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HomeMy WebLinkAboutCity of Seward Heat Pump System Economic Evaluation - Sep 2015 - REF Grant 7091242 TM YourCleanEnergy LLC 308 G Street #215, Anchorage AK 99501 907-274-2007 www.yourcleanenergy.us ECONOMIC EVALUATION OF GROUND SOURCE HEAT PUMP SYSTEM TO PROVIDE PRIMARY HEAT FOR CITY LIBRARY & MUSEUM CITY HALL ANNEX CITY HALL FIRE HALL FOR CITY OF SEWARD, ALASKA FINAL REPORT COMPLETED SEPTEMBER 12, 2015 BY ANDY BAKER, PE TM YourCleanEnergy LLC TABLE OF CONTENTS EXECUTIVE SUMMARY STARTER GROUND SOURCE HEATING DISTRICT ALTERNATIVE B .......... ....... 4 SCOPE OF ECONOMIC EVALUATION FOR STARTER GROUND SOURCE HEATING DISTRICT .................. 5 INTRODUCTION ..................................................................................................................................................... 7 EXAMPLES OF SUCCESSFUL OCEAN /GROUND SOURCE HEATING SYSTEMS IN ALASKA ...................... 8 A SUMMARY OF THE FOUR CITY BUILDINGS INCLUDED IN THIS EVALUATION .......................................... 9 RECENT HISTORY OF ELECTRICITY COSTS FOR CITY OF SEWARD BUILDINGS ..................................... 10 RECENT HISTORY OF GRID ELECTRICITY USAGE BY CITY BUILDINGS ..................................................... 11 OPPORTUNITIES FOR INCREASING ENERGY EFFICENCY OF ELECTRICAL LOADS ................................ 12 RECENT HISTORY OF HEATING OIL COST FOR CITY BUILDINGS IN SEWARD .......................................... 13 RECENT HISTORY OF HEATING OIL USAGE BY CITY BUILDINGS ............................................................... 14 RECENT AND PROJECTED HEATING FUEL COSTS FOR THE CITY OF SEWARD ...................................... 15 SUMMARY OF EXISTING BOILERS AND ESTIMATE OF PEAK HOURLY & ANNUAL HEAT LOADS ............ 16 SOLAR HEATING OF THE OCEAN ALONG THE EQUATOR IS MOVED BY GYRES TO ALASKA ................. 17 SEA WATER TEMPERATURE IN RESURRECTION BAY PEAKS EACH YEAR AFTER FALL STORMS ........ 18 GEOLOGY AND SUB-SURFACE WATER RESOURCE BELOW WATER FRONT PARK ................................. 19 CONCEPTUAL DESIGN OF VERTICAL GROUND LOOPS TO EXTRACT OCEAN HEAT ............................... 20 EXAMPLE PROJECT USING DOUBLE U-BEND VERTICAL LOOPS WITH SEPARATOR CLIPS ................... 21 CONCEPT DESIGN OF STARTER GROUND SOURCE DISTRICT HEATING SYSTEM .................................. 22 DRAWING G-1: CONCEPT PLAN OF GSHP PROJECT - ALTERNATIVE A & B .............. .............................. 23 DRAWING G-2: PROJECT SCHEMATIC OF HEATING PUMP SYSTEM ........................................................ 24 TRENCHING OF SUPPLY & RETURN MAINS ALONG AND UNDER CITY STREETS AND ALLEYS ............. 25 INSULATED AND JACKECTED HDPE SUPPLY AND RETURN GROUND SOURCE MAINS .......................... 26 GROUND SOURCE HEAT PUMP OPERATION AND COEFFICIENT OF PERFORMANCE (COP) ................. 27 SELECTION OF WATER SOURCE HEAT PUMPS SUITABLE FOR USE IN CITY BUILDINGS ....................... 28 SUMMARY OF OPERATION & MAINTENANCE COSTS FOR STARTER DISTRICT HEAT SYSTEM ............. 29 GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 3 OF 38 f TM with YourCleanEnergy LLC TABLE OF CONTENTS (Continued) COST OPINION - ALT B: GROUND SOURCE DISTRICT HEAT FOR ALL FOUR CITY BUILDINGS .............. 31 COST OPINION - ALT B: GROUND SOURCE DISTRICT HEAT FOR ALL FOUR CITY BUILDINGS (CONTINUED) ....................................................................................................................................................... 32 APPENDIX A: ANNEX BUILDING - OIL BOILER - FUEL USE VS. OUTSIDE TEMP - DATA LOGGER .......... 33 APPENDIX B: FIRE HALL - OIL BOILER - FUEL USE VS. OUTSIDE TEMP - DATA LOGGER ....................... 34 APPENDIX C: CITY HALL - OIL BOILER - FUEL USE VS. OUTSIDE TEMP - DATA LOGGER ....................... 35 APPENDIX D: QUOTE TO DRILL AND INSTALL 2 TEST HOLES & 10 VERT GROUND LOOPS ................... 36 APPENDIX E: QUOTE FOR INSULATED HDPE PIPE WITH JACKET- SUPPLY & RETURN MAINS ............. 37 APPENDIX F: QUOTE FOR HEAT PUMPS, LOOP PUMPS, BUFFER TANKS, U-BEND COILS ..................... 38 GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 4 OF 38 f TM with YourCleanEnergy LLC EXECUTIVE SUMMARY STARTER GROUND SOURCE HEATING DISTRICT ALTERNATIVES 50 Year Present Worth Financial Analysis Of Starter Heating District Alternative B: Alternative B: All Four City Bldgs 17 Boreholes Description Of Financial Component 8 Heat Pumps Total Installed Project Cost Opinion -$850,000 Electricity use by source pumps - Year 1 -$2,290 Present worth of electricity use by source pumps - over 50 year project life* -$114,500 Electricty use by heat pumps - Year 1 -$37,208 Present Worth of electricity use by heat pumps - over 50 year project life* -$1,860,400 Maintenance Cost - District Heat System - Year 1 -$1,200 Present Worth of Maintenance Cost For District Heat System - over 50 year project life** -$185,800 #1 Heating Oil Saved By Heat Pumps - Year 1 $60,462 Present Worth of #1 Heating Oil Saved By Heat Pumps - Over 50 year project life*** $4,466,637 Net Present Worth Of Project Over 50 Years $1,455,937 Net Annual Savings At End Of Year 1 $19,764 Benefit To Cost Ratio 1.48 Notes: * Grid electricity at industrial user rate from City of Seward, with 3% per year escalation ** Maintenance labor costs escalating at 3% per year *** Unit cost of #1 heating oil escalating at 4.5% per year - Discount rate applied to all financial components is 3% per year - Current Large General Service rate for City of Seward grid electricity is $.184/KWH - Cost of #1 heating oil is estimated to be $3.02/gallon at start of project GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 5 OF 38 f TM with YourCleanEnergy LLC SCOPE OF ECONOMIC EVALUATION FOR STARTER GROUND SOURCE HEATING DISTRICT 1. Provide background of and scope for the Economic Evaluation, and overall goals of the City to establish a starter heating district using a vertical ground source loop field near the ocean, and heat pumps in the City Library and Annex that are supplied from trunk lines connected to the ground loops. 2. Evaluate the historical cost of heating in downtown Seward using heating oil, and straight electric heat for the past ten years. Based on the latest price projections and information from both heating oil suppliers and City Electric Department, estimate anticipated escalation of heating oil and grid electricity prices in downtown Seward for the next 30 years. Estimate inflation and discount rates anticipated over the same time period. 3. Provide several examples from Southcentral and Southeast Alaska of similar ground or ocean source heating system that have displaced oil or electric heat through the winter heating season for at least two years. Describe the size of these systems, # of customers, and annual heating loads served. For the purpose of comparison to City of Seward, indicate the method of delivered heat price determination and the actual savings realized over other conventional fuels that are displaced by this system. 4. Develop a conceptual design schematic of a starter district heat system to initially serve the Library and Annex buildings. This concept would include a vertical borehole ground source loop field on City property adjacent to Resurrection Bay, a supply and return trunk line along Adams Street, variable speed drive district loop pumps in the Library basement, and water source heat pumps to replace boilers currently located in the basement of both the Library and Annex. A conceptual design schematic illustrating the conversion of medium temperature heat distribution appliances within each of these buildings will also be included. The conceptual design schematic will consider expansion of the starter district in the future to provide source heat for the City Hall and Fire Hall. 5. Develop conceptual design for a field of vertical geothermal boreholes on City shoreline property at the base of Adams Street. Discuss anticipated subsurface soil conditions, thermal conductivity, depth to bedrock, ground water levels, influence of ocean tides, salinity, borehole depth and spacing, manifold arrangement. Identify adjacent areas where the borehole field may be expanded in future to serve additional buildings via the trunks proposed along Adams Street for the Library and Annex. Recommend a scope of work for a driller to install several test boreholes to confirm subsurface conditions in the area of the proposed borehole field. 6. Develop concept level typical sections for the anticipated trenching of district loop supply and return trunk lines along and under city streets, sidewalks and frontage. Identify an appropriate type of pipe material, depth of bury, insulation requirements, shut off valves, and other details that will have cost implications for the buried piping included in the district system. Determine whether branch supply and return lines may be placed in the same trench with new water lines or other GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 6 OF 38 f TM with YourCleanEnergy LLC buried utilities already scheduled for replacement by the City. Discuss optimal depth for buried trunk lines. 