Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
Review of Power Quality Applications of Energy Storage System 1998
CONTRACTOR REPORT SAND98-1513 Unlimited Release Review of Power Quality Applications of Energy Storage Systems Shiva Swaminathan Rajat K. Sen Sentech, Inc. 4733 Bethesda Avenue Suite 608 Bethesda MD 20814 Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000. Approved for public release; distribution is unlimited. Printed July 1998 cy) Sandia National Laboratories Issued by Sandia National Laboratories, operated for the United States Department of Energy by Sandia Corporation. NOTICE: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Govern- ment nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, prod- uct, or process disclosed, or represents that its use would not infringe pri- vately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government, any agency thereof, or any of their contractors or subcontractors. The views and opinions expressed herein do not necessarily state or reflect those of the United States Govern- ment, any agency thereof, or any of their contractors. Printed in the United States of America. This report has been reproduced directly from the best available copy. Available to DOE and DOE contractors from Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831 Prices available from (615) 576-8401, FTS 626-8401 Available to the public from National Technical Information Service U.S. Department of Commerce 5285 Port Royal Rd Springfield, VA 22161 NTIS price codes Printed copy: A03 Microfiche copy: A01 SAND98-1513 Distribution Unlimited Release Category UC-1350 Printed May 1997 Review of Power Quality Applications of Energy Storage Systems* Shiva Swaminathan Rajat K. Sen Sentech, Inc. 4733 Bethesda Avenue Suite 608 Bethesda, MD 20814 Abstract Under the sponsorship of the U.S. Department of Energy (DOE) Office of Utility Technologies, the Energy Storage Systems Analysis and Development Department at Sandia National Laborato- ries contracted Sentech, Inc., to assess the impact of power quality problems on the electricity supply system. This report contains the results of several studies that have identified the cost of power quality events for electricity users and providers. The large annual cost of poor power quality represents a national inefficiency and is reflected in the cost of goods sold, reducing U.S. competitiveness. The Energy Storage Systems (ESS) Program takes the position that mitigation merits the attention of not only the DOE but affected industries as well as businesses capable of assisting in developing solutions to these problems. This study represents the preliminary stages of an overall strategy by the ESS Program to understand the magnitude of these problems so as to begin the process of engaging industry partners in developing solutions. “The work described in this report was performed for Sandia National Laboratories under Contract No. AV-5396. ACKNOWLEDGMENTS Sandia National Laboratories would like to thank Dr. Christine E. Platt of the U.S. Department of Energy’s Office of Utility Technologies for the support and funding of this work. We would also like to acknowledge the National Power Laboratories, which conducted a study that provided data summaries for four types of power quality events and input from 130 user sites, and Duke Power, which conducted a study that provided detailed data from 198 indus- trial and commercial users, making it possible to derive approximations of the national impact of power quality events. Thanks are also due to Paul Butler of Sandia’s Energy Storage Analysis and Development Department for providing valuable technical review before the final study was published. iv REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS CONTENTS Contents 1. Executive Summary ......cscsesesesseresensseeeeneeeen wsecscsnenesvesoeonvoseeseosononsesoece eccesvevensesceseossessososoeseseeesee ececsweveveveseseseseeeee 1-1 2. OVErVieW...r.cccsccsrscessscerssencsncessncesescssseees asecssescescesesoeonsocoveone evsaasassesassesoconssvovs ecoseoes acesseesesoesesovensnsseseseveconseoseoes soe 2° 3. Problem Description.......... seabesesa® 3-1 Scope of Power Quality Problems 3-1 The NPL Survey Results ............0:000+ Cost of Poor Power Quality to Customers Estimation of National Cost of Poor Power Quality... 4. Technology Options............. acoesreeee Matching the Power Quality Problem with the ‘Technology Solutions Cost-Benefit Analysis Example...............c.0scsrscssssssescsesecssssssensasecrsrensssasacasesessasssessscncesesescosonees 5. Conclusions. ....c..c.ccccccccscscoereseoeves ecrecereesceccecncscosesecssoeonceseseece a ovsceceeseeseececocsceensessosseesessoesececsssesecococsscocoesesesseseeeeeee® 5-1 Appendix A. Graphical Illustration Of Power Quality Events ............ssscsesssseeseseseeneees eoncareoerscres wovveveceveveveveveses An ll Figures 8-1 The) GBEMA Curves sssccsccsaressresoserccnrsssvesseres 3-2 CBEMA Curve Analysis of the NPL Survey 3-6 3-3 Difference in Commercial and Industrial Customer Interruption Cost. 3-8 4-1 Off-Line Configuration of Energy Storage Systems. ............ 4-1 4-2 Line-Interactive Configuration of Energy Storage Systems... es 4-3 On-Line Configuration of Energy Storage Systems. ..........ssssecsssesseesesesnersenenneneenenesnssesnsscsnsecsnsesscsesnsseenserenssees 4-2 Tables 1-1. Mitigation Capabilities of Protection Devices. 1-2. NPL Summary of Disturbances ............::0:00+0+++ 1-3. Duke Power Survey on Cost of Power Quality Events... 1-4. National Cost Estimate for Large Industrial Customers ... 3-1. Categories of Power Quality Variations ...........::ssseseeee 3-2. Summary of Power Quality Variation Categories and Causes* 3-3. Summary Overview of the CEA, NPL, and EPRI Power Quality Surveys 3-4. Definition of Events in NPL Survey 3-5. Duration Summary Statistics for All NPL Data.. 3-6. Events per Month Based upon All NPL Data and Individual Location Statistics 3-7. Components of Outage Costs by Scenari0...........sseseeesee 3-8. National Cost Estimate for Large Industrial Customers .. 