5.7 6.2 6.5 6.4 6.0 5.3 4.1 3.8 5.3 Lat+15 4.3 4.9 5.2 5.3 5.0 5.3 5.6 5.8 5.7 5.3 4.3 4.1 5.1 Single axis tracker , Lat-15 4.3 5.5 6.5 7.6 8.1 9.2 9.6 9.1 7.9 6.3 4.4 3.9 6.9 Latitude 4.7 5.8 6.7 7.6 7.8 8.9 9.2 8.9 7.9 6.6 4.8 4.4 6.9 Lat+15 4.9 5.9 6.6 73 7.4 8.3 8.7 8.5 7.6 6.7 5 4.6 6.8 Dual axis tracker 5.0 5.9 6.7 77 8.2 9.4 9.8 9.1 8.0 6.7 5.0 47 7.2 CONCORD NH Latitude:43.20 degrees Elevation:105 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec AvgFixedarray- Lat-15 3.1 4.1 4.8 Latitude 3.5 4.5 . Lat+15 3.8 47 5.0 Single axis tracker Lat-15 3.7 5.0 6.1 6.7 74 7.9 7.9 74 6.3 4.8 3.2 2.9 5.8 Latitude 4.1 5.4 6.3 6.6 7.1 7.5 7.7 73 6.3 5.0 3,4 3.2 5.8 Lar+15 4.3 5.5 6.2 6.3 6.7 7 7.2 6.9 6.1 5.1 3.5 3.4 5.7 Dual axis tracker 43 55°63 6.7 75 8.1 8.1 7.4 6.3 5.1 3.5 3.5 6.0 5.7 5.9 6.0 5.7 5.0 3.9 2.7 2.5 4.6 1 5.3 5.4 5.6 5.5 5.0 4.2 3.0 2.8 4.6 7 4.7 4.7 49 49 4.8 4.2 3.1 3.1 44 ATLANTIC CITY NJ Latitude:39.45 degrees Elevation:20 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec AvgFixedarray Lar-15 3.0 3.8 4.6 5.3 5.7 6.0 5.9 5.6 5.0 4.3 3.2 4.6 Latitude 3.5 4.1 4.8 5.2 5.3 5.5 5.5 5.4 5.1 4.6 3.6 4.6 Lat+15 3.7 4,4.7 48 47 4.8 4.8 4.9 4.9 4.6 3.8 4.4 2.7 3.1 3.3 Single axis ttacker Lat-15 3.7 47 5.8 |67 7.2 7.7 75 7.2 6.4 5.4 3.9 3.2 5.8 Latitude 4.0 5.0 5.9 6.6 7.0 7.4 7.2 7.0 6.4 5.6 4.2 3.6 5.8 Lar+15 4.2 5.1 5.9 6.4 6.5 6.9 6.8 6.7 6.3 5.7 4.4 3.7 5.7 Dual axis tracker 43 5.1 60 67 73 7.9 76 72 64 57 44 38 6.0 NEWARK NJ Latitude:40.70 degrees Elevation:9 meters Jan Feb Mar Apr May Jun Jul Avg Sep Oct Nov Dec Avg Fixed array Lat-15 2.9 3.7 5.2 5.8 5.8 4.9 4.1 2.9 2.4 4.44.5 .5.5 .5.5 Latitude 3.3 4.0 4.6 5.1 5.2 5.4 5.4 5.3 5.0 44 3.2 2.8 45 Lat+15 3.5 4.1 4.5 4.6 ..4.8 4,7 4.4 3.3 3.0 43 Single axis tracker - Lat-15 3.5-4.5 5.6 6.5 7.0 7.4 7.4 6.9 6.1 5.1 3.4 2.9 5.5 Latitude 3.8 47 5.7 6.5 6.7 7.1 7 6.8 6.2 5.3 3.7 3.1 5.6 Lat+15 4 4.8 5.6 6.2 6.3 6.6 6.6 6.5 6 5.3 3.8 3,3 5.4 Dual axis tracker 4.0 4.8 5.7 6.6 7.0 7.5 7.5 7.0 6.2 5.4 3.8 3.3 57 234 APPENDIX B -SOLAR DATA ALBUQUERQUE NM Latitude:35.05 degrees Elevation:1619 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed 5 46054 73477 +78 (74 72 66 48 43 63 ie]wude 53 60 65 7.2 72 7A 69 69 68 65 55 50 64 : )tee 15 58 6265S iCGi(iC iC OS GSS CD 'nole axis tracker :eS 59 7.1 83 100 106 108 929 95 88 7.9 63 5.5 8.4 Latitude 6.5 75 86 99 103 104 95 £4293 °9.0 8.3 6.8 6.1 8.5 la+15 69 77 85 95 97 97 8.9 89 88 84 7.1 6.5 8.4 Dual axis tracker 6.9 7.7 8.6 10.0 10.8 11.1 10.0 9.5 9.0 8.4 7.2 6.6 8.8 TUCUMCARI NM Latitude:35.18 degrees Elevation:1231 meters Jan Feb Mar Apc May Jun.Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 4.3 5.1 5.9 6.8 70°7.2 7.1 6.8 6.2 5.6 4.5 4.0 5.9 Latitude 5.0 5.6 6.2 6.7 6.6 6.6 6.6 6.5 6.3 6.1 5.2 4.8 6.0 Lar+15 5.4 5.9 6.1 6.2 5.8 5.7 5.7 5.9 6.1 6.2 5.5 5.2 5.8 Single axis tracker Lar-15 5.5 6.6 7.9 9.3 9.5 9.9 9.6 9.1 8.3 7.5 5.9 5.2 7.9 'Latitude 6.0 7.1 8.1 9.2 9.3 9.5 9.3 9.0 8.4 7.9 6.4 5.7 8.0 Lat+15 6.9 7.7 8.5 9.5 9.7 9.7 8.9 8.9 8.8 8.4 7.1 6.5 8.4 Dual axis tracker 6.4 7.2 8.1 9.3 9.6 10.1 9.8 9.2 8.4 8.0 6.7 6.2 8.3aeandaeNO,ecardsGeiaseELKO NV Latitude:40.83 degrees Elevation:1547 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.3 41 -4.9 5.7 6.4 6.9 7.3 7.0 6.5 5.2 3.5 3.1 -53 Latitude 3.8 4.5 5.1 5.6 6.0 6.3 6.8 6.8 6.6 5.7 4.0 3.6 5.4 Lat+15 4.1 4.7 5.0 5.2 5.3 5.4 5.9 6.1 6.4 5.8 4.2 3.9 5.2 Single axis tracker ; : Lat-15 4.1 5.2 6.4 7.7 8.8 9.8 10.5 9.9 8.9 6.9 4.3 3.8 7.2 Latitude 4.5 5.5 6.5 7.6 8.5 9.5 10.2 9.7 9.0 7.2 47 4.2 7.3 Lat+15 47 5.6 6.4 7.3 8 8.9 9.6 9.3 8.9 7.3 4.9 4.5 71 Dual axis tracker 4.8 5.6 6.5 7.7 8.9 10.1 10.7 9.9 9.1 7.3 4.9 4.5 7.5 ELY NV Latitude:39.28 degrees Elevation:1906 meters Fixed array Lat-15 4.0 4.7 5.5 63.6.6 7.2 7.2 6.9 6.6 5.5 4.1 3.6 5.7 Latitude 4.6 5.2 5.7 6.2 6.2 6.6 6.6 6.6 6.7 6.0 4.7 4.3 5.8 Lat+15 5.0 5.5 5.6 5.7 5.5 5.6 5.7 6.0 6.5 61°5.0 4.7 5.6 Single axis tracker Lat-15 5.0 6.1 7.2 8.5 9.2 .10.3 10.3 9.6 9.1 7.3 5.2 4.6 7.7 Latitude 5.5 6.5 7.4 8.4 8.9 9.9 9.9 9.5 9.2 7.7 5.6 5.1 7.8 Lat+15 5.8 6.6 7.3 8.1 8.4 9.2 9.3 9 9 7.7 5.9 5.4 7.7 Dual axis tracker , 5.9 6.6 7.4 8.5 9.3 10.5 10.5 9.7 9.2.7.8 5.9 5.5 8.1 5ReemseeesetAeEP235 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL LAS VEGAS -NV Latitude:36.08 degrees Elevation:664 m_._.'s Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 4.4 5.3 6.4 75 7.8 8.1 7.7 7.5 71 6.1 4.8 4.2 6.4 Latitude 5.1 5.9.67 7A 7.3 7.4 7.1 7.2 7.2 6.6 5.5 4.9 6.5 Lat+15 5.6 6.1 6.6 6.8 6.5 6.3 6.2 6.5 7.0 6.8 5.9 5.4 6.3 - Single axis tracker Lat-15 5.7 6.9 8.5 10.3 11.0 11.5 10.8 10.4 9.7 8.1 6.2 5.3 8.7 Latitude 6.2 7.3 8.8 10.2 10.6 11.1 10.4 10.3 9.8 8.6 6.7 5.9 8.8 Lat+15 6.5 75 8.7 9.8 10 10.3 9.8 9.8 9.6 8.7 7 6.2 8.7 . Dual axis tracker 6.6 7.5 8.8 10.3 11.1 11.8 11.0 °10.5 9.8 8.7 7.1 6.3 9.1 RENO NV Latitude:39.50 degrees Elevation:1341 meters Jan Feb Mar Apr May «sun.Ss Jul,«Ss Aug.«Sep,Ss Oct”«=Noy Dec AugFixedarray Lat-15 3.6 4.4 5.5 6.5 7.1 7.4 7.7 74 6.8 5.6 3.9 3.3 5.8 Latitude 4.1 4.9 5.7 6.4 6.6 6.8 7.1 7.1 6.9 6.1 4.4 3.9 5.8 Lat+15 4.4 5.1 5.6 5.9 5.8 5.8 6.1 6.4 6.7 6.2 4.6 4.2 5.6 Single axis trackerpoLa-15 44 56 72 88 98 105 111 104 94 #74 £48 4.1 7.8 _Latitude 4.8 6.0 7.4 8.7 9.5 10.1 10.8 10.3 9.5 7.8 5.2 4.5 7. Lat+15 5.1 6.1 7.3 8.4 9 9.4 10.1 9.8 9.3 7.9 5.4 4.8 7.7 Dual axis tracker 5.1 6.1.7.4 8.8 10.0 10.8 11.4 10.5 9.5 7.9 55 49 8.2 TONOPAH NV Latitude:38.07 degrees Elevation:1653 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec AvgFixedarray Lat-15 41 49 5.8 6.7 7.1 7.6 77 7.3 6.9 5.9 4.4 3.8 6.0 | Latitude 4.8 5.4 6.1 6.6 6.7 6.9 7.1 7.1 7.1 6.4 5.0 4.5 6.1 Lat+15 5.1 5.6 6.0 6.1 5.9 5.9 6.1 6.4 6.8 6.5 5.3 4.9 5.9 Single axis tracker Lat-15 5.2 6.4 7.8 9.2 10.0 10.9 11.0 10.3 9.6 7.9 5.6 4.9 8.2 Latitude 5.7 6.8 8.0 92 97 104 106 102 9.8 8.3 61 5.4 8.4 Le Lat+15 6 6.9 7.9 8.8 9.1 9.8 9.9 9.7 96 °84 6.4 5.7 8.2 :Dual axis tracker . 6.1 6.9 8.0 9.3 10.1 11.1 11.2 10.4 9.8 8.4 6.4 5.8 8.6 WINNEMUCCA NV Latitude:40.90 degrees Elevation:1323 meters Jan Feb Mar Apr «=May «sun «Ss Jul'«=Aug”«Sep «=Oct'«Nov Dec AugFixedarray Lat-15 3.3 4.1 5.0 6.0 6.7 7.1 |7.6 7.2 6.6 5.3 3.5 3.0 5.5 Latitude 3.7 4.5 5.2 5.9 6.2 6.5 7.0 6.9 6.7 5.7 3.9 3.5 5.5 Lat+15 4.0 4.6 5.1 5.5 5.5 5.6 6.0 63°6.5 5.8 4.1 3.8 5.2 Single axis tracker Lat-15 4.0 5.1 6.5 8.0 9.2 10.1 10.9 10.2 9.1 7.0 43.37 74 Latitude 4.4 5.4 6.7 8.0 8.9 9.7 10.6 10.0 9.2 7.3 47 4.1 74 Lat+15 4.6 5.5 6.6 7.7 8.4 9.1 9.9 9.6 9 7.4 4.8 43 7.2 Dual axis tracker 4.6 5.5 6.7 8.1 9.3 10.4 11.2 10.2 9.2 7.4 4.9 4.4 7.7 236 APPENDIX B -SOLAR DATA ALBANY NY Latitude:42.75 degrees Elevation:89 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg 5.0Fixeda7364A5 SS SB OSS BT 2A 4 fade 30 «2390 45049 SL SK SS 5.2 4B 8D 26 2443 favis 320641044 4S 4G GB 4B 4G 8D 27S A Single axis trackerIos32 440A OK 70 7S 77 70 60 4S 27 KSA Iotiude 35 4Gi "SC B72 7S 6D OGD GSA Dt+15 360 «47084 6 A TT OS 5 4G 5D Dual axis tracker 3.7 4.7 5.5 6.4 7.1 7.7 7.9 7.1 6.1 4.7 3.0 2.8 5.6 BINGHAMTON NY Latitude:42.22 degrees Elevation:499 meters Jan Feb Mar.Apr May Jun Jul Aug Sep Oct Novy Dec AvgFixedarrayholat-15 25 33 42 48 53 56 57 53 .45 35 23 19 41 4 latitude 28 35 43 £47 #2450 52 53 51 45 37 24 21 4) 46 43 37 25 22 38poeLat+15 2.9 36 42 44 44 #445 46 Q Single axis tracker Lat-15 2.9 3.9 5.1 6.1 6.8 73 75 6.8 5.7 4.3 2.6 2.2 5 Latitude 3.1 4.1 5.2 6.0 6.6 7.0 7.2 6.7 5.7 44 2.7 2.3 5. Lat+15 3.2 4.2 5.2 5.7 6.2 6.5 6.7 6.3 5.5 4,4 2.8 2.4 4 Dual axis tracker 33.«42 0«45.2.«61 669)O75 7G 6B OT KSB 5B BUFFALO NY Latitude:42.93 degrees _..Elevation:215 meters Jan Feb Mar Apr May un Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 2.2 3.1 4.1 5.0 5.6 .6.0 6.0 5.5 4.6 3.4 2.1 . Latitude 2.4 3.3 4.2 4.8 5.2 5.5 5.5 5.3 4.6 3.6 2.3 1.9 4.1 Lat+15 2.5 3.4 4.1 4.5 4.6 4.8 4.8 4.8 43 3.6 2 Single axis tracker Lat-15 2.5 3.6 5.0 6.3 7.2 7.9 7.9 7.2 5.8 41 24 .19 5 Latitude 2.7 3.8 5.1 6.2 7.0 7.6 7.7 7.0 5.8 4.3 2.5 2.1 5. Lar+15 2.8 3.8 5 6 6.6 7.1 7.2 6.7 5.6 4.3 2.5 2.2 5 Dual axis tracker 2.8 3.8 5.1 6.3 7.3 8.1 8.1 7.2 5.8 4.3 2.6 2.2 5.3 MASSENA NY Latitude:44.93 degrees Elevation:63 meters Jan Feb ©Mar Apr May Jun Jul Aug Sep Oct Novy Dec Avg Fixed array Lat-15 2.7 3.8 4,7 5.2 5.6 5.9 6.0 5.4 4.6 3.5 2.2 2.1 4.3 Latitude 3.0 4.2 4.9 5.0 5.2 5.4 5.6 5.2 4.7 3.7 2.4 2.3 4.3 Lat+15 3.2 4.3 4.8 4.7 4.6 4.7 4.9 4.7 4.4 3.7 2.5 2.5 4.1 Single axis tracker Lat-15 3.2 4.7 6.0 6.7 7.4 8.0 8.2 7.2 6.0 4.3 2.5 2.4 5.6 ;Latitude 3.4 5.0 6.1 6.6 7.2 7.6 7.9 7.1 6.0 4.5 2.7 2.6 5.6 ;Lat+15 3.6 5.1 6.1 6.4 6.8 7.2 7.4 6.7 5.8 4.5 2.8 2.8 5.4 Dual axis tracker : i 3.6 5.1 6.1 6.7 7.6 8.2 8.4 7.3 6.0 4.5 2.8 2.8 5.8 237 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL NEW YORK CITY Jan Fixed array Lat-15 2.9 Latitude 3:2 Lat+15 3.4 Single axis tracker Lat-15 3.4 Latitude 3.7 Lat+15 3.9 Dual axis tracker 3.9 ROCHESTER Jan Fixed array Lat-15 2.3 Latitude 2.5 Lar+15 2.6 Single axis tracker Lat-15 2.6 'Latitude 2.8 Lar+15 2.9 Dual axis tracker 2.9 SYRACUSE Jan Fixed array Lat-15 2.4 Latitude 2.7 Lat+15 2.8 Single axis tracker Lat-15 2.8 Latitude 3.0 Lat+15 3.1 Dual axis tracker 3.1 AKRON an Fixed array Latr-15 2.3 Latitude 2.5 Lat+15 2.7 Single axis tracker Lat-15 2.6 Latitude 2.8 Lat+15 2.9 Dual axis tracker 3.0 238 Feb 4.] NY Apr 5.3 5.2 4.8 6.7 6.6 6.3 6.7 Latitude:40.78 degrees 5.8 6.0 5.4 5.5 4.8 4.8 7.2 75 6.9 7.2 6.5 6.7 7.3 7.7 Jul 6.0 5.6 4.9 7.5 7.2 6.7 7.6 7.1 Latitude:43.12 degrees May -Jun 5.6 5.9 5.2 5.4 4.6 47 7.3 7.9 7.1 7.6 6.6 7.1 74 8.1. Jul 7.2 Latitude:43.12 degrees May -Jun 56 5.9 5.2 5.4 46 47 73 7.9 7.0 7.6 66 7.1 74 81 Jul 6.0 5.6 4.9 8.0 7.8 7.3 8.2 Aug 5.5 3.3 4.8 7.2 7.1 6.7 7.2 Latitude:40.92 degrees May Jun 5.5 5.9 5.2 5.5 46 °47 7.0 7.6 6.8 7.3 6.3 6.8 7.1 7.8 Jul Elevation:57 meters Oct 4.) 4.4 4.4 5.1 5.3 5.3 5.3 Nov 2.9 3.2 3.3 3.4 3.7 3.8 3.8 Avg 4.5 4.6 43 5.6 5.6 5.5 5.8 Elevation:169 meters Oct Nov Dec 3.4 2.1 1.8 3.6 2.3 2.0 3.6 2.3 2.0 4.2 2.4 2.0 4.3 2.5 2.1 4.3 2.6 2.2 4.3 2.6 2.2 Elevation:124 m Oct Nov Dec 3.5 2.1 1.8 3.7 2.3 3.7 2.3 4,3 2.4 2.0 4.4 2.5 2.2 4,4 2.6 2.3 4.5 2.6 2.3 - Avg eters 5.4 Elevation:377 meters Oct 3.8 4.0 4.0 45 4,7 4.7 4.8 Nov 2.3 2.5 2.6 Dec 1.8 2.0 2.1 2.0 2.2 2.3 2.3 Avg 4.2 4.1 3.9 viebeciaguradyt,Lat-15 2.2Latitude2.4 Lat+15 2.5SingleaxistrackerLat-15 2.5 Latitude 2.6 Lat+15 2.7 Dual axis tracker 2.8 COLUMBUS Jan Fixed array Lar-15 2.5 Latitude 2.7 Lat+15 2.9 Single axis tracker Lat-15 2.8 Latitude 3.1 Lat+15 3.2 Dual axis cracker 3.2 DAYTON an Fixed array Lat-15 2.7 Latitude 3.0 Lar+15 3.1 Single axis tracker Lat-15 3.1 Latitude 3.4 Lat+15 3.5 Dual axis tracker 3.6 MANSFIELD | Jan Fixed array Lat-15 2.3 Latitude 2.6 Lat+15 2.7 Single axis tracker Lat-15 2.7 Latitude 2.9 Lat+15 3 Dual axis tracker 3.0 Latitude:41.40 degrees May Jun 5.6 6.0 5.3 5.5 47 48 72 7.8 69 7.5 6.5 7 7.3 8.0 Jul 6.1 5.6 4.9 7.9 7.6 7.1 8.0 Aug 5.6 5.3 4.9 7.2 Latitude:40.00 degrees May Jun 55 5.9 5.2 5.4 46 47 7.0 7.5 68 7.2 64 67 710 7.7 Jul 7.6 Aug 7.1 Latitude:39.80 degrees May jun 5.7 6.1 5.3 5.6 47 48 73 «7.9 7.1 7.6 66 7.1 74 81 Jul 8.0 Aug 5.7 5.5 5.0 7.4 7.3 6.9 7.5 Latitude:40.82 degrees May =Jun 56 5.9 52 5.5 46 47 7107.7 68 7A 64 69°- 720°=«79° Jul 6.0 5.5 4.8 7.7 7.4 7 7.9 _Aug 5.6 5.3 4.9 APPENDIX B -SOLAR DATA Elevation:245 meters Oct Nov 3.6 2.2 3.8 2.4 3.8 2.4 4.3 2.5 4.5 2.6 4.5 2.7 45 2.7 Dec 1.7 1.9 2.0 1.9 2.0 2.1 2.1 Avg Elevation:254 meters Oct Nov 4.0 2.6 4.3 2.8 4.3 2.9 4.9 2.9 5.1 3.1 5.1 3.2 5.2 3.2 Dec 2.0 ©2.2 23 23 2.5 2.5 2.6 Avg 4.2 4.2 4.0 5.4 Eievation:306 meters Oct Nov 4.1 2.7 4.4 2.9 4.4 3.0 5.1 3.1 5.3 3.3 5.3 3.4 5.3 3.4 Dec 2.1 2.4 2.5 2.4 2.6 2.8 2.8 Elevation:395 meters Oct =Nov 3.8 2.4 4.1 2.6 4.1 2.7 4,7 2.7 4.8 2.9 4.8 3 4.9 3.0 Dec 1.9 2.1 2.2 2.1 2.3 2.4 2.4 Avg 4.2 4.2 3.9 5.2 (5.2 p) 5.4 239 .PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL TOLEDO Jan FebFixedarray Lat-15 2.5 3,4 Latitude 2.8 3.7 Lar+15 3.0 3.8 Single axis tracker Lat-15 2.9 4.1 Latitude 3.2 4,3 Lac+15 3.3 4.4 Dual axis tracker 3.3 44. YOUNGSTOWN Jan =FebFixedarray Lat-15 2.2 3.0 Latitude 2.4 3.2 Lat+15 2.5 3.2 Single axis tracker Lat-15 2.4 3.5 Latitude 2.6 3.6 Lat+15 2.7 3.7 Dual axis tracker 2.7 3.7 OKLAHOMA CITY Jan Fixed array Lat-15 3.9 Laticude 4.4 Latr+15 4.7 Single axis tracker Lat-15 4.8 Latitude 5.3 Lat+15 5.5 Dual axis tracker 5.6 TULSA Jan Fixed array Lat-15 3.5 Latitude 4.0 Lat+15 4.3 Single axis tracker Lat-15 4.4 Latitude 4.8 Lat+15 5 Dual axis tracker 5.0 240 , Feb 4.4 | 4.9 OH Mar 4.2 4.3 42 Latitude:41.60 degrees May 7.6 Jun 6.2 5.7 5.0 8.3 Jul 6.2 5.7 5.0 8.1 7.8 7.3 8.2 Aug 7.5 Latitude:41.27 degrees May 5.4 5.0 4.5 6.7 6.5 6.1 6.8 Jun 7.6 jul 7.6 Aug 6.7 Latitude:35.40 degrees May 6.2 5.8 5.2 8.1 7.9 7.4 8.2 May Jun 6.6 - 6.0 5.2 8.8 8.4 7.9 9.0 jun 6.3 5.8 5.0 8.3 7.9 7.4 8.5 Jul 6.8 6.3 5.5 9.3 8.9 8.4 9.4 Jul 6.6 6.1 5.3 8.8 8.5 8 9.0 Aug 6.5 63 5.7 8.7 8.6 8.1 8.7 _Latitude:36.20 degrees' Aug 6.3 6.0 5.5 8.3 8.2 7.8 8.4 Elevation:211 meters Oct 5.0 Nov 2.5 2.7 2.8 2.8 3.0 3.1 3.1 Dec 2.0 2.2 2.3 2.2 2.4 2.5 2.5 Avg 44 4.4 4] 5.5 5.5 5.3 5.7 Elevation:361 meters Oct 3.6 3.8 3.7 4.3 4.4 4.4 4.5 Nov 2.2 2.4 2.4 Dec Avg 4.0 3.9 3.7 4.9 4.9 "47 5.1 Ejievation:397 meters Oct 5.0 5.4 5.5 6.5 6.8 6.8 6.8 Nov 5.6 Dec 5.1 Avg 5.3 5.4 5.2 6.9 7.0 6.9 7.3 Elevation:206 meters Oct 4.7 5.1 5.1 6.0 6.3 6.3 6.4 Nov Dec 3.2 3.7 4.0 3.9 4.3 4.5 4.6 APPENDIX B -SOLAR DATA ASTORIA OR Latitude:46.15 degrees Elevation:7 meters Jan Feb Mar Apr May Jun Jul =Aug)Sep =Oct =Nov Dec Avg. Beod amy 14 34 43 50 52 54 51 47 3.3 2.0 LS 37 L vitude 19 26 34 42 #47 47 50 49 47 3.5 2.1 17 3.6 att 41 4]44.44 45 3.5 2.2 1.8 3:4Lat+15 2.0 2.6 3.3 3.8 Single axis trackerres1.9028 40 53 2 6 6B 64 59 400 22 TS Tarieude 21 4029 41 52 60.61 66 63 59 41 23 18 45 lat+15 2.2 29 4 49 56 57 G61 6 58 41 24 #19 43 Dual axis tracker 2.2 3.0 4.1 5.3 6.3 6.6 7.0 6.5 6.0 4.2 2.4 1.9 4.6 BURNS OR Latitude:43.58 degrees Elevation:1271 meters Jan Eeh Mar Apr May =Jun =Jul ©Aug «Sep,«=Oct.=Nov Dec AugFixedarray Lac-15 2.8 3.7 4,7 5.8 6.5 6.9 7.5 7.0 6.3 4.8 2.8 2.4 5.1 Latitude 3.1 4.0 4.9 5.7 6.1 6.3 -69 6.8 6.4 5.2 3.1 2.7 5.1 Lat+15 3.3 4.1 4.8 5.3 5.4 5.4 6.0 6.1 6.1 5.2 3.3 2.9 4.8 Single axis tracker Lat-15 3.3 4.5 6.0 77 9.0 9.8 10.9 10.0 8.6 6.2 3.4 2.8 6.8 Latitude 3.5 4.8 6.1 7.6 8.7 9.4 10.5 9.8 8.7 6.5 3.6 3.1 Lat+15 3.7 4.8 6.1 73 8.2 8.8 9.9 9.3 8.5 6.5 3.7 3.2 6.7 Dual axis tracker 3.7 4.9 6.2 7.7 9.1 10.0 11.1 10.0 8.7 6.5 3.7 3,3 7.1 EUGENE OR Latitude:44.12 degrees Elevation:109 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 1.8 2.6 3.8 4.8 5.6 6.0 6.7 6.3 5.4 3.6 1.9 1.4 4.2 Latitude 2.0 2.7 3.8 4,7 5.3 5.5 6.2 6.0 5.5 3.8 2.1 1.6 4.1 Lat+15 2.0 2.8 3.7 4.3 4.6 4.8 5.4 5.5 5.2 3.8 2.1 1.6 3.8 Single axis tracker Lat-15 2.0 3.0 4.5 6.0 7.3 °°8&4 9.4 8.5 7.1 4.4 2.2 1.6 5.3 Latitude 2.1 3,1 4.6 5.9 7.1 7.8 9.1 8.4 7.1 46 -2.3 1.7 5.3 Lat+15 2.2 3.1 4.5 5.6 6.7 7.3 8.5 8 6.9 4.6 2.3 1.7 5.1 Dual axis tracker 2.2 3.2 4.6 6.0 7.4 8.3 9.6 8.6 71 4.6 2.3 1.7 5.5 MEDFORD OR Latitude:42.37 degrees Elevation:396 meters Jan Feb +=Mars Apr_-=-May =Jun Ss Jul «=Aug.«Sep «=Oct.«SNe «Dec AgFixedarray Lat-15 21 3.2 4.5 5.7 6.6 7.1 7.7 7.2 6.3 4.5 2.3 1.7 4.9 Latitude 2.3 3.5 4.6 5.6 6.2 6.5 7.1 6.9 6.4 4.8 2.4 1.9 4.9 Lat+15 2.4 3.5 4.5 5.2 5.5 5.6 6.2 6.3 6.2 4.8 2.5 2.0 4.5 Single axis tracker Lat-15 2.4 3.8 5.5 7.4 89 869.9 ULL 10.0 8.5 5.6 2.5 1.9 6.5 3 Latitude 2.6 4.0 5.6 7.3 8.7 9.5 10.7 9.9 5.9 2.7 2.0 1.8 6.5 k Lat+15 2.6 4 5.5 7 8.1 8.9 10.1 9.4 8.4 5.9 28 21 6.2 Dual axis tracker 2.7 4.0 5.6 7.4 9.0 10.1 11.3 10.1 8.6 5.9 2.8 2.1 6.76gREEBakeenOeettadenPasewsBSL 241 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL NORTH BEND Jan Fixed array Lat-15 2.4 Laticude 2.6 Lat+15 2.7 Single axis tracker Lat-15 2.7 Latitude 3.0 Lat+15 3.1 Dual axis tracker 3.1 PENDLETON Jan Fixed array Lat-15 2.0 Latitude 2.2 Lat+15 2.2 Single axis tracker Lat-15 2.2 Latitude 2.4 Lar+15 2.4 Dual axis tracker 2.5 PORTLAND Jan Fixed array Lat-15 1.7 Latitude 1.9 Lat+15 1.9 Single axis tracker Lat-15 1.9 Latitude 2.0 Lat+15 2.1 Dual axis tracker 2.1 REDMOND Jan Fixed array Lat-15 2.6 Latitude 3.0 Lat+15 3.1 Single axis tracker Lat-15 3.1 Latitude 3.4 Lat+15 3.5 Dual axis tracker 3.6 242 Latitude:43.42 degrees May 5.8 5.5 4.8 7.4 7.2 6.7 7.5 Jun 6.1 5.6 4.8 7.8 75 6.9 8.0 Jul 6.5 6.1 5.3 8.5 8.2 7.7 8.7 Aug 6.0 5.8 5.3 7.7 7.6 7.2 7.8 Latitude:45.68 degrees May 6.3 5.9 5.2 8.6 8.4 7.9 8.8 Jun 6.8 6.2 5.3 9.7 Jul 7.4 6.8 5.9 10.7 10.4 9.8 10.9 Aug 9.8 Latitude:45.60 degrees May 6.9 Jun 7.7 Jul 6.3 5.8 5.1 8.4 .8.1 7.6 8.6 Aug 7.7 Latitude:44.27 degrees May 6.6 6.2 5.5 9.1 8.8 8.3 9.2 Jun Jul 7.6 7.0 6.1 11.0 10.6 10 11.2 Aug Elevation:5 meters Oct 4.0 4.3 4.3 4.9 5.1 5.2 5.2 Nov 2.6 2.8 2.9 3.0 3.2 3.3 3.3 Dec 2.1 2.4. 