7. Based on actual heating fuel usage for the past four years, and installed boiler sizes, estimate annual heat load and peak hourly heat demand rates for the Library, Annex, City Hall, and Firehall. This work item will require that the City install, within two weeks of Notice To Proceed for this evaluation, a fuel meter (total gallons consumed) on each operating oil boiler, and a KWH meter on the electric boiler in the Library. Heat load estimates can then be calibrated against actual fuel usage recorded over the winter of 2014/15. 8. For the Library and Annex buildings, an inventory of the existing heating appliances, heat loads and hydronic supply temperatures shall be made, based on the Design/As-Built mechanical and electrical drawings for this building. A strategy will be developed for the conversion of medium temperature (140F to 180F) heating loads to low temperature (100F to 130F), assuming replacement of the oil boiler and/or electric boiler with heat pumps of similar capacity. 9. For the Library and Annex buildings, estimate if a net increase in electrical power service will be required for the building in order to integrate heat pumps. Discuss whether a need for standby power exists for either building. 10. For the initial Library and Annex ground source heating district, develop an opinion of probable cost for design and construction, expressed in 2015 dollars. 11. For the initial Library and Annex ground source heating district, estimate the anticipated annual Operation and Maintenance costs, including electricity usage, operational staff, parts, maintenance, technical support, etc. 12. For the initial Library and Annex ground source heating district, estimate the annual savings in 2015 dollars anticipated from the ground source district heat system over continued use of the existing oil and electric boilers. 13. For the initial Library and Annex ground source heating district, develop an itemized opinion of probable cost for design and construction. Develop a Net Present Worth analysis with 30 year life cycle, using the current energy costs and projected escalation rates, discount rate, and inflation rate appropriate for this type of City-owned infrastructure project. This analysis will indicate years to payback investment of ground source district heat versus the base case of continuing with existing heating oil and electric boilers/resistance heat. 14. Estimate the portion of the design and construction costs that could likely be funded by federal and/or state renewable energy grant programs currently available to the City. 15. Produce deliverable Economic Evaluation report in PDF format that includes above items, schematics, graphs, technical information, cost estimates, etc, in a simple easy to read format. 16. Make one public presentation in Seward to communicate the results of the evaluation. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 7 OF 38 f TM with YourCleanEnergy LLC INTRODUCTION On December 12, 2014, the City of Seward secured the services of YourCleanEnergy (YCE) to prepare an Economic Evaluation of Starter Heating District to serve the City Library and Annex buildings in downtown Seward (described here in as "ALT A"). The evaluation also considers an expanded system that includes City Hall and the Fire Hall in the starter heating district (described here in as "ALT B"). The Annex is currently heated with an oil fired boiler; the Library is heated with an oil fired boiler and an electric boiler. The City Hall and Fire Hall both have two oil fired boilers in them. The concept of this evaluation is based on converting the primary source of heat from existing heating oil and electric boiler heat systems to ground source heat pump systems. The ground source loops would derive source heat from a closed loop vertical borehole field located in the City owned park adjacent to Resurrection Bay. BACKGROUND Significant operational savings are anticipated over time by replacing heating oil boilers in select City buildings with ground or ocean source heat pumps. The anticipated savings are based on results of other ground source and ocean source heat pump systems in the Seward area that are operating at about half the cost of oil or straight electric heat systems. The City owns Waterfront Park along Resurrection Bay that is currently used for recreation and camping; these areas lie above water saturated deep alluvial deposits that have strong potential for cost effective and low impact installation of vertical ground loops fields. These fields can supply a district loop to serve heat pumps installed in City Buildings. Vertical ground loops, up to 300 foot depth, installed in ocean frontage areas may be warmed by the ground and ocean heat from the Bay, without the challenges of directly pumping sea water. Initial starter heating district loops can be designed with capacity for expansion to serve more nearby heat loads in the future. There are four City buildings downtown in close proximity to the Bay frontage property, and to each other, that have potential for conversion to heat pumps: the City Library, City Annex, City Hall and the Fire Station. Of these buildings, the City Library is the most appropriate for conversion to heat pumps due to its new construction with well insulated envelope, radiant floors, and modern hydronic system. The Annex is adjacent to the Library and has had recent envelope improvements that are likely to make a conversion of this building to a heat pump system cost effective. The City Hall and Fire Hall are older multi-use buildings that would benefit significantly from both a comprehensive energy audit and fundamental energy efficiency improvements. However they are also good candidates even in their present condition for receiving district heat. As more energy efficiency improvements are made over time to the City Hall and Fire Hall, the heat production required from heat pumps will reduce. This will in turn free up heat capacity for other potential buildings or customers. Energy audit services for City Hall and the Fire Hall were not included in the scope of this district heating system evaluation. The evaluation herein will consider a starter heating district that initially serves the City Library and Annex buildings (Alternative A), with planned capacity and connections for City Hall and the Fire Hall (Alternative B). Economic, technical, and operational success with these first two buildings may then demonstrate the potential benefits of expanding the district loop to other City buildings. Due to economy of scale, there may be an advantage to constructing a district heat system to serve all four buildings from the start (Alternative B). At the present time there are multiple sources of state and federal grant funds that the City may apply for to finance such a project. The Economic Evaluation proposed herein can be leveraged as the basis for grant funding and/or appropriation to finance the design and construction for the initial starter district. The Alaska Energy Authority Renewable Energy Fund receives grant applications in September of each year for projects that may be funded in the following fiscal year. Acknowledgements. YCE would like to thank City Council for taking steps towards a district energy plan that taps the immense and natural heat resource that is Resurrection Bay. Thanks is also expressed to Ron Long, Jim Hunt and Susie Towsley for City contract administration; Stefan Nilsson for coordinating access to City personnel, buildings & drawings; Valarie Kingsland for Library tours; WC Casey for advice on utilities; John Foutz for advice on electric rates; Steve Audette for testing boilers; Dwayne Atwood for providing planning maps; Phil Kaluza for sage advice, data loggers and annual fuel use analysis. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 8 OF 38 f TM with YourCleanEnergy LLC EXAMPLES OF SUCCESSFUL OCEAN /GROUND SOURCE HEATING SYSTEMS IN ALASKA Alaska SeaLife Center, Seward. In 2009, an Economic Evaluation comparing the installation and use of sea water heat pumps to replace existing oil boilers was completed by YourCleanEnergy. In 2010, the 120,000 square foot Alaska SeaLife Center received grant funds from the Denali Commission and Alaska Energy Authority to design and install two 90 ton heat pumps that utilize sea water from ice free Resurrection Bay to provide heat for indoor spaces, outdoor sidewalks, and domestic hot water. In December 2012, the two existing oil boilers were turned off and the sea water heat pump system performance was monitored continuously through December 2013. Throughout 2013, the heat pump system displaced 48,104 gallons of heating oil, producing a net savings of $120,000 and a net CO2 emission reduction of 420,000 lbs. The average system COP (coefficient of performance) for the year was 2.77; this represents an efficiency of 277% over heating oil or straight electric heat. In 2014, AEA provided an Emerging Energy Technology grant to design and install additional heat pumps that utilize CO2 as refrigerant and lift from sea water temperatures (40 degrees F) up to 194 degrees F for baseboard heat in the offices and labs. This project is currently under design by YourCleanEnergy. International Airport, Juneau. This project was placed on line in May 2011. The use of ground source heat at the Juneau International Airport Terminal is part of an overall renovation and expansion project. The Airport was constructed on filled wetlands that receive sub-surface influence of ocean tides and fresh water drainage. Based on a feasibility study, a Ground Source Heat Pump (GSHP) scheme offered a financial incentive to move away from traditional fuel oil-based heating systems to one that extracts heat from the ground and obtains most of its purchased energy from cleaner hydroelectric sources. The system is comprised of a closed ground loop with 108 vertical borings, each 360 ft. deep; 6 miles of HDPE pipe in the field; 26 water to air heat pumps(Climate Master); 3 water to water heat pumps (McQuay); and one Climate Master Direct Outside Air Supply (DOAS) unit. The loop field has dimensions of 110 ft. x 275 ft and is located under the commuter/charter aircraft tie-down area. Implementing this new system is affording annual savings in heating oil to the City of 35,000 gallons worth @$115,000 along with $10,000 a year in staff labor and $1,000 in snow removal equipment. Seldovia House Ground Source Heat Pump System. A new heat pump system for this 17,000 sq ft senior and low income housing complex was placed on-line in December of 2014. Evaluation of replacing oil boilers with ten x 300 ft deep vertical ground loops (in solid basalt) and two heat pumps was completed by YCE in 2013. Grant funding from Alaska Energy Authority under the REF Round 7 allowed for design to be completed by YCE in August 2014; construction was completed by November 2014. For winter of 2014/2015, the heat pumps displaced approximately 80% of the heating oil normally used. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 9 OF 38 f TM with YourCleanEnergy LLC A SUMMARY OF THE FOUR CITY BUILDINGS INCLUDED IN THIS EVALUATION A summary of basic information regarding the four city buildings included in this evaluation is given below: Building Name Sq Ft Date Built Type Of Use Fire Hall 7,262 1963 Emergency Response, Bldg Inspector City Annex 8,192 1950 Elect Dept, Planning Offices City Hall 20,532 1966 City Admin, State & Federal Offices Library/Museum 24,323 2012 Public Library & Historical Museum Building Name # of Boilers Boiler Type Liquid Fuel Type Fuel Tank Size Fire Hall Two Oil Fired #1 Heating Oil 2000 Gallons* City Annex One Oil Fired #1 Heating Oil 500 Gallons City Hall Two Oil Fired #1 Heating Oil 2000 Gallons* Library/Museum Two (Oil Fired + Electric) #1 Heating Oil 2000 Gallons *Fire Hall and City Hall share a single tank located adjacent to the Fire Hall GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 10 OF 38 f TM with YourCleanEnergy LLC RECENT HISTORY OF ELECTRICITY COSTS FOR CITY OF SEWARD BUILDINGS Buildings owned and operated by the City of Seward are currently charged by the Seward Electric Utility at either the Small General Service or Large General Service rate. Seward Electric Utility purchases firm power from Chugach Electric Association (CEA) with the exception of local diesel generation when Chugach power is interrupted by avalanches or other events. The Small General Service and Large General Service electric rates consist of the following price components: Primary Charge ($/KWH) + Additional Charge ($/KWH) + Peak Demand Charge ($/KW) + CEA Fuel Charge ($/KWH) + Monthly Charge ($/Month) = Total Monthly Charge For simplicity, an Effective Electricity Rate ($/KWH) is used in this evaluation report to estimate future costs for loop pumps and heat pumps. The Effective Electricity Rate ($/KWH) is express as the Total Monthly Charge ($) divided by Total Monthly Energy (KWH) used. There can be some significant variation in the Effective Electricity Rate between buildings at times when one building has low occupancy, or when an electric heating appliance is imposing a high demand charge on the meter account. This is seen below for the Annex during a times it was unoccupied in 2013, and for the Library when the electric boiler was used instead of the oil fired boiler in 2013 and 2014. The Small General Service rate is the highest of all tariff rates applied to City buildings and has a current effective rate of $0.205/KWH. The Large General Service currently has an effective rate of $0.184/KWH. The proposed Ground Source Heat Pump Project will house all heat pumps and loop pumps in either the Library or City Hall; only the Large General Service rate will apply to the project. The future price escalations in electricity cost in Seward are closely tied to those of Chugach Electric Association. The unit price of grid electricity from Chugach Electric Association has risen at a rate of approximately 3% per year for the past four years. This increase has been tempered by the fact that 15% hydro-electric which has stabilized the retail cost of electricity; and load sharing between utilities on the rail belt grid of Alaska has prevented any one utility from subjecting customers to rapid price escalations. The primary factor expected to determine the escalation rate of ity is the cost of natural gas generation. This cost can vary due to regional Henry Hub pricing and available supply in the region for this commodity. Another factor that may influence the wholesale price of power from CEA in coming years is the size of their customer base in relation to their generating capacity. An increase in the purchase of wind generation may help stabilize pricing. The economic evaluations contained in this report are based on the rate of grid electricity from City of Seward escalating at an average rate of 3% per year for the next 30 years. The addition of local hydro electric power to the Seward City grid could further stabilize the retail price by reducing dependence on natural gas generation by Chugach Electric and by providing some alternative to emergency diesel generation during those times when supply from Chugach is interrupted. $0.1400 $0.1900 $0.2400 $0.2900 $0.3400 $ / KWH EffecƟve Electricity Rate For City Buildings - 2010 thru 2014 Annex (Small General Service) Fire Hall (Small General Service) City Hall A (Large General Service) City Hall B (Large General Service) GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 11 OF 38 f TM with YourCleanEnergy LLC RECENT HISTORY OF GRID ELECTRICITY USAGE BY CITY BUILDINGS The amount of City budget spent on electricity for City Buildings has been significant for the previous four heating seasons. For the heating season of 2013/2014 the total cost of electricity used by all four city buildings was $162,329. This high amount of electricity usage is attributed in part to high levels of occupancy (lighting, office equipment, computer servers, communication equipment, ventilation); and to the use of electric resistance type space heaters in the older buildings, City Hall in particular. Average annual electricity usage in KWH by City buildings over the past four heating seasons (July 2010 thru June 2014) are shown below. In terms of average annual electricity usage, the City Hall has been by far the largest. This is due in part to the high occupancy and multi-use features of the building. It is self evident that some amount of electric resistance space heating is occurring in the winter months in this building to compensate for the poor insulation value of the walls, windows, and roof. The Library/Museum is a relatively new facility however it was noted during site visits to this building that efficiency improvements can be made in both lighting and HVAC controls. One specific example is replacing the incandescent spots in the Museum exhibit hall with LED lamps. Another is recovering some of the solar heat gain from the second floor reading rooms that is currently wasted by opening clear story windows when the rooms over heat on sunny days. A comprehensive energy audit of all four City buildings would very useful to increase their efficiency. Fire Hall Annex City Hall Library 2010/11 $12,202 $8,971 $46,341 2011/12 $12,261 $10,085 $49,877 2012/13 $12,606 $6,391 $48,332 $52,061 2013/14 $13,927 $6,246 $48,238 $45,679 $0 $10,000 $20,000 $30,000 $40,000 $50,000 Annual Electricity Expense (July 2010 thru June 2014) Fire Hall Annex City Hall Library KWH 65,360 40,114 282,024 197,660 0 50,000 100,000 150,000 200,000 250,000 KWHAnnual Electricity Usage (4 Yr Avg - July 2010 thru June 2014) GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 12 OF 38 f TM with YourCleanEnergy LLC OPPORTUNITIES FOR INCREASING ENERGY EFFICENCY OF ELECTRICAL LOADS It is useful to review the relative size of the four city buildings when evaluating the amount of energy used by those buildings: It is