4-1. Individual Solutions to Single-Category Power Quality Events 5 4-2. Power Quality Solutions and Their Ability to Protect against Events in Multiple Power Quality Categories... 4-4 4-3. Competitiveness of Energy Storage Systems for Power Quality Applications ............scsssssesesesestesesresesesneneeess 4-4 CONTENTS ASD CBEMA CEA DOE EPRI ESS IEEE NPL Pe PG&E RMS UPS Var VL REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS Acronyms and Abbreviations adjustable speed drive Computer Business Equipment Manufacturers Association Canadian Electrical Association U.S. Department of Energy Electric Power Research Institute Energy Storage Systems Institute of Electrical and Electronics Engineers National Power Laboratories personal computer Pacific Gas & Electric root mean square uninterruptible power supply volt-ampere reactive REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS EXECUTIVE SUMMARY 1. Executive Summary In America, electricity has become ubiquitous. It is present virtually everywhere there is a need, it is available in seemingly limitless quantities, and it per- forms an uncountable variety of tasks. However, unnoticed by most users, the electricity supply often exhibits imperfections. The magnitude and preva- lence of these imperfections, together with the occa- sional total interruption or outage, constitute the ingredients of power quality. Increased automation in homes and factories has in- creased the impact of power quality deviations. Power quality has been defined as any problem mani- fested in voltage, current, or frequency deviations that results in failure or misoperation of utility or end-user equipment. Examples of power quality events and of devices capable of protecting against their effects are shown in Table 1-1. Storage systems are seen to pro- vide by far the broadest range of power quality pro- tection. While storage provides comprehensive protection, it may not be the economic choice for each of the power quality events listed in the table. However, because of their ability to detect and respond to the energy deficiency in the supply source rapidly, energy storage systems are the preferred solution for voltage sags, undervoltages, and interruptions. Data on the frequency of power quality disturbances are not widespread and are often proprietary. Three surveys conducted to determine the extent of power quality issues have been identified. While the de- tailed results of the surveys are not available in the public domain, data summaries have been published. The most useful summary for this study was pub- lished by the National Power Laboratories (NPL) and included data on 130 user sites consisting of 31% industrial, 24% small business, 18% multistory buildings, 17% residential, and 10% institutional. Table 1-2 summarizes NPL data for four types of power quality events. Because the data show great variance between the number of events in the best locations (zero) and the number in the worst locations (over 1,000 per month for three of the disturbances), it is likely that the median, rather than the average, is more representative of typical performance. Conse- quently, for this study, the more conservative median is used in subsequent analyses. Table 1-1. Mitigation Capabilities of Protection Devices Power Quality Event Impulsive Oscillatory Sag/ Under-/Over- Transient Transient Swell voltage Surge arrestor x x Filter x x lsolation transformer x x Constant voltage transformer x x Dynamic voltage restorer x x Backup generator Humidity control Energy storage - Off-line x x x x - Line-interactive x x x x - On-line x x x x Harmonic Voltage Interruption Distortion Flicker x x x x x x x x x x Electrostatic Noise Discharge x x x x x x x REVIEW OF POWER QUALITY APPLICATIONS OF EXECUTIVE SUMMARY ENERGY STORAGE SYSTEMS Table 1-2. NPL Summary of Disturbances Worst Best Locations Locations Median Average (events/month) (events/month) (events/month) (events/month) Sags/Undervoltages (low RMS) 0 1,660 41 27.9 Swells/Overvoltages (high RMS) 0 1,450 3.4 13.9 Transients 0 1,166 15.7 63.5 Interruptions 0 10 1.0 1.3 Information regarding the cost to electricity custom- ers of power imperfections is even less widely avail- able than data on the imperfections. However, a survey conducted by Duke Power has been published that contains information suitable for deriving ap- proximations of national impact. Duke surveyed 198 large industrial and commercial customers and col- lected information on the components of interruption costs under varying outage conditions. Analyzing the average interruption costs of the various outage conditions showed that the most costly occurrences resulted from electricity outages and voltage sags. The costs for these occurrences are summarized in Table 1-3, in which the greater impact of longer- duration events and the benefits of prior notice are clearly evident. Few estimates of the national cost of power quality events have been attempted. An article in Spectrum, a publication of the Institute of Electrical and Electron- ics Engineers (IEEE), suggested a cost of $25 billion, and an Electric Power Research Institute (EPRI) re- port estimated a cost of $400 billion. The first value was based on 1.5-3% of sales of the U.S. manufactur- ing industry, and the second was based on estimates of idled employee-hours due to power quality prob- lems in the commercial sector. The combination of NPL and Duke Power data pro- vides a third opportunity to estimate national impact, in particular to estimate the national cost of power quality events that energy storage systems could re- solve. Using the frequency of events from the NPL survey and extrapolating the Duke Power data to a national electricity level, a total cost (to large indus- trial customers) of U.S. power outages and voltage sags—and thus a potential power quality market for storage—can be developed. As shown in Table 1-4, the resulting estimate is approximately $150 billion annual cost. The $150 billion value is developed using only un- dervoltage/sag and interruption data because these are the two categories of power quality problems in the Duke Power survey for which storage systems are a