2.5 2.4 2.7 2.8 2.8 Avg 4.4 4.4 4.2 5.7 Etevation:456 meters Oct 5.9 Nov Dec 1.7 1.9 1.9 2.1 2.2 2.2 Avg 6.5 Elevation:12 meters Oct 3.4 3.6 3.6 4.1 4.3 4.2 43 Noy 1.9 2.1 2.1 2.1 2.2 2.3 2.3 Dec Avg 5.1 Elevation:940 meters Oct 4,7 5.1 Nov 2.9 3.2 3.3 3.4 3.6 3.7 3.8 Dec 2.4 2.7 2.9 2.7 3.0 3.2 3.2 Avg APPENDIX B -SOLAR DATA OR Latitude:44.92 degrees Elevation:61 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec AvgSALEM ixedeee1g kT 8B AB 5G 6D HD 364220 #218 «4255.3 Latitude 2.0 2.8 3.9 4.7 5.2 5.5 6.1 6.0 5.4 3.8 2.2 1.6 4.1 Lat+15 2.1 2.8 3.7 43 4.6 4.7 5.3 5.4 5.1 3.8 2.2 1.7 3.8 Single axis trackerTis20 30 46 60 72 79 91 83 69 44 22 16 53Toumde22«23202«46 57 7G BD 70 4S KB OSB ltrs 23 32 45 56 66 71 82 78 68 45 24 18 5.1 Dual axis tracker 2.3 3,2 47 6.0 73 8.1 9.2 8.4 |7.0 4.6 2.4 1.8 5.4 ALLENTOWN PA Latitude:40.65 degrees Elevation:117 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed arrayLat-15 28 36 44 51 £55 5.8 58 55 48 40 27 #4223 44 Latitude 3.1 3.9 4.5 5.0 5.2 5.4 5.4 5.3 4.9 4.2 3.0 2.6 4,4 Lat+15 3.3 4.0 4,4 4.6 4.6 4.7 4.8 4.8 4.6 4.2 3.1 2.8 4,2 Single axis tracker Lat-15 3.3 4.4 5.4 6.4 6.9 7.4 7.4 6.9 6.0 4.8 3,2 2.7 5.4 Latitude 3.6 4.6 5.5 6.3 6.7 7.1 7.1 6.8 60 .5.0 3,4 2.9 5.4 Lar+15 3.8 4,7 5.4 6 6.2 6.6 6.6 6.5 5.9 5.1 3.5 3.1 5.3 Dual axis tracker 3.8 4.7 5.6 6.4 7.0 75 7.5 7.0 6.0 5.1 3.6 3.1 5.6 BRADFORD PA Latitude:41.80 degrees |Eijevation:600 meters |Jen Feb =Mars Apr May =Jun Ss Jul Aug”«Sep «=Oct Nov,Dec AgiFixedarray i Lat-15 2.4 3,4 43 5.0 5.4 5.8 5.8 5.3 4,5 3.6 2.3 1.9 4.2 Latitude 2.7 3.7 4.4 4.8 5.1 5.3 5:4 5.1 4.5 3.8 2.4 2.1 4.1 :Lat+15 2.8 3.8 44 45 4.5 4.6 4,7 4.6 4,3 3.8 2.5 2.2 3.9 co Single axis tracker.;; Lat-15 2.8 41 5,2 6.2 6.9 7.5 7.5 6.8 5.6 4.3 2.6 2.1 5.1 Latitude 3.0 43 5.4 6.1 6.7 7.2 7.2 6.6 5.6 4.5 2.7 2.3 5.1 Lar+15 3.1 44 5.3 5.9 6.3 6.7 6.8 6.3 5.5 4.4 2.8 2.4 5 Dual axis tracker 3.2 4.4 5.4 6.2 7.0 7.7 7.6 6.8 5.7 4.5 2.8 2.4 5.3 ERIE PA Latitude:42.08 degrees Elevation:225 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 211 3,1 4.0 5.0 5.7 6.1 6.2 5.6 4.7 3.5 2.1 1.6 42 Latitude 2.3 3.3 4.1 49 5.4 5.6 5.8 5.4 4.7 3.7 2.2 1.8 41 Lat+15 2.4 3.4 4.0 4.5 4.8 4.9 4.5 3.7 2.3 1.8 3.94.9 5.0 Single axis tracker ft Lat-15 2.3 3.6 4.9 6.3 7.4 8.0 8.1 7.2 5.9 4.2 2.3 1.8 5.2 Latitude 2.5 3.8 4.9 6.2 7.1 77°78 7.1 5.9 4.3 2.5 1.9 5.2 Lat+15 2.6 3.8 4.9 6 6.7 7.2 7.3 6.7 5.8 4.3 2.5 1.9 5 Dual axis tracker 2.6 3.8 5.0 6.3 75 8.2 8.3 7.3 6.0 4.4 -°2.5 1.9 5.3Francecuneeeesa5 243 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL HARRISBURG Jan =FebFixedarray Lar-15 2.9 3.7 Latitude 3.2 4.0 Lat+15 3.5 4.1 Single axis tracker Lat-15 3.4 4.5 Latitude 3.7 48 Lat+15 3.9 4.9 Dual axis tracker 3.9 4.9 PHILADELPHIA Jan =FebFixedarray Lar-15 2.9 3.7 Latitude 3.3 4.0 Lat+15 3.5 4.1 Single axis tracker Lat-15 3.5 4.5 Latitude 3.8 4.8 Lar+15 4 4.9 Dual axis tracker -«4.0 4.9 PITTSBURGH Jan Feb Fixed array Lat-15 2.4 3.2 Latitude 2.6 3.4 Lat+15 2.7 3.5 Single axis tracker Lat-15 2.7 |3.7 Latitude 2.9 3.9 Lat+15 3 4 Dual axis tracker 3.0 4.0 WILKES-BARRE Jan FebFixedarray Lat-15 2.5 3.4 Latitude 2.8 3.6 Lat+15 3.0 3.7 Single axis tracker Lat-15 2.9 4.0 Latitude 3.2 4.2 Lat+15 3.3 4.3 Dual axis tracker 3.3 4.3 244 Latitude:40.22 degrees May 5.6 5.3 4.7 7.1 6.8 6.2 7. Jun 6.0 5.5 7.8 Jul 7.6 _70 Latitude:39.88 degrees May 5.6 5.3 4.7 Jun 6.0 5.5 4.8 7.7 7.3 6.8 7.8 Jul 5.9 5.5 4.8 75 73 6.8 7.7 Aug 5.7 5.5 5.0 7.2 7.1 6.7 7.3 Latitude:40.50 degrees May 7.0 Jun 7.7 Jul 5.9 5.5 4.8 74 7.2 6.7 7.6 Aug 6.9 Latitude:41.33 degrees May Jun Sep 4.8 4.8 4.6 5.9 6.0 5.8 6.0 Sep 4.7 4.7 4.5 5.8 5.8 5.6 5.8 Elevation:106 meter Oct 5.3 Elevation:9 Oct 4.2 4.4 4.5 5.2 5.4 5.4 5.4 Nov 2.9 3.2 3.3 3.4 3.6 3.7 3.8 Nov 4.] Dec 2.4 2.7 2.9 2.8 3.1 3.2 3.3 meters Dec 2.6 2.9 3.1 3.0 3.3 3.5 3.5 Avg 5.9 Elevation:373 meteis Oct 4.9 Nov 2.4 3.0 Dec Avg 5.3 Elevation:289 meters Oct 3.8 4.0 4.0 4.6 . 4.8 |48 4.8 Nov 2.4 2.6 2.7 Dec 2.0 2.2 2.4 2.3 2.5 2.6 2.6 Avg 4.2 4.2 4.0 5.2 5.2 5 5.4 NLLIAMSPORT Fixed array Lar-15 2.6 3.4 Latitude 2.9 3.7 Lat+15 3.0 3.8 Single axis crackerLac-15 3.0 4.1. Latitude 3.2 43 Lar+15 3.4 4.4 Dual axis cracker 3.4 4.4 GUAM an Feb Fixed array Lat-15 4.3 4.8 Latitude 5.0 5.2 Lar+15 5.3 5.4 Single axis cracker . Lat-15 5.6 6.1 Latitude 6.1 6.4 Lac+15 6.3 6.6 Dual axis tracker 6.4 6.6 SAN JUAN an Feb Fixed array Lat-15 4.5 5.1 Latitude 5.1 5.6 Lat+15 5.5 5.8 Single axis tracker Lat-15 5.8 6.5 Latitude 6.3 6.9 Lar+15 6.6 7.1 Dual axis tracker 6.6 7.1 PROVIDENCE Jan FebFixedarray Lac-15 3.0 3.7 Latitude 3.4 4.1 Lat+15 3.6 4.2 Single axis tracker Lat-15 3.5 4.6 Latitude 3.9 4.9 Lat+1t5 4.1 5 Dual axis tracker 4.1 5.0 PA Latitude:41.27 degrees May fun 5 5.9 5.1 5.4 46 47 6.9 7.5 6.6 7.2 6.2 67 6.9 7.6 Jul 5.9 5.5 4.8 7.4 7.1 6.7 7.5 Aug 5.4 5.2 4.8 6.7 6.6 6.2 6.8 Latitude:13.55 degrees May Jun 5.7 5.5 5.4 5.1 4.9 4.5 7.3 6.9 7.0 6.6 6.6 6.1 7.3 7.0 Jul 6.3 Aug 4.9 47 4.4 5.9 Latitude:18.43 degrees May -Jun 5.7 6.0 5.4 5.5 49 4.8 7.2 7.5 6.9 7.2 6.5 6.7 7.2 77 Latitude:41.73 degrees May -Jun 5.6 5.9 53 5.4 47 4.7 71 7.5 69 7.2 65 67 720 7.7 Jul 6.0 5.6 5.0 7.6 7.3 6.8 7.7 Jul Aug 6.0 5.8 5.3 7.5 74 7 7.6 Aug APPENDIX B -SOLAR DATA Elevation:243 meters Oct 3.7 3.9 ° 3.9 4.4 4.5 4.5 46. Nov 2.4 2.6 2.7 3.0 Dec 2.1 2.3 2.4 2.3 2.5 2.6 2.6 Avg 4.2 4.2 4.0 5.2 5.2 5 5.3 Elevation:110 meters Oct 46 4.9 4.9 5.7 5.9 5.9 6.0 Oct 5.0 5.4 5.5 6.4 6.7 6.7 6.7 Nov 6.2 6.4 Dec Avg : 4.9 5.1 5.0 6.2 6.3 6.2 6.5 Avg 7.2 Elevation:19 meters Oct Nov 2.9 3.2 3.3 3.4 3.6 3.7 3.8 Avg 4.5 4.5 4.3 5.6 5.6 5.5 5.8 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL CHARLESTON sc 'Latitude:32.90 degrees Elevation:12 meters Jan Feb Mar Apr Mays duns Jul')Aug.«Sep =Oct,SsNow Dec AugFixedarray Lat-15 3.5 4.3 5.3 6.2 6.2 6.1 6.0 5.6 5.1 . Latitude 4.0 47 5.5 6.1 5.8 5.6 5.6 5.4 5.2 5.2 4.5 Lat+15 4.3 4.9 54 5.7 5.2 4.9 4.9 4.9 5.0 Single axis tracker Lat-15 4.4 5.4 6.7 8.1 7.9 7.6 7.5 6.9 6.3 6.1 49 Latitude 4.8 5.8 6.9 8.0 77 73 7.2 6.8 6.4 6.3 53 Lat+15 5 5.9 6.8 7.7 7.2 6.8 6.7 6.4 6.2 6.4 5.5 Dual axis tracker 5.0 5.9 6.9 8.1 8.0 7.8 7.6 7.0 6.4 6.4 5.5 4.9 6.6 3.4 5.0 3.9 5.1 5.2 4.7 4.2 4.9 4.2 6.3 4.6 4.8 6.4 6.3 COLUMBIA sc Latitude:33.95 degrees Elevation:69 meters Jan Feb Mar May =Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Apr Lat-15 3.4 42 5.1 6.0 6.1 6.1 6.0 5.7 5.2 4.8 3.8 3.3 5.0 Latitude 3.9 4.6 5.3 5.9 5.7 5.7 5.6 55 5.3 5.2 4.3 3.8 5.1 Lat+15 4.1 4.8 5.2 5.5 5.1 4.9 4,9 5.0 5.1 5.2 4.6 4.1 4.9 Single axis tracker , Lat-15 4.2 5.3 6.5 7.8 7.8 7.8 7.5 7.1 6.5 6.1 4.8 4.0 6.3 Latitude 4.6 5.6 6.6 7.8 75 7.4 7.2 6.9 6.6 6.4 5.2 4.4 6.4 Lat+15 4.8 5.7 6.5 7.5 7.1 6.9 6.7 6.6 6.4 6.4 5.3 47 6.2 Dual axis tracker 4.8 5.8 6.6 7.8 7.8 7.9 7.6 7 6.6 6.4 5.4 4.7 6.6 GREENVILLE sc Latitude:34.90 degrees Elevation:296 mete:s Fixed array Lat-15 3.5 4.2 5.1 5.9 6.0 61 9 59 5.7 5.2 4.8 3.8 3.2 5.0 Latitude 4.0 4.6 5.3 5.8 5.6 5.6 5.5 5.5 52 52 43 3,7 5.0 Lat+15 4.2 4.8 5.2 5.4 5.0 4,9 4.8 5.1 5.0 5.2 4.5 4.0 4.8 Single axis tracker Lat-15 4.3 5.4 6.5 7.7 7.7 =78 7.5 7.3 6.5 6.1 4.7 3.9 6.3 _ Latitude 4.7 5.7 6.7 7.7 7.4 7.5 7.2 7.1 6.6 6.4 5.10 4.3 6.4 a Lat+15 5 5.8 6.6 74 7 7 6.7 6.8 6.4 6.5 5.3 46°6.2 fy Dual axis tracker 5.0 5.8 6.7 7.8 7.8 8.0 7.6 7.3 6.6 6.5 5.4 4.6 6.6 HURON SD Latitude:44.38 degrees Elevation:393 meters a -Jan Feb Mar Apr May Jun Jul Aug Oct Nov Dec Avg ee Fixed array Lat-15 3.0 3.8 4.7 5.4 »Latitude 3.4 4.2 4.8 5.3 5.6 5.9 6.2 6.1 Lat+15 3.7 4.3 4.8 4.9 4.9 5.1 5.4 5.5 Single axis tracker Lat-15 3.6 47 5.9 7.0 8.0 8.8 9.2 8.6 7.0 5.4 3.6 3.0 .6.2 Latitude 4.0 5.0 6.0 6.9 7.7 8.5 8.9 8.4 7.1 5.6 3,4 6.3 6.5 Lat+15 4.2 5.1 6.6.7 7.3 7.9 8.3 8 6.9 5.6 4 3.6 4 Dual axis tracker 4.2 5.1 6.0 7.0 8.1 9.0 9.4 8.6 7.1 5.7 4.0 3.6 6.5 4.6 3.3 3.0 4.8 Sep 60 64 67 63 53 43 30 26 48 5.4 52 46 35 32 46 246 PIERRE Jan Fixed array Lat-15 3.1 Latitude 3.6 Lat+15 3.8 Single axis tracker Lat-15 3.7 Laticude 4.1 Lat+15 4.3 Dual axis cracker 4.4 RAPID CITY Jan Fixed array Lat-15 3.2 -Latitude 3.7 Lat+15 4.0 Single axis tracker Lat-15 3.9 Latitude 4.3 Latr+15 4.5 Dual axis tracker 4.6 SIOUX FALLS Jan Fixed array Lat-15 3.1 Latitude 3.6 Lar+15 3.8 Single axis tracker Lat-15 3.8 Laticude,4.2 Lat+15 44 Dual axis tracker 4.4 BRISTOL Jan Fixed array Lat-15 2.9 Latitude 3.3 Lat+15 3.5 ”Single axis tracker Lat-15 3.5: Latitude 3.8 Lat+15 4 Dual axis tracker 4.0 pala)ic"rRBSBSNSWnnnAWto"fonApr 5.4 5.2 4.8 7.0 6.9 6.6 7.0 Apr 5.4 9.3 4.9 6.9 6.8 6.5 6.9 Latitude:44.38 degrees May Jun 6.1 6.6 5.7 6.0 5.1 5.2 8.2 9.0 8.0 8&7 7.5 8.1 8.3 9.3 Jul 9.7 Aug 6.5 6.3 5.7 8.9 8.8 8.4 9.0 Latitude:44.05 degrees May Jun 6.1 6.6 5.7 6.0 5.0 5.2 8.3 9.2 8.0 8.8 7.6 8.3 8.4 9.4 Jul 6.8 6.3 5.5 9.5 9.2 8.7 9.7 Aug 6.6 6.4 5.8 9.2 9.1 8.6 9.3 Latitude:43.57 degrees 5.9 6.4 5.5 5.8 4.9 5.1 7.9 8.7 7.6 8.3 7.2 7.8 8.0 8.9 Jul 6.6 6.1 5.3 9.0 8.7 8.2 9.2 Aug 6.1 5.9 5.3 8.3 Latitude:36.48 degrees May =Jun 5.7 6.0 5.4 5.5 48 48 7.2 7.6 70 7.3 6.6 6.8 73 7.8 Jul Aug 5.6 5.4 5.0 7.1 6.9 6.6 7.1 APPENDIX 8 -SOLAR DATA Elevation:526 meters Oct 6.0 Noy 4.3 Dec 2.7 3.1 3.3 3.2 3.5 3.7 3.8 Avg 6.8 Elevation:966 meters Oct 6.5 Nov 3.4 3.9 4.1 4.2 4.6 4.7 4.8 Dec 3.0 3.4 3.7 3.6 4.0 4.2 4.3 Avg 7.1 Elevation:435 meters Oct 43 4.6 4.6 5.7 Nov 4.0 Dec 3.7 Ayg 4.8 4.8 4.6 6.2 6.2 6.1 6.5 Elevation:459 meters Nov 3.2 3.6 3.7 3.9 4.2 4.3 4.3 Dec 2.7 3.1 3.3 3.2 3.5 3.7 3.7 Avg 247 wee EN PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL CHATTANOOGA Jan FebFixedarray Lar-15 3.1 3.8 Latitude 3.5 4.] Lat+15 3.7 4.2 Single axis tracker Lat-15 38 47 Latitude 4.1 4.9 Lar+15 4.2 5 Dual axis tracker 4.3 5.0 KNOXVILLE Jan FebFixedarray Lat-15 3.0 3.7 Latitude 3.4 4.0 Lat+15 3.6 4.1 Single axis tracker Lat-15 3.6 4.6 Latitude 3.9 4.8 Latr+15 4.1 4.9 Dual axis tracker 4.1 4.9 MEMPHIS an Feb Fixed array Lat-15 3.3 4.0 Latitude 3.7 4.4 Lat+15 4.0 4.5 Single axis tracker Lat-15 4.0 5.0 Latitude 4.4 5.3 Lat+15 4.6 5.4 Dual axis tracker 4.6 5.4 NASHVILLE an Feb Fixed array Lat-15 3.1 3.9 Latitude 3.5 4.2 Lat+15 3.7 4.3 Single axis tracker Lat-15 3.8 4.8 Latitude 4.1 5.0 Lat+15°4.2 5.1 Dual axis cracker 4.3 5.1 248 ™N Apr Latitude:35.03 degrees May 5.8 5.4 4.9 7.4 Jun 6.0 5.5 4.8 7.6 7.2 6.7 7.7 Jul 7.3 Aug 5.7 5.5 5.0 7.1 Latitude:35.82 degrees May 7.4 Jun 6.1 5.6 4.9 7.7 7.4 6.9 7.9 74 7.2 Latitude:35.05 degrees May =Jun Jul 6.1 6.4 6.4 5.8 5.9 6.0 5.1 5.1]5.2 8.0 8.5 8.4 7.7 81 8.1 7.3 7.6 7.6 8.0 86 8.5 Aug 6.2 6.0 5.5 8.1 7.9 7.5 8.1 Latitude:36.12 degrees May 6.0 5.7 5.0 7.7 7.5 7 7.8 Jun 6.4 5.9 5.1 8.1 7.8 7.3 8.3 Jul 6.2 5.8 5.1 7.8 7.5 7 7.9 7.5 5.9 5.7 5.2 7.3 6.9 75 Sep Sep 6.8 Elevation:210 meters Oct 4.6 4.9 4,9 5.7 5.9 6 6.0 Nov 3.4 3.8 4.0 4.6 Dec 2.8 3.2 3.4 3.4 3.7 3.9 3.9 Avg 4.7 4.7 4.5 5.8 5.9 5.7 6.0 Elevation:299 meters Oct 6.0 Nov 4.4 Dec Avg 6.0 Elevation:87 meters Oct 4.9 5.2 5.3 6.2 6.5 6.5 6.5 Noy 4.8 Dec 3.0 3.4 3.6 4.2 Avg 5.0 5.0 4.8 6.4 6.4 6.3 6.6 Elevation:180 meters Oct 4.6 4.9 5.0 5.8 6.0 6.1 6.1 Nov 3.3 3.6 3.8 © 4.0 4.2 4.4 4.4 Dec 2.8 3.1 3.4 3.3 3.6 3.8 3.8 Avg 4.8 4.9 4.6 6.0 6.1 5.9 6.3 APPENDIX B -SOLAR DATA ABLIENE TX Latitude:32.43 degrees Elevation:534 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fe Al 48 58 64 65 G68 68 65 S57 53 43 39 56 lane 4753 (6.063 GL GD 63 GB 5B ST 49 4S 5.a st 55 60 SB SASS ST 5G 5B 52 AD SS ingle axis trackereS52)62 7H BS GOL BT TS 6D 5S 4D 7B ede 57 66 78 84 84 87 89 86 76 7.2 60 54 74es6COOTO7TB79828ABDTK7B62577B Dual axis cracker 6.0 6.7 7.8 =8.5 8.7 9.3 9.4 8.8 7.6 7.3 6.3 5.8 7.7 ye AMARILLO T™X Latitude:35.23 degrees Elevation:1098 meters -Jan Feb Mar =Apr_-«s Mays duns Jul «Ss Aug «Sep,Oct «=Noy Dec AgEsFixedarray ie Lat-15 42 49 65 66 69 69 65 59 5.5 44 3.9 5.7 Latitude 4.9 5.4 6.0 6.4 6.2 6.3 6.4 6.3 6.0 5.9 5.0 4.6 5.8 Lat+15 5.3 5.7 6.0 5.5 5.5 5.5 5.7 5.8 6.0 5.3 5.0 5.6 Single axis tracker Lat-15 5.4 6.4 7.6 8.8 8.9 9.4 9.4 8.8 7.8 7.2 5.6 5.0 7.5 Latitude 6.0 6.8 7.8 8.7 8.6 9.0 9.0 8.7 7.9 7.6 6.1 5.5 7.6 Lat+15 6.3 6.9 7.7 8.4 8.1 8.4 8.4 8.2 77 7.7 6.4 5.9 75 Dual exis tracker 6.3 7.0 7.8 8.8 9.0 9.6 9.5 8.9 7.9 77 6.4 6.0 7.9 AUSTIN TX Latitude:30.30 degrees Elevation:189 meters Fixed array Lat-15 3.7 4.4 5.2 5.6 5.8 64 °67.65 5.7 5.0 4.1 3.5 5.2 Latitude 4.2 4.8 5.4 5.5 5.5 5.9 6.2 6.3 5.8 5.4 4.6 5.3 5.4 Lat+15 4.4 5.0 5.3 5.1 4.9 5.1 5.4 5.7 5.5 5.5 4.8 4.3 5.1 Single axis tracker Lat-15 4.6 5.6 6.6 7.1 7.3 8.3 8.7 8.5 7.3 6.5 5.1 4.4 6.7 Latitude 5.0 5.9 6.7 7.0 7.1 8.0 8.4 8.3 7.3 6.8 5.5 4.8 6.7 Lat+15 5.2 6 6.6 6.7 6.7 7.4 7.8 7.9 7.2 6.8 5.7 5 6.6 Dual axis tracker 5.2 6.0 6.7 7.1 °7.4 8.5 8.9 8.5 7.4 6.9 5.7 5.1 7.0 i . BROWNSVILLE TX Latitude:25.90 degrees Elevation:6 meters an Feb Mar Apr May -Jun jul Aug Sep Oct Nov Dec AvgFixedarray. Lat-15 4.3 5.3 6 6.3 6.4 7.1 7.4 7.3 6.9 6.7 5.4 43 6.1 Latitude 3.6 4.3 5.0 5.3 5.4 5.7 5.9 5.8 5.5 5.3 4.4 3.6 °5.0 Lat+15 3.8 4.4 4.9 5.0 4.8 5.0 5.2 5.3 5.3 5.4 4.6 3.8 4.8 Single axis tracker Lat-15 3.9 5.0 6.0 6.6 7.1 7.9 8.2 7.8 6.9 6.3 4.9 3.8 6.2 Latitude 4.2 5.2 6.1 66 68 7.6 7.9 7.7 7.0 6.6 5.3 4.1 6.3 Lat+15 3.9 5.0 6.0 6.6 7.1 7.9 8.2 7.8 6.9 6.3 4.9 3.8 6.2 Dual axis tracker 4.4 5.3 6.1 6.6 7.1 8.1 8.4 7.8 7.0 6.7 5.5 4.4 6.5andatseetessheets 249 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL CORPUS CHRISTI Jan Fixed array Lat-15 3.2 Latitude'3.6 Lat+15 3.8 Single axis tracker Lat-15 3.9 Latitude 4.2 Lat+15 4.4 Dual axis tracker 44 EL PASO Jan Fixed array Lat-15 4.6 Latitude 5.3 Lat+15 5.8 Single axis tracker Lat-15 5.9 Latitude 6.5 Lat+15 6.9 Dual axis tracker 6.9 FORT WORTH Jan Fixed array Lat-15 3.8 Latitude 4.3 Lat+15 4.6 Single axis tracker Lat-15 4.7 Latitude 5.1] Lat+15 5.3 Dual axis tracker 5.4 HOUSTON Jan Fixed array Lat-15 3.2 Latitude 3.6 Lat+15 3.8 Single axis tracker Lat-15 3.9 Latitude 4.2 Lat+15 43 Dual axis tracker 4.4 250 Feb 4.0 4.3 4.5 5.0 5.2 5.3 5.3 10.2 10.1 10.2 Apr 5.9 5.7 5.3 7.5 7.4 7.1 7.5 Apr 5.2 5.1 4.7 6.4 6.4 6.1 6.5 Latitude:27.77 degrees 5.4 5.9: 5.1 5.5 4.6 4.8 6.8 7.6 6.5 7.3 6.1 6.8 6.8 7.7 Jul 6.1 5.7 5.0 8.0 7.7 7.2 8.1 Aug 77 Latitude:31.80 degrees May =Jun 78 77 730°7) 64 6.0 10.7 10.6 10.4 10.2 98 9.5 10.8 10.9 Jul 7.2 6.7 5.8 9.5 9.2 8.6 9.7 Aug 6.9 6.7 6.1 9.1 9.0 8.5 9.2 Latitude:32.63 degrees May Jun 6.2 67 5.8 6.2 5.2 5.3 7.9 8.8 7.7 84 7.2 7.8 8.0 9.0 Jul 6.9 6.4 5.6 9.1 8.8 8.2 9.3 Aug 6.5 6.3 5.7 8.6 8.5 8 8.6 Latitude:29.98 degrees May Jun 56 5.9 5.3 54 47 47 70 75 68 7.2 64 67 710-77 Jul 5.8 5.4 4.8 7.4 7.2 6.7 7.6 Aug 5.7 5.9 9.0 7.3 7.2 6.8 7.3 Elevation:13 meters Oct 4.8 5.2 5.3 6.3 6.5 6.6 6.6 Noy 5.5 Elevation:1194 Oct 8.3 Elevation:16 Oct 6.8 Nov 4.9 5.7 6.1 6.4 7.0 7.3 74 Nov 5.7 Dec =Avg 3,1 4,8 3.6 4.9 3.8 4.7 38 ©61 4.2 6.1 44 6 44 6.3 meters Dec Ayg 4.4 6.3 5.1 6.5 5.6 6.2 5.6 8.4 6.3 8.6 6.6 8.4 6.7 8.9 4 meters Dec Avg 35 5.3. 4)5.4 4.4 5.2 44 6.9 49 6.9 5.1 6.8 5.2 7.2 Elevation:33 meters Oct Nov 3.7 4.1 4,3 4.6 4.9 5.1 5.1 Dec 3.0 3.5 3.7 3.7 4.0 4.2 4.2 Avg PortseeLUBBOCK Jan FebFixedarray Lac-15 4.2 5.0 Latitude 4.9 5.5 Lat+15 5.3 5.7 Single axis trackerLat-15 5.4 6.4 Laticude 5.9 6.8 Lac+15 6.2 7 Dual axis tracker 63 7.0 LUFKIN Jan Feb Fixed array Lat-15 3.4 4} Latitude 3.8 4.5 Lat+15 4.0 4.6 Single axis tracker Latr-15 4.1 5.2 Latitude 4.4 5.5 Lat+15 4.6 5.5 Dual axis tracker 4.6 5.6 MIDLAND Jan Feb Fixed array Lar-15 4.3 5.1 Latitude 5.0 . Lat+15 5.4 5.9 Single axis tracker Lat-15 5.6 6.7 Latitude 6.1 7.1 Lat+15 6.4 7.3 Dual axis tracker 6.5 7.3 PORT ARTHUR Jan =FebFixedarray Lat-15 3.3 4.1 Latitude 3.7 4.4 Lat+15 3.9 4.5 Single axis tracker Lat-15 4.0 5.1 Latitude 4.3 5.3 Lat+15 4.4 5.4 Dual axis tracker 4.5 5.4 Apr 6.8 6.7 6.2 9.1 9.0 8.7 9.1 Apr 5.3 5.2 4.9 6.7 6.6 6.3 6.7 Latitude:33.65 degrees 6.7 6.9 6.3 6.3 5.6 5.4 9.0 9.3 8.7 8.9 8.2 8.3 9.1 9.5 Jul 6.8 6.3 5.5 9.3 8.9 8.4 9.4 Aug 6.5 6.3 5.7 8.8 8.6 8.2 8.8 Latitude:31.23 degrees 5.9 6.2 5.6 5.8 4.9 5.0 74 8.0 7.2 7.7 6.7 7.1 7.5 8.2 Jul 6.3 5.9 5.2 8.0 7.8 7.2 8.2 Aug 6.2 6.0 5.4 7.9 7.8 7.4 8.0 Latitude:31.93 degrees 7.0 7.1 6.5 6.5 5.8 5.6 9.3.95 9.0 9.1 8.5 8.5 9.4 9.7 Jul 6.9 6.4 5.5 9.3 9.0 8.4 - 9.5 Aug 6.6 6.4 5.8 8.8 8.7 8.3 8.9 Latitude:29.95 degrees May =Jun 5.8 6.1 5.5 5.7 49 49 7.30 7.9 710°7.5 6.7 7 74 8.0 Jul 6.0 5.5 4.9 7.6 7.3 6.8 7.7 Aug 5.8 5.6 5.2 7.4 7.3 6.9 7.5 APPENDIX B -SOLAR DATA Elevation:988 meters Oct Nov Dec Avg 4.4 3.9 5.75.4 5.9 5.1 4.6 5.8 »6.0 5.4 5.0 5.6 7.2 5.7 5.0 7.5 75 6.2 5.6 7.6 7.6 6.5 5.9 7.5 7.6 6.5 6.0 7.9 Elevation:96 meters Oct Nov Dec Avg 5.0 3.9 3.2 5.0 5.4 4.3 3.7 5.1 5.4 4.6 4.0 4.9 6.4 4.8 4.0 6.3 6.6 5.2 4.3 6.4 '6.7 5.3 4.5 6.2 67 °5.4 4.6 6.6 Elevation:871 meters Oct Nov Dec Avg 5.5 4.6 4.1 5.8 60 53 48 6.0 61 56 52 5.8 7.3 6.0 53 77 7.6 6.5 5.8 7.9 77 6.8 6.2 77 7.7 6.8 6.3 8.1 Elevation:7 meters Oct Nov Dec Avg 4.9 3.8 3.2 4.9 5.3 42 3.6 4.9 5.4 4.4 3.9 4.7 6.3 4.7 3.9 6.1 6.6 5.0 4.2 6.2 6.7 5.2 4.4 6 6.7 5.2 4.5 6.4 251 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL SAN ANGELO an Feb Fixed array Lat-15 4.1 4.9 Latitude 4.7 5.4 Latr+15 5.1 5.6 Single axis tracker Lat-15 5.2 6.3 Latitude 5.7 6.7 Lar+15 6 6.8 . Dual axis tracker 6.1 6.9 SAN ANTONIO Jan Feb Fixed array Lat-15 3.7 4.5 Latitude 4.3 4.9 Lat+15 4.5 5.0 Single axis tracker Lat-15 4.7 5.7 Latitude 5.1 6.0 Lat+15 5.3 6.1 Dual axis tracker 53 6.1 VICTORIA Jan Feb Fixed array Lar-15 3.3 4.1 Latitude 3.7 4.5 Lat+15 3.9 4.6 Single axis tracker Lar-15 4.1 5.1 Latitude 4.4 5.4 Lat+15 4.5 5.5 Dual axis tracker 4.6 5.5 WACO Jan Feb Fixed array Lat-15 3.7 4.4 Latitude 4.2 4.8 Lat+15 4.5 5.0 Single axis tracker Lat-15 4.6 5.6 Latitude 5.0 5.9 Lat+15 5.3 6 Dual axis tracker 5.3 6.0 252 TX Apr Latitude:31.37 degrees 6.5 6.7 6.1 6.2 5.4 5.3 8.4 9.0 8.2 8.6 7.7 8 8.5 9.2 jul 6.8 6.3 5.5 9.2 8.8 8.3 9.3 Aug 6.5 -6.3 5.7 8.7 8.6 8.2 8.8 Latitude:29.53 degrees 5.9 6.5 5.6 6.0 5.0 5.2 7.3 8.3 7.1 7.9 6.7 7.4 74 8.4 5.6 6.1 5.3 5.6 47 4.9 7.0 7.7 6.7 74 6.3 6.9 7.0 7.9 ll 8.8 5.7 5.0 7.8 7.5 7.1 7.9 Aug 6.6 6.3 5.8 8.4 8.3 7.9 8.4 "Latitude:28.85 degrees Jul 6.1 Aug 5.9 5.7 5.2 7.6 7.5 7.1 7.7 Latitude:31.62 degrees May Jun 6.0 6.5 5.6 6.0 5.0 5.2 7.6 8.6 74 8.2 7 7.6 7.7 8.7 Jul 6.8 6.3 5.5 9.1 8.7 8.2 9.2 Aug 6.5 6.3 5.7 8.7 8.5 8.1 8.7 Elevation:582 meters Oct Nov Dec Avg 5.3 44 3.9 5.6 5.7 5.0 4.6 5.7 5.8 5.4 5.0 5.5 6.9 5.7 5.0 7.3 7.2 6.2 5.5 74 7.3 6.4 5.8 7.3 7.3 6.5 5.9 7.7 Elevation:242 meters Oct Nov Dec Avg 5.1 4.1 3.5 5.3 5.5 4.6 4.1 5.4 5.6 4.9 4.4 5.2 6.6 5.2 4.4 6.7 6.9 5.6 4.8 6.8 6.9 5.8 5 6.6 69 58 51 7.0. Elevation:32 meters Oct Noy Dec Avg 4.9 3.9 3.2 4.9 5.3 4.3 3.6 4.9 5.4 4.6 3.8 47 6.3 4.8 3.9 6.1 6.6 5.2 4.2 6.2 6.6 5.4 4.4 6 6.7 5.4 44 .64 Elevation:155 meters Oct Nov Dec Avg 5.0 4.0 3.6 5.3 5.4 4.5 4.1 5.4 5.5 4.8 4.4 5.1 6.5 5.1 4.4 6.8 6.8 5.5 4.9 6.9 6.9 5.7 5.1 6.7 6.9 5.7 5.2 7.1 FreerememHemeneysternAPPENDIX B -SOLAR DATA WICHITA FALLS TX -Latitude:33.97 degrees Elevation:314 meters Jan .Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.9 4.6 5.4 6.1 6.4 6.7 6.8 6.5 5.7 5.1 4.1 3.6 5.4 Latitude 4.5 5.0 5.6 6.0 6.0 6.2 6.3 6.3 5.8 5.5 46°42 5.5 Lat+15 4.8 5.2 5.5 5.6 5.3 5.3 5.5 5.7 5.6 56 .49 4.5 5.3 Single axis tracker Lar-15 4.9 5.8 7.0 8.0 8.4 9.0 9.2 8.7 7.5 6.7 5.1 4.5 7.1 Latitude 5.3 6.2 7.2 7.9 8.1 8.6 8.9 8.6 7.6 7.0 5.6 5.0 7.2 Lat+15 5.6 6.3 7.1 7.6 7.6 8.1 8.3 8.2 7.4 7.1 5.8 5.2 7 Dual axis tracker 5.6 6.3 7.2 8.0 8.5 9.2 9.4 8.8 7.6 7.1 5.8 5.3 7.4 CEDAR CITY UT Latitude:37.70 degrees Elevation:1712 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array ; Lac-15 4.0 4.7 5.5 6.4 7.0 7.5 7.1 6.8 6.6 5.6 4.2 3.7 5.8 Latitude 4.6 5.2 5.7 6.3 6.5 6.8 6.6 6.6 6.7 6.1 4.8 4.4 5.9 Lat+15 5.0 5.4 5.7 5.9 5.7 5.9 5.7 6.0 6.5 6.2 5.1 4.8 5.7 Single axis tracker Lat-15 5.1 6.1 7.3 8.8 9.7 10.8 10.1 9.5 9.1 7.55 5.4 4.7 7.9 Latitude 5.6 6.5 75 8.7 9.4 10.3 9,7 9.4 9.3 7.9 5.9 5.3 8.0 Lar+15 5.9 6.6 7.4 8.4 8.9 9.7 9.1 9 9.1 8 6.1 5.6 7.8 Dual axis tracker 6.0 6.6 7.5 8.8 9.9 11.0 10.3 9.6 9.3 8.0 6.2 5.7 8.3 SALT LAKE CITY UT Latitude:40.77 degrees Elevation:1288 meters Jan Feb =Mar =Apr ="Mays Jun Ss ul'«Ss Aug,«Sep «=Oct,ssNov Dec AgFixedarray Lat-15 2.9 4.0 5.0 5.9 6.6 7.2 7.3 7.0 6.3 5.0 3.3 2.5 5.2 Latitude 3.2 43 5.2 5.8 6.2 6.6 6.7.36.7 6.4 5.4 3.7 2.9 5.3 Lar+15 3.4 4.4 5.1 5.4 5.5 5.6 5.8 6.1 6.1 5.5 3.9 3.1 5.0 Single axis tracker Lat-15 3.4 4.8 6.3 77 8.9 10.0 10.2.9.6 8.5 6.5 4.0 3.0 6.9 Latitude 3.7 5.1 6.5 77 8.7 9.6 9.8 9.4.8.6 6.8 4.3 3.3 7.0 Lat+15 3.8 5.2 6.4 74 8.2 9 9.2 9 8.4 6.9 4.5 3.4 6.8 Dual axis tracker 3.9 5.2 6.5 7.8 91 103 104 9.6 8.6 6.9 45 3.5 7.2 LYNCHBURG VA Latitude:37.33 degrees Elevation:279 meters Jan Feb Mar Apr May -Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.4 4.2 5.1 5.8 6.1 6.3 6.1 5.9 5.3 4.6 3.6 3.1 5.0 Latitude 3.9 4.6 5.3 5.7 5.7 5.8 5.7 5.7 5.3 5.0 4.0 3.6 5.0 Lat+15 4.2 4.8 5.2 5.3 5.1 5.0 5.0 5.2 5.1 5.0 43 3.8 4.8 Single axis tracker . Lat-15 4.2 5.3 6.5 75 7.8 8.2 7.8 7.5 6.7 5.9 44 3.8 6.3 Latitude 4.6 5.6 6.6 74 7.6 7.8 7.5 7.3 6.7 6.1 4.8 4.1 6.4 Lar+15 4.8 5.7 6.6 7.1 710°(743 7 7 6.6 6.2 5 4.4 6.2 Dual axis tracker 4.9 5.7 6.7 75 7.9 8.3 7.9 75 6.8 6.2 5.0 4.4 6.6 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL NORFOLK Jan Fixed array Lat-15 3.2 Latitude 3.6 Lat+15 3.8 Single axis tracker Lat-15 3.9 Latitude 4.2 Lar+15 4.4 Dual axis tracker 4.4 RICHMOND Jan -Fixed array Lat-15 3.2 « Latitude 3.6 Lat+15 3.9 Single axis tracker _Lat-15 3.9 'Latitude 4.3 Lar+15 4.5 Dual axis tracker 4.5 ROANOKE Jan Fixed array Lat-15 3.3 Latitude 3.7 Lat+15 3.9 Single axis wacker Lat-15 4.0 Latitude 4.3 Lat+15 4.5 Dual axis tracker 4.6 STERLING Jan Fixed array Lat-15 3.1 Latitude 3.5 © Lat+15 3.7 Single axis tracker Lat-15 3.7 Latitude 4.0 Lat+15 4.2 Dual axis tracker 4.3 204 VA Apr Latitude:36.90 degrees” May -Jun 5.8 6.0 5.5 5.6 4.8 4.8 7.4 77 7.1 74 6.7 6.9 7.4 7.9 Jul 7.5 Aug 5.6 5.4 4.9 7.1 7.0 6.6 7.1 Latitude:37.50 degrees May -Jun 5.8 6.1 5.5 5.6 49°«49 74 7.8 7.2 7.5 6.8 7 75 8.0 Jul 7.6 Aug 5.7 5.5 5.0 7.1 7.0 6.7 7.2 Latitude:37.32 degrees May Jun 5.8 6.0 55 5.6 49 48 74.77 72 74 67 69 75 7.9 Jul 7.6 Aug 7.2 Latitude:38.95 degrees May Jun 5.8 6.1 5.5 5.7 4.8 4.9 73°78 7.1 74 6.7 6.9 7.4 7.9 Jul 6.0 5.6 4.9 7.5 7.2 6.7 7.6 Aug 5.7 3.9 5.0 7.0 6.9 6.5 7.1 Elevation:9 meters Oct 4.3 4.6 47 5.4 5.6 5.7 5.7 Nov 4.8 Dec Elevation:50 m Oct 4.4 4.7 4.8 5.5 5.7 5.8 5.8 Nov 3.5 3.9 4.1 4.2 4.6 4.8 4.8 Elevation:358 meters Oct 6.0 Oct Nov 47 Nov 3.2 3.6 3.7 3.9 4.2 4.3 4.3 Dec Avg 6.3 Avg 4.7 4.7 4.5 APPENDIX B -SOLAR DATA BURLINGTON VT Latitude:44.47 degrees Elevation:104 meters Jan Feb Mar Apr May =fun =Jul «©Aug.«Sep «=Oct =Nov Dec AgFixedarray Lat-15 2.6 3.6 4.5 Latitude 2.9 3.9 4.7 Latr+15 3.1 4.1 4.6 Single axis tracker Lat-15 3.0 4.4 5.7 6.4 7.3 7.8 8.0 7.2 6.0 4.2 2.5 2.2 5.4 Latitude 3.3 4.6 5.8 6.3 7.0 7A 7.7 7A 6.0 4.4 2.6 2.4 5.4 Lar+15 3.4 4.8 5.7 6.1 6.6 6.9 7.2 6.7 5.8 4.4 2.7 2.5 5.2 Dual axis tracker 3.5 4.8 5.8 6.4 7.4 8.0 8.2 7.3 6.0 4.4 2.7 2.5 5.6 5.6 5.9 6.1 5.6 4.7 3.5 2.2 1.9 4.3 5.3 5.4 5.6 5.3 4.8 3.7 2.4 2.1 4.3 4.6 4.7 4.9 4.8 4.5 3.7 2.4 2.2 4.0 OLYMPIA WA Latitude:46.97 degrees Elevation:61 meters Jan Feb Mac Ape May fun Jul Aug Sep Occ Nov Dec AvgFixedarray Lar-15 1.4 3.4 4.4 5.1 5.5 5.5 4.6 3.0 1.6 3.72.3 ...5.9 1.2 Latitude 1.5 2.4 3.4 4.2 4.7 5.0 5.5 5.2 4.6 3.1 1.7 1.3 3.6 Lac+15 1.6 2.4 .4.8 47 4.4 3.0 1.8 1.4 3.3 Single axis tracker Lac-15 1.6 2.5 4.0 53 .a)7.1 5.8 3.5 1.8 . Latitude 1.7.2.6 4.}5.2 6.2 6.8 7.6 7.0 5.9 3.6 1.9 1.4 4.5 Latr+15 1.7 2.6 4 5 5.9 6.3 7.1 6.6 5.7 3.5 1.9 . Dual axis tracker 1.7 2.7 4.1 5.3 6.6 7.3 8.0 7.2 5.9 3.6 1.9 1.5 4.7 QUILLAYUTE WA Latitude:47.95 degrees Elevation:55 meters ,Jan Feb Mar Apr May un jul Aug Sep Oct Nov Dec Avg Fixed array Lar-15 1.5 2.3 3.2 4.1 4.8 5.0 5.2 4.9 4.4 3.0 1.8 1.4 3.5 Laticude 1.6 2.4 3.3 4.0 4.5 4.6 4.8 4.7 4.4 3.1 1.9 1.5 3.4 Lat+15 1.7 2.4 3.2 3.7 4.0 4.0 4.2 4.2 4.2 3.1 2.0 1.6 3.2 Single axis tracker Lat-15 1.7 2.7 3.9 5.1 6.0 6.3 6.6 6.2 5.5 3.6 2.0 1.5 4.3 Latitude 1.8 2.8 4.0 5.0 5.8 6.0 6.4 6.1 5.6 3.7 2.1 1.6 4,2 Lat+15 1.8 2.8 3.9 4.7 5.5 5.6 6 5.7 5.4 3.7 2.2 1.7 4.1 Dual axis tracker 1.9 2.8 4.0 5.1 6.1 6.5 6.8 6.2 5.6 3.7 2.2 1.7 4.4 SEATTLE WA Latitude:47.45 degrees Elevation:122 meters jan Feb =Mar Apr May uns ul =Aug”Sep Oct 3=-Nov Dec AvgFixedarray Lat-15 1.5 2.3 3.5 4.6 5.4 5.7 6.1 5.6 4.7 3.0 1.7 1.3 3.8 Latitude 1.6 2.5 3.6 4.4 5.]5.2 5.7 5.4 4.7 3.2 1.8 1.4 3.7 Lat+15 1.7 2.5 3.5 4.1 4.5 45 4.9 4.9 4.5 3.2 1.8 1.4 3.5 Single axis tracker Lac-15 1.6 2.7 4.2 5.6 6.9 7.3 8.2 7.3 5.8 3.6 1.9 1.4 4.7 Latitude 1.8 2.8 4.3 5.5 6.7 7.0 .79 7.2 5.9 3.7 2.0 1.5 47 Lac+15 1.8 2.8 4.2 5.3 6.3 6.6 7.4 6.8 5.7 3.7 2 1.5 4.5 Dual axis tracker , 1.8 29 43 5.6 67.0 7.5 8.3 7.4 5.9 3.7 2.0 1.5 49 255 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL SPOKANE Jan Fixed array Lat-15 2.1 Latitude 2.3 Lat+15 2.4 Single axis tracker Lar-15 2.4 Latitude 2.5 Lat+15 2.6 Dual axis tracker 2.7 YAKIMA Jan Fixed array Lat-15 2.2 Latitude 2.5 Lat+15 2.6 Single axis tracker Lat-15 2.5 Laticude 2.8 Lat+15 2.9 Dual axis tracker 2.9 EAU CLAIRE an Fixed array Lar-15 2.9 Latitude 3.3 Lat+15 3.6 Single axis tracker Lat-15 3.5 Latitude 3.8 Lat+15 4 Dual axis tracker 4,] GREEN BAY an Fixed array Lat-15 2.9 Latitude 3.3 Lat+15 3.5 Single axis tracker . Lat-15 3.4 Latitude 3.8 Lat+15 3.9 Dual axis tracker 4.0 256 Latitude:47.63 degrees May 6.0 5.6 4.9 8.2 8.0 7.5 8.3 jun 6.4 5.9 5.] 9.1 8.7 8.2 9.3 Jul 7.0 6.5 5.6 10.2 9.9 9.3 10.4 Aug 6.6 6.3 5.7 9.3 9.2 8.7 9.4 Latitude:46.57 degrees May 6.4 6.0 5.3 8.9 8.6 8.2 9.0 Jun 6.8 6.2 5.3 9.6 9.2 8.6 9.8 | Jul 7.3 6.7 5.8 10.5 10.2 9.6 10.7 Aug 6:8 6.6 5.9 9.6 9.5 9 9.7 Latitude:44.87 degrees May 5.7 5.3 4.7 7.5 7.3 6.9 77 Jun 8.2 Jul 6.1 5.6 4.9 8.2 7.9 7.2 8.3 7.5 Latitude:44.48 degrees May Jun 6.1 5.6 4.9 8.2 7.9 7.4 8.4 Jul 6.1 5.7 4.9 8.2 7.9 7.4 8.4 Aug 5.6 5.4 4.9 - 7.4 7.2 6.9 7.4 Elevation:721 meters Oct 5.4 Nov 2.1 2.3 2.4 2.4 2.6 2.6 2.7 Dec 2.2 Avg” 6.2 Elevation:325 meters Oct 4.4 4.7 4.8 5.6 5.8 5.8 5.9 Nov °Dec 245 Avg 4.8 4.8 4.5 6.5 6.5 6.3 6.7 Elevation:273 meters Oct 3.7 3.9 3.9 4.5 4.7 4.7 4.7 Nov 2.4 2.7ee 2.8 2.8 3.0 3.1 3.1 Dec 2.3 2.6 2.8 2.6 2.9 3.1 3.1 Avg 4.4 4.4 4.2 5.9 Elevation:214 meters Oct 3.6 3.8 3.8 4.4 4.6 4.6 4.6 Nov 2.4 2.6 2.7 2.8 3.0 3.1 3.1 Dec 2.3 2.6 2.8 2.6 2.9 3.1 3.1 Avg 4.4 4.4 4.2 APPENDIX B -SOLAR DATA LA CROSSE Wi Latitude:43.87 degrees __Elevation:205 meters jan Feb Mar Apr May Jun =ul.»Aug.«Sep «=Oct,Nov Dec Aug Fixed 5B 29)8D 4H OSB SB 4B 8B 2G 4S finde 33 43 48 5.0 54 56 58 55 48 41 28 26 45 feels 3606 440«A747 48 49 505.4 KT 2B 43 Single axis tracker , es 35048 C5 6G 7G BBG GL 473857 Ininde 39 4051)(58.9577 BOTA O48 SB lrels 41 (528 OGD BTS OTL 5 4D 8B BL 5G Dual axis tracker 4.1 5.2 6.0 6.6 7.7 8.4 8.5 7.6 6.1 4.9 3.3 3.2 6.0 mt MADISON WI Latitude:43.13 degrees Elevation:262 meters Fixed array Lat-15 3.0 3.9 4.5 Latitude 3.4 4.3 47 Lat+15 3.6 4.4 4.6 Single axis tracker Lat-15 3.5 4.8 5.6 6.5 7.5 8.1 8.0 7.3 6.0 4.6 2.9 2.7 5.6 Latitude 3.9 5.0 5.8 6.4 7.3 7.8 7.7 7.1 6.0 4.8 3.2 3.0 5.7 Lat+15 4 5.2 5.7 6.1 6.8 7.2 7.2 6.8 5.8 4.8 3.2 3,1 5.5 Dual axis tracker ; 41 5.2 5.8 6.5 7.6 8.3 8.2 7.3 6.0 4.8 3.3,3.2 5.9aserencecadeagetseap515862625744838252345 50 55 S57 58 55 48 40 28 26 45 46 48 49 50 50 46 40 29 28 43 MILWAUKEE WI Latitude:42.95 degrees Elevation:211 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec AvgFixedarray Lat-15 2.8 3.6 4.3 5.1 Latitude 3.2 3.9 44 4.9 Lat+15 3.4 4.1 4.4 4.6 Single axis tracker Lat-15 3.3 4.4 5.3 6.4 7.6 8.3 8.4 7.6 6.2 47 2.6 5.6 5.9 Latitude 3.7 4.6 5.4 6.3 7.4 7.9 8.1 7.4 6.2 4.9 3,2 2.8 5.7 Lat+15 3.8 4,7 54 6 6.9 7.4 7.6 7.1 6.1 4.9 3.2 3 5.5 Dual axis cracker 3.9 47 5.5 6.4 7.7 8.5 8.5 7.6 6.3 49 3.3 3.0 5.9 5.9 6.2 6.3 5.8 4.9 3.8 2.5 2.2 4.5 5.5 5.7 5.8 5.6 4.9 4.0 2.8 2.5 4.5 4.9 5.0 5.1 5.0 4.7 4.0 2.9 2.7 4.2 emberiteeadeepMeeute'CHARLESTON WV Latitude:38.37 degrees Elevation:290 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array 5.1Lac-15 2.7 3.3 4.3 .5.6 5.9 5.7 5.5 4.9 4.1 2.9 2.3 4.4 Latitude 2.9 3.6 4.4 5.0 5.3 5.4 53 5.3 4.9 44 3.1 2.6 4.4 Lar+15 3.1 3.7 4.3 4.6 4.7 4.7 47 4.9 4.7 4.4.3.3 2.7 4.1 Single axis tracker Lat-15 3.1 4.0 5.3 6.4 7.1 75 7.2 6.9 6.0 5.1 3.4 2.7 5.4 Latitude 3.3 4.2 5.3 6.3 6.9 7.2 6.9 6.7 6.1 5.3 3.6 2.9 5.4 Lat+15 3.5 4.2 53 6 6.5 6.7 6.5 6.4 5.9 5.3 3.7 3 5.2 Dual axis tracker 3.5 4.3 5.4 6.4 7.2 7.6 7.3 6.9 6.1 5.3 3.7 3.0 5.6eteeBBPATECEeeLeaemaeae AoneOaglaraid257 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL ELKINS WV Latitude:38.88 degrees Elevation:594 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oca Nov Dec -AvgFixedarray Lat-15 2.6 3.3 4.1 4.8 5.3 5.6 5.5 5.2 4.6 3.9 2.7 2.2 4.2 Latitude 2.9 3.5 4.2 4.7 5.0 5.2 5.1 5.1 4.7 4.1 2.9 2.4 4.2 Lat+15 3.0 3.6 4.)4.4 44 4.5 4.5 4.6 4.5 4.)3.0 2.6 3.9 Single axis tracker , Lat-15 3.0 3.9 5.0 6.0 6.6 6.9 67 6.4 5.6 4.6 3.1 2.5 5.0 Latitude 3.2 4.0 5.0 5.9 6.4 6.6 6.4 6.2 5.6 4.8 3.3 2.7 5.0 Lat+15 3.3 4.)5 56 6 6.1 6 5.9 5.4 4.8 3.4 2.8 4.9 Dual axis wacker 3.4 4.1 5.]6.0 6.7 71 6.8 6.4 5.6 4.9 3.4 2.9 5.2 HUNTINGTON WV Latitude:38.37 degrees Elevation:255 meters Jan Feb Mar Apr May -Jun Jul Aug Sep Oct Novy Dec Avg Fixed array Lat-15 2.6 3.4 43 5.1 5.6 5.9 5.7 5.4 4.9 4.)2.8 2.3 4,4 Latitude 2.9 3.6 4.4 4.9 5.3 5.4 5.3 5.2 4.9 4.4 3.1 2.5 4.3 Lar+15 3.1 3.7 43 4.6 4.7 4,7 47 48 4.7 44 3.2 2.7 4.1 Single axis tracker Lar-15 3.1 4.)5.2 6.4 7.1 7.5 73 6.8 6.1 5.1 3.3 2.6 5.4 Latitude 3.3 4.3 5.3 6.3 6.9 7.2 7.0 °6.7 6.1 5.3 3.6 2.8 5.4 Lat+15 3.4 4.3 5.2 6 6.5 6.7 6.6 6.4 5.9 5.3 3.7 2.9 5.3 Dual axis tracker 3.5 4.3 5.4 6.4 7.2 77 74 6.9 6.1 5.4 3.7 3.0 5.6 CASPER wy Latitude:42.82 degrees Elevation:1612 meters Jan Feb Mar Apr May”Jun Jul Aug Sep Oct Nov Dec AvgFixedarray Lat-15 3.4 4.3 5.2 5.8 6.2 -68 70 68 6.0 4.8 3.6 3,1 5.2 Latitude 3.9 47 5.4 5.7 5.8 6.2 6.5 6.5 6.1 5.2 4.}3.6 5.3 Lar+15 4.3 4.9 5.3 5.3 5.1 5.3 5.6 5.9 5.9 5.3 4.3 3.9 5.1 Single axis tracker Lat-15 4.2 5.4 6.7 77.8.4 9.6 9.9 9.5 8.1 6.3 4.5 3.8 7.0 Latitude 4.6 5.8 6.9 7.6 8.2 9.2 9.5 9.3 8.2 6.6 4.9 4.2 7] Lat+15 4.9 5.9 6.9 7.3 7.7 8.6 9 8.9 8 6.6 5.1 4.4 7 Dual axis tracker 4.9 5.9 6.9 7.7 8.5 9.8 10.1 9.5 8.2 6.7 5.1 4.5 7.3 CHEYENNE Wy Latitude:41.15 degrees Elevation:1872 meters .Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed array Lat-15 3.6 4.4 5.3 5.9 6.0 6.5 6.6 6.3 5.8 5.0 3.8 3.3 5.2 Latitude 4.1 4.9 5.5 5.8 5.6 6.0 6.1 6.1 6.0 5.4 4.3 3.9 5.3 Lat+15 4.5 5.]5.5 5.4 5.0 5.1 5.3 5.5 5.7 5.5 4.6 4.2 5.1 Single axis tracker Lat-15 4.5 5.7 6.9 7.9 8.1 9.0 9.2 8.7 7.8 6:6 4.8 4.]6.9 Latitude 4.9 6.0 71 7.8 7.9 8.7 8.9 8.6 7.9 6.9 5.2 4.6 7.0 Lat+15 5.2 6.2 7 7.5 74 8.1 8.3 8.2 7.7 6.9 5.4 4.9 6.9 Dual axis tracker . 9.2 6.2 7.1 7.9 8.2 9.3 9.3 8.8 7.9 6.9 5.4 4.9 7.3 We)olpe) APPENDIX B -SOLAR DATA LANDER Wy -Latitude:42.82 degrees Elevation:1696 meters jan 'Feb Mar Apr «May =n Jul «Aug.«Sep,«Oct,Nov Dec Aug i ira-Baed Yn7 48 «(570 CO6OS CBC .5.5 fede 43 «253°«60)«G1 G1 6K 6S 6S 25S 4 40 5G fevls 46 56 59 57 54 55 56 59 60 5.6 5.4 Single axis crackeraes460«Gli7H BB BT OB DO 8Tide5046502=C«72G-is-SOKO BBfr+15 530 (67768 8 88 9 88 81 7 «54 #49 73 Dual axis tracker 6.7 7.7 8.3 8.9 10.0 10.1 9.5 8.4 7.0 5.4 5.0 7.7 ROCK SPRINGS WY Latitude:41.60 degrees | 'Elevation:2056 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg Fixed arrayobLat-15 3.5 4.4 5.3 6.0 6.5 7.0 7.1 6.9 6.3 5.2 3.7 3.2 5.4 fo"Latitude 4.0 48 5.5 5.9 6.1 6.4 6.6 6.6 6.4 5.6 4.1 3.7 5.5 :Lat+15 4.3 5.1 5.5 5.5 5.4 5.5 5.7 6.0 6.1 5.7 4,4 4)5.3 Single axis tracker Lat-15 43 5.6 6.9 8.0 90 100 101 9.6 8.5 6.8 4.6 3.9 7.3 Latitude 4.7 6.0 7.1 8.0 8.7 9.6 9.8 9.4 8.6 7.1 4.9 4.4 74 Lat+15 5 6.1 7 7.7 8.2 9 9.2 9 8.5 7.2 5.1 4.6 7.2 Dual axis tracker50 Gl ZL 81 1 103 103 96 82 22 S52 42 26 SHERIDAN Wy |.Latitude:44.77 degrees Elevation:1209 meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg fo Fixed array :Lat-15 3.1 4.0 5.0 5.6 5.9 6.5 6.9 6.6 5.7 4.5 3.2 2.8 5.0 }Latitude 3.5 4.4 5.2 5.5 5.6 6.0 64°6.3 5.8 4.8 3.6 3.2 5.0 Lat+15 3.7 4.6 5.1 5.1 4.9 5.1 5.5 5.7 5.5 4.9 3.8 3.5 4.8 Single axis tracker Lat-15 3.7 5.0 6.4 74 8.0 9.1 9.8 9.2 7.6 5.7 3.9 3.3 6.6 Latitude 4.0 5.3 6.5 7A 78 8.8 9.5 9.0 7.7 6.0 4.3 3.7 6.7 Lat+15 4.2 5.4 65 7.1 73 8.2 8.9 8.6 7.5 6 4.4 3.9 6.5 Dual axis tracker 43.54 «65 «#275 «681)CtiA('(itistiaTT(iCiK KOC NIEa?259 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL World Daily Insolation Data (KWh/m?') BISKRA,ALGERIA Location:34.85°N,5.73°W,124 Meters Latitude Tilt -15° Fixed Array 4,2]4.98 6.01 6.36 663 6.79 660 5.69 486 4.05 3.79 5.47 Tracking Array 4.87 6.29 7.97 8.74 9.2)9.36 8.83 7.25 6.07 4.69 4,20 7.04 Latitude Tilt? , 5.64 7.05 Fixed Array 4.86 5.47 5.82 5.84 5.93 6.07 6.27 6.30 5.74 5.22 4.60 4.43 5.55 Tracking Array 5.64 6.97 7.40 7.93 833 8.60 882 863 7.46 6.61 5.37 4.94 7.22 Laticude Tilt +15° Fixed Array 5.23 5.66 5.70 Tracking Array 6.02 7.18 =7.26TwoAxisTracking6.07.7.19 7.43 5.39 5.26 5.28 549 5.72 549 530 489 4.82 5.35 7.35 7.35 740 7.69 7.85 7.16 670 5.68 5.33 6.91 8.03 8.76 9.29 940 885 7.47 673 5.70 5.40 7.35 LUANDA,ANGOLA Location:8.82°N,13.22°W,42 Meters an Feb Mar Apr May Jun Jul Aug Sep Oct ov ec =YrLatitudeTilt-15° Fixed Array 5.92 607 543 489 460 4.18 3.36 3.70 4.57 5.06 560 6. 2 7 16 4.96 Tracking Array 7.62 7.83 7.02 6.19 5.61 5.01 4.17 4.7 5.96 666 7.27 87 =6.33 Latitude Tilt® Fixed Array 5.56 5.87 549 519 5.11 4.75 3.71 3.95 4.68 497 5.31 5.72 5.03 Tracking Array 7.20 7.66 7.19 668 6.34 5.80 478 5.21 621 660 693 7.36 6.50 Latitude Tilt +15° Fixed Array 4.94 540 530 5.27 542 5.14 393 4.0 4.60 466 477 5.02 4.87 Tracking Array 6.28 6.96 689 676 6.70 6.27 5.11 5.36 608 611 611 6.33 6.25 Two Axis Tracking 7.67 7.84 7.20 6.79 6.73 6.34 5.14 5.37 6.23 669 7.30 7.95 6.77 BUENOS AIRES,ARGENTINA Location:34°58'S,58°48'W,25 Meters an Feb Mar Apr May Jun Jul Aug Sep Oct ov Dec Yr Latitude Tilt -15° ; Fixed Array 7.13 649 545 446 3.57 2.93 3.24 411 5.07 5.90 647 7.12 5.16 Tracking Array 9.80 8.72 7.02.5.50 4.07 3.13 3.57 4.98 638 7.86 890 9.85 6.65 Latitude Tilt? Fixed Array 6.58 619 547 475 4.02 3.39 3.70 448 5.19 5.71 602 651 5.17 Tracking Array 9.24 8.52 7.20 5.97 464 3.67 4.14 5.51 668 7.80 846 9.18 6.75 Latitude Tilt +15° Fixed Array 5.77 5.62 5.21 480 4.25 3.65 3.95 460 5.06 5.27 5.33 5.65 4.93 Tracking Array 8.05 7.74 689 603 4.90 3.96 4.42 566 652 7.21 7.44 7.88 6.39 Two Axis Tracking9.85 8.74 7.22 607 491 401 445 567 670 7.91 892 9.94 7.03 CORRIENTES,ARGENTINA Location:27.47°S;58.82°W;52 Meters an Feb.Mar Apr May Jun Jul -Aug Sep Oct ov ec Yr Latitude Tilt -15° Fixed Array 675 636 568 471 3.90 349 3.61 440 530 5.97 665 662 5.29 Tracking Array 9.08 844 7.29 5.75 464 3.98 419 5.34 669 7.87 892 8.95 6.76 i Latitude Tile?ae Fixed Array 6.26 6.09 5.71 5.02 438 4.03 4.11 4.79 5.44 5.80 6.2]6.08 5.32 ;' Tracking Array 8.56 8.24 7.47 624 5.29 467 485 5.90 7.00 7.81 8.47 8.33 6.90 Latitude Tile +15° Fixed Array 5.51 5.54 545 5.07 4.63 435 439 4.93 5.31 5.36 5.51 5.30 5.11 Tracking Array 745°748 7.15 630 5.58 5.03 5.18 6.07 683 7.21 7.45 715 6.57 a Two Axis Tracking9.13.8.45 7.49 634 5.60 5.09 5.21 6.08 7.02 7.92 894 9.03 7.19 ye 260 APPENDIX B -SOLAR DATA PATAUGNES,ARGENTINA Location:40.80°S;62.98°W;34 Meters Jan Feb Apr May Jun Jul Aug Sep Oct Nov Dec jtude Tile -15°Fed Array 6.88 6.46 443 336 2.96 282 4.05 491 5.60 653 693 5.03 9.60 Mar 5.45TrackingArray9.44 8.57 7.02 5.40 3.64 3.01 291 4.74 6.24 7.50 8.93LatitudeTile® Fixed Array 6.69 644 5.57 -Tracking Array 8.91 8.38 7.21LatitudeTilt+15° Fixed Array 6.37.627 545 496 413 383 3.54 471 5.10 5.26 612 634 5.17TrackingArray7.77 7.62 691 5.93 439 3.83 3.61 540 639 689 7.49 7.70 6.16TwoAxisTracking9.48 8.59 7.23 5.97 440 3.86 3.63 541 656 7.56 895 9.68 6.78 4.81 3.85 348 327 449 5.12 5.53 639 669 5.19 5.87 415 3.53 3.37 5.25 654 7.45 850 896 6.51 SAN CARLOS DE BARILOCHE,ARGENTINA Location:41.2°S;71.3°W;825 Meters Jan Feb Mar Apr May Jun Jul Aug «Sep,«Oct Nov Dec Ye Latitude Tilt -15° Fixed Array 6.99 678 548 3.95 2.78 1.81 2.39 3.39 482 5.94 696 6.62 .4.83 Tracking Array 9.59 8.95 7.07 469 2.92 1.81 242 3.83 613 7.91 9.47 9.21 6.17 Latitude Tilt? .Fixed Acray 6.79 676 558 426 3.15 2.08 2.74 3.73 5.02 5.86 680 639 4.93 Tracking Array 9.02 8.73 7.24 5.07 3.32 2.08 2.79 423 641 7.83 8.98 8.56 6.19 Latitude Tile +15° Fixed Array 6.47 6.57 546 437 3.36 2.25 2.95 3.89 499 5.57 651 6.07 4.87 Tracking Array 7.84 7.91 692 5.11 3.50 2.25 2.99 4.34 6.25 7.22 7.89 7.33 5.80 Two Axis Tracking9.64 8.97 7.26 5.15 3.51 2.26 2.99 435 642 7.95 9.49 9.30 6.44 4 SANTIAGO DEL ESTERO,ARGENTINA Location:27.8°S;64.3°W; an Feb Mar Apr May Jun Jul Aug Sep Oct Novy Dec ¥r B Latitude Tile -15° of Fixed Array 6.42 602 544 444 3.62 3.20 3.77 455 517 622 654 652 5.16 4 Tracking Array 8.68 8.03 7.02 546 4.21 3.57 443 553 654 817 879 883 6.60eoLatitudeTilt® :Fixed Array 5.96 5.77 5.47 4.73 406 3.68 431 497 531 605 611 5.99 5.20 4 Tracking Array 8.19 7.85 7.21 5.93 481 419 5.13 613 685 811 8.37 823 6.75 Latitude Tilt +15° Fixed Array 5.27.5.26 5.23 4.77 428 3.97 462 5.12 5.18 5.60 5.43 5.24 5.00 Tracking Array 7.14 7.14 6.91 6.00 5.09 4.53 .5.48 631 6.70 7.51 7.37 7.08 6.44TwoAxisTracking8.71 8.04 7.22 6.03 5.10 458 5.52 632 687 823 881 890 7.03 DARWIN,AUSTRALIA Location:12.43°S,30.87°W,27 Meters Jan Feb Mar Apr May =Jun Jul Aug Sep Oct Nov Dec YrLatitudeTilt-15° Fixed Array 5.17 5.33 5.57 5.05 5.14 496 5.25 614 641 652 622 5.68 5.62 Tracking Array 6.83 7.02 7.18 634 615 5.79 619 746 809 838 806 7.41 Latitude Tilt® Fixed Array 4.87 5.15 561 535 5.75 5.71 5.98 669 660 637 5.86 5.28 5.77 Tracking Array 6.45 6.85 7.34 682 6.93 669 7.07 817 842 830 7.67 691 7.30LatitudeTilt+15° Fixed Array 436 475 540 542 612 623 646 695 648 5.92 5.23 4.65 5.66 Tracking Array 5.61 6.22 7.02 689 7.31 7.22 7.54 8.40 8.22 7.67 6.74 5.93 7.06TwoAxisTracking6.88 7.03 7.36 6.93 7.34 7.30 7.59 841 844 842 809 7.49 7.61 SempraDate261 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL MELBOURNE,AUSTRALIA Jan Latitude Tilt -15° Fixed Array 7.15 Tracking Array 9.95 Latitude Tilt® Fixed Array 6.60 Tracking Array 9.39 Latitude Tilr +15° Fixed Array 5.78 Tracking Array 8.19 Two Axis Tracking 9.99 LA PAZ,BOLIVIA Jan Latitude Tilt -15° Fixed Array 4.80 Tracking Array 6.47 Latitude Tilt? Fixed Array 4.52 Tracking Array 6.10 Latitude Tilt +15° Fixed Array 4.06 Tracking Array 5.31 Two Axis Tracking 6.50 BELEM,BRAZIL Jan Latitude Tilt -15° Fixed Array 5.55 Tracking Array 7.06 Latitude Tilt? Fixed Array 5.22 Tracking Array 