useful to compare the intensity of electricity use among City buildings because this will indicate whether large differences in lighting, appliances, and/or electric space heating loads are occurring between the buildings. This intensity can be expressed as KWH / square foot building area / year: As shown below, City Hall has by far the highest level of electricity use per square foot. It is recommended that a comprehensive energy audit of the Fire Hall and City Hall be performed to determine what cost effective improvements in lighting, HVAC pumps/ventilation, and electrical appliances, can be made to reduce electrical energy usage. Sub-metering of major electric loads can help to identify the largest categories of power usage. It appears that a large number of individual electric space heater may be in use to supplement building heat on cold and windy winter days. Increasing envelope insulation and retro-commissioning of the heating and ventilation system of the buildings can eliminate the need for supplemental space heaters and afford large energy savings. Fire Hall Annex City Hall Library Sq Ft 7,262 8,192 20,532 24,323 0 5,000 10,000 15,000 20,000 25,000 Square Feet of Floor Area Usable Interior Floor Area Of City Buildings Fire Hall Annex City Hall Library KWH/Yr/Sq Ft 9.00 4.90 13.74 8.13 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 KWH / Year / sq ft bldg area Electricity Use / Year / Sq Ft Bldg Floor Area (4 Yr Avg) GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 13 OF 38 f TM with YourCleanEnergy LLC RECENT HISTORY OF HEATING OIL COST FOR CITY BUILDINGS IN SEWARD In order to plan for energy efficiency and district heat projects for buildings in Seward, it is useful to review the trend of heating oil cost ($/gallon delivered) from the past ten heating seasons (July 2004 thru June 2014). The City of Seward purchases #1 heating oil from Shoreside Petroleum for their buildings. Over the past four years, the price of heating oil in Seward has varied greatly, as can be seen in the graph above of heating oil bill fuel prices from 2010 to 2014. A large price spike occurred in May 2011, with prices hitting over $3.90/gal. Following the 2011 spike, prices remained in the range of $3.60/gal through August of 2014. A surplus of oil supply in the global market starting in September of 2014 has driven prices down temporarily to the range of $3.20/gal. It is anticipated that global supply will reduce in the near future, and the market price for heating oil in Seward will return to the range of $3.90/gal. The total amount of City budget spent on heating oil for the four city buildings reached $67,605 for the 2012/2013 heating season due to a cold winter and moderately high oil prices. While it is not the largest of the four buildings, City Hall consumes the greatest amount of heating oil by a noticeable margin. City Hall is an older structure that can benefit from a comprehensive energy audit and various energy efficiency improvements that include increased wall and roof insulation, new thermally broken thermo- pane windows, retro-commissioning of existing HVAC system, and clearing the air path to baseboards. $2.50 $2.70 $2.90 $3.10 $3.30 $3.50 $3.70 $3.90 $4.10 Aug 9 2010Oct 19 2010 Dec 13 2010 Feb 3 2011 Apr 7 2011 Jun 2 2011 Aug 11 2011 Oct 11 2011Jan 5 2012 Feb 15 2012 Apr 19 2012 Jul 16 2012 Oct 20 2012 Dec 21 2012 Jan 15 2013 mar 6 2013 may 23 2013 sep 13 2013 nov 22 2013 Jan 23 2014 Mar 28 2014 May 13 2014 Sep 10 2014 Nov 18 2014Price Per Gallon Delivered Recent Price Of #1 HeaƟng Oil For City Of Seward Buildings Fire Hall Annex City Hall Library 2010/2011 $8,973 $6,347 $20,937 $0.00 2011/2012 $11,563 $7,940 $26,979 $0.00 2012/2013 $11,318 $8,322 $26,408 $21,557.51 2013/2014 $9,723 $7,133 $22,688 $17,487.00 $0 $5,000 $10,000 $15,000 $20,000 $25,000 $30,000 Annual HeaƟng Oil Cost - City Buildings - 2010 thru 2014 GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 14 OF 38 f TM with YourCleanEnergy LLC RECENT HISTORY OF HEATING OIL USAGE BY CITY BUILDINGS The overall efficiency of heating oil usage in the four City buildings can be compared to each other by dividing the total amount of heating oil used each year in the building by the total usable floor area. While the Fire Hall is the smallest of the buildings, it has consumed the greatest amount of heating oil per unit floor area. This is attributed in part to the regular opening of large overhead doors for vehicles throughout winter days; and also to poor insulation in portions of the building envelope, in particular the roof. Fire Hall Annex City Hall Library Sq Ft 7,262 8,192 20,532 24,323 0 5,000 10,000 15,000 20,000 25,000 Square Feet of Floor Area Usable Interior Floor Area Of City Buildings Fire Hall Annex City Hall Library Gallons 3,325 2,475 7,480 6,064 0 2,000 4,000 6,000 8,000 Gallons of #1 Heating Oil Annual HeaƟng Oil Usage (4 Yr Avg - July 2010 thru June 2014) Fire Hall Annex City Hall Library BTU/Yr/Sq Ft 45,624 27,434 33,408 26,149 0 10,000 20,000 30,000 40,000 BTU / year / sq ft BTU / Year / Sq Ft Area (4 Yr Avg - July 2010 thru June 2014) GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 15 OF 38 f TM with YourCleanEnergy LLC RECENT AND PROJECTED HEATING FUEL COSTS FOR THE CITY OF SEWARD For the past twenty years or more, the City of Seward has utilized heating oil as the primary fuel source for space heating boilers and back power generation. In recent years, the City has purchased large quantities of #1 heating oil at bulk rate from Shoreside Petroleum. The actual price paid per gallon for recent years is shown below. While there have been fluctuations in the unit cost of crude oil products in the past four years, the overall price escalation has been on a baseline of 6% per year from August 2010 ($2.80/gallon) through December 2014 ($3.60/gallon). The recent surplus of crude in the global market has driven down heating oil price since September of 2014, however this is likely a short term effect. Healthy economic growth in the USA is expected in coming years, along with some reduction in crude oil demand in the USA due to efficiency increase. The long term global shortage of crude oil supplies and growing global demand, especially that of China and India, may increase the escalation rate. The use of a 4.5% per year escalation for heating oil in Seward is both conservative and realistic given the past and projected history of crude oil prices. An electric boiler was installed in the new Library/Museum as an alternate heating method to burning heating oil. The electric boiler has not been used often due the fact that the recent price of oil has made operation of the two stage (low and high fire) oil boiler far more cost effective. At current retail electricity and fuel oil rates (Dec 2014), using ground source heat pumps with electricity priced at the Large General Service (LGS) rate will be approximately 1.6 times more cost effective than heating with oil boilers. Using ground heat pumps with electricity priced at the Large General Service (LGS) rate will be approximately 2.5 times more cost effective than using an electric boiler. Cost of making 1,000,000 BTU with #1 heating oil (using 85% eff boiler, $3.90/gal) = $34.24 Cost of making 1,000,000 BTU with electric heat (@ LGS Rate of $0.182/KWH) = $53.33 Cost of making 1,000,000 BTU with heat pump system (COP 2.8, $0.182/KWH) = $19.05 $2.50 $2.70 $2.90 $3.10 $3.30 $3.50 $3.70 $3.90 $4.10 Aug 9 2010 Oct 12 2010 Nov 9 2010 Jan 5 2011Feb 3 2011 Mar 29 2011 May 13 2011 Jun 23 2011 Aug 11 2011 Sep 21 2011 Nov 22 2011 Jan 12 2012 Feb 15 2012 Apr 9 2012 Jun 1 2012 Aug 24 2012 Oct 20 2012Dec 13 2012jan 8 2013 jan 31 2013 mar 6 2013 apr 25 2013 jul 18 2013 oct 3 2013 nov 22 2013 Jan 9 2014 Feb 11 2014 Apr 3 2014 May 13 2014 Jul 15 2014 Oct 23 2014Dec 1 2014 Price Per Gallon Delivered Recent Price Of #1 HeaƟng Oil For City Of Seward Buildings + 6%/Yr EscalaƟon Line GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 16 OF 38 f TM with YourCleanEnergy LLC SUMMARY OF EXISTING BOILERS AND ESTIMATE OF PEAK HOURLY & ANNUAL HEAT LOADS In January 2015, the City of Seward performed field testing of the existing oil fired boilers in City Hall, Annex and the Fire Hall. While the boilers were running hot, an analysis of combustion flue gas temperature and composition was performed. Additionally, run time data loggers were installed on these oil boilers for the entire month to determine how often the boilers were running on the coldest days. From these field measurements and equipment data, the peak hourly heat load (Btu/hour) of the buildings was estimated for the design winter outside air temperature of 5F. It was then possible to estimate the size of new hi-efficiency water source heat pumps that could effectively replace the heating capacity of the existing boilers: Data from the run time loggers was used to create heat load graphs for each building that are based the typical winter outside air temperatures measured in recent years in Seward. These graphs are shown in the Appendix of this