likely solution. Costs resulting from power quality problems in other categories are excluded. Thus the estimate is conservative in the sense that there may be cases where storage could provide cost-effective so- lutions for other power quality problems, possibly some not covered in the Duke survey. It should be recognized that computing a national loss number with data from a single region can be a risky undertaking; opportunities to introduce error are rela- tively high. Nevertheless, it is noteworthy that the $150 billion estimate falls between the estimates of $25 billion and $400 billion cited earlier. Whatever the actual number, one can postulate with increasing Table 1-3. Duke Power Survey on Cost of Power Quality Events Event 4-Hr Outage, 1-Hr Outage, 1-hr Outage Momentary Voltage No Notice No Notice with Notice Outage Sag Average cost of event $74,835 $39,459 $22,973 $11,027 $7,694 1-2 REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS EXECUTIVE SUMMARY ——"—X—X—X—X—X—“"“_"__—_——_—_—_===_[laa_a=aE|_—_—----===az»aaja==aj=nqanananma=|S|> Table 1-4. National Cost Estimate for Large Industrial Customers Average Annual Cost to Large Industrial Customers Estimated Cost for National Customer Group Estimated Cost for Duke Power Customer Group Undervoltages/sags $377,000 $ 3.2B $114B Interruptions $132,000 $1.1B $39B Total estimated U.S. cost (rounded): $150B confidence that the market value of energy storage systems addressing power quality problems could total tens of billions of dollars annually. The market for such systems has grown in the recent past because of the proliferation of microprocessor- controlled equipment and power electronic motor controls, which are susceptible to distortions in sup- ply waveform. At present, part of the market is served by a variety of uninterruptible power supplies. Largely overlooked, however, are energy storage systems capable not only of meeting large industrial loads during interruptions but also of correcting for voltage magnitude variances and waveform imper- fections. Such systems have been installed in recent years, but large gaps persist in power ratings, protec- tion durations, performance capabilities, flexible sit- ing and operation, cost, and installation ease. Until these shortcomings are overcome, manufacturers and their customers will continue to experience higher than necessary costs. The large annual cost of poor power quality repre- sents a form of national inefficiency and is reflected in the cost of goods sold, reducing U.S. competitive- ness. This cost is ultimately paid by consumers, both domestic and foreign. Its mitigation merits the atten- tion of the affected industries as well as businesses capable of developing solutions and the U.S. Depart- ment of Energy (DOE). 1-3 REVIEW OF POWER QUALITY APPLICATIONS OF EXECUTIVE SUMMARY ENERGY STORAGE SYSTEMS Intentionally Left Blank 1-4 REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS OVERVIEW 2. Overview The electric utility industry is expected by the public to provide a reliable and uninterrupted supply of electricity—a goal that the industry has achieved to a great extent. Although the reliability of the electricity supply system is high, there are occasional unsched- uled outages caused by a variety of unpredictable events. Industries such as telecommunications that cannot tolerate unscheduled outages have installed backup generation and/or energy storage systems in order to alleviate the problem. In recent years, with increased automation and greater use of microprocessor-controlled processes, indus- tries have begun to realize that unscheduled outages are only one of many power quality problems. Very short perturbations (measured in milliseconds) in the supply waveform sometimes affect sensitive equip- ment, resulting in significant losses in productivity. The utility industry has begun to feel increased pres- sure from industrial customers not only to supply reliable and uninterrupted power, but also to ensure that the quality of the power supply is adequate for their equipment to operate smoothly. The deregula- tion pressures on the electric utility industry and the associated increases in customer choices only exacer- bate the utility industry’s need to provide the higher- quality power that their customers are demanding. EPRI has undertaken a major effort to analyze the nature and causes of the power quality problems. A major thrust of the DOE’s Energy Storage Systems (ESS) Program at Sandia is to minimize or eliminate power quality and reliability problems that cost U.S. companies productivity and revenues. To accomplish this, the ESS Program conducts its own analyses and exchanges analyses with industry partners and various industry organizations. It then develops suitable projects to address power quality and reliability problems using energy storage technologies/solutions. For example, a mid-voltage power quality system is being developed to solve power quality problems at the substation (15-kV) level. The PQ2000, a 2- MW/15-sec power quality system, has demonstrated its ability to address power quality problems by pro- tecting a lithograph plant in Homerville, Georgia, against short-duration power outages; it was designed to do the same at the utility level, and will soon do so at a Virginia utility. Power quality problems will also be mitigated with modular energy storage systems such as the 250-kW PM250 system and the Advanced Battery Energy Storage System (ABESS). These technologies are being advanced by the ESS Program and its partners and will offer benefits such as im- proved power plant operation and higher-reliability power for utility customers. This study reviews the existing literature dealing with power quality issues and summarizes the nature, scope, and costs associated with poor power quality. It also discusses the technology options available to address power quality issues and identifies the role energy storage systems can play in mitigating these power quality problems. 