6.66 Latitude Tilt +15° Fixed Array 4.65 Tracking Array 5.80 Two Axis Tracking 7.10 CUIABA,BRAZIL Jan Latitude Tilt -15°- Fixed Array -4.47 Tracking Array 6.06 Latitude Tilt® Fixed Array 4.21 Tracking Array 5.72 Latitude Tilt +15° Fixed Array 3.80 Tracking Array 4.98 Two Axis Tracking 6.09 Feb Mar Location: Apr May 4.14 3,51 5.06 3.93 4.41 3.96 5.49 4.49 4.45 4.20 5.55 4.74 5.58 4.76 Location: Apr May 5.03 5.19 6.24 6.08 5.36 5.88 6.77 6.93 5.43 6.27 6.84 7.32 6.88 7.34 Location: Apr May 4.71 4,93 6.06 6.13 4.99 5.48 6.52 6.91 5.07 5.82 6.59 7.29 6.63 7.32 Location: Apr May 444 417 5.60 5.01 4.71 4.66 6.08 5.72 476 4,92 6.15 6.04 6.18 6.06 37.82°S,44.97°W,35 Meters Jun Jul Aug 3.13 3.31 3.72 3.32 3.61 4.37 3.65 3.80 4.05 3.90 419 4.85 3.96 4.08 4.17 422 448 499 427 451 4.99 16.5°S;69.6°W;3658 Meters Jun Jul Aug 5.49 4.59 4.61 6.21 535 5.66 646 5.26 5.01 728 619 6.26 7.08 5.66 5.16 786 661 643 795 6.65 644 1.47°S;48.48°W jun Jul Aug 5.20 5.57 6.13 6.35 6.84 7.68 5.96 6.33 6.68 7.34 7.82 8.42 6.51 6.85 6.95 7.91 835 8.65 8.00 840 8.67 Sep 4.61 5.89 4.72 6.17 4.59 6.04 6.19 Sep 5.93 7.48 6.12 7.83 6.00 7.65 7.85 Sep 6.66 8.45 6.88 8.80 6.78 8.59 8.82 © 15.60°S;56.10°W Jun ful Aug 3.78 4.09 4.13 444 483 5.15 4.34 464 4.46 5.21 5.60 5.70 4.67 4.97 4.58 5.62 5.98 5.86 5.68 6.02 5.87 Sep 4.33 5.65 4.43 5.92 4.33 5.79 5.94 Oct 5.36 7.27 5.18 7.22 4.77 6.68 7.32 Oct dh )oOCOUW)boOaCONONXNSINGWanOooOIOis)NNERDTNCHyNONeBROSBHON ignoreeplemcen6ooCobenegasVeyAPPENDIX B -SOLAR DATA MACEIO,BRAZIL Location:9.57°S;35.78°W;15 Meters Latitude Tile -15° Fixed Array 667 633 586 5.29 464 428 443 497 564 633 652 6.58 5.63 Tracking Array 8.50 814 7.53 664 5.65 5.11 5.35 618 7.20 8.13 835 8.37 Latitude Tilt?. Fixed Array 6.22 6.11 5.92 561 5.16 487 4.99 5.38 580 6.19 6.14 6.08 Tracking Array 8.03 7.95 7.70 7.15 637 5.91 611 678 7.50 8.05 7.94 7.82 7.28 Latitude Tilt +15° Fixed Array 5.49 560 5.71 5.70 547 5.27 5.35 5.55 5.70 5.77 547 5.31 5.53 Tracking Array 6.99 7.22 7.37 7.22 6.73 6.38 653 697 7.33 7.45 699 6.71 6.99 Two Axis Tracking 8.55 816 7.72 7.26 675 645 657 698 7.52 8.17 837 846 7.58 MANAUS,BRAZIL Location:3.13°S;60.03°W Latitude Tilt -15°; Fixed Array 448 425 413 3.89 398 422 457 5.15 5.35 5. Tracking Array 5.91 5.71 5.54 5.10 5.00 5.17 563 649 690 7. Latitude Tile? Fixed Array 4.24 4.15 417 409 436 4.77 513 557 5.50 5. Tracking Array 5.57 5.56 5.65 .5.48 «05.63 5.96 642 7.11 7.17 6.93 624 5.77 6.13 Latitude Tilt +15° Fixed Array.3.83 3.86 404 413 459 5.14 -550 5.76 541 4.97 433 3.97 4.63 Tracking Array 484 5.04 540 5.53 5.93 642 685 7.29 699 640 548 494 5.93 Two Axis Tracking5.95 5.71 5.66 5.56 5.95 649 689 7.31 7.19 7.04 659 6.27 6.38 PORTO NACIONAL,BRAZIL _Location:10.70°S;48.42°W Jan Feb Mar Apr May Jun Jul Aug,Sep Oct No De Yr Latitude Tilt -15° Fixed Array 5.66 5.26 5.08 5.00 503 490 5.05 5.71 568 562 541 5.44 Tracking Array 7.37 6.91 661 629 606 5.77.601 7.00 7.24 7.31 7.08 7.09 Laticude Tilt? Fixed Array 5.32 5.09 5.12 530 563 564 5.74 621 584 5.50 5.12 5.07 Tracking Array 6.96 6.75 6.77 678 685 667 687 768 7.54 7.25 6.75 6.63 6.96 Latitude Tilt +15° Fixed Array 474 470 4.94 5.38 5.99 6.15 620 645 5.74 5.14 462 4.49 Tracking Array 6.06 6.14 648 6.86 7.23 7.21 7.35 7.91 7.37 6.70 5.94 5.69 Two Axis Tracking7.41 6.92 6.78 689 7.26 7.29 7.40 7.92 7.56 7.35 7.11 7.16 SAO PAULO,BRAZIL Location:23.6°S;46.6°W;60 MetersJanFebMarApr=May Jun Jul Aug «Sep Oct No Dec YrLatitudeTilt-15°. Fixed Array 5.34 5.31 4.63 428 3.54 3.51 3.37 3.79 4.65 5.J Tracking Array 7.25 7.12 6.09 5.35 415 4.06 3.86 469 5.99 6.93 7.33 Latitude Tilt? Fixed Array 4.99 5.10 4.64 454 3.93 4.04 381 4.09 4.75 5.07 5.10 4.95 4.58 Tracking Array 6.83 6.96 6.25 5.80 474 476 447 5.19 627 687 6.97 6.76 5.99 Latitude Tilt +15°. Fixed Array 4.45 467 443 457 413 436 405 418 463 4.70 4.57 |4.38 4.43TrackingArray5.95 632 5.99 5.86 5.00 5.14 4.78 533 612 635 613 5.80 5.73TwoAxisTracking7.28 7.14 6.27 5.90 5.02 5.19 4.81 5.34 629 6.97 7.34 7.32 6.24 263 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL PRAIA,CABO VERDE Location:14.90°N;23.52°W;27 Meters 264 Jan.Feb Mar Apr May Jun Jul Aug Sep Oat Nov Latitude Tilt -15°; Fixed Array .5.45 6.19 7.31 7.81 746 7.23 622 5.73 5.93 5.87 5.12 Tracking Array 6.34 7.46 9.10 9.93 9.56 9.27 8.08 7.49 7.58 7.21 6.06 Latitude Tilt° Fixed Array 6.20 675 7.556 7.64 699 665 5.80 553 5.99 627 5.74 Tracking Array =7.25,8.19 9.51 9.87)9.13 8.67)7.64 7.330 (7.77,7.79 (6.86 Latitude Tilt +15° Fixed Array 6.70 7.02 746 7.10 620 5.76 5.13 5.08 5.78 640 6.12 Tracking Array 7.75 844 9.32 9.16 8.06 746 665 667 7.47 7.90 7.26 Two Axis Tracking7.80 845 9.54 9.99 9.59 9.36 8.13 7.50 7.79 7.94 7.29 SANTIAGO,CHILE Location:33.45°S;70.67°W;520 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Latitude Tilt -15°: Fixed Array 7.57 7.70 640 5.07 3.23 2.63 2.92 3.58 432 6.34 6.65 Tracking Array 10.33 10.18 8.08 6.35 3.62 2.76 3.17 421 5.59 837 9.09 Latitude Tilt® Fixed Array 6.98 7.35 644 543 361 3.01 3.30 387 441 615 6.19 Tracking Array 9.73 9.94 828 689 412 3.24 366 465 5.85 831 8.64 Latitude Tilt +15° Fixed Array 6.11 666 615 550 380 3.23 3.51 3.96 4.27 5.67 5.48 Tracking Array 847 9.02 7.93 696 4.35 3.49 3.91 478 5.71 7.67 7.60 Two Axis Tracking]0.38 10.20 830 7.00 436 3.53 3.93 479 5.86 843 9.11 SHANGHAI,CHINA Location:31.28°N,21.47°W,3 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Qet Nov Latitude Tilt -15°; Fixed Array 3.38 3.07 427 485 534 469 582 5.99 5.20 4.38 3.47 Tracking Array 3.74 3.55 5.54 658 7.38 663 801 8.04 672 5.37 3.90 Latitude Tilt®; Fixed Array 3.82 3.28 4.35 470 499 433 5.38 5.72,5.22 466 3.88 Tracking Array 4.31 3.92 5.80 653 7.02 617 7.53 7.84 690 5.83 4.45 Latitude Tilt +15° Fixed Array 4.06 3.33 4.23 434 445 383 474 5.20 498 4.71.4.08 Tracking Array 4.59 4.02 5.67 604 617 5.29 654 7.11 661 5.89 4.70 Two Axis Tracking 4.62 4.03 5.82 662 7.40 669 806 805 691 593 4.72 BOGOTA,COLOMBIA Location:4.6°N;74.1°W;2,560 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oa Nev Latitude Tilt -15° Fixed Array 481 487 473 438 453 480 496 491 476 3.93 4.12 Tracking Array 5.88 6.13 6.16 5.85 5.98 623 642 644 624 5.12 5.14 Latitude Tilt Fixed Array 5.40 525 487 432 432 449 467 477 482 414 4.54 Tracking Array 6.72 6.73.644 5.81 5.70 5.82 606 6.29 639 5.52 5.81 Latitude Tilt +15° Fixed Array 5.79 542 480 408 3.92 3.98 4.17 441 467 4.18 4.78 Tracking Array 7.17 6.93 630 5.38 5.02 5.00 5.27 5.72 6.14 5.60 6.14 Two Axis Tracking7.22 694 646 5.88 599 630 646 645 640 5.62 6.17 APPENDIX B -SOLAR DATA QUITO,ECUADOR Location:0°28'S,78°53'W,2851 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec »¥r Latitude Tilt -15° Fixed Array 5.38 5.21 409 410 3.82 3.91 4.23,5.30 4.47 4.88 5.12 5.14 4.64 Tracking Array 6.84 676 5.49 5.37 485 484 5.27 671 5.89 640 659 655 5.96 Latitude Tilt? Fixed Array 5.06 5.06 4.14 433 418 438 471 5.74 460 4.81 4.87 4.81 4.72 Tracking Array 6.45 659 561 5.77 5.46 5.59 601 7.34 613 633 626 6.11 6.13 Latitude Tilt +15° Fixed Array 4.51 468 402 4.38 439 4.71 503 595 453 452 439 424 4.61 Tracking Array 5.61 5.98 5.36 5.83 5.76 6.03 642 7.54 5.98 5.85 5.50 5.23 5.92TwoAxisTracking6.89 6.77 5.62 586 5.78 609.646 7.556 614 643 661 662 6.40 SAN SALVADOR,EL SALVADOR Location:13.6°N;89.2°W;698 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec YrETATAtTNTUNE8wh:Sarena:9:GLagaenoeAaconHSRaprammpmrecmtienedntspe,Latitude Tilt -15° Fixed Array 5.75 6.29 649 637 615 5.24 619 693 5.23 5.78 5.80 . Tracking Array 6.72 7.61 8.16 821 7.98 6.90 8.01 8.90 6.77 7.14 684 6.66 7.50 Latitude Tilt?. Fixed Array 6.56 686 6.70 6.24 5.79 488 5.77 667-527 616 653 6.71 6.18 Tracking Array 7.67 8.35 852 815 7.61 645 7.56 869 694 7.70 7.73 7.71 7.76 Latitude Tilt +15° Fixed Array 7.08 7.12 659 $5.81 5.17 431 5.09 609 5.08 628 698 7.35 6.08 Tracking Array 8.18 8.59 834 7.55 671 554 657 789 666 7.79 8.17 832 7.52 Two Axis Tracking8.24 8.60 854 826 801 698 807 891 695 7.83 820 842 8.08nSimeeeRigenteers PARIS-ST.MAUR,FRANCE Location:48.82°N,2.50°W,50 Meters Jan Feb Latitude Tile -15° Fixed Array 1.77 2.47 Tracking Array 1.77.2.54 Latitude Tile? Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yr 3.75 4.56 Fixed Array 2.006 2.75 3.90 425 4.78 5.05 4.87 445 402 2.95 195 1.83 3.57. 4.79 3,88 4.69 4.81 4.32 501 5.37 5.14 459 395 2.74 L771 6.02 7.39 804 766 660 5.04 301 171 Tracking Array 2.06 2.82 5.99 7.05 7.550 7.21 646 5.19 3.27 1.95 1.83 4.68 Latitude Tilt +15° Fixed Array 2.24 2.91 Tracking Array 2.24 2.94 Two Axis Tracking 2.24 2.94 4.04 441 461 447 418 3.93 3.02 2.11 2.02 3.49 5.54 6.22 645 628 587 498 331 2.11 2.02 439 6.06 7.41 810 7.69 662 520 3.33 2.11 2.02 4.88 GEORGETOWN,GUYANA Location:7.8°N;58.1°W an Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec YriLatitudeTilt-15° i Fixed Array 4.25 4.77 5.00 5.25 489 482 5.29 555 561 5.10 453 3.99 4.92 ;Tracking Array 5.18 5.98 646 686 642 631 685 7.20 7.22 643 5.56 482 6.27 Latitude Tilt® Fixed Array 4.74 514 5.15 5.17 465 451 497 537 568 542 5.03 449 5.03 Tracking Array 5.92 "6.56 6.75 681 6.13 5.90 647 7.04 7.40 6.95 628 5.59 6.48 Latitude Tilt +15° Fixed Array 5.04 5.30 507 484 420 400 443 495 549 5.51 5.32 483 492 a |Tracking Array 6.32 6.76 661 632 541 5.07 5.63 640 7.11 7.004 665 603 6.28 Two Axis Tracking6.36 6.76 6.77 690 644 637 690 7.21 742 7.07 668 6.11 6.75 265 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL NEW DELHI,INDIA an Laticude Tilr -15° Fixed Array 5.04 Tracking Array 6.38 Latitude Tilt? Fixed Array 5.83 Tracking Array 7.38 Latitude Tilt +15° Fixed Array 6.28 Tracking Array 7.87 Two Axis Tracking 7.92 TOKYO,JAPAN Jan Latitude Tile -15° Fixed Array 2.95 Tracking Array 3.14 Latitude Tile? Fixed Array 3.34 Tracking Array 3.63 Latitude Tile +15° Fixed Array 3.55 Tracking Array 3.87 Two Axis Tracking 3.90 NAIROBI,KENYA an Latitude Tilt -15° Fixed Array 6.93 Tracking Array 8.57 Latitude Tilt® Fixed Array 6.46 Tracking Array 8.08 Latitude Tilt +15° Fixed Array 5.67 Tracking Array 7.02 Two Axis Tracking 8.62 PUERTO STANLEY,MALVINAS an Latitude Tilt -15° Fixed Array 5.37 Tracking Array 7.88 Latitude Tilt? Fixed Array 5.28 Tracking Array 7.43 Latitude Tile +15° Fixed Array 5.09 Tracking Array 6.48 Two Axis Tracking 7.92 as)(o>)(o>)Feb 6.37 8.09 7.04 8.97 7.3) 9.23 9.24 Feb 4.56 6.45 4.56 6.30 4.46 5.73 6.47 Mar 4.1] 5.28 4.18 5.42 4.07 5.19 5.43 Location:28.58°N,77.20°W,210 Meters Apr May 7.12»7.38 9.23 9.83 6.94 6.87 9.17 9.36 6.42 6.08 8.50 8.25 9.30 9.86 Location: Apr May 3.63 3.8) 5.21 5.61 3.50 3.58 5.18 5.34 3.23 3.2) 4.80 4.71 5.25.5.62 Location: Apr May 5.32 4.40 6.78 5.51 5.65.4.86 7.29 6.21 5.75 5.13 7.36 866.55 7.40 6.57 Location: Apr'May 3.00 2.29 3.31 2.30 3.24 2.62 3.59 2.62 3.32 2.81 3.63 2.81 3.65 2.81 jun 6.76 9.15 6.19 8.53 5.38 7.32 9.23 Jul 4.50 6.3) 4.20 5.94 3.75 5.17 6.34 Aug 5.53 7.44 5.30 7.27 4.83 6.60 "7 AG Sep 5.66 7.23 5.70 7.44 5.46 7.13 7.45 Oct 6.09 7.34 6.57 7.99 6.69 8.09 8.13 35.68°N,39.77°W,4 Meters Jun 3.32 5.03 3.09 4.69 . 2.76 4.03 5.08 1.30°N,36.75°W,1799 Meters jun 4.13 5.09 4.66 5.88 5.02 6.34 6.41 Jul 3.68 5.47 3.43 9.15 3.07 4.48 5.49 Jul 3.46 4.37 3.81 4.98 4.02 5.32 5.35 Aug 3.80 5.49 3.30 4.88 5.50 Aug 4.02 5.19 4.30 5.68 4.42 5.83 5.84 Sep 2.99 4.28 2.96 4,40 2.80 4.23 4.4] Sep 5.26 6.80 5.42 7.08 5.33 6.91 7.09 Oct Oct 5.80 7.44 5.69 7.37 5.32 6.81 7.48 51.7°S;57.9°W;23 Meters Jun 1.76 1.76 2.07 2.07 2.26 2.26 2.26 Jul 1.99 1.99 - 2.31 2.31 2.50 2.50 2.50 Aug 2.90 3.04 3.20 3.37 3.34 3.48 3.48 Sep 4.13 5.14 431 5.38 4.28 5.25 5.39 Oct 5.07 7.06 5.00 7.01 4.74 6.48 7.11 CAP:etmeaahotentsAPPENDIX B -SOLAR DATA CHIHUAHUA,MEXICO Location:7.8°N;58.1°W Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Latitude Tile -15° Fixed Array 5.05 5.83 658 7.08 7.38 7.04 697 6.79 671 632 5.23 4.51 Tracking Array 6.43 7.17 8.10 9.17 9.82 9.47 9.34 8.93 843 7.51 5.47 Latitude Tile Fixed Array 5.83 642 6.81 6.90 688 644 643 650 6.78 6.82 5.97 5.27 . Tracking Array 7.42 7.94 849 9.11 9.34 882 8.79 8.73 867 8.16 7.76 6.41 8.30 Latitude Tilt +15° Fixed Array 6.29 665 668 638 608 5.58 563 590 651 6.96 6.37 5.74 Tracking Array 7.92 8.17 830 844 823 7.57 7.64 7.92 8.31 8.26 8.20 6.92TwoAxisTracking7.97 8.19 8.51 9.24 984 9.55 9.39 8.95 869 8.30 8.23 7.00 GUAYMAS,MEXICO Location:.27.50°N;110.0°W an Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yr Latitude Tilt -15°; Fixed Array 5.05 5.83 658 7.08 7.38 7.37 697 6.79 671 6.71 . Tracking Array 6.43 7.17 8.10 9.17 9.82 9.88 9.34 893 843 7.95 6.79 7.26eonaentnateaie2SAGbolainearinbany 8.12 Latitude Tilt Fixed Array 5.83 642 681 690 688 6.73 643 6.50 6.78 5.97 5.27 6.48 Tracking Array 7.42 7.94 8.49 9.11 9.34 9.21 8.79 8.73 8.67 8.65 7.76 6.41 8.38 Latitude Tilt +15° Fixed Array 6.29 665 668 638 608 583 563 590 651 7.41 46.37 5.74 6.29 Tracking Array 7.92 8.17 8.30 8.44 8.23 7.90 7.64 7.92 8.31 8.75 8.20 6.92 8.06 Two Axis Tracking7.97 8.19 8.51 9.24 984 997 9.39 895 869 880 823 7.00 8.73 MEXICO D.F.,MEXICO Location:19.3°N;99.2°W;2,268 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec YrLatitudeTilt-15° Fixed Array 4.32-624 7.71 622 5.93 4.94 4.92 543 500 4.454 4.50 4.51 5.36 Tracking Array 5.06 7.39 9.5]8.07 7.84 666 664 7.19 651 5.67 5.29 5.54 6.78 Latitude Tilt? Fixed Array 4.90 686 7.99 607 5.57 458 460 5.22 504 482 5.06 5.23 5.50 Tracking Array 5.85 8.17 9.96 8.02 7.45 620 624 702 669 615 604 649 7.04 Latitude Tile +15° Fixed Array 5.23 7.11 7.86 564 497 406 410 478 484 487 5.36 5.68 5.38 Tracking Array 6.23 840 9.74 7.41 6.56 5.32 5.42 637 641 622 638 6.99 6.79 Two Axis Tracking6.27,8.41 9.99 8.13 7.86 6.72 667 7.20 6.70 626 640 7.07 7.31 NAVAJOA,MEXICO Location:25.0°N;109.0°W an eb Mar Apr May Jun Jul Aug =Sep ct Nov Dec Yr Latitude Tilt -15° Fixed Array 4.28 5.00 560 609 6.26 630 5.65 5.75 543 5 Tracking Array 5.14 5.96 °7.04 7.98 8.37 846 7.65 7.65 7.00 6. Latitude Tilt Fixed Array 4.87 544 5.76 592 585 5.77 525 5.550 546 580 4.91 4.30 5.40 Tracking Array 5.92 6.58 7.36 7.91 7.95 7.86 7.18 7.46 7.18 7.07 5.99 5.01 6.96 Latitude Tilt +15° Fixed Array 5.20 560 563 548 5.20 503 463 5.01 5.23 5.88 5.20 4.63 5.23 Tracking Array 6.30 6.75 7.19 7.30 6.98 6.73 622 6.75 687 7.14 631 5.39 6.66 Two Axis Tracking 6.33.6.76 7.38 803 839 854 769 7.67 7.19 7.18 633 5.45 7.25 267 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL PUERTO VALLARTA,MEXICO Jan Latitude Tilt -15° Fixed Array 4.60 Tracking Array 5.45 Laticude Tilt Fixed Array 5.24 Tracking Array 6.28 Latitude Tilr +15° Fixed Array 5.60 Tracking Array 6.68 Two Axis Tracking 6.72 el zoTACUBAYA,MEXICO Jan Latitude Tile -15° Fixed Array 4.70 Tracking Array 5.50 Latitude Tilt® Fixed Array 5.37 Tracking Array 6.36 Latitude Tilt +15° Fixed Array 5.75 Tracking Array 6.78 Two Axis Tracking 6.82 TODOS SANTOS, an Latitude Tilt -15° Fixed Array 4.4]. Tracking Array 5.32 Latitude Tilt Fixed Array 5.02 Tracking Array 6.13 Latitude Tile +15° Fixed Array 5.36 Tracking Array 6.52 Two Axis Tracking 6.55 TUXTLA GUTIERREZ,MEXICO an Latitude Tilt -15° Fixed Array 3.94 Tracking Array 4.67 Latitude Tilt Fixed Array 4.44 Tracking Array 5.40 Latitude Tilt +15° Fixed Array 4.72 Tracking Array 5.76 Two Axis Tracking 5.80 MEXICO Feb 5.0] 5.99 5.45 6.61 5.61 6.78 6.79 Feb 4.74 5.79 5.14 6.41 5.29 6.59 6.60 Mar Mar 4.79 6.17 4.92 6.47 4.81 6.33 6.49 Location: Apr May 5.93 6.09 7.75 8.05 5.78 5.70 7.68 7.64 5.37 5.08 7.09 6.71 7.79 8.07 Location: Apr May 6.04 5.68 7.86 7.53 5.90 5.34 7.81 7.17 5.48 4.77 7.23 6.31 7.92 7.55 Location: Apr May 6.07 6.73 7.94 8.89 5.9]6.28 7.87 8.45 5.48 5.57 7.27 7.42 7.99 8.92 Location: Apr May 4.65 4.74 6.22 6.39 4.55 4.48 6.19 6.08 4.25 4.05 5.73 5.36 6.27.6.41 20.0°N;106.0°W Jun 5.94 7.88 5.46 7.32 4.78 6.26 7.95 19.40°N;99.10°W Jun "5.50 7.34 5.09 6.83 4.48 5.86 7.40 23.0°N;110.0°W jun 6.67 8.86 6.10 8.23 5.30 7.04 8.95 17.50°N;93.0°O Jun 4.39 5.98 4.10 5.57 3.66 4.78 6.03 jul 6.06 8.02 5.62 7.53 4.95 6.52 8.07 Jul 4.86 6.56 4.54 6.17 4.06 5.36 6.60 Ju 6.23 8.31 5.77 7.80 5.07 6.76 8.35 Ju! 4,74 6.40 4.45 6.02 3.98 5.23 6.43 Aug 5.99 7.87 5.75 7.67 5.24 6.95 7.88 Aug 5.06 6.76 4.87 6.60 4.47 5.99 6.77 Aug 4.62 6.22 4.46 6.08 4.1] 5.52 6.23 5.47 7.05 5.51 7.23 5.29 6.92 7.25 ;2,300 Meters Sep 4.46 5.89 4.49 6.05 4.3] 5.80 6.06 Sep 5.75 7.37 5.80 7.56 5.55 7.23 7.57 Sep 4.04 5.41 4.06 5.56 3.90 5.33 5.57 Oct 4.53 5.65 Noy APPENDIX B -SOLAR DATA "VERACRUZ,MEXICO Location:19.20°N;96.13°W;12 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct No Dec Latitude Tile -15° -Fixed Array 3.98 5.24 542 583 686 7.09 5.76 °645 614 594 5.12 5.02 Tracking Array 4.68 631 7.05 7.63 8.96 9.24 7.64 840 7.82 7.21 5.93 6.38 Latitude Tile° Fixed Array 449 $72 612 5.78 641 648 535 619 620 638 5.79 585 5.90 Tracking Array 5.40 6.98 7.80 7.23 851 860 7.18 820 803 7.83 677 7.46 Latitude Tilt +15° _Fixed Array 477 5.90 621 5.71 5.69 561 474 564 596 649 6.16 6.37 Tracking Array 5.75 7.16 7.78 =7.23 7.49 7.37 623 7.43 7.69 7.91 7.14 8.04TwoAxisTracking5.78 7.17 815 7.92 898 9.33 7.68 842 804 7.96 7.17 8.12 ULAN-BATOR,MONGOLIA Location:47.85°N,6.75°W Jan Feb Mar Apr May Jun Jul Aug Sep Oct NovLatitudeTilt-15° Fixed Array 4.06 497 5.81 Tracking Array 4.12 5.68 7.83 7.63 9.41 8.90 839 7.74 6.59 i Latitude Tilt? Dec 5.61 665 606 5.74 5.57 498 4.3.21 5 3.21 3 Fixed Array 4.81 564 6.12 5.55 633 569 543 542 510 492 4.01 385 5.24 F 3.85 4.28 4.28 4.28 Tracking Array 4.83 6.29 8.22 7.60 8.97 830 7.91 7.57 6.78 5.79 4.03 Laticude Tile +15° Fixed Array 5.31 604 613 5.27 582 5.18 497 5.08 4.99 5.10 4.38 Tracking Array 5.31 647 8.05 7.04 7.92 7.14 688 6.88 6.51 5.86 4.38 Two Axis Tracking5.31 648 8.24 7.69 943 897 843 7.75 680 5.89 4.38 6.97 HUANCAYO,PERU Location:12.0°S;75.3°W;3,313 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yr Latitude Tilt -15°. Fixed Array 7.85 6.03 664 6.19 568 5.58 5.95 658 696 741 7.38 7.00 Tracking Array 9.97 7.83 845 7.65 677 649 698 7.98 873 944 942 8.94 Latitude Tilt® :Fixed Array 7.27 581 670 660 638 646 680 7.18 7.16 7.23 6.90 6.44 Tracking Array =9.39 7.63,8.62 8.22 7.61 748 7.95 873 9.08 934 894 833 8.44LLatitudeTilt+15° . "ode Fixed Array =»6.35 55.32)6.43 6.71 «6.80 =7.06 7.36 746 7.03 669 6.11 5.60 Tracking Array 8.15 6.91 823 829 802 8.05 847 896 884 861 7.85 7.13 Two Axis Tracking10.04 7.84 864 834 804 814 852 897 9.10°9.49 9.46 9.06 SAN JUAN,PUERTO RICO Location:18.47°N;66.10°W;6 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yr Latitude Tilt -15° Fixed Array 5.22 5.85 684 