report. From the simulation software associated with the data loggers, the design annual heat load and heating oil usage was estimated. These design heat loads are then used in the economic evaluation to establish how much heating oil will be displaced by heat pumps, how much electrical energy is required for loop pumps and heat pumps, and what annual savings that will produce. Site Library / Museum Library / Museum City Hall City Hall Fire Hall Fire Hall Annex Bldg. Burnham Lattner Electric System 2000 Weil McLain System 2000 System 2000 Weil McLain V904A S135LW EK-3F V600 EK-1 EK-1 P-768-WT Lead boiler Lag boiler Lead boiler Lag boiler #1 #2 Stack Temp.370* 360* 440* 400* 350* 480* CO2 11.60% 3.20% 2.20% 8.20% 7.70% 7.50% CO 37 ppm 18 ppm 84 ppm 0.0 ppm 0.0 ppm 17 ppm 2 4.90% 16.50% 19.20% 9.60% 9.50% 10.60% Extra Air 28.20% 34.50% 51.90% 78.30% 53.80% 93.10% 2.1 low fire 4.3 high fire Nozzle 2.1 2.6 1 N/A Flow Rate gal/hour gal/hour Gross Output 281,400 460,000 348,400 134,000 248,000 BTU/Hour on low fire Field Measured 86.20% Efficiency on low fire Net BTU/Hour 242,567 No Data 255,029 110,550 194,928 Run Time @5F 95.00% No Data 95.00% 90.00% 45.00% Peak Hourly Heat Load @5F BTU/Hour 230,438 No Data 242,277 99,495 87,718 Heat Pump Cap (Tons) Req'd To Offset Boilers 19 21 9 8 Design Annual Heat Load (MMBTU)700 734 368 261 Design Annual Oil Usage (Gallons)6,064 7,480 3,325 2,475 Site Library / Museum Library / Museum City Hall City Hall Fire Hall Fire Hall Annex Bldg. Boiler Nozzle 2.00-60A 250-60A .75-70A 1.25-60A No Data 73.20% 68.20% 82.50% 85.00% 78.60% .75-70A GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 17 OF 38 f TM with YourCleanEnergy LLC SOLAR HEATING OF THE OCEAN ALONG THE EQUATOR IS MOVED BY GYRES TO ALASKA The natural delivery of warm sea water to Resurrection Bay is part of the global heat engine. Large amounts of solar energy are absorbed by the ocean and atmosphere and are transported poleward. A simple example is that winds and currents from the south are generally warmer than those from the north. In the North Atlantic Ocean, the Gulf Stream carries warm water from the tropics to high latitudes along the East Coast of the U.S. It then moves across the North Atlantic and warms Europe. This clockwise gyre or circular pattern fills the North Atlantic. The North Pacific is also warmed by a similar ocean circulation with the Kuroshio Current bringing water from the tropics northward along Japan and then eastward across the North Pacific. This current hits North America offshore of Seattle where it splits into the southward flowing California Current and the northward flowing Alaska Current. The Alaska Current brings warm water into the Gulf of Alaska. warm, salty tropical water. This lid overlies the subsurface source of warm water in the Alaska Current. The Alaska Current flows around the Gulf of Alaska in a counterclockwise direction along the shelf break which is about 100 miles offshore near Seward. As the rains increase in autumn, a lot of freshwater enters the ocean from the coast. As it piles up along the coast, it begins to move offshore. The water beneath this upper layer of freshwater is mixed a little and is also carried offshore. It is replaced with water from below. This upper layer offshore moving layer allows deeper water to move to the coast. This deep layer of warm water supplies the heat from the tropics that warms Resurrection Bay each fall. This same heat has been successfully tapped to heat the Alaska SeaLife Center through long sub-arctic winters since 2011 using high efficiency heat pumps. The Seward Line is a line of reference to obtain the oceanographic properties across the shelf and into the deep Gulf of Alaska. The GAK1 monitoring station and Seward Line was established in December 1970. 17 years ago it was expanded to include biology and it continues to be sampled. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 18 OF 38 f TM with YourCleanEnergy LLC SEA WATER TEMPERATURE IN RESURRECTION BAY PEAKS EACH YEAR AFTER FALL STORMS It has long been known that sea water temperatures in Resurrection Bay remain well above freezing through the long Alaska winter. The Bay stays ice free and is often steaming on cold days in early winter. This is due primarily to a large influx of warm sea water from the Alaska Coastal Current that is drawn into the bay each fall due to high volumes of fresh water storm runoff. The Alaska Coastal Current is in turn heated by the North Pacific Gyre that gains immense solar heat during its three year journey along the equator. Resurrection Bay is a world class source to operate a district heating system from. Seawater temperatures recorded for a recent five year period (2003 through 2008) at the Alaska SeaLife each month. The maximum monthly seawater temperature (56F) and minimum monthly seawater temperature (37F) were also identified. As shown in the graph below, it is evident that the large mass of seawater contained in Resurrection Bay is slightly charged by local solar during the spring and summer months, and is heavily charged by warm ocean currents in advance of the winter heating season. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 19 OF 38 f TM with YourCleanEnergy LLC GEOLOGY AND SUB-SURFACE WATER RESOURCE BELOW WATER FRONT PARK The existing geology and subsurface water resources of Waterfront Park in Downtown Seward show great promise as a utility grade heat source for ground source heat pumps. Most of the high density area of Seward rests upon an alluvial fan of gravel and silt deposits that have washed down from the Lowell Creek Canyon for thousands of years. Due to the steep sloping bedrock under the town site, the thickness of alluvial gravel along the shoreline is in excess of 300 feet thick. This thick layer of gravel is water saturated due to the presence of fresh water drainage from higher elevations, and seawater infiltration from the adjacent Resurrection Bay. The sea water heat is of great interest for this project. In 1967, in response to the Good Friday Earthquake of 1964, the United States Geological Survey (USGS) compiled a report of the existing geology of Seward, with attention to the fracture zone that is parallel to the shoreline. Much of the infrastructure built along the shoreline prior to the 1964 earthquake, including rail tracks, fuel tanks, and buildings, were heavily damaged in the 1964 seismic event. The City of Seward owns the Waterfront Park that now exists adjacent to the shoreline between Ballaine Boulevard and the ocean, including the green belt bike path. A geologic profile section was developed along Adams Street, and a 300 ft deep borehole (S-100) was drilled to map the depth of gravel deposits. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 20 OF 38 f TM with YourCleanEnergy LLC DRILLING, CONSTRUCTION, AND TESTING OF TEST BOREHOLE NEAR BIKE PATH AUG 2015 The City secured the services of Denali Drilling of Anchorage in mid July 2015 to install a 300 feet deep x 4 diameter screened test borehole near the Bike Path. The purpose of this test well was to allow measurement of the subsurface water column and confirm the influence of ocean tides in the aquifer below. The scope of the work was to drill and drive 6 diameter steel casing to depth, then insert the 4 PVC screened casing; and then extract the steel casing. This work was performed as required, leaving a 4 water column in the test borehole that closely resembles the natural water column in the aquifer. Once installed, the City rented a Cast-Away marine data logger that could be lowered down the 4 water column. This data logger sampled temperature, salinity and depth once per second while being lowered and raised, thus profiling the thermal characteristics of the water column. Data was collected from mid August thru early September at both high and low tides to determine the difference in ocean tide influence. The data shows that the deeper portion of the aquifer (180ft to 300ft below water surface) remains a constant 42F with high salinity. The upper portion of the aquifer (0ft to 180ftbelow water surface) shows a strong influence of warm subsurface ocean water that peaks about 30 minutes after high tide. The temperature of ocean tide water in the test borehole closely resembles that measure off- shore at similar depth. The fact that warm ocean water is moving thru the gravel affords an attractive opportunity to extract heat from that ocean water via vertical HDPE ground loops that are piped to heat pumps in nearby buildings. Example temperature and salinity profiles from the data logger are below: LOW TIDE (-1.6 ft) AUG 18 2015 10:08am HIGH TIDE (+12.1 ft) AUG 31 3:14pm The sub-surface water table begins at 18ft to 22 ft below grade. Vertical loops inserted in the deep gravel will then experience full contact with moving tidal water from 20ft below grade to 200 ft below grade, and full contact with the stationary aquifer from 200ft to 300ft below grade. With 280 ft out of the 300 ft loop length submerged in water, and the use of double 1 HDPE u-bends in each production hole, it is anticipated that approximately 3.4 tons of heat pump capacity can be extracted from each production borehole constructed in this aquifer. This is similar to a fully submerged lake or ocean loop system. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 21 OF 38 f TM with YourCleanEnergy LLC CONCEPTUAL DESIGN OF VERTICAL GROUND LOOPS TO EXTRACT OCEAN HEAT Vertical ground loops offer several advantages over direct pumping of sea water for the extraction of ocean heat. By using inert HDPE tubing that acts as a submerged leak tight heat exchanger, vertical loops eliminate the need for a sea water intake that requires corrosion proof pumps and heat exchanger, and risks of storm damage, boat anchors and marine bio-fouling. A mixture of water and 20% methanol is pumped 300 ft down hole in the 1" diameter HDPE tubing and loops back up to the surface, collecting ground water heat along this path. A series of vertical boreholes spaced 20 feet apart can be piped in reverse return via horizontal manifold pipes buried 4 ft below the ground surface. This ensures that flow is split evenly between all boreholes. A single HDPE supply and return trunk line can then deliver the ground source heat to City buildings via source side loop pumps for the individual heat pumps. Thus the City has only to operate and maintain a simple closed loop that is pumped from each building at a flow rate required by the heat pumps in operation at any one time. This approach minimizes pumping energy. The industry accepted design life of properly installed and buried HDPE ground source loops is 50 years. Recent ground source heat pump project research in the USA has shown that the heat extraction rate from a typical vertical ground loop can be increased by approximately 40% by using two loops per hole that are held in separation by simple "quad bone" clips. These high strength plastic clips are spaced every four feet along the vertical loops. The clips keep the four HDPE pipes equally spaced at the perimeter of the bore, so that any one pipe does not lose significant heat to another. In water saturated gravel this approach affords a marked increase in heat transfer rate as compared to a single loop in the same borehole. Discussions with drillers in the region that have certification from the International Ground Source Heat Pump Association (IGSHPA), suggests the following procedure for 300 feet deep vertical loop installation in the deep and water saturated alluvial gravels below Waterfront Park near the bike path: 1. Drill and case the 6" diameter borehole to depth of 300 feet. The casing will be needed to keep the borehole from collapsing due to instability of sand and gravel submerged in the water table. 2. Fill HDPE double loops with water and insert to depth of hole, using a weight to sink the loops and to anchor end of loops to bottom of hole. Each loop will have round trip length of 600 feet. 3. Extract casing slowly section by section, allowing the natural sand, silt and gravel down the hole to fall in and fill voids in between the four vertical 1" HDPE u-bend pipes. The option of filling void space at depth with sand, pea gravel and/or drilling mud via a retractable 1 1/4" tremie pipe, routed thru the center of the quad bones, may be recommended pending further research. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 22 OF 38 f TM with YourCleanEnergy LLC EXAMPLE PROJECT USING DOUBLE U-BEND VERTICAL LOOPS WITH SEPARATOR CLIPS GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 23 OF 38 f TM with YourCleanEnergy LLC CONCEPT DESIGN OF STARTER GROUND SOURCE DISTRICT HEATING SYSTEM By using heat pumps sized to displace the heat load on existing oil boilers in the Library, Annex, City Hall, and Fire Hall, the amount of ground source heat needed for this project can be estimated and several alternatives can be developed for a district heating system. The first alternative "A" would be a system to initially serve the Library and Annex, with source loop trunk size for expansion to the City Hall and Fire Hall. The second alternative "B" would be a system to serve all four city buildings. For both alternatives, the borehole field and trunk supply and return mains would be sized to meet the peak hourly heat load of the winter design day of 5F with moderate winds. A table that summarizes the sizing of critical elements of these two alternatives "A" and "B" is given below. Note that the main trunk noted below is the buried supply and return pipes that carry ground source flow from the boreholes to the first building (Library). Peak Hourly Load # Of 6" Dia x 300' Max Source Flow Req'd Trunk ALT Bldgs Served @5F Winter Day Boreholes Req'd In Main Trunk Pipe Size "A" LIB + ANX 320,000 BTU/HR 9 100 GPM 3" "B" All 4 Bldgs 672,000 BTU/HR 17 225 GPM 4" A concept level piping schematic for ALT A and ALT B is given on the following page. A description of critical elements of the proposed district heat system is given below: Borehole Field - Vertical Ground Loops. Boreholes are 20 feet apart and staggered along bike path to allow equal access to ocean side heat for each vertical loop. A piping manifold along boreholes will be piped in reverse return configuration, sending and returning an equal amount of flow to each vertical loop. A 4" diameter full depth (300 ft) test/monitoring hole has already been constructed to confirm the temperature, salinity and static level of the subsurface water resource. This test well will be used as a production hole with a single u-bend loop installed to full depth and become part of the final loop field. Supply & Return Trunk Mains. There exists a nearly straight alignment along the south unpaved shoulder of Adams Street that currently has no other parallel buried utilities. The alignment from the bike path to the north wall of the Library includes several water and sewer main crossings, however these lines are at least six feet deep and the new trunk lines can easily cross above them. The remainder of trunk main alignment shown from the Library to the Fire Hall is the simplest and most utility free corridor available. The supply and return mains are essentially one unitary closed loop that will be pressurized to 30 psi at the highest point (Fire Hall) with a 20% methanol / 80% clean water mixture for anti-freeze protection. Heat Pumps And Source (Cold) Side Loop Pumps. Each heat pump will receive 25 GPM source side flow at 36F to 46F and reject heat into 20 GPM load side flow at 125F to 145F. A packaged push/pull double centrifugal pump station is proposed for the source side loop pumps; this ensures that adequate flow is delivered thru the long trunk mains and thru the in-line strainer and heat pump evaporator coils. The source and load side pumps are enabled when the heat pump is enabled by a call for heat. Load (Hot) Side Loop Pumps & Buffer Tank. Unlike oil fired boilers that are designed to burn hard and fast to cover the immediate heat load in the hydronic system, heat pumps work best by first supplying a large buffer storage tank that then supplies the hydronic system. This approach levels out the heat load that is required of the heat pumps and allows for higher efficiency operation. Additionally it is possible to also tie the existing oil fired boilers to the buffer tank so they can assist if required. This creates redundancy and reliability of the heating system and makes use of equipment already installed. The set point at which the heat pumps will typically reach their capability is 145F. Above 145F the oil boilers may be needed during extreme cold weather and high winds, or if heat pump units should be off-line. Connections To Existing Hydronic Systems. All buildings have medium temperature hydronic baseboards, some also have fan coils or heating coils. The Library has low temperature radiant floors. With the exception of a few heating coil replacements, the existing hydronic systems will be used. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 24 OF 38 f TM with YourCleanEnergy LLC DRAWING G-1: CONCEPT PLAN OF STARTER HEATING DISTRICT (11 X 17 PDF OF G-1 CONCEPT PLAN IS ATTACHED SEPARATELY) GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 25 OF 38 f TM with YourCleanEnergy LLC DRAWING G-2: PROJECT SCHEMATIC OF DISTRICT HEATING SYSTEM FOR ALTERNATIVE A (11 X 17 PDF OF G-2 PROJECT SCHEMATIC IS ATTACHED SEPARATELY) GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 26 OF 38 f TM with YourCleanEnergy LLC TRENCHING OF SUPPLY & RETURN MAINS ALONG AND UNDER CITY STREETS AND ALLEYS The quantity of open cut trenching required in both shoulder and paved streets to install district source heat piping is significant for the concept designs presented herein. The recommended strategy to minimize the cost of trenching, pipe installation, backfilling, and surface restoration is as follows: For ground source flow, the use of pre-insulated SDR 11 HDPE with field heat fusion joints is recommended. The insulation will allow the pipe to be installed with the minimum cover of 4 feet above, and allow the supply and return pipes to lay close together in the trench without heat loss to each other. The heat fusion joints will ensure long lasting integrity and flexibility of the piping at shallower depths below road grade. Properly fused HDPE pipe installations operating at low system pressures (30 to 50 psi) have proven design life of 50 years or more. The shallow cover depth above the pipe allows open trench excavation without trench boxes or wide cuts because the risk of trench wall collapse is very low. This reduces the amount of earth that must be removed and replaced, the cost of pipe installation, and the surface area to be restored. The shallow depth of the HDPE mains also allows them to pass over both water and sewer mains without conflict. The native soil is alluvial sand and gravel and is likely suitable for both bedding and backfill material; this will reduce the need for importing materials to support and protect the pipe installation. The alignment of mains along Adams Street from Ballaine Boulevard to Sixth Street can be routed in the unpaved shoulder on the south side of Adams Street where no parallel buried utilities currently exist. A typical pavement cut and trench section for the largest supply and return source trunk mains (4" inside diameter HDPE) is shown below. The detail shows that the shallow trench could be kept to a minimum of 4 feet width if native soils will hold a 3'-6" vertical face, this would reduce cost of trenching significantly. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 27 OF 38 f TM with YourCleanEnergy LLC INSULATED AND JACKECTED HDPE SUPPLY AND RETURN GROUND SOURCE MAINS For district heat piping mains, High Density Polyethylene (HDPE) is a proven, reliable, and structurally strong choice for core pipe material and standard jacketing. The tough, rugged nature of HDPE complements its flexibility and structural strength, guarding against cracking, star-crazing or other damage often caused by abuse or rough handling. HDPE core pipe and jacketed piping is non-corrosive, requiring no cathode protection or special coatings. The seamless property of HDPE jacketing insures the watertight integrity of HDPE. Each length of factory-preinsulated pipe is "pressure tested" when polyurethane foam is injected between the HDPE jacket and the pipe, using state-of-the-art, high pressure polyurethane foam equipment. The expanding polyurethane foam flows between specially designed support spacers, completely filling the annular space while exerting pressure against the jacket, insuring that the jacket is watertight without any pinholes, cracks or crazes that can allow moisture penetration into the insulation. Pre-insulated HDPE piping is available in 20 or 40 foot lengths with standard component (HDPE) fittings. The carrier pipe is high density polyethylene (HDPE), conforming to ASTM D-3350. Pipe and fittings are manufactured from extra high molecular weight polyethylene compound E4710 and fabricated to Standard Dimensional Ratio 11 (SDR) wall thickness in standard IPS sizes. Available pressure ratings range from 50 psi (SDR-32.5) to 255 psi (SDR-7.3) at 73° F, with operating temperatures from -50°F to +140°F. The insulation is rigid, 90 to 95% closed cell polyurethane with 2 to 4 pounds per cubic foot density and a "K° factor of .14 at 75°F per ASTM C 518. The polyurethane foam is CFC free and comply with HH-I- 1751/4. The polyurethane foam is injected into the annular space with low-pressure foam equipment. Centering spacers are factory-installed to insure uniform insulation around the pipe. Insulation thickness will be 2" to 3" in thickness. The outer protective jacket is High Density Polyethylene (HDPE) per ASTM D 1248, Type III, Category 5, Class C, Grade E4710. The HDPE jacket is seamless and pressure tested for watertight integrity during foaming. Mastic moisture barriers are factory-applied to each pipe end. End seals are mastic completely sealing the exposed end of the insulation. Heat fusion butt-welded fittings are used to join adjacent pipe sections. Fittings are either HDPE butt fused bare fittings, insulated with a two peace polyurethane foam half shell set with a Polyurea jacket, or a pre-insulated HDPE fitting with a appropriate HDPE stub. All joints are field-insulated per the manufacturer's recommendation, using a two-part foam injection method or a pre-formed half shell with a full-length Aluminum Band. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 28 OF 38 f TM with YourCleanEnergy LLC GROUND SOURCE HEAT PUMP OPERATION AND COEFFICIENT OF PERFORMANCE (COP) Coefficient Of Performance (COP) for a heat pump is the ratio of total heat output to electricity input. For ground source heat pump projects, a minimum COP value of 2.8 is desirable as this can lead to viable economic returns. Ground source heat pumps are water to water heat pumps that operate by using electricity powered compressors in combination with the physical properties of an evaporating and condensing fluid known as a refrigerant. The refrigerant used in the heat pumps in this evaluation is known as R-134a. The vapor compression cycle of the refrigerant is what allows heat to be lifted from ground temperature (36F to 46F) up to building loop temperature (100F to 140F). When the refrigerant vapor is compressed, its temperature is raised; this reality of physics is what allows the lifting of heat to occur at a high efficiency. It is typically far more cost effective to move or lift heat than to make it directly through the combustion of organic carbon, or through heat of resistance in an electrical element. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 29 OF 38 f TM with YourCleanEnergy LLC SELECTION OF WATER SOURCE HEAT PUMPS SUITABLE FOR USE IN CITY BUILDINGS The process of removing heat from ground source water and making that same heat useful for space heating and domestic hot water heating is now both proven and increasingly common in Southcentral Alaska. The engineering challenge of achieving this for City of Seward is made greater by the distance that exists between the borehole field near the ocean and the buildings that require heat. The heat transfer fluid that will be used is clean water with 15% methanol for freeze protection during winter months. An alternative anti-freeze is propylene glycol, however this choice imposes a reduction in heat transfer rate, and an increase in pumping cost due to its higher viscosity at colder temperatures. There are several manufacturers in the USA at this time who have considerable experience with manufacturing water to water heat pumps that can lift commercial quantities of heat energy from a temperature range of 35F to 50F on the evaporator side to as great as 140F on the condenser side. These manufacturer's include Water Furnace and Climate Master who have both developed high quality models and a healthy competition in the Alaska market. In this evaluation, simulations that define the glycol flow rates, evaporator and condenser temperatures, coefficient of performance (COP), electricity demand and heat output, are based on Water Furnace (WF) Series 5 Hi Efficiency 7 Ton Capacity units. These heat pumps are commercially available as compact self contained units which can be shipped to Seward, placed on floor stands, and piped and wired in place. A vertical loop ground source heat pump project completed in the Seldovia House in late 2014 by Cook Inlet Housing Authority is an example: Concept designs for heat pumps included in this evaluation for City buildings are based upon: MFG Model Capacity Heat Output Peak Load Dimensions Weight WF 5 Series 7 Tons 84,000 BTU/Hr 10 KW 34 24 26"W 420 LBS GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 30 OF 38 f TM with YourCleanEnergy LLC SUMMARY OF OPERATION & MAINTENANCE COSTS FOR STARTER DISTRICT HEAT SYSTEM Like most City owned and operated utilities, a ground source district heating system will have certain on- going operation and maintenance (O&M) costs throughout its useful design life. It is necessary then to include costs in the project Net Present Worth Analysis, and account for the escalation rates that will impact these costs each coming year. The principal elements of O&M cost addressed in this evaluation for both Alternative A and B are given below and the cost of these elements in Year 1 is estimated: Electrical energy used by source and load side loop pumps, and by the heat pumps and associated controls. A single energy monitor will be installed in each building to measure all electrical energy used to move heat from the ground source loop, through the heat pump, and into the hydronic system. ALT A (LIB+ANX Only): Electricity - Loop Pumps = 6,220 KWH/yr @$0.184/KWH = $1,145/yr ALT A (LIB+ANX Only): Electricity - Heat Pumps = 101,110 KWH/yr @$0.184/KWH = $18,770/yr ALT B (Four City Bldgs): Electricity - Loop Pumps = 12,440 KWH/yr @$0.184/KWH = $2,290/yr ALT B (Four City Bldgs): Electricity- Heat Pumps = 202,220 KWH/yr @$0.184/KWH = $37,210/yr Annual monitoring service