2-1 REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS PROBLEM DESCRIPTION 3. Problem Description The term power quality often means different things to different people. Electric utilities are primarily responsible for a reliable and uninterruptible supply of electricity, but this is just one facet of good power quality. The manufacturers of equipment define power quality as the characteristics of a power supply that are required to make end-user equipment work properly. These characteristics can be very different depending on the type of equipment and the manufac- turing process in question. Since end users are ulti- mately affected by poor power quality, the definition of power quality must accommodate their concerns. Thus, an EPRI Power Quality Workbook! defines power quality as any problem manifested in voltage, current, or frequency deviations that results in failure or misoperation of utility or end-user equipment. An ideal voltage supply is a pure sinusoidal wave- form with constant magnitude and frequency. Several types of distortions in the power supply can be the cause of power quality problems. These distortions result from a wide variety of events ranging from switching events within the end-user facility to faults hundreds of miles away on the utility transmission line. Perturbations that fall within the category of power quality events can be categorized as transient disturbances, fundamental frequency disturbances, and variations in steady state. Table 3-1 lists power- quality-related events and defines the characteristics of those events. Graphical descriptions of these per- turbations are provided in Appendix A. The phenomena listed in Table 3-1 affect different equipment in different ways. Switching an air condi- tioner on may cause a sag in voltage, which might dim the lights momentarily. However, plugging in a coffee pot to the same receptacle as a PC might cause a voltage sag that could scramble data every time the heater of the coffee pot is turned on or off.” Industrial equipment with microprocessor-based con- trols and power electronic devices that are sensitive to disturbances are affected most by poor power quality. Control systems can be affected by momentary volt- age sags or small transient voltages, resulting in nui- sance tripping of important processes. Furthermore, many of these sensitive loads are interconnected in ' “Power Quality—Electric Power Research Insti- tute’s Power Quality Workbook,” TR-105500, April 1996. > EPRI Journal, July/Aug 1991. extensive networks and automated processes. This interconnected nature makes the whole system de- pendent on the most sensitive device when a distur- bance occurs. Examples of industries with such inter- connections include steel, plastic, glass, paper, and often chemical manufacturers. A growing percentage of loads utilize power electron- ics in some type of power conversion process. Such systems generate harmonic currents that result in voltage distortion when they interact with the system impedance. Adjustable speed drives (ASDs), for ex- ample, can generate harmonics that can excite reso- nance with low-voltage capacitors and cause equipment failure. In addition to ASDs, factory effi- ciency upgrades and demand-side management initia- tives often involve the application of equipment such as high-efficiency motors and electronic ballasts. These devices also have significant power quality compatibility issues. Changes in the load characteris- tics that result from the use of such equipment con- tribute further to the problems encountered by the end user. Because microprocessor-based controls and power electronic devices are most susceptible to distur- bances in voltage, the Computer Business Equipment Manufacturers Association (CBEMA)° has defined the operational design range of voltage for computers. The CBEMA curve given in Figure 3-1 defines the tolerance of microprocessor-based equipment to volt- age deviations. Microprocessor-based equipment is typically de- signed to withstand and operate normally during dis- turbances as long as the event is within the shaded portion of the curve. The curve depicts the ability of equipment to withstand large voltage swings (100- 200% under/over nominal voltage) for short durations (given in microseconds) and smaller voltage swings for longer durations. Scope of Power Quality Problems The types of power quality disturbances that may be present are highly dependent on location. If a facility is located at the end of a distribution feeder, 3 Presently known as the Information Technology Industry Council. 3-1 PROBLEM DESCRIPTION REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS Table 3-1. Categories of Power Quality Variations Major Category Specific Category Defining Characteristics Transient Distur- IMPULSIVE TRANSIENTS Unidirectional bances Typically <200 microseconds OSCILLATORY TRANSIENTS Decaying Oscillations - low-frequency <500 Hz - medium-frequency 500-2000 Hz - high-frequency >2000 Hz Fundamental SHORT-DURATION VARIATIONS Duration 0.5-30 cycles Frequency - sags 10%-90% nominal Disturbances - swells 105%-173% nominal LONG-DURATION VARIATIONS >30 cycles - undervoltages - overvoltages INTERRUPTIONS Complete loss of voltage - momentary <2 sec - temporary 2 sec—2 min - long-term >2 min Variations in HARMONIC DISTORTION Continuous distortion (V or |) Steady State Components to 50th harmonic VOLTAGE FLICKER NOISE Intermittent variations in 60-Hz voltage magnitude; frequency component <25 Hz Continuous high-frequency component on voltage or current; freq: >3000 Hz * Source: Power Quality Assessment Procedures, EPRI CU-7529 (December 1991). depending on the loading level of the feeder, under- voltage may be prevalent at the location. Areas with high isokeraunic levels (high incidences of lightning) are more prone to surges. The reverse is also often observed; regions with high isokeraunic levels have transmission and distribution systems better designed to cope with lightning surges, resulting in lower inci- dences at the customer end. In addition, harmonics created by neighboring facilities may affect each other. Voltage sags could be experienced when large motors, like those in a sawmill, start up, drawing 2 to 3 times full load current, and dipping the voltage well below acceptable levels for up to 5 seconds. Table 3-2 lists the causes of the power quality events listed in Table 3-1. In order to ascertain the impact of power quality problems, one must ascertain the frequency of these occurrences as well as determine how severe these disturbances must be to cause disruption of service and production. There are three surveys of power quality problems that form the basis for much of the discussion related to power quality issues. Table 3-3 provides an over- view of the scope of the surveys as well as the pa- rameters measured. Detailed results of these surveys are not available in the public domain. The surveys conducted by the Canadian Electrical Association* * Canadian National Power Quality Survey, Cana- dian Electrical Association, Project 220 D 711A, August 1995. 