7.06 641 7.03 7.39 662 6.29 5.78 5.07 5.19 6.23 .Tracking Array 5.97 6.99 850 9.06 8.38 9.15 958 859 7.98 7.04 5.90 6.24 7.78 Latitude Tilt® Fixed Array 6.00 6.42 7.08 6.89 6.00 6.44 6.82 6.36 6.36 6.21 5.74 6.08 6.37 Tracking Array 690 7.73 8.92 9.00 7.98 852 9.0]8.39 8.21 7.66 6.74 7.32 8.03 Latitude Tilt +15°. Fixed Array 646 665 696 640 535 558 5.96 5.80 612 632 6.11 664 6.19 Tracking Array 7.36 7.95 8.72 8.33 7.03 7.31 7.83 7.62 7.87 7.75 7.12 7.90 7.73 Two Axis Tracking7.40 7.96 8.94 9.12 840 9.23 9.63 861 822 7.79 7.15 7.99 8.37 269 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL STOCKHOLM,SWEDEN Location: Jan Feb Mar Apr May Latitude Tilt -15° Fixed Array 143 2.46 3.85 4.12 5.17 Tracking Array 1.43 2.47 4.63 5.82 8.16 Latitude Tilt® Fixed Array 167 2.76 4.02 4.05 4.91 Tracking Array 1.67 2.76 4.85 5.77 7.76 Latitude Tilt +15° Fixed Array 1.81 2.91 3.99 3.82 4,52 Tracking Array 1.81 2.91 474 5.34 6.83 Two Axis Tracking 1.81 2.91 486 5.86 8.18 BANGKOK,THAILAND Location: Jan Feb Mar Apr May Latitude Tilt -15° Fixed Array 4.95 562 5.23 5.62 5.63 Tracking Array 5.84 6.85 669 7.33 7.37 Latitude Tile° Fixed Array 5.60 610 5.37 5.51 5.32 Tracking Array 6.67 7.51 699 7.28 7.03 Latitude Tilt +15° Fixed Array 6.01 6.32 5.27 5.14 4.77 Tracking Array 7.12 7.73 685 6.75 6.20 Two Axis Tracking7.17.7.74 7.01 7.37 7.39 PUERTO DE ESPANA,TRINIDAD Location: an Feb Mar Apr May Latitude Tilt -15° Fixed Array 4.93 5.94 673 5.87 5.44 Tracking Array 5.90 7.28 846 7.60 7.10 Latitude Tilt' Fixed Array 557 646 695 5.76 5.15 Tracking Array 6.73 7.98 883 7.55 6.76 Latitude Tilt +15° Fixed Array 5.97 670 685 5.38 4.63 Tracking Array 7.19 8.22 8.65 6.99 5.97 Two Axis Tracking7.23 8.23 886 7.64 7.12 MONTEVIDEO,URUGUAY Location: Latitude Tilt -15°_ Fixed Array 747 7.14 620 5.0)4.01 Tracking Array 10.24 °9.51 7.84 6.31 4.71LatitudeTilt® Fixed Array 6.89 6.82 624 5.37 4.55 Tracking Array 9.67 9.30 8.05 6.87 5.38 Latitude Tilt +15° Fixed Array 6.04 619 5.97 545 4.84 Tracking Array 843 846 -7.72 6.95 5.69 Two Axis Tracking]0.28 9.53 8.07 6.98 5.71 270 59.35°N,17.95°W,43 Meters Jun 5.45 8.94 5.12 8.33 4.67 7.14 9.03 Jul 5.27 8.5] 4.98 8.00 4.56 6.95 8.56 Aug 4.57 6.79 4.42 6.62 4.13 6.00 6.80 Sep 3.46 4.42 3.52 4.53 3.42 4.34 4.54 Oct 2.09 2.20 2.25 2.38 2.30 2.41 2.43 13.73°N,0.50°W,20 Meters Jun 5.30 6.97 4.93 6.52 4.36 5.60 7.05 _Jul 4.53 6.09 4.27 5.74 3.84 5.00 6.12 Aug 4.67 6.24 4.52 6.10 CNOBtowetWINOOSep 4.32 5.73 4.35 5.87 4.9 5.64 5.88 10.63°N;61.40°W Jun 5.23 6.83 4.87 6.38 4.31 "5.48 6.90 34.87°S;56.17°W;15 Meters jun 3.28 3.58 3.82 4.2] 4.14 4.55 4.60 lul 5.28 6.90 4.95 6.50 4.4) 5.66 6.94 Jul 3.39 3.77 3.88 4.37 4.16 4.68 4.7] Aug 6.11 7.88 5.89 7.70 5.4] 7.00 7.90 Aug 4.16 5.05 4.54 5.60 4.68 5.76 5.77 Sep 6.19 7.89 6.26 8.09 6.04 7.76 8.10 Sep 5.23 6.56 5.37 6.88 5.24 6.73 6.90 Oct Oct 6.13 8.13 5.94 8.08 5.48 7.48 8.19 APPENDIX B -SOLAR DATA BARCELONA,VENEZUELA Location:10.12°N;64.68°W;7 Meters an Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yr Latitude Tilt -15° Fixed Array 5.05 5.57 5.89 5.70 5.52 5.18 5.65 5.83 602 535 4.98 Tracking Array 6.04 6.87 7.49 7.41 718 6.76 7.31 7.56 7.70 6.71 6.02 6.90 epee Larieude Tile?; le Bived Array «5.69 6.03 6.06 5.59 5.21 4.82 5.28 5.62 6.08 5.68 5.54 5.60 Latitude Tilt +15° Fixed Array 6.10 6.24 5.96 5.21 467 425 467 5.16 5.85 5.77 5.87 Tracking Array .7.33 7.72 7.62 6.78 6.01 5.40 5.97 6.68 7.54 7.29 7.16 4.85 5.74 5.53 Tracking Array 6.88 7.52 7.80 7.34 683 630 688 7.37 7.87 7.22 679 662 7.12 6.00 7.A3 Two Axis Tracking7.37 7.73 7.82 744 7.21 685 7.37 7.57 7.89 7.34 7.18 7.21 CARACAS,VENEZUELA Location:10.5°N;66.9°W;862 Meters Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec YrLatitudeTilt-15° Fixed Array 5.00 5.95 6.12 599 5.02 5.23 5.58 5.84 5.70 492 4.54 469 5.38 Tracking Array 5.98 7.29 7.75 7.73 662 682 7.24 7.56 7.32 621 5.53 5.55 6.80 Latitude Tilt® Fixed Array 5.64 647 631 587 476 487 5.22 5.68 5.76 5.22 504 5.35 5.51 jo Tracking Array 6.82 8.00 8.08 7.68 6.30 637 682 7.39 7.50 669 624 642 7.03 Latitude Tilt +15° Fixed Array 6.06 6.71 621 548 430 430 463 5.17 5.55 5.30 5.33 5.80 5.40 Tracking Array 7.27 8.22 7.91 7.1L 5.56 547 5.93 6.71 7.19 678 660 6.92 6.81TwoAxisTracking7.32 8.23 811 7.78 .664 690 7.29.7.58 7.51 6.81 6.62 7.00 7.32 ,2874 nee paren Tne Appendix C:Sun Charts 28°NL bearingEAST sajBue apnyye _SOUTH SUN PATH CHART28°NLFigureC-1 ple32°NL 90°rT 80° 70° 60° =,50° - = 2 40° 30° 20° 6 pm| 10° __pA.WN | 45°9°99°105°'120° bearing SOUTH angles WEST SUN PATH CHART 32°NL Figure C-2 TVANVWNOLLVTIVLSNIONYNDISAG'SOIVLTOACLOHd APFENDIX C-SUN CHARTS 120° 36°NL 105°90° WEST 75°60°45°30° angles 15°0 SOUTH SUN PATH CHART 36°NL Figure C-2 15°30°45° bearing 60°75°90° EAST 105°20° sajbue apnyye 27s 9L¢altitudeangles90° 80° 70° 60° 50° 4o° 30° 20° 10° 40°NL T rT TTT TTT TTT oo oT TT Py \Sem / - = 'AL?pm 20°105°«gg°e 475°)«660°45°30°15"go 15°30°45°GOP 75°Qe =105°120° EAST bearing SOUTH angles WEST SUN PATH CHART 40°NL Figure TVANVWNOLLVTIVLSNIGNYNDISZC'SOIVLTOAOLOHd 90°i |Io i |tol 1 |I ||a)a)To][4 t |id tf |i |Td a |4 g0°$ere se woe eee wee -+--4 ee ee ee coo ! i __ 70°[her 4 4 . °WZ nn aa ioe een eee6010aimey \ a |en ee en13Ww7&L \&:<21altitudeanglesuooSfe)|wompNeav7SS\40°Sami /\wa\\ =yi C/WA '<e 4pm \1||i\e¥30°Wy /Y vaL\/HNAY \ 20°iN xX P hee'Wane 4 /\\\\ \ J |_|[|ia |{||_|L |||{|{| \y //{7 pm /// // {|Lt al 20°105°«gge)«675°60"45°30°15°0°15°30°45° EAST bearing -SOUTH angles - SUN PATH CHART 44°NL Figure C-5 Lle75°90° WEST 105°120°SLYVHONNS-2XIGNAddV 8L?ealtitudeangles90° 80° 70° 60° 50° 40° 30° 20° 10° 48°NL tod it 1]||14 |i ||im 1 [||1 |i |1 | a ; _ --Lpam/a \'oN i =N \F 7 4 'ZA \\''ANNColeTTTSepnetNee 8am VW :aa Seta,1 Nv wrZ I /,a|iA J \KO \ae ON,f \JNhbpagegeTEeaeeeSgOE: %a nas 4 Ge Ce ee a E "y \//. 7 /\\\'Wo No aN //\LM yg Bann fen ay 16amWAVi/v yest 8 )\|)\}6 pm._;i _ 5am/{'J .\\!{/!/\ /VA \\\\aN !\X \1 \VA // ' LN Lu Ll J i Lu |]|4 td L4 Lo |i |i Lin 44 20°105°gg?75° 3©60°=4°-s 330°15°g°15°.30°45?-s-«<i-"(sS7H,-s«QQD.SCs«*T!OSS'”-s«*120° EAST bearing SOUTH angles WEST SUN PATH CHART 48°NL Figure IVANNOLLYTIVLSNGNVNOISAC:SOIVLETONOLOHd ee ee cee ee 6L¢altitudeangles90° 80° 70° 60° 50° 40°} 30° 20°een5 10°}. |r / jt bearing 0° SOUTH SUN PATH CHART 52°NL Figure C-7 75°90° WEST 105°120°-3XiGN3SadV¥SLUVHONGS 082altitudeangles90° 2 70° 60° 50° 40° 30° 20° 10° i 1 vANAA beer AL {|Lt i 20°105°$0° EAST 45°30°---15°a°15°bearing SUN PATH CHART 56°NL Figure C-8 75°90° WEST. 105°120°TVNNVWNOLLYTIVLSNIONYNOISSC-SOIVLTIOAOLOHd Appendix D:System Sizing Worksheeis 281 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Stand-Alone Electric Load Worksheet (abbreviated) Individual |Qty X Volts X Amps =Wats X Use X Use +7 =Watt Hours Loads AC {|DC hrs/day |days/wk days |AC |DC 7 7 7 7 7 7 7 7 7 *AC Total Connected Watts:a *AC Average Daily Load:____* DC Total Connected Watts:DC Average Daily Load: Inverter Sizing Worksheet AC Total . DCSystem _Maximum DC Estimated Listed Desired Connected Watts *Voltage Amps Continuous Surge Watts Features Inverter Specification Make:-Model: Battery Sizing Worksheet AC Average -Inverter +DC Average -DC System Average Amp- Daily Load :Efficiency Daily Load ,Voltage hours/Day [(+)+]+= Average X Days of +Discharge - BatteryAH JT Batteries in Amp-hours/day .Autonomy Limit Capacity Parallel xX >== DC System 2 Battery _Batteries X Batteriesin =_Total Voltage ,Voltage in Series Parallel Batteries a _ , x = Battery Specification _Maker 2 Model: 282 APPENDIX D -SYSTEM SIZING WORKSHEETS Array Sizing Worksheet Average .Battery .Peak Sun _Array Amp-hrs/day *Efficiency ,Hrs/day Peak Amps Array .Peak _Modules Module Short Peak Amps *Amps/module in Parallel Circuit Current DC System ,Nominal Module _=Modules Modules in =__Total Voltage °Voltage in Series Parallel Modules >=X = Panel Specification Make:Model: Controller Sizing Worksheet Module Short =y Modules Array Short Controller Listed Desired125=Circuit Current in Parallel Circuit Amps Array Amps Features x X 125 = 7 DC Total =DCSystem T Maximum DC Controller Connected Watts Voltage Load Amps .-Load Amps Controller Specification Make:Model: 283 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Stand-Alone Electric Load Worksheet (abbreviated) Individual |Qry X Volts X Amps =Watts X Use X Use +7 =Watt Hours Loads AC |DC hrs/day |days/wk days AC |DC 7 7 7 7 7 7 7 7 7 AC Total Connected Watts:AC Average Daily Load:a DC Total Connected Watts:.DC Average Daily Load:___ inverter Sizing Worksheet AC Total .DC System Maximum DC Estimated Listed Desired Connected Watts *Voltage .Amps Continuous Surge Watts .Features Inverter Specification Make:Model: Battery Sizing Worksheet AC Average -Inverter 4 DC Average =DC System .Average Amp- Daily Load Efficiency Daily Load Voltage hours/Day [(+)+)+=: Average x Days of +Discharge = BatteryAH JT Batteries in Amp-hours/day Autonomy 'Limit Capacity Parallel xX +>= DC System -Battery -Batteries x Batteriesin _Total Voltage :Voltage in Series Parallel -Batteries +=Xx = Battery Specification .,Makes _Model: 284 APPENDIX D -SYSTEM SIZING WORKSHEETS _Array Sizing Worksheet |Average 7 Battery Peak Sun _Array Ampz-hrs/day *Efficiency °Hrs/day Peak Amps Array . Peak _Modules Module Short Peak Amps .Amps/module in Parallel Circuit Current DC System .Nominal Module _Modules x Modules in Total Voltage ,Voltage in Series Parallel Modules >=X = Panel Specification Make:Model: Controller Sizing Worksheet Module Short x Modules y 495 =Array Short Controller Listed Desired Circuit Current in Parallel Circuit Amps Array Amps Features X X 125 = DC Total .DCSystem Maximum DC Controller Connected Watts Voltage Load Amps Load Amps Controller Specification Make:Model: 285 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL System Wire Sizing Worksheet Use the following worksheet to determine system wire sizes. PV Combiner Box to BatteryYoucansizethissectionasone wire run from PV to Battery,due to the fact that the controller is basicallyapassthroughdevice.You can also break this wire run into two sections,PV to Controller and ControllertoBattery(see wire sizing worksheet below). A.NEC Requirement Isc of #of modules =TotalAmps X 1.25 X 1.25 =NEC required ampsmodulesinparallel X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps: One Way Distance:Voltage Drop(%): Wire Size from voltagé drop tables (Tables 9-5 through 9-10):Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.*Ifno,use the wire size from A. PV Combiner Box to ControllerAttimes,it can be advantageous to break up the PV to Battery wire run into two separate wire runs,PVtoControllerandControllertoBattery.Since the Controller is usually very close to the battery,you canusuallysizethissectionwithwiresmallerthanthePVtoControllersectionaslongasitpassestheNEC required ampacity from the PV array. A.NEC Requirement Isc of .,#of modules __modules Xin parallel =TotlAmps X 1.2 X 1.25 =NEC required amps X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps: Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10): One Way Distance: Is this equal to or greater than the size wire needed for safety? *If yes,this is your answet.*If no,use the wire size from A. *Note:Circuits operating at less than 50 volts,which are most DC circuits in PV systems require #12 copperorequivalentconductorminimum.Conductors for appliance branch circuits supplying more than onapplianceorappliancereceptacleshallnotbesmallerthan#10 copper or equivalent (NEC,Article 720). page 1 of2 286 APPENDIX D -SYSTEM SIZING WORKSHEETS Controller to Battery A.NEC Requirement Isc of Xx #of modules _Total Amps X 1.25 X 1.25 =NEC required ampsmodulesinparallel X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps: One Way Distance:Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10): Is this equal to or greater than the size wire needed for safety? °If yes,this is your answer.¢If no,use the wire size from A. Battery to DC Load Center A.NEC Requirement DC load watts +DC voltage =DC total amps X 1.25 =NEC required amps =X 1.25 = __ Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements: System Voltage:-Total Amps: Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10): One Way Distance: Is this equal to or greater than the size wire needed for safety? *Ifyes,this is your answer.*Ifno,use the wire size from A. Battery to Inverter A.NEC Requirement DCSystemInverter.Inverter .'-Inverter _ 'Rated Watts °Efficiency °(lowest opwaene)Total 'Amps 1.25 NEC required amps =X125= Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps: Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10) One Way Distance: Is this equal to or greater than the size wire needed for safety? *lf yes,this is your answer.”° *See note on previous page Tf no,use the wire size from A. see NEC Tables 310.16 and 310.17. Temperature deration is not included in the wire sizing worksheets.For information on temperature deration page 2 of 2 287 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL System Wire Sizing Worksheet Use che following worksheet to determine system wire sizes. PV Combiner Box to Battery You can size this section as one wire run from PV to Battery,due to the fact that the controller is basically a pass through device.You can also break this wire run into two sections,PV to Controller and Controller to Battery (see wire sizing worksheet below). A.NEC Requirement Isc of #of modules __.modules *in parallel.Total Amps X 1.25 X 1.25 =NEC required amps X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:,'Total Amps: One Way Distance:Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10) Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.*Ifno,use the wire size from A. PV Combiner Box to Controller At times,it can be advantageous to break up the PV to Battery wire run into two separate wire runs,PV to Controller and Controller co Battery.Since the Controller is usually very close to the battery,you can usually size this section with wire smaller than the PV to Controller section as long as it passes the NEC required ampacity from the PV array. A.NEC Requirement Isc of #of modules __ ;modules in parallel =Total Amps X 1.25 X 1.25 =NEC required amps X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= 'B.Voltage Drop Requirements System Voltage:Total Amps: One Way Distance::Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10): Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.¢If no,use the wire size from A. *Note:Circuits operating at less than 50 volts,which are most DC circuits in PV systems require #12 copper or equivalent conductor minimum.Conductors for appliance branch circuits supplying more than one appliance or appliance receptacle shall not be smaller than #10 copper or equivalent (NEC,Article 720). page 1 of2 288 SenateeraesegeeteeeepeeAPPENDIX D -SYSTEM SIZING WORKSHEETS a Controller to Battery A.NEC Requirement Isc of #of modules __oymodulesinparallelTotalAmpsX1.25 X 1.25 =NEC required amps X =X 1.25 X 1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements 'System Voltage:Total Amps: One Way Distance:__Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10): Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.¢If no,use the wire size from A. Battery to DC Load Center A.NEC Requirement DC load watts +DC voltage =DC total amps X 1.25 =NEC required amps =X1.25 = Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements: System Voltage:Total Amps: One Way Distance:Voltage Drop(%): Wire Size from voltage drop tables (Tables 9-5 through 9-10): Is this equal to or greater than the size wire needed for safety? °If yes,this is your answer.,*If no,use the wire size from A. Battery to Inverter A.NEC Requirement DC SystemInverter.Inverter ..Inverter . Tone +(1 =2) =Rated Watts ©Efficiency (wr alege Total Amps X 1.25 NEC required amps +=X1.25= Amperage satisfying NEC =Wire Size from Table 9-4*= B.Voltage Drop Requirements System Voltage:Total Amps:______ One Way Distance:Voltage Drop(%):_____ 'Wire Size from voltage drop tables (Tables 9-5 through 9-10) Is this equal to or greater than the size wire needed for safety? *If yes,this is your answer.