labor by City staff for the heat pump equipment. One or more individuals on the City Public Works staff may be assigned to oversee the daily monitoring of performance, and prepare reports for the City on the system. While the heat pump equipment is covered under standard warranties, there will be a need for the City to adjust equipment and controls during the design life of the project. ALT A (LIB + ANX Only): 0.5 hrs/week labor time @ $50/hr x 52 weeks/yr = $750/yr ALT B (All Four City Bldgs): 0.8 hrs/week labor time @ $50/hr x 52 weeks/yr = $1,200/yr GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 31 OF 38 f TM with YourCleanEnergy LLC COST OPINION - ALT B: GROUND SOURCE DISTRICT HEAT FOR ALL FOUR CITY BUILDINGS Item Description Installed Installed Unit Total Ground Source Borehole Field Quantity Unit Price Price Mobilization / Demobolization Of Drilling Contractor 1 LS $4,000 $4,000 Drill & Case 6" Vertical Well To 300 FT Depth, 16 Ft Spacing Between Boreholes 16 Each $13,500 $216,000 Install 305 Ft Double U-Bend Loops = 1" Dia HDPE SDR 11 w/Quad Bone Spacers 16 Each $1,800 $28,800 Extract Well Casing To Leave Double U-Bends Intact In Saturated Natural Gravel 16 Each $2,000 $32,000 Remove test well steel casing, install 305 Ft Single U-Bend Loop = 1" Dia HDPE SDR 11 1 Each $1,800 $1,800 Excavate & Backfill 4 Ft Deep Trenching For Borehole Manifolds 160 CY $20 $3,200 Install 3" Dia Insulated Manifold Piping To Connect Vertical Loops - HDPE SDR11 400 LF $25 $10,000 Restore Surface Of Recreation Area 440 SY $10 $4,400 Sub-Total $300,200 Source Trunk Supply & Return Mains Along Adams Street 4" Dia Insulated Supply & Return Main - HDPE SDR11 540 LF $75 $40,500 3" Dia Insulated Supply & Return Main - HDPE SDR11 - LIB to 5th Ave 200 LF $65 $13,000 Flush Ground Source Loop, Charge With Water w/20% Methanol 1 LS $3,400 $3,400 Trench Excavation & Backfill for Supply & Return Mains - 4 Ft Deep Trench 440 CY $20 $8,800 Restore Unpaved Shoulder Along Adams Street 310 SY $15 $4,650.00 Core Drill Holes/Install Sleeves In Library Basement Wall For Supply & Return Main 2 Each $800 $1,600 Restore Base Course & Asphalt Pavement at Ballaine Blvd Crossing 20 SY $75 $1,500.00 Restore Base Course & Asphalt Pavement at 6th Ave Crossing 20 SY $75 $1,500.00 Restore Base Course & Asphalt Pavement In Library Parking Area 40 SY $75 $3,000.00 Sub-Total $77,950 Library Basement Mechanical Room Construct New Interior Walls & Doorway For District Energy Room In Basement 1 LS $4,000 $4,000 Source Side Piping, Valves & Connections To Loop Pumps & Heat Pumps 1 LS $4,000 $4,000 Source Side Packaged Push/Pull Loop Pumps (WF Flow Center) 25 GPM 4 each $1,000 $4,000 Hi-Efficiency Water Source Heat Pump, 7 Ton, w/ Package Controls 4 each $11,700 $46,800 Load Side Hot Water Buffer Tank - 360 gal - ASME 120 psi Insulated w/6 side taps 1 each $8,000 $8,000 Load Side Circ Pumps, Piping & Connections To Exist Hydronic System 1 LS $6,000 $6,000 Install New Low Temp Heating Coil in Existing Air Handler AHU-2 + Insulated Piping 1 each $3,000 $3,000 Local Power Panel w/Energy Monitor, Elect Power Wiring To Pumps, HPs 1 LS $6,000 $6,000 Instrumentation Devices (Pressure, Temp, Flow), Testing & Commisioning 1 LS $6,000 $6,000 Sub-Total $87,800 Hydronic Hot Water Supply & Return Mains To Serve Annex Trench Excavation & Backfill - Supply & Return Hot Water Mains - 4 Ft Deep Trench 30 CY $30 $900 Core Drill Holes/Install Sleeves In Annex Basement Wall For Supply & Return Main 2 Each $800 $1,600 1.5" Dia AquaTherm Supply & Return w/2" poly ins & HDPE Jacket, buried 4ft 60 LF $60 $3,600 1.5" Dia AquaTherm Supply & Return w/1.5" FG insulation - Inside To Buffer Tank 80 LF $50 $4,000 Load Side Hot Water Buffer Tank - 120 gal - ASME 120 psi Insulated w/6 side taps 1 each $4,000 $4,000 Load Side Hot Water Circ Pumps, Piping & Connections To Hydronic System 1 LS $4,000 $4,000 Power Wiring - Load Side Pumps; Tank Temp Sensor w/Buried Cable To Library 1 LS $3,000 $3,000 Modify & Upgrade Local HVAC Controls To Integrate Heat Pump/Boiler Operations 1 LS $3,000 $3,000 Instrumentation Devices (Pressure, Temp ), Testing & Commisioning 1 LS $3,000 $3,000 Restore Base Course & Gravel Surface In Alley Between Library & Annex 40 SY $20 $800.00 Sub-Total $27,900 GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 32 OF 38 f TM with YourCleanEnergy LLC COST OPINION - ALT B: GROUND SOURCE DISTRICT HEAT FOR ALL FOUR CITY BUILDINGS (CONTINUED) Item Description Installed Installed Unit Total Source Trunk Supply & Return Mains Along 5th Avenue + City Hall Branch Quantity Unit Price Price 3" Dia Insulated Supply & Return Main - HDPE SDR11 - Up To City Hall 140 LF $65 $9,100 Trench Excavation & Backfill for Supply & Return Mains - 4 Ft Deep Trench 178 CY $20 $3,560 3" Dia Insulated Supply & Return Main - HDPE SDR11-City Hall Branch 60 LF $65 $3,900 Trench Excavation & Backfill for Supply & Return Mains - 4 Ft Deep Trench 18 CY $20 $360 Restore Base Course & Asphalt Paving - Crossing Of Adams Street at 5th Ave 20 SY $75 $1,500.00 Restore Base Course & Asphalt Shoulder Along 5th Avenue 114 SY $75 $8,550.00 Restore Base Course & Asphalt Paving - Crossing Of 5th Ave At City Hall 20 SY $75 $1,500.00 Core Drill Holes/Install Sleeves In City Hall Basement Wall For Supply & Return Main 2 Each $800 $1,600 Restore Sidewalk Where Mains Enter City Hall 6 SY $120 $720.00 Sub-Total $30,790 City Hall Basement Mechanical Room Source Side Piping, Valves & Connection Of Loops To Heat Pumps 1 LS $4,000 $4,000 Source Side Packaged Push/Pull Loop Pumps (WF Flow Center) 25 GPM 4 each $1,000 $4,000 Hi-Efficiency Water Source Heat Pump, 7 Ton, w/ Package Controls 4 each $11,700 $46,800 Load Side Hot Water Buffer Tank - 360 gal - ASME 120 psi Insulated w/6 side taps 1 each $8,000 $8,000 Load Side Circ Pumps, Piping & Connections To Exist Hydronic System 1 LS $8,000 $8,000 Power Panel w/Energy Monitor, Elect Power Wiring To Pumps, HPs 1 LS $6,000 $6,000 Instrumentation Devices (Pressure, Temp, Flow), Testing & Commisioning 1 LS $6,000 $6,000 Modify & Upgrade Local HVAC Controls To Integrate Heat Pump/Boiler Operations 1 LS $3,000 $3,000 Sub-Total $85,800 Fire Hall Basement Mechanical Room Trench Excavation & Backfill for Supply & Return Mains - 4 Ft Deep Trench 100 CY $20 $2,000 Core Drill Holes/Install Sleeves In Fire Hall Basement Wall For Supply & Return Main 2 Each $800 $1,600 1.5" Dia AquaTherm Supply & Return w/2" poly ins & HDPE Jacket, buried 4ft 180 LF $60 $10,800 1.5" Dia AquaTherm Supply & Return w/1.5" FG insulation - Inside To Buffer Tank 20 LF $50 $1,000 Restore Base Course & Gravel Surface In Alley Between City Hall & FireHall 120 SY $20 $2,400.00 Load Side Hot Water Buffer Tank - 120 gal - ASME 120 psi Insulated w/6 side taps 1 each $4,000 $4,000 Load Side Circ Pumps, Piping & Connections To Exist Hydronic System 1 LS $4,000 $4,000 Power Wiring - Load Side Pumps; Tank Temp Sensor w/Buried Cable To City Hall 1 LS $3,000 $3,000 Instrumentation Devices (Pressure, Temp ), Testing & Commisioning 1 LS $3,000 $3,000 Modify & Upgrade Local HVAC Controls To Integrate Heat Pump/Boiler Operations 1 LS $3,000 $3,000 Sub-Total $34,800 Total Installation Cost Opinion for ALT B $645,240 City Project Manager/Administration $37,000 14% for final design services $83,880 3% for construction phase services $19,356 10% Contingency $64,524 Total Project Cost Opinion - ALT B: Ground Source District Heat For All Four City Buildings $850,000 GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 33 OF 38 f TM with YourCleanEnergy LLC APPENDIX A: ANNEX BUILDING - OIL BOILER - FUEL USE VS. OUTSIDE TEMP - DATA LOGGER Note: Closest temperature data base set available in energy software was Kodiak. Seward temperatures are about 5 F colder on average, and accordingly fuel use may be slightly higher than shown. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 34 OF 38 f TM with YourCleanEnergy LLC APPENDIX B: FIRE HALL - OIL BOILER - FUEL USE VS. OUTSIDE TEMP - DATA LOGGER Note: Closest temperature data base set available in energy software was Kodiak. Seward temperatures are about 5 F colder on average, and accordingly fuel use may be slightly higher than shown. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 35 OF 38 f TM with YourCleanEnergy LLC APPENDIX C: CITY HALL - OIL BOILER - FUEL USE VS. OUTSIDE TEMP - DATA LOGGER Note: Closest temperature data base set available in energy software was Kodiak. Seward temperatures are about 5 F colder on average, and accordingly fuel use may be slightly higher than shown. GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 36 OF 38 f TM with YourCleanEnergy LLC APPENDIX D: QUOTE TO DRILL AND INSTALL 2 TEST HOLES & 10 VERT GROUND LOOPS GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 37 OF 38 f TM with YourCleanEnergy LLC APPENDIX E: QUOTE FOR INSULATED HDPE PIPE WITH JACKET- SUPPLY & RETURN MAINS GSHP SYSTEM EVALUATION FOR CITY BLDGS CITY OF SEWARD 9/12/15 PAGE 38 OF 38 f TM with YourCleanEnergy LLC APPENDIX F: QUOTE FOR HEAT PUMPS, LOOP PUMPS, BUFFER TANKS, U-BEND COILS