3-2 REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS PROBLEM DESCRIPTION 300% 200% 100% wt 30% S +6% E 120 Nominal Line Vottage 6 a 30% |-13% = -42% fe) 70% 2 8 ! Cycles —.001 01 0.1 1.0 1 100 ] Seconds ———l0Qis 1000ps 8.3ms .lsec .5sec 2sec Duration Figure 3-1. The CBEMA Curve. —_—_—_—_— —C°°CClClC[—yyCCyqqqqqqqqeeeeeeeeSS asso Table 3-2. Summary of Power Quality Variation Categories and Causes* Category Method Of Characterization Cause IMPULSIVE Magnitude Lightning, TRANSIENTS Duration load switching OSCILLATORY Waveforms Lightning, line/cable switching, capacitor TRANSIENTS switching, transformer switching, load switching SAGS/SWELLS Waveforms, Remote faults RMS vs. Time UNDERVOLTAGES/ RMS vs. Time Overloading of feeder/motor starting, load OVERVOLTAGES changes, compensation changes INTERRUPTIONS Duration Breaker operation/fault clearing, maintenance HARMONIC. Waveforms, Nonlinear loads, system response character- DISTORTION Harmonic Spectrums istic VOLTAGE Magnitude Intermittent loads, arcing loads, motor FLICKER Frequency of Modulation starting NOISE Noise, Coupling Method, Power electronic switching, arcing, electro- Frequency magnetic radiation * Source: Power Quality Assessment Procedures, EPRI CU-7529 (December 1991). 3-3 PROBLEM DESCRIPTION REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS Table 3-3. Summary Overview of the CEA, NPL, and EPRI Power Quality Surveys Survey Monitor Period Quantity of Data Number of Measured Parameters (Monitor Months) Sites CEA 1991 to 1994 530 550 Voltage NPL 1990 to 1995 1200 130 Voltage EPRI 1993 to 1995 5691 277 Voltage & Current (CEA) and the NPL* can be purchased, while the most extensive survey conducted by EPRI® is not available to non-EPRI members. Summary reports are available in the public domain for each of the three studies, with NPL reporting most of its survey data in an IEEE Industrial Application publication.’ The CEA survey, conducted in the service territories of 22 Canadian utilities, monitored residential, com- mercial, and light industrial customers for 25 days at their 120-V or 347-V service entrance panels. Heavy electricity users connected at voltages over 29 kV were not included in this study. The NPL study, in contrast, monitored a smaller number of sites over a longer period of time. It also included heavy indus- tries (8 heavy industries and 33 light industries, in a survey sample of 130). Single-phase, line-to-neutral data were collected at the standard wall receptacle. While the CEA and NPL surveys focused on the end user, the objective of the EPRI study was to describe the power quality levels on primary distribution sys- tems in the U.S. The feeders monitored represented a diverse sampling of U.S. distribution systems, with voltage ratings from 4.16 kV to 34.5kV and line lengths from | to 80 kilometers. The feeders also represented a wide geographic sampling of the nation, and included rural, suburban, and urban load densities and residential, commercial, and industrial load types. The feeder selection process identified a population of monitoring locations that would be an unbiased representation of the types of distribution feeders present across the U.S. National Power Laboratory Power Quality Study, Best Power Technology, Inc., Necedah, WI. “An Assessment of Distribution System Power Quality,” EPRI TR-106249, May 1996. Douglas Dorr, “Point of Utilization Power Quality Study Results,” JEEE Transactions on Industrial Applications, Vol. 31, No. 4, July/August 1995. 3-4 The NPL Survey Results The sites surveyed in the NPL study included a wide range of building locations, building types, building ages, and population areas. It included locations where participants felt they had power quality prob- lems and also those where a problem was not per- ceived. Of the 130 locations surveyed, 31% were industrial, 17% residential, 24% small businesses, 10% institutional, and 18% multistoried building customers. Table 3-4 defines the four events studied. The definitions of these events conform to the Ameri- can National Standards Institute’s ANSI C84.1-1989 standard, which defines normal conditions of voltage. Table 3-5 lists the variations in event duration for the four types of disturbances recorded in the NPL sur- vey. In interpreting the summary statistics in Ta- bles 3-5 and 3-6, one should note that the distribution and site event occurrence rates for each category are highly skewed; thus, average or median values for these parameters clearly do not represent any kind of “typical” performances and should not be interpreted as such. However, for a preliminary estimation of the national cost of poor power quality, some of these numbers will be used later in this chapter under “Estimation of National Cost of Poor Power Quality.” Table 3-6 describes the frequency of events on a monthly basis at individual locations. It is apparent from Table 3-6 that transients are the most prevalent events, whereas interruptions account for less than 1% of all recorded disturbances. However, the table statistics do not reveal whether the event caused a disruption; nor do they describe the extent of losses. Since the differences between the best and worst lo- cations in Table 3-6 reflect highly skewed data, the average numbers do not necessarily represent typical performance. It is likely