°If no,use the wire size from A. *See note on previous page Temperature deration is not included in the wire'sizing worksheets.For information on temperature deration see NEC Tables 310.16 and 310.17.page 2 of2 289 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Utility-Interactive System Sizing Worksheet Electric Load Estimation 1.Figure out approximate monthly and daily average energy usage: Yearly average energy consumption:_____Kilowatt-hrs/yr Kilowatt-hrs/yr +12 months =average Kilowatt-hrs/month average Kilowatt-hrs/month +30 days =Kilowatt-hrs/day (This is your Average Daily Load.) %of power to be generated from PV system Kilowatt-hrs/day X %of power to be from PV os ______PV System Kilowatt-hrs/day Array Sizing 2.Find out your Average Sun Hours Per Day:- 3.Figure out the PV system kilowatts needed (the initial size of the array): PV System Kilowatt-hrs/day +average peak sun hours per day =PV System Kilowatts 4.Factor in inverter inefficiency: PV System Kilowatts +inverter efficiency =PV array Kilowatts needed PV array Kilowatts X 1000 watts/Kilowatt =PV array watts 5.Choose a PV module: We will use the PTC ratings to pick a module because remember Standard Test Condition ratings where cell temperature =25°C (77°F)is not very realistic when solar panels are out in the sun.For mote realistic test conditions (Ambient air temperature =20°C)and module ratings (PTC)see the following website: www.consumerenergycenter.org/erprebate/eligible_pvmodules.html Make:Model: STC watt rating:Voc:Vmax: PTC watt rating: PV array watts +PTC watt rating =__#of modules needed page 1 of 2 290 APPENDIX 3 -SYSTEM SIZING WORKSHEETS Utility-Interactive System Sizing Worksheet -Continued Inverter Sizing 6.Choose an inverter (or a combination of inverters)that has an appropriate continuous wattage rating (remember you can leave room for future system expansion when sizing your inverter): With utility-interactive PV systems we choose an inverter based on the amount of watts we are trying to pass through it at any one time (unlike stand-alone PV systems where the inverter size is based on our AC total connected load). #of PV modules needed x STC watt rating =max watts inverter(s)must pass. Make:Model: Watt rating (continuous power):DC input Voltage Range: 7.Calculate how many of these inverters the system will require,and how many modules will be wired into each inverter: max watts inverter must pass +inverter watt rating =#of inverters #of PV modules needed +#of inverters =#of modules per inverter 8.Find out how many of our modules the chosen inverter requires in series? Check with the inverter manufacture to see how many modules this inverter tequires in series for it's DC input voltage window. (For SMA inverters use the string sizing program on their website: www.sma-america.com to figure out how many modules in series it needs ) Using our chosen PV modules,how many modules does the inverter need in series? Does this divide evenly into the #of panels that we need per inverter? Remember,if using more than one inverter,you will need to break up the PV array up into sub-arrays that will feed each inverter.Each inverter must have the appropriate number of modules in series to match it's DC input voltage range.If not,then our options are to either round the number of modules in our array up or down (which will affect our %of power to be generated by the PV system). Alternatively we can choose a different module or inverter to be used in our system. page 2 of 2 291 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Utility-Interactive System Sizing Worksheet Electric Load Estimation 1.Figure out approximate monthly and daily average energy usage: Yearly average energy consumption:Kilowatt-hrs/yr Kilowatt-hrs/yr +12 months =average Kilowatt-hrs/month average Kilowatt-hrs/month +30 days =Kilowatt-hrs/day (This is your Average Daily Load.) %of power to be generated from PV system Kilowatt-hrs/day X %of power to be from PV =PV System Kilowatt-hrs/day Array Sizing 2.Find out your Average Sun Hours Per Day: 3.Figure out the PV system kilowatts needed (the initial size of the array): PV System Kilowatt-hrs/day +average peak sun hours per day =PV System Kilowatts 4,Factor in inverter inefficiency: PV System Kilowatts +inverter efficiency =PV array Kilowatts needed PV array Kilowatts X 1000 watts/Kilowatt =PV array watts 5.Choose a PV module: We will use the PTC ratings to pick a module because remember Standard Test Condition ratings where cell temperature =25°C (77°F)is not very realistic when solar panels are out in the sun.For more realistic test conditions (Ambient air temperature =20°C)and module ratings (PTC)see the following website: www-consumerenergycenter.org/erprebate/eligible_pvmodules.huml Make:Model: STC watt rating:Voc:Vmax: PTC watt rating: ) PV array watts+__ss PTC watt rating =___-__#of modules needed page 1 of2 292 APPENDIX D -SYSTEM SIZING WORKSHEETS Utility-Interactive System Sizing Worksheet -Continued Inverter Sizing 6.Choose an inverter (or a combination of inverters)that has an appropriate continuous wattage rating (remember you can leave room for future system expansion when sizing your inverter): With utility-interactive PV systems we choose an inverter based on the amount of watts we are trying to pass through it at any one time (unlike stand-alone PV systems where the inverter size is based on our AC total connected load). #of PV modules needed X STC watt rating =max watts inverter(s)must pass. Make:Model: Watt rating (continuous power):DC input Voltage Range: 7.Calculate how many of these inverters the system will require,and how many modules will be wired into each inverter: max watts inverter must pass +inverter watt rating =#of inverters #of PV modules needed +#of inverters =#of modules per inverter 8.Find out how many ofour modules the chosen inverter requires in series? Check with the inverter manufacture to see how many modules this inverter requires in series for it's DC input voltage window. (For SMA inverters use the string sizing program on their website: www.sma-america.com to figure out how many modules in series it needs ) Using our chosen PV modules,how many modules does the inverter need in series? Does this divide evenly into the #of panels that we need per inverter? Remember,if using more than one inverter,you will need to break up the PV array up into sub-arrays that will feed each inverter.Each inverter must have the appropriate number of modules in series to match it's DC input voltage range.If not,then our options are to either round the number of modules in our array up or down (which will affect our %of power to be generated by the PV system). Alternatively we can choose a different module or inverter to be used in our system.- |:page 2 of 2 293 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Installation -Tools and Materials Lists Basic Tools: O pencil O volt-ohm meter with spare battery O sockets and wrench O drill bits D hand operated drill C screwdriver(s)(1 slotted and 1 #2 (i tape measure DO hacksaw blade CO knife O wire cutter 0 wire strippers Oi slip joint pliers 0 torpedo level Phillips head) Initial Site Visit Tools: OD pencil O compass 0 50-foot tape measure 1 personal gear D maps O first aid kit O solar siting device O inclinometer CO paper O camera Non-Motor Transported Installation Tools: Q pencils CD rope 0 c-clamps CO wood chisel O drill bits O Phillips driver bit O drill bit extender 0 expansion bit OD level O prick punch O slip joint O pliers O slotted screwdrivers (tape measure O string line 0 hole saw D utility knife O torque wrench O collapsible shovel D volt-ohm meter 1 wire cutter (8” handle) O soldering iron D flashlight CO system operations literature D carabiners H tool belt D drill ©nut driver bits 1 paddle bits O brace and bit D uni bit O socket set with extender . O Phillips screwdrivers O file Dadjustable wrench C hand saw D hack saw O caulk gun 2 hammer 0 combination square CJ wire stripper/crimper O needle-nose pliers | O black polyethylene C component product literature O resealable plastic bags Motor Transported Installation Tools: D pencils QO 1000-watt inverter O 4-gang ouclet with extension cord 'DO reciprocating saw with blades 0 full drill bit index jig saw blades O chain saw D extension ladder O shovel C pry bar OC pipe wrenches O aviation snips O carpenters 6'6”level CD open end wrenches O extension cord O circular saw with blades 0 1/2”electric drill Chole saw bits 0 hole punches i step ladder O sledge hammer O pick O nail puller O vise grip O rasp O framing square RUENEEAPRARNNNNHNHeAPPENDIX D -SYSTEM SIZING WORKSHEETS Sample Installation Materials This following checklist contains the materials and components needed for installing a 12-volt,direct current,stand-alone PV system with a pole mount,battery storage,and controller. component/item/materialArray/Mounting 2 2 8 2 1 2 4 l 1 1 1 2 2 4 4 photovoltaic modulessplitboltconnectors#8 x %”bolts,nuts,washers,lock washers photovoltaic panelinterconnect cables pole mounting structure4”x 3%”bolts,nuts,washers,lock washers cable ties 2 %”weatherhead 1'2 ¥galvanized steel pipe 24x 2%"x2 galvanized tee 2 #x 90 degree galvanized elbow 2%”close nipples 2 %”floor flanges4x6”lag bolts and washerswoodshims 25°#10-2 Romex with ed. 3 2 1 3 #10-uf tubes silicon caulk fused disconnect switch and enclosure 30-amp fuses Grounding 15°46 bare copper ground wire ©=eelelleeleleienelcopper ground rod ground clamp. X%”x 1”bolt,nut,washer,lock washer terminal vy»..4”strain relief connector box Romex staples attery "No Smoking”sign "Danger”sign batteries prefabricated insulated battery box battery interconnect cables (#2 AWG) #8 THHN (black) #8 THHN (red) terminal lugs 10-amp fuses 4 x 1”bolts,nuts,washers,lock washers 1”polyethylene pipe 1”tankwall flange 1”MPT slip fitting adapter 1”slip fitting elbows 2”x 2”screen 1”hose clamps %”bushings 1 %”x2”nipple 4 1”conduit clamps 8 #10x %”screws Controller/Load Center 1 DPST 30-amp safety switch 1 controller with low voltage disconnect,voltmeter,and ammeter 20 #10 spade crimp connectors12”x 12”NEMA Type I electrical enclosure104”x 10 %”enclosure panel #10 x 14”sheet metal screws with washers %”chase nipple with nut and bushing ¥”strain relief connector fuse block (6 circuit) boxes 20A glass fuses terminal bus bars (6 circuit) Type T disconnect switches 2-gang junction boxes 2-gang switch plates 12 #10 x %”bolts,nuts,washers,lock washers 6 4”Romex,.connectors Lighting Load 7 %°Romex connectors 50'#10-2 Romex with ed. 24 #10 x 1%”sheet metal screws with washers 1 round junction box 4 pull chain light fixtures 1 socket adapter #593 3 #1141-21 12V direct current incandescent lights 12 25-watt 12V direct current incandescent bulbs slip-on bulb lampshades swag lamp fixture direct current ballast 20-watt fluorescent tubes fluorescent fixture 2-junction box Type T switch 1 switchplate cover Miscellaneous Wiring Materials wire ties solder anti-oxidizing compound small bottle dish soap or pulling grease duct tape red and black electrical tape assorted wire nuts assorted nails and screws assorted electrical fittings and screwsNNNNNRRKKSRee -eeND i E te a.be teroteli. 4 'in Resource Guide This guide provides additional sources that can be used to further explore photovoltaics.You will find selectedorganizations,publications,and websites.If you know ofother appropriate resources that could prove valuabletofuturesolarstudents,please contact:Solar Energy International (SEI),PV Manual Department,email: sei@solarenergy.org Phone:970-963-8855,Fax:970-963-8866 www.solarenergy.org Selected Organizations American Solar Energy Society (ASES):A national membership-based organization of solar professionals dedicated to advancing of the use of solar energy. The website and magazine contain the history of renewables,economics,and both residential and commercial applications.The ASES magazine Solar Today,covers PV,passive solar,solar thermal,wind energy,and solar building case studies. Webiste:www.ases.org 303-443-3130 Censolar:An established solar center located in - Spain,exclusively dedicated to the dissemination of solar energy information.Censolar is SEI's European affiliate and an SEI]INVEST partner.Censolar offers workshops,distance courses,and numerous high quality Spanish solar related publications. Webiste:www.censolar.org Enersol Associates:A private,humanitarian non- profit organization using solar energy to improve people's lives in rural Latin America.Enersol is an SEI INVEST partner. Webiste:www.enersol.org European Photovoltaic Industry Association: Falling beneath the umbrella of the European Renewable Energy Council this website ties you in with what's new tn the photovoltaic industry in Europe.A easy site to use with many useful links leading one to many places of unknown curiousity. Webiste:www.epia.org/07news/news.asp Florida Solar Energy Center (FSEC):An organization that assists individuals in making the right decisions when choosing to use solar energy systems.FSEC offers educational workshops, _training,and technical research reports on topics including:photovoltaics,solar thermal,energy efficiency,moisture issues,and cooling strategies. Webiste:www.fsec.ucf.edu Home Power magazine:A bi-monthly magazine that is "information central”for details on working and living with PV and other renewable and sustainable technologies.The website has many links to databases,events,non-profits,businesses,and has the current magazine issue available for free viewing.The site also contains an archive of Home Power magazines.Books,videos and CD-ROMs are also available.PO.BOX 520,Ashland,OR,97520,USA. Phone:916-475-3179 Email:hp@homepower.com Webiste:www.homepower.com The Institute for Solar Living (Solar Living Center):This multi-acre institute,is a non-profit environmental education/demonstration center.The SLC offers a variety of short workshops that promote energy efficiency,renewable energy technologies and sustainable building.The Solar Living Center,Hopland,CA 95449. Webiste:www.solarliving.org International Solar Energy Society (ISES):A UN- accredited NGO that supports the advancement of renewable energy technology,implementation and education all over the world.ISES is a professional membership based organization. Webiste:www.ises.org 297 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Institute for Sustainable Power (ISP):A non-profit umbrella organization working worldwide,striving to improve the quality of renewable energy projects,and the development of sustainable,local jobs.An infrastructure providing accreditation to qualified educational organizations and trainers that provide high quality PV training.Director -Mark Fitzgerald. Webiste:www.ispq.org Midwest Renewable Energy Association (MREA): Non-profit network for sharing ideas,resources,and information to promote a sustainable future through renewable energy and energy efficiency.MREA offers workshops and sponsors the annual Midwest Renewable Energy Fair (MREF). Webiste:www.the-mrea.org North American Board of Certified Energy Practitioners (NABCEP):Organization developing voluntary standards for renewable energy professionals, beginning with certification for solar electric installers. Webiste:www.nabcep.org Northern California Solar Energy Association (NCSEA):A website containing many links to educational organizations.The organization puts out a monthly newsletter of the latest happenings in the California solar world as well as sponsor a variety of events that promote the use of solar energy. Webiste:www.norcalsolar.org/ National Renewable Energy Laboratory (NREL): Affiliated with U.S.Department of Energy,and is America's national solar R&D laboratory.NREL is working toward securing an energy future that is environmentally and economically sustainable. Portions of the vast website are interactive,and a large photo library is online.Resources,images,and extensive links are available for the novice student as well as the solar professional. Webiste:www.nrel.gov Rahus Institute:A non-profit,research and educational organization focusing on resource efficiency and renewable energies in California. Email:info@rahus.org Webiste:www.rahus.org 298 SEI INVEST Program:International Volunteers in Environmentally Sustainable Technologies. Graduates of SEI's courses are connected with organizations working in rural development.Within these organizations alumni can volunteer to help electrify rural communities with renewable energy, build sustainable houses,and train local users and technicians. Webiste:www.solarenergy.org/programs/INVEST/ Solar Electric Light Fund (SELF):A non-profit charitable organization founded in 1990 to promote, develop,and facilitate solar rural electrification and energy self-sufficiency in developing countries.SELF is an SE]affiliate,and an INVEST partner,and has pioneered rural PV Solar Home Systems worldwide. Webiste:www.self.org State and Territory Energy Offices National Association of State Energy Officials:The website contains links to the energy offices of all 50 states.A variety of information exists on each state and territory website. Webiste:www.naseo.org/members/states.hum Books General Photovoltaics (PV) Anderson,Teresa.Doig,Alison.Rees,Dai.Khennas, Smail.Rural Energy Services:A handbook for sustainable energy development,London,UK. Intermediate Technology Publications Ltd.,1999. Archer,Mary D.,Robert Hill,Photoconversion of Solar Energy,Vol 1,Clean Electricity from Photovoltaics,Colorado,USA.Imperial College Press,2001. Canadian Photovoltaic Industries Association, Photovoltaic Systems Design Manual,Canada. CANMET-Energy,Mines &Resources,1991. Censolar,Centro de Estudios de la Energia Solar,La Energia Solar:Aplicaciones Practicas,Spain, Promotora General de Esudios,S.A.1999.149p. 5 4 !eteee"Cole,Nancy.Sderrett,J.P.Renewables are Ready:PeopleCreatingRenewableEnergySolutions,Vermont,USA.-Chelsea Green Publishing Company,1995 239p. Davidson,J.The New Solar Electric Home:The-Photovoltaics How-to Handbook,Michigan,USA. 1987. Derrick,Francis,&Bokalders,Solar PV Products -A Guide for Development Workers,London,UK.Intermediate Technology Publications Ltd,1991. Duffie &Beckman,Solar Engineering of Thermal Processes,2nd edition,New York,USA.John Wiley &Sons,1991. Ewing,&¢Ewing,Power with Nature:Solar and Wind Energy Demystified,Colorado,USA.PixyJack Press, 2003,255 p. Green,Solar Cells,Operating Principles,Technology &System Applications,New York,USA.Prentice- Hall,1982. Hackleman,Michael,Better Use of...Your Electric Lights,Home Appliances,Shop Tools-Everything that Uses Electricity,California,USA.Peace Press,1981,166 p. Halacy,Home Energy,Pennsylvania,USA.Rodale Press,1984,288 p. Hankins,Mark,Solar Electric Systems for Africa:A Guide for Planning and Installing Solar Electric Systems in Rural Africa,London,UK. Commonwealth Science Council,1995,135 p. Imamura,Helm,Palz,Stephens,&Associates, Photovoltaic System Technology -A European Handbook,Bedford,UK.Commission of the European Communities,1992. Johannsson,(Ed.)Renewable Energy,Sourcesfor Fuels and Electricity,Washington DC,USA.Island Press, 1993. Komp,R.Practical Photovoltaics:Electricity from Solar Cells,Third Edition,Michigan,USA.Aatec Publications,1995,197 p. RESOURCE GUIDE Landolt-B'rnstein,Numerical Data &Functional Relationships in Science and Technology,Berlin, Germany.New Series,Vol.4c,Climatology,Part 2, 1989. Lasnier,GanAng,&Hilger,Photovoltaic Engineering Handbook,Pennsylvania,USA,IOP Publishing,1990. Lorenzo,E.Zilles,R.Caamano-Martin,E. Photovoltaic Rural Electrification:A Fieldwork Picture Book,Spain,Promotora General de Estudios,S.A. 2001. Lorenzo,Eduardo,et al.,Solar Electricity:Engineering ofPhotovoltaic Systems,Sevilla,Spain.1994,316 p. (Published in Spanish as Electricidad Solar). Markvart and Tomas,(Ed.)Solar Electricity, Southampton,UK.John Wiley &Sons Ltd.,1994. Maycock and Stirewalt,A Guide to the Photovoltaic Revolution -Sunlight to Electricity in One Step, Pennsylvania,USA.Rodale Press,1985. Perlin,John,From Space to Earth:The Story of Solar Electricity,Michigan,USA.Aatec Publishing,2001, -207 p.email:aatecpub@mindspring.com Parker,(Ed)Solar Energy In A griculture,Amsterdam, The Netherlands.1991 Roberts,Solar Electricity -A Practical Guide to Designing and Installing Small Photovoltaic Systems, New Jersey,USA.Prentice Hall,1991. Roth,&Schmidt,(Ed.)Photovoltaik-Anlagen, Freiburg,Germany.Photovoltaik-Anlagen, Begleitbuch zum Seminar,1994, Shepperd,Lisa,W.Richards,Elizabeth,H.Solar Photovoltaics for Development Applications,Sandia National Laboratories,1993,44 p. Sherman,Robin.Renewables are Ready:A Guide to Teaching Renewable Energy in Junior and Senior High School Classrooms,Massachusettes,USA.Union of Concerned Scientists,2003,89 p. 299 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Solar Energy International (SEI),Photovoltaics: Design and Installation Manual,Co-published with New Society Publishing,2004. Solar Energy Research Institute (SERI),Photovoltaic Fundamentals,Colorado,USA.National Renewable Energy Laboratories (NREL),1991. Spring,Cario &Stage,Lisa.When the Light Goes On:Understanding Energy,Arizona,USA.Emerald Resource Solutions 2001,119 p. Stamenic &Ingham,A Power for the World:Solar Photovoltaics Revolution,North Vancouver,BC. Canada.Sunology International,Inc.,1995,262 p. Strong,S.J.The Solar Electric House,Chelsea Green, Vermont,USA,1991. Zweibel &Hersch,Basic Photovoltaic Principles and Methods,New York,USA.Van Nostrand Reinhold Company,1984. System Design Asociacion De La Industria Potovoltaica,Sistemas de Energia Fotovoltaica,Manual del Instalador,Spain, Promotora General de Estudios,S.A.2002. Brotherton,Miner.The 12 Volt Bible for Boats, Maine,USA.Seven Seas Press/International Marine, 1985,174 p. Canadian Photovoltaic Industries Association, Photovoltaic Systems Design Manual,Canada. CANMET-Energy,Mines &Resources Canada,1991. Chapman,R.N.Sizing Handbook for Stand-alone Photovoltaic/Storage Systems,Albuquerque,USA. Sandia National Laboratories,1987. Davidson,J.The New Solar Electric Home -The Photovoltaics How-to Handbook,Michigan,USA. Aatec Publishers,1987. 300 Kiskorski,A.S.Power Tracking Methods in Photovoltaic Applications,Proceedings PCIM '93, Nurnberg,Germany.1993,p.513-528. Messenger,Roger,A.Ventre,Jerry &Ventre, Gerard,G.Photovoltaic Systems Engineering 2nd Edition,Florida,USA.CRC Press,2003. Paul,Terrance,D.How to Design an Independent Power System,Wisconsin,USA.Best Energy Systems for Tomorrow,Inc.,1981,123 p. Sandia National Laboratories,Science Applications, Inc.Design Handbook for Photovoltaic Power Systems, McLean,USA.1981 Sandia National Laboratories,Photovoltaic System Design Assistance Center (DAC)The Design of Residential Photovoltaic Systems,(10 volumes)New Mexico,USA,1988. Solar Energy International (SEI),Photovoltaics: Design and Installation Manual,Co-published with New Society Publishing,Canada,2004. Wills R.The Interconnection ofPV Power Systems with the Utility Grid:An Overview for Utility Engineers,New Mexico,USA.Sandia National Laboratories,1994. Yago,Jeffrey,R.Achieving Energy Independence-One Step at a Time,Virginia,USA.Dunimis Technology, Inc.1999,184 p. Components Donepudi,Pell,8¢Royer,Storage Module Survey:Task 16 -Photovoltaic in Buildings,JEA-Solar Heating and Cooling Program,Ottawa,Canada,1993. Dunselman,Weiden,Zolingen,Heide,Design Specification for AC Modules,Holland,The Netherlands.Ecofys report nr.E265,Utrecht,1993. Hill &McCarthy,PV Battery Handbook,Ireland. Hyperion Energy Systems Ltd.1992. Linden,(Ed.),Handbook ofBatteries and Fuel Cells,USA.McGraw-Hill Inc.1984. Panhuber-Fronius 8¢Edelmoser,Resonant ConceptforthePower-Section ofa Grid-Coupled Inverter,Amsterdam,The Netherlands.Proc.of 12th European Solar Energy Conference and Exhibition,1994. Perez,Richard,A.The Complete Battery Book,Pennsylvania,USA.TAB Books,Inc.,1985 185 p. |Rapp,D.Solar Energy,NJ,USA.Prentice-Hall, .Englewood Cliffs,1981,516 p. *Russell,M.C.Residential Photovoltaic System Design Handbook,Massachusetts,USA.MIT 1984. Schaeffer,J.Alternative Energy Sourcebook,California, USA.Real Goods Trading Corporation,1992. Wilk,H.40 kW-Photovoltaic System with IGBT Inverter on the Sound barriers ofMotorway Al, Montreux,Switzerland.11th European Photovoltaic Solar Energy Conference,1992. Wilk H.200 kW Photovoltaic Rooftop Programme in Austria,Budapest,Hungary.ISES World Congress, 1993. Wilk,H.200 kW PV Rooftop Programme in Austria, First Results,Amsterdam,The Netherlands.Proc.of 12th European Solar Energy Conference and Exhibition,1994. Architectural Integration Fiffert and Kiss,Building-Integrated PhotovoltaicDesignsforCommercialandInstitutionalStructures,A Sourcebook for Architects,Colorado,USA.National Renewable Energy Laboratories (NREL),2000. Independent Energy Guide,Vermont,USA.Chelsea Green Publishing Company,1996. Kiss,G.et al.Building-Integrated Photovoltaics, Colorado,USA.National Renewable Energy Laboratory,1993. RESOURCE GUIDE Kiss,G.et al.Building-Integrated Photovoltaics:A Case Study,Colorado,USA.National Renewable Energy Laboratory (NREL),1994. Kiss,G.et al.Optimal BIPV Applications,Colorado, USA.National Renewable Energy Laboratory (NREL),1995. Jones,D.L.Architecture and the Environment: Contemporary Green Buildings,New York,USA,The Overlook Press,1998. NREL,Photovoltaics in the Built Environment:A Design Guide for Architects and Engineers,Colorado, USA,National Renewable Energy Laboratory,1997. Roaf,S.Ecohouse:A Design Guide,USA. Architectural Press,2001,352 p. Sick and Erge,Photovoltaics in Buildings:A Design Handbook for Architects and Engineers,London,UK. James &James Ltd.1996. Installation and Maintenance Cauldwell,Rex,Wiring a House,Connecticut,USA. The Taunton Press,Inc.2002. Kardon,Redwood,Hansen,Douglas,&Casey,Code Check Electrical:A Field Guide to Wiring a Safe House, Connecticut,USA.Taunton Press,Inc.2002,28 p. Maintenance and Operation of Stand-Alone Photovoltaic Systems,New Mexico,USA.Sandia National Laboratories,1991 Wiles,J.C.Photovoltaic Power Systems and the National Electric Code,New Mexico,USA.NM State University,1991 Related Reading Berger,Charging Ahead:The Business ofRenewable Energy and What it Means for America,New York, USA.Henry Holt and Company,1997,331 p. 301 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Butti,K.&Perlin,J..A Golden Thread:2500 Years of Solar Architecture and Technology,New York,USA. Cheshire Books,1980. Eiffert,PR The Borrowers Guide to Financing Solar Energy Systems,A Federal Overview,2nd Edition, Colorado,USA.National Renewable Energy Laboratories,1998. Eiffert,P.&Leonard,G.&Thompson,A.Guidelines for the Economic Analysis ofBuilding Integrated Photovoltaic Systems,Colorado,USA.National Renewable Energy Laboratories (NREL),2001. Haas,R.The Value ofPhotovoltaic Electricity for Society,USA.Solar Energy,Vol.54,No.1,1995. Leggett,Jeremy,(Ed.)Climate Change and the Financial Sector:The Emerging Threat -The Solar Solution,Munich,Germany.Gerling Akademie Verlag,1996,220 p. Publishers Chelsea Green Publishing:A publisher of books on a variety of subjects related to sustainable living.RO Box 428,White River Junction,Vermont 05001 USA. Phone:800-639-4099 Website:www.chelseagreen.com Intermediate Technology Publications Ltd.(TDG): A publisher that builds on the skills and capabilities of people in developing countries through the dissemination of information in many forms.They are an offshoot of Intermediate Technology Development Group,ITDG.ITDG aims to reduce poverty in countries through the use of sustainable technologies. Phone:01206 796351 Fax:01206 799331 Email:sales@portlandpress.com Website:www.itdg.org/ Maya Books:Environmental Publisher with sustainable technology titles.P.O.Box 379, Twickenham TW1 2SU.UK. Phone/Fax:+44-(0)-181-287-9068 Email:sales®@mayabooks.ndirect.co.uk Website:www.mayabooks.ndirect.co.uk 302 New Society Publishers (NSP):Publishes books about how to build in a sustainable manner,and how to further a just society.All NSP books are printed in an environmental manner.P.O.Box 189, Gabriola Island,BC,VOR IX®,Canada. Website:www.newsociety.com Newsletters &Journals Energy -Monthly international multi-disciplinary _ resource journal for activities relating to the development,assessment,and management of energy- related topics.Elsevier Science Ltd.,The Boulevard, Langford Lane,Kidlington,Oxford OX5 1GB,UK; -655 Ave.of the Americas,New York,NY 10010 USA. Phone:212-633-3730 Fax:212-633-3680 Photon -das Solarstrom-Magazin:A bi-monthly magazine (in German)on PV and the PV industry, concentrating on Europe.Editor:Ms.Annegret Kreutzmann,Solar Verlag GmbH,Wilhelmstrasse 34,52070,Aachen,Germany. Phone:0241-47055-0 Fax:47055-9 Photon -The International Photovoltaic Magazine: English-language bi-monthly magazine covering the PV industry worldwide.Editor:Michael Schmela, Solar Verlag GmbH,Wilhelmstrasse 34,D-52070 Aachen,Germany. Email:michael.schmela@photon-magazine.com Website:www.photon-magazine.com Photovoltaics Bulletin -Editor:Roberta Thomson, Elsevier Advanced Technology,RO.BOX 150, Kidlington,Oxford 0X5 1AS UK. Phone:+44 1865 843 194 Fax:+44 1865 943 971 Email:R.Thomson@elsevier.co.uk Photovoltaic Insider's Report -Monthly newsletter on the PV industry.Editor:Richard Curry,1011 W. Colorado Blvd.,Dallas,TX 75208,USA. Phone/Fax:214-942-5248 Email:rcurry@pvinsider.com Website:www.pvinsider.com _Monthly newsletter on the PV industry."Gditor:Paul Maycock,PV Energy Systems,4539at'abut Road,Warrenton,VA 20187,USA.'Phone/Fax:540-349-4497Email:pves@pvenergy.com "Website:www.pvenergy.com pv News -.Renewable and Sustainable Energy Reviews -AninternationaljournalofREresearch.Editor-in-Chief:Lawrence L.Kazmerski,Elsevier Science,The i Boulevard,Langford Lane,Kidlington,Oxford OX5"1GB,UK,655 Ave.of the Americas,New York,NY 10010,USA. Phone:212-633-3730 Fax:212-633-3680 Renewable Energy -Monthly international journal to "promote and disseminate knowledge of renewable |energy.Editor:Ali Sayigh,Elsevier Science Ltd., Langford Lane,Kidlington,Oxford OX5 1GB,UK. Fax:+44 (0)1865 843952; or Elsevier Science,655 Ave.of the Americas,New York,NY 10010,USA. Phone:212-633-3730 Fax:212-633-3680 Renewable Energy Bulletin -Bi-monthly collection from a wide range ofjournals.Multi-Science Publishing Co.,Ltd.,107 High St.,Brentwood Esses CM14 4RX,UK. Phone:+44 1277 223453; or P.O.BOX 176,Avenel,NJ 07001 USA Renewable Energy World -James &James (Science Publishers)Ltd 35-37 William Road,London NW1 3ER,United Kingdom. Email:james@jxj.com Website:www.jxj.com Solar Energy International journal for scientists, engineers,and technologists published by {International Solar Energy Society (ISES).Editor: K.G.Terry Hollands,Elsevier Science Lrd.,The Boulevard,Langford Lane,Kidlington,Oxford OX5 1GB,UK.; Fax +44 (0)1865 843952; or Elsevier Science,655 Ave.of the Americas,New York,NY 10010,USA RESOURCE GUIDE Solar Industry Journal -Quarterly magazine including news,projects,and solar issues of the Solar Energy Industries Association (SEIA).SEIA,122 C Street NW,Washington,DC 20001 USA. Phone:202-383-2600 Fax:202-383-2670 Website:www.seia.org. Solar Today Magazine -Official magazine of the American Solar Energy Society (ASES).Bi-monthly magazine covering all renewable energy applications, new products,and events.ASES,2400 Central Avenue,Suite G-1,Boulder,CO 80301,USA. Phone:303-443-3130 Fax:303-443-3212 Website:www.ases.org Sun World -Quarterly magazine of the International Solar Energy Society (ISES).Editor:Leslie F. Jesch,The Franklin Company Consultants Ltd.,192 Franklin Road,Birmingham,B30 2HE,UK. Email:sunworld@tfe-bham.demon.co.uk Website:www.demon.co.uk/tfc/sunworld.html. The Solar Letter -Bi-weekly newsletter on all aspects of RE.Editor:Allan L.Frank,ALFA Publishing, 9124 Bradford Rd.,Silver Spring,MD 2090,USA. Phone:301-565-2532 Fax:301-565-3298 Videos Residential Solar Electricity with Johnny Weiss: Practical answers given to the most often asked questions about designing and installing residential photovoltaic systems.Andrews,Scott,S.Renewable Energy with the Experts,1997.” Solar Water Pumping with Windy Dankoff:Topics include watering livestock and crop irrigation. Answers given to the details of solar water pumping. Andrews,Scott,S.Renewable Energy with the Experts,1998. 303 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Storage Batteries for Renewable Energy System with Richard Perez:Considered the heart of a stand-alone systems,battery operation remains a mystery to many RE users.The role of batteries,their limitations and maintenance issues are presented in a clear and concise manner.Andrew,Scott,S. Renewable Energy with the Experts,1998. Selected PV Websites Australian National University:Centre for Sustainable Energy Systems:Activities in the area of photovoltaics and concentrating solar thermal. Webiste:www.engn.anu.edu.au/solar CANMET Energy Diversification Research Laboratory (Canada):R&D programs designed to help reduce greenhouse emissions,promote energy efficiency,and deploy renewable energy sources. Webiste:www.cedrl.mets.nrcan.ge.ca/eng/ programmes_retd.html Database of State Incentives for Renewable Energy: Established in 1995,DSIRE is an ongoing project of the Interstate Renewable Energy Council (IREC), funded by the U.S.Department of Energy's Office of Power Technologies and managed by the North Carolina Solar Center.Comprehensive information on state,local,and utility incentives that promote renewable energy. Webiste:www.dsireusa.org DOE PV Program:Information on howa solar cellworkscompletewithanimation,links to other pages and documents. Webiste:www.eren.doe.gov/pv/ Energy Efficiency &Renewable Energy Network: .Comprehensive resource of the DOE's renewable energy and energy efficiency information,including 600 links and access to over 80,000 documents. Webiste:www.eren.doe.gov 304 Energy Star:Introduced by the US Environmental Protection Agency in 1992 asa voluntary labeling program designed to identify and promote energy- efficient products,in order to reduce carbon dioxide emissions.EPA partnered with the US Department of - Energy in 1996 to promote the ENERGY STAR label. Webiste:www.energystar.gov Florida Solar Energy Center (FSEC):Research institute of the University of Florida.Site includes information on solar energy and photovoltaics, equipment testing,education and training,hydrogen energy and teacher resources. Webiste:www.fsec.ucfiedu Georgia Tech,Univ.Center of Excellence for PV Research and Education:DOE funded research facility working on fabrication of high efficiency PV cells and providing educational experiences. Webiste:www.ece.gatech.edu/research/UCEP International Solar Center:German based organization promoting renewable energies _throughout the world.Webiste:www.emsolar.ee.tu--berlin.de/© iscb/home.html Million Solar Roofs,USA:DOE program working to remove barriers to solar technologies.Information on financing and resources. Webiste:www.eren.doe.gov/millionroofs National Renewable Energy Laboratory (NREL): DOE laboratory for renewable energy research 8 development.Located in Golden,CO USA.Website includes information on RE basics,national programs, image library,and links to many RE documents.Webiste:www.nrel.gov Office of Scientific and Technical Information: DOE's Science and Technology Information and Resources.Links to DOE's research and publications. Webiste:www.osti.gov PV GAP (Global Approval Program for PV):Anot-for--profit organization,registered iin Switzerland,that certifies the quality of PV components. Webiste:www.pvgap.org incl P dissemination 0 V Power:A site for the coordination andfinformationofglobalPV "sechnologies,applications,history,and resources.SiteudesalistingofPVmanufacturersworldwide. Webiste:www.pvpower.com PV Portal:A link thar contains breaking news in thehotovoltiacindustryabouttheglobe,updated routinely the information is pertinant and cutting edge.Many links to manufacterers,designers and tnstallers. Webiste:www.pvportal.com Sacramento Municipal Utility District (SMUD)PV Program:Innovative utility program,promoting conservation and PV for its customers. Webiste:www.smud.org Sandia National Laboratories:Sandia's PV program goals are to reduce the life-cycle cost of PV systems, reduce barriers to systems acceptance,provide systems best practices and guidelines,performance and reliability testing,standardization,and validation.Site includes basic information on PV systems and balance of system components.Several publications are available for free. Webiste:www.sandia.gov/pv Solar Energy International (SEI):Authors of this text -Photovoltaics:Design and Installation Manual, teach SEJ's Renewable Energy Education Program (REEP).SET provides hands-on and online training in the practical use of solar,wind,and water power and in environmental building technologies.Website has training schedule. Webiste:www.solarenergy.org Univ.of New South Wales-Center for PV Devices &Measurements:Conducting solar cell research and PV education in Australia. Webiste:www.pv.unsw.edu.au Utility Photovoltaic Group (UPVG):A collaboration of the photovoltaic industry working to create and encourage commercial use of new solar electric power business models.Site includes info on PV events,and utility industry news. Webiste:www.solarelectricpowet.org RESOURCE GUIDE Technology Education Resources" Arizona Solar Center:Source for solar information in Arizona.Site contains maps,data,and AZ solar information., Webiste:www.azsolarcenter.com/welcome.html Ecological Footprint Quiz:A great place to go to figure out your rate of consumption within a world context.Fifteen questions are asked,from the answers it is determined how many Earths would be needed to support the entire human race consumed as you do. Webiste:www.earthday.net/footprint/index.asp Rainbow Power Company Ltd.:Australian RE company.Designs,manufactures,sells,and installs renewable energy equipment. Webiste:www.rpc.com.au San Juan College:New Mexico community college offering an Associate Degree in Renewable Energy. Webiste:www.sjc.cc.nm.us/RENG/RENG.html Solar Energy International (SEI):Renewable Energy Education Program teaches the practical use of solar,wind and water power through hands-on workshops and on-line education. Webiste:www.solarenergy.org Sol Energy:An interactive website that explains the basics of the solar energy to how a photovoltaic system utilizes such energy to produce electricity. Webiste:www.projectsol.aps.com/ inside/inside_pv.asp US.Department of Energy (DOE):A website devoted to current energy practices within the USA. Webiste:www.energy.gov/engine/content.do U.S Solar Radiation Resource Maps:An insolation resource for technical solar radiation data including the extremes in the USA and nearby territories. Webiste:www.rredc.nrel.gov/solar/old_data/ nsrdb/redbook/atlas 305 Setepreita”PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL Associations American Council for an Energy-Efficient Economy (ACEEE):A non-profit organization promoting energy efficiency as a means of fostering both economic prosperity and environmental protection. Offers a list of energy appliances,cars,and trucks. Webiste:www.aceee.org American Solar Energy Society (ASES):A national organization dedicated to advancing the use of solar energy for the benefit of U.S.citizens and the global environment.Publishes Solar Today Magazine. 