that the median values are more typical. The survey results also do not provide any indication of the variation of the frequency of occurrences between different customer classes. REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS PROBLEM DESCRIPTION Table 3-4. Definition of Events in NPL Survey Event/Disturbance Voltage Level Duration Sag/Undervoltage (Low RMS) <104 Vrms >2048 us Swell/Overvoltage (High RMS) >127 Vrms >2048 us Transient >100 Vpeak 25-2048 us Interruption (Outage) 0 Vrms 24 ms Table 3-5. Duration Summary Statistics for All NPL Data Minimum Maximum Median Average Sags/Undervoltages (Low RMS) 0.01s 1.75 hr 0.26 s 21's Swells/Overvoltages (High RMS) 0.01 s 170 hr 60s 44.2 min Transients <1us >2048 us 21 us 63.4 us Interruptions 0.004 s 71.1 hr 24s 21.1 min Table 3-6. Events per Month Based upon All NPL Data and Individual Location Statistics Worst Individual Location Average Best Locations Locations Median (events/month) (events/month) (events/month) (events/month) Sags/Undervoltages (Low RMS) 0 1,660 41 27.9 Swells/Overvoltages (High RMS) 0 1,450 3.4 13.9 Transients 0 1,166 15:7, 63.5 Interruptions 0 10.2 1.0 1.3 Since the differences between the best and worst lo- cations in Table 3-6 reflect highly skewed data, the average numbers do not necessarily represent typical performance. It is likely that the median values are more typical. The survey results also do not provide any indication of the variation of the frequency of occurrences between different customer classes. A CBEMA curve analysis of these events, as shown in Figure 3-2, results in 289 power line deviations per site per year (~24 events/site/month) falling some- where outside the high and low threshold limits of the curve. Nineteen of such events lying outside the shaded region were transients, 164 were swells or overvoltages, 90 were sags or undervoltage condi- tions, and 16 were interruptions. The median of the number of events given in Table 3-6 is comparable to this CBEMA curve analysis. Cost of Poor Power Quality to Customers Costs associated with power quality problems arise from lost production as well as other related disrup- tions suffered by customers, such as equipment dam- age, startup costs, etc. The costs of power-quality- related disruptions are largely dependent on the in- dustrial and commercial activities that are impacted, the time of occurrence, and the duration of the event. Many electric utilities have conducted surveys of 32 wn REVIEW OF POWER QUALITY APPLICATIONS OF PROBLEM DESCRIPTION ENERGY STORAGE SYSTEMS 300% 19 transients per year outside the CBEMA limits 200% 100 V impulse level 100% 164 swells and overvoltages per year outside the CBEMA limits 30% BS Oy € 120 Nominal Line Voltage 2 H }-30% |-13% a -42% & -70% 2 . oO 90 sags/undervoltages and 18 interrup- me tions outside the CBEMA limit l Cycles —.001 01 0.1 1.0 1 100 1000 Seconds 10Qis 1000s 8.3ms .lsec .5sec 2sec Duration Figure 3-2. CBEMA Curve Analysis of the NPL Survey (number of line deviations per site per year). power-quality-related costs within their service terri- tories. The detailed results are proprietary; however, summaries have been published. The summary of a survey conducted by Duke Power® is presented in Table 3-7. The utility surveyed 198 of its industrial and commercial customers and reported the results in terms of five types of reliability and power quality events. The magnitude and composi- tion of the interruption costs change dramatically as a function of outage duration and type of problem. The largest impact is obviously from long-duration outages, where approximately 90% of all production- related activity in a facility is affected. The corre- sponding numbers for voltage sags and momentary outages are 37% and 57% respectively. In all outage categories, more than 50% of the average total cost of the outage is due to lost product revenue (revenue change), with the remainder coming from damage to input feedstock and equipment. Mike Sullivan, “Power Interruption Costs to Indus- trial and Commercial Consumers of Electricity,” Commercial and Industrial Systems Technology Conference, 1996. 3-6 Figure 3-3 illustrates the cost of distribution for in- dustrial and commercial customers for a 1-hour out- age on a summer afternoon without advance notice. The commercial and industrial customers of Duke Power surveyed had interruption costs ranging from $0 to $100,000 and from $0 to over $1 million, re- spectively. Figure 3-3 illustrates that greater than 35% of all in- dustrial and about 8% of all commercial customers surveyed experienced an interruption cost of greater than $10,000 on a hot summer day. The sample size for this survey consisted of 210 large industrial and commercial customers and 1,080 small/medium in- dustrial and commercial customers. It may be fair to assume that most of the 210 large customers surveyed will experience a loss of greater than $10,000 per interruption lasting 1 hour and will experience at least the average costs listed in Table 3-7. One must be extremely cautious in generalizing about the costs associated with power quality problems on the basis of only one survey’s results. The costs are very site- and time-specific and depend to a very large extent on the type of equipment and industrial processes that are impacted. To add further perspective to the cost of power quality disturbances, references to two additional studies were located. A REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS PROBLEM DESCRIPTION Table 3-7. Components of Outage Costs by Scenario (average of 198 large customers in the Duke Power service territory)* 4-Hr Outage, 1-Hr Outage, 1-Hr Outage Momentary Voltage Cost Element No Notice No Notice With Notice Outage Sag Production Impacts Production Time Lost (Hours) 6.67 2.96 2.26 0.70 0.36 Percentage of Work Stopped 91% 91% 91% 57% 37% Production Losses Value of Lost Production $81,932 $32,816 $28,746 $7,407 $3,914 Percentage of Production Recovered 36% 34% 34% 19% 16% Revenue Change $52,436 $21,658 $18,972 $5,999 $3,287 Loss Due to Damage Damage to Raw Materials $13,070 $8,518 $3,287 $2,051 $1,163 Hazardous Materials Cost $323 $269 $145 $136 $90 Equipment Damage $8,421 $4,977 $408 $3,239 $3,143 Cost to Run Backup and Restart Cost to Run Backup Generation $178 $65 $65 $22 $22 Cost to Restart Electrical Equipment $1,241 $1,241 $171 $29 $29 Other Restart Costs $401 $368 $280 $149 $74 Savings Savings on Raw Materials $1,927 $645 $461 $166 $114 Savings on Fuel and Electricity $317 $103 $85 $12 $9 Value of Scrap $2,337 $874 $450 $228 $140 Labor Management Ap- proach During Recovery Percentage Using Overtime 33% 26% 25% 7% 6% Percentage Using Extra Shifts 1% 1% 0% 1% 1% Percentage Working Labor More Intensively 3% 4% 4% 7% 4% Percentage Rescheduling Operations 4% 5% 5% 0% 0% Percentage Other 1% 2% 2% 1% 0% Percentage Not Recovering 59% 62% 64% 84% 89% Labor Costs and Savings Cost to Make Up Production $4,854 $1,709 $1,373 $254 $60 Cost to Restart $665 $570 $426 $192 $114 Labor Savings $2,139 $644 $555 $0 $0 Average Total Costs Total Costs $74,800 $39,500 $23,100 $11,000 $7,700 * Source: Mike Sullivan, Commercial and Industrial Systems Technology Conference, 1996. PROBLEM DESCRIPTION P 85 ii e r —_ i 30 e n 25 — t a g 20 i e M 15 f 10 Ss a m 5 il P a 1 0 0.00<0.01 0.01-0.1 0.1-1.0 e REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS 1.0-10 10-100 100-1000 >1000 Cost of 1-Hour Outage (thousands of dollars) Figure 3-3. Difference in Commercial and Industrial Customer Interruption Cost (Duke Power data). survey carried out by Pacific Gas & Electric (PG&E) covered 51 industrial customers ranging from elec- tronics, automotive, instrument, apparel, and trans- portation equipment manufacturers to petroleum refineries, metal mines, and real estate offices. The cost of a 15-second interruption at these facilities was estimated to average $70,000 per customer, with the cost ranging from $25,000 to $270,000 per cus- tomer.” Finally, a survey of residential customers in the New England Electric System indicated that 3% of homes in their service territory had PCs primarily for business. The study found a momentary interrup- tion for a home-based business costs about $25 per interruption. A survey of small commercial customers in Canada'° also provides useful insights, with that survey finding losses in the range of hundreds of dollars for interruptions lasting up to 1 hour. Estimation of National Cost of Poor Power Quality The foregoing discussion illustrates the difficulty of developing precise estimates of the national impact of ° EPRI Signature, Summer 1995. '©R.K. Subramaniam, “Understanding Commercial Losses Resulting from Electric Service Interrup- tions,” JEEE Transactions on Industrial Applica- tions, January/February 1993. power quality problems. Prior estimates of the cost of poor power quality have ranged from $25 billion to $400 billion per year. The estimate of $25 billion’! was based on the assumption that 1.5 to 3 cents of every sales dollar in the U.S. manufacturing industry was spent on correcting power quality problems. The $400 billion figure’? was based on the estimate that employees were idle 37.3 million hours in 1991 due to power quality problems experienced by commer- cial customers. This idle time translates to an em- ployee productivity loss, and therefore a loss to U.S. businesses, of $400 billion. Utilizing the NPL survey data on the frequency of power-quality-related events and Duke Power’s esti- mation of its large industrial and commercial custom- ers’ productivity losses, it is possible to develop an estimate of the national cost of poor power quality in this sector. For purposes of this study, the loss in- curred in the large industrial sectors as a result of momentary outages and voltage sags is of most inter- est, since energy storage systems provide the pre- ferred comprehensive solution for these power quality problems. Thus the estimate provides a basis on which to assess this market segment for storage sys- "Carel DeWinkel, “Storing Power for Critical Loads,” JEEE Spectrum, June 1993. "2 “Dower Quality in Commercial Buildings,” EPRI- BR105018. 3-8 REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS PROBLEM DESCRIPTION tems. In the interest of taking a conservative ap- proach, Sentech’s estimate is limited to the indus- trial/large customer sector, because the disruptions caused in this sector are the costliest (as discussed earlier under “Cost of Power Quality to Customer”), and hence investment in storage systems by this sec- tor may be justifiable. The NPL survey data in Table 3-6 provide the aver- age and median interruptions and sags/undervoltages recorded in all 130 sites surveyed but do not differ- entiate between customer classes. Comparison of av- erages and medians indicates that there are a disproportionately smaller number of sites experienc- ing very poor power quality compared to the greater number of sites with good power quality records. The use of the median number instead of the average removes much of this distortion in the survey data and will indicate the extent of disturbance experi- enced by at least 50% of survey participants. There- fore, the survey medians will be assumed to be representative of what is experienced by at least 50% of the larger industrial customers. Hence, from Ta- ble 3-6 it may be concluded that at least 50% of in- dustrial customers experience 12 interruptions and 49 sags/undervoltages per year.'