'Webiste:www.ases.org/index.html Institute for Sustainable Power (ISP): Accreditation/Certification:Providing a globally recognized accreditation infrastructure of content modules,training guidelines,testing standards,and third-party qualification. Webiste:www.pvpower.com/isp.html Interstate Renewable Energy Council (IREC): Non-profit organization whose mission is to accelerate the sustainable utilization of renewable . energy sources and technologies in and through state and local government and community activities. Includes "Schools Going Solar”program. Webiste:www.irecusa.org North Carolina Solar Center:Programs and resources for North Carolina and beyond.Services available to the public include a toll-free hotline,a professional referral service,technical assistance and design reviews,free publications,curriculum . materials for teachers,training programs. Webiste:www.nesc.ncsu.edu Center for Renewable Energy &Sustainable Technology (CREST):Information on RE policy issues and RE in general. Webiste:www.solstice.crest.org/index.huml International Solar Energy Society (ISES): Worldwide membership organization with links and international solar information. Webiste:www.ises.org 306 Solar Energy Industries Association (SEIA): National trade association of solar energy manufacturers,dealers,distributors,contractors and installer for both PV and solar thermal.Site includes list of members,solar information,national energy policy,legislation and related news. Webiste:www.seia.org us Solar Educational Resources ORGANIZATION: Alternative Energy Institute West Texas A&8¢M University Box 60248;2501 4th Avenue Canyon,TX 79016-0001 Phone:806-651-2295 Fax:806-651-2733 Email:aeimail@mail.wtamu.edu Website:www.wtamu.edu/research/aei/ _Appalachian State University Department of Technology Boone,NC 28608 Phone:828-262-6361 Fax:828-265-8696 Email:scanlindm@appstate.edu Website:www.appstate.edu Colorado State University Solar Energy Applications Laboratory SEAL College of Engineering Fort Collins,CO 80523 Phone:970-491-8617 Fax:970-491-8544 Email:seal@lamar.colostate.edu Website:www.colostate.edu/Orgs/SEAL Farmingdale State University Solar Energy Center 2350 Broadhollow Road Farmingdale,NY 11735 631-420-2450 Website: www.info.lu.farmingdale.edu/depts/met/solar/fsec.html Florida Solar Energy Center FSEC 1679 Clearlake Road Cocoa,FL 32922-5703 Phone:321-638-1000 Fax:321-638-1010 Email:info@fsec.ucs.edu Websice:www.fsec.ucfedu RESOURCE GUIDE S cy W e wr SSSPPd<&.S -&EN &x PS vo SS Ser SF A 4 YViviv v v v oe Yiv vY v v v Y 307 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL US Solar Educational Resources ORGANIZATION: 'Georgia Institute of Technology:-University Center of Excellence for Photovoltaics Research and Education School of Electrical and Computer Engineering777AtlanticDrive Atlanta,GA 30332-0250 Phone:404-894-4658 Fax:404-894-4832 Email:ucep@ee.gatech.edu Website:www.ece.gatech.edu/research/UCEP Midwest Renewable Energy Association MREA7558DeerRoad,Custer,WI 54423 Phone:715-592-6595 Fax:715-592-6596 Email:info@the-mrea.org Website:www.the-mrea.org North Carolina Solar Center North Carolina State University Box 7401 Raleigh,NC 27695-7401 Phone:919-515-5666 Fax:919-515-5778 Email:ncsun@ncsu.edu Website:www.ncsc.ncsu.edu San Juan College 4601 College Blvd Farmington,NM 87402 Phone:505-326-3311 Email:bickford@sjc.cc.nm.us Website:www.sanjuancollege.edu/academics/ technology/RENG/index.htm 'Solar Energy International SET .--+PO.Box 715 _- Carbondale,CO 81623 Phone:970-963-8855 Fax:970-963-8866 Email:sei@solarenergy.org Website:www.solarenergy.org 308 :US Solar Educational Resources -ORGANIZATION: Solar Living Institute PO.Box 836 13771 S.Highway 101 Hopland,CA 95449 Phone:707-744-2017 Fax:707-744-1682 Email:sli@solarliving.org Website:www.solarliving.org SoLEnergy PO.Box 217 Carbondale,CO 81623 Fax:559-751-2001 Email:SoL@SoLenergy.org Website:www.solenergy.org Southwest Technology Development Institute New Mexico State University PO.Box 30001 MSC 3 Solar Las Cruces,NM 88003-8001 Phone:505-646-1846 Fax:505-646-2960 Email:tdi@nmsu.edu Website:www.NMSU.Edu/-tdi/ Sunnyside Solar 1014 Green River Road Guilford,VT 05301 Phone:802-257-1482 Fax:802-254-4670 Email:info@sunnysidesolar.com Website:www.sunnysidesolar.com University of Massachusetts-Amherst Mechanical and Industrial Engineering Department Box 2210 Amherst,MA 01003-2210 Phone:413-545-2505 Fax:413-545-1027 Email:mie@ecs.umass.edu Website:http://energy.caeds.eng.um].edu/ *Classes for professional installers only RESOURCE GUIDE e Ro soe 3 &of ae ae e se seo:'BS oa Po :ofoe”s w nN ad Y geaos©OO v v v v v v v v 309 -US Solar Educational Resources ORGANIZATION:ORGANIZATIVIN Solar'Living Institute PO.Box 836-13771 S.Highway 101 Hopland,CA 95449Phone:707-744-2017 Fax:707-744-1682 Email:sli@solarliving.org Website:www.solarliving.org SoLEnergy PO.Box 217 Carbondale,CO 81623 Fax:559-751-2001 Email:SoL@SoLenergy.org Website:www.solenergy.org Southwest Technology Development Institute New Mexico State University | PO.Box 30001 MSC3 Solar Las Cruces,NM 88003-8001 Phone:505-646-1846 Fax:505-646-2960 Email:cdi@nmsu.edu Website:www.NMSU.Edu/-tdi/ Sunnyside Solar 1014 Green River Road Guilford,VT 05301 Phone:802-257-1482 -Fax:802-254-4670 Email:info@sunnysidesolar.com Website:www.sunnysidesolar.com University of Massachusetts-Amherst . Mechanical and Industrial Engineering Department Box 2210 Amherst,MA 01003-2210 Phone:413-545-2505 Fax:413-545-1027 Email:mie@ecs.umass.edu Website:hetp://energy.caeds.eng.uml.edu/ *Classes for professional installers only RESOURCE GUIDE a)5 <%&e&Ny 5ssseSKP@Sve&S AN *SS RexYSeeSFeteFPKSSFof v v v v v Y v v 809 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL US Solar Educational Resources ORGANIZATION: University of Massachusetts-Lowell -:_ Mechanical Engineering Department One University Avenue Lowell,MA 01854 Phone:978-934-2968 Fax:978-934-3048 Email:john-duffy@uml.edu Website:www.eng.uml.edu/Dept/Energy University of Wisconsin at Madison:Solar Engineering Program . 1303 Engineering Research Building 1500 Engineering Drive Madison,WI 53706-1687 Email:beckman@engr.wisc.edu Website:http://sel.me.wisc.edu/ FOR INTERNATIONAL TRAINING CONTACT: The International Solar Energy Society ISES Villa Tannheim Wiesentalstr.50 79115 Freiburg Germany Tel.:+49 -761 -45906-0 Fax:+49 -761 -45906-99 Email:hq@ises.org Website:http://www.ises.org/ 310 "batteriescharging See charge controllersdaysofautonomy,factors in ..........6,62installing6...e eee ee eee eee eens 159 life expectancy -.1...se eee eee eee eee 65lowvoltagedisconnect,protect with ......61 maintenance 6.eee eee eee ee eee 168 measuring state of charge............--.66 rate and depth of discharge .............63 safety considerations with .............-67sealed,types Of...0...eee eee eee 61 types Of 6...eee eee eee eee eee 60 .using charge controls with ..............61voltagesetpointsfor............eee eee 62wiringconfigurationfor..........+0065 70 CAPACITY 6 ee eee eens 63 building-integrated systems benefits of 0...ccc cee eee 137 Costs for...cececeteeee 137 PV atrium oo...eeeee 136 PV facades...cece eee ne 136 PV roofing...66.ceceeeeeae 134 PV shade screens .......0.000 eee eaee 137 retrofitting to existing buildings ........134 charge controller " fearures Of 2...ceceees 75 specifying for a systeM..........0.sees 76temperaturesensorsfor.........esse eee 76typesOf2.occeeeees 74 checking CONUMUIEY oe ee eee eee es 171 polarity 6.66...cee cee eee eee 173 checklists final installation...0...ceeees 163 installation wiring ..2...eee eee eee 163 of tools and materials for installation .154-157 tools and materials for maintenance .....168 troubleshooting ..........000 eee eee 17k troubleshooting common issues .........174 circuit breakers See overcurrent protection conduit,wiring iN oeeeeeeeeee 88 index diodes See also shading blocking,preventing feedback with .......56 bypass,countering shading using.........56 isolation...eee eee ee eee tees 56 CISCOMNECES 2.ee cee eee eens 106 checking during installation ...........164 maximum allowable for PV systems .....106 electrical boxes,using 2...eee eee eee eee 161 CHCUIES 2.ee ee ee eee 11 CUITENE LYPES oe ee ee eee 10 firstaid ...0 cccceceeee 185 'fuses See overcurrent protection grounding checking during installation ...........165 ground-fault protection ...............109 NEC definitions for 1...00.0...000s 106 size of wires for...2...eeeeee 109 types Of 6...eee eee 106 hybrid system advantages Of ..1.1...eee eee 151descriptionOf..0.6...eee eee eee 150 insolation,defined ........00000ccceeeees 28 installation,materials checklist for ..........156 installingbattery...eee ee eee ees 159chargecontrollers..6...6...eee eee 160 final checklist for ...........0-eee 163 mounting considerations .............-157 safety SIGNS...eee 166 site visit prior (0 2...eee eee eee eee 154 cools and materials for............0005.154 Te 161 interconnection agreements ......6...ee eee 128 311 PHOTOVOLTAICS:DESIGN AND INSTALLATION MANUAL inverters checking operation of during installation .165featuresOf1.0...eee eee ....80 installing 2.0...cece ee ceceeee 160 operating principles of .............00-5 80 problem loads with .............0e000 81specifyingforasystem......ee eee eee 82 types Of 26...eee eee eee eee eens 81 lighting controls for...0.ccc cee eens 14] efficiency of...20...eee eee eee 14] fluorescent,description of .............143 high intensity discharge (HID),types of ..144 incandescent,types of .............04.143 light emitting diode (LED),description of 145 maintenance ...cece cece cee eens 169 lightning arrestors «6...6...cece eee ee eee 129 loads cycling ..6...ceceeeeee 40EStIMATINGooeeeeee41 phantom ....6...cece eee eee eee eens 40 reducing occeeeeeeee 40 0 41 magnetic declination ..........00eeeeeeee 29 maintenance batteries 0...eeeeee 168 of lighting ©6 6....kee 169 of modules...0.2...ceceeee 168 of refrigeration ..6...ccc cece cece eee 170 problems See also troubleshooting , MaxiMUM POWEL POINE.....ee ee eee eee eee 50 measuring array OULPUL.2...eee ee eee ee 159 CUITENE oe eeeeees voce nee ees 172 Voltage ooeeeeens 172 modules effects of temperature ON ..........00008 51 performance Of .....cece eee eee ee 49 structure Of 2.....ccc ce cece ee neces 49 wiring dissimilar together ..............53 312 mounts bracket....6.eeeeee 55 considerations when choosing ..........157 ground ...eeeeeeeeeeee 55integralroof...keeeeee 158 Le)Cl 55 POOF oe eeeeeeees 56 tracking...6...eee eee 56 multimeter,using for troubleshooting .......171 National Electric Code (NEC) grounding specifications in .........04.109 requirements for utility-connected systems 129 Article 690 for PV systems ..........00.86 disconnect requirements in .........-.-106 wiring ampacity requirements in .........88 wiring specifications in ..........00000.86 NEl METELING.eeee 127 open circuit voltage 2...eee eae 50 overcurrent protection checking during installation ...........164 circuit breakers for...1...ee cee eee eee 104 proper placement for ..........0000005 104 Sizing Of 66...eeeeeee 104 parallel circuits...2...cece cece cece ee eee 12 phantom loads .....2.0...cect e eee ees 40 photovoltaic system advantages Of 1.1...cece eee eee eee 3 BIPV See building-integrated systemscomponentsOf........6...008 cee anes 4 concerms With wv...cee ceceeee 3 disadvantages Of 6.6...eee eee eee eee eee 3 opportunities with .......2...cece eee eee 2 powering electronics using .............141 powering lighting using .............4.141 powering tools with .........0...cee 140 principles of...0...ccc cee eee eee eee 48 pumping using See pumps ; "sizing using six-step process .........655 112 typesOf ceceeeeeeeeeeees 4 - photovoltaic technology,history of ........++-2 polarity,checking ............cece eee ees 173powerrequiredbyhouseholdappliances....--45 .pumps i. y t performance of .....eee Lode eens 146selectingocceeeeeeeeeeeeeens146 terminology rr ee 145 types of ee eae ewe renee 146 recombinator cell caps for batteries ..........61 refrigeration maintenance ........ec eee eee ee eee 170 operating principles ........eee ...149 options for...6...eee eee eee ees ...149 selecting efficient .............seeae es 150 safety ; basics oc.cee eee veveaceeees180 current and voltage design for ..........180. equipment ............6.Lecce eens 183 first-aid 2...ceeee re 185 grounding for ...........64 keeneee 181 hazards around PV systems ............182 on work Site.ccceenee 184 organizations providing standards for ....180 precautions on the work site ...........171 SEFl€S CICUITS 6.ee eee ees wee 12 shading 1.0...eee cece eee 33,52,56 short circuit Current .....0c cece eee wee 50 sizing charge controller using worksheet ........77 design penalties ........000.0 eee e eee 112 overcurrent protection using worksheet ...105 Systems using stx-step Process .........-112 using PV system sizing worksheet ...113-115 utility-interactive system with worksheet ..131 wiring using worksheet.............97-103 solar radiation,defined.............0000055 28 solar,access calculating with sun chart ..........1...34 determining for low latitudes...........-35 INDEX solar altitude 2.0...ce cee eee 31 design month ............0.006 wena 32 insolation charts ............0005 wee 33 path ceceeeeeee 28 site analysis ......beeen eee ween 32 window visualizing .........Scenes 35 surge loads 6...6.6.0 eee eee eee 41 SUIBE SUPPFESSION 2.6...eee ee ee 129 trackers,benefits of ........Lcd eee ene 56 troubleshooting checking for continuity ...............171 COMMON iSSUCS 2.1...ce eeeeeees .174 general checklist for .......re ..171 using multimeter ..6.0...00.eee eee 171 utility-interactive systems advantages Of...02...eee eee eee ee 122 interconnection agreements for .........128 metering with «00....cee cece eee eee 127withbattery2.0...ee cee eee eee 125 without battery 6.0.0...ccc eee eee 124 without battery economic considerations with ..........126 volt,defined...ce ee ee Lees 10 voltage drop in Wiring 21.6...cece ee eee eee 89 voltage regulator See charge controllers voltage set points .........44.beeen eens 62 water pumps See pumps watt,defined ............2.00.Lee ee ee eae 10 wiring ampacity Of 6...ec eee e eee ees .o ee 88 checking during installation ...........163 color coding for .......00...eee eee 87 COMNECEOMS,USING...ee eee eee 161 In conduit...6.eeeeee 88 "installation...0.ceeeeee 161 sizing charts for...0...eee e eee eee eee 90 types of ........0008.eteeeeeeee 86 voltage drop with 1...0...cece 89 installation checklist 2..........000000-163 313 SOLAR ENERGY INTERNATIONAL (SEI) PO Box 715 Carbondale,Colorado 81623-0715 Phone:970-963-8855 Fax:970-963-8866 Email:sei@solarenergy.org Website:www.solarenergy.org Solar Energy International (SEI)is a non-profit educational organization whose mission is to help others use-renewable energy and environmental building technologies through education and technical assistance.SEI was founded in 1992 in the belief that renewable energy resources of sun,wind and water can improve the quality of life and promote a sustainable future for people throughout the world.SEI educates decision-makers,technicians and users of renewable energy systems.Decision-makers gain the information they need to choose renewable energies with confidence.Technicians and users'learn the practical skills they need to implement renewable energy technologies sustainably.SEI's programs include the Renewable Energy Education Program (REEP),International Training courses, i Solar in the Schools,and International Volunteers in Environmentally Sustainable Technologies (INVEST). SEI's main adult educational program is REEP.Each year hundreds of people from around the world attend hands-on workshops seeking practical experience and skills to use renewable energy resources and technologies.Classroom and laboratory work are complemented by case studies,field tours and professional installations with commercial equipment in practical applications.Instruction is provided by industry experts in the following workshops: be 1 i i i Micro-Hydro Power Solar Hot Water Systems Introduction to Renewable *Photovoltaic (PV)Design & Installation -Renewable Energy for the *Advanced Photovoltaics Energy Developing World *Unility-Interactive *Solar Home Design *Renewable Fuels Photovoltiacs *Natural House Building *Biodiesel Fuel °homens PV Design &*Advanced Straw-Bale *Successful Solar Businesses .Wa me,;Construction *Photovoltaic Design Online ww enceowes ¢Advanced Natural Building *Solar Home Design Online*Homebuilt Wind Generators and Building Science .6 SEI personnel travel domestically and internationally training people in renewable energy technologies. :SEI has taught thousands of students how to install renewable energy systems in the United States,LatinAmerica,Asta,Africa,the Pacific and the Caribbean.SEI's international programs stress in-country training of trainers,decision makers,technicians,and end-users.Developing local and regional capabilities at each of these levels is critical to successful renewable energy utilization.Standard training packages and custom programs are available to meet particular program needs.SEI's Solar In the Schools program targets grade school youth and focuses on experiential learning ofenergyconceptsandissues.The goal is to have students understand energy as it relates to all living things ontheplanet.SEI's INVEST program (International Volunteers in Environmentally Sustainable Technologies)offers alumni of our workshops an opportunity to volunteer overseas with one of our partner organizations to help bring renewable energy technologies to communities in the developing world. 315 most compre}vailable in the 780865"7