? The figures in Table 3-7 indicate that it is fair to as- sume that the large industrial customers (excluding large commercial customers) in Duke Power's service territory will incur an average cost of $11,027 and $7,694 for each occurrence of momentary outage and voltage sag, respectively. Multiplying the loss for each of these occurrences with the frequency of their occurrence" results in an average loss of $509,000 per year for each of Duke Power's large industrial customers. Given that there are 8,700'° large indus- trial customers in Duke Power’s service territory, the total loss by this customer class will be on the order of $4.4 billion. The total industrial electricity sales in the U.S. and within Duke Power's service territory are 1,004 TWh and 28.2 TWh, respectively. If one were to extrapo- late the estimated $4.4 billion loss experienced by ' Twelve interruptions (12 months/year*! event/ month) and 49 sags/undervoltages (4.1 events/ month*12 months/year) per year. '*1(12 * $11,027) + (49 * $7,694) = $509,000] 'S The EL&P Electric Utility Industry Directory— 1995 indicates that Duke Power has 8,693 indus- trial/large customers among its total customer base of 1.7 million. large industrial customers in Duke Power's service territory to the entire U.S. using electricity sales to the industrial sector as a base, the result would be an es- timated national loss of $150 billion per year. This is summarized in Table 3-8. It should be recognized that computing a national loss number with regional data can be a risky undertaking; the opportunities to introduce error are relatively high. Nevertheless, it is interesting to note that the $150 billion value derived from the Duke Power and NPL data falls between the $25 billion and $400 bil- lion figures cited earlier. The extent of the $150 billion loss that storage sys- tems can address at present/near-term prices can be estimated as follows. The median loss incurred by each of the customers is $509,000,'° which implies that 50% of the customers experienced a loss greater or equal to $509,000 per year. Assuming that an an- nual loss of at least $500,000 would have to be in- curred for a large industrial customer to be able to justify the installation of large protective storage sys- tems, the national market for storage equipment will be at least one-half the losses incurred annually by all large industrial customers, namely $75 billion. The cost-benefit analysis for installing a storage system is provided later under “Cost-Benefit Analysis Exam- ple.” Whatever the actual number, one can postulate with increasing confidence that the annual market potential of energy storage systems addressing power quality problems should total tens of billions of dollars. Unserved markets of this size beg explanation. The market for such systems has grown in the recent past because of the proliferation of versatile microproces- sor-controlled systems and power electronic motor controls, which are susceptible to distortions in the supply waveform. At present, part of the market is served by a variety of uninterruptible power supplies. Largely overlooked, however, are energy storage systems capable not only of meeting large industrial loads during interruptions but also of correcting for voltage magnitude variances and waveform imper- fections. Such systems have been installed in recent years, but large gaps persist in power ratings, protec- tion durations, performance capabilities, flexible sit- ing and operation, cost, and installation ease. Until '® Median number of power quality disturbances ex- perienced each year x average loss per disturbance. 3-9 REVIEW OF POWER QUALITY APPLICATIONS OF PROBLEM DESCRIPTION ENERGY STORAGE SYSTEMS Table 3-8. National Cost Estimate for Large Industrial Customers Average Annual Cost to Large Estimated Cost for Estimated Cost for Industrial Customers Duke Power Customer National Customer Group Group Undervoltages/ $377,000 $ 3.2B $ 114B sags Interruptions $132,000 $1.1B $ 39B Total estimated U.S. cost (rounded): $ 150B these gaps are overcome, manufacturers and their in the cost of goods sold, reducing U.S. competitive- customers will continue to experience higher than ness. The cost is ultimately paid by consumers, do- necessary costs. mestic and foreign. The mitigation of these costs merits the attention of the affected industries, busi- The large annual cost of poor power quality repre- nesses capable of developing solutions, and the DOE. sents a form of national inefficiency and is reflected REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS TECHNOLOGY OPTIONS 4. Technology Options There are three general approaches to solving power quality problems: e Eliminate or modify the source of the distur- bances. e Eliminate or modify the path for the disturbances between the source and the affected equipment. e Protect the affected equipment. Generally, consideration of all three options is neces- sary to develop a cost-effective solution. Determining the least-cost approach to mitigating power quality problems often requires that an industrial customer initiate an extensive internal survey to determine the nature of the problem. Such a survey is commonly done in partnership with the local utility, and the so- lutions that are implemented are often developed with strong input from the utility and in some instances even with financial assistance from the utility. Many technology solutions exist to deal with the dif- ferent power quality events. Devices that are com- monly used for this purpose include the following: Surge arrestors e Filters ¢ Isolation transformers © Constant voltage ¢ Uninterruptible power transformers supply (UPS)/energy ¢ Backup generators storage systems ¢ Series capacitors © Static Var systems ¢ Dynamic voltage e Wiring and grounding restorer ¢ Shielding ¢ Humidity control Energy storage systems can be placed off-line, in a line-interactive mode, or on-line to deal with power STORAGE CHARGER TRANSFER RELAY DC/AC INVERTER quality problems. Off-line (also called standby) en- ergy storage systems (see Figure 4-1) are cost- effective for small, less critical, stand-alone applica- tions such as isolated PCs and peripherals. However, when an outage occurs in the utility supply, this con- figuration may not be able to switch to its storage power supply fast enough to prevent disturbances in highly sensitive equipment. If filters are present, standby systems will protect against most transients by limiting excess voltage, but their ability to protect against sags and surges is significantly less than on- line or line-interactive designs. Line-interactive systems (see Figure 4-2) provide highly effective power conditioning and energy stor- age backup. Their voltage boost circuitry and fast- acting transfer switches protect against most voltage sags and surges and provide extremely quick response to disturbances. Transfer switches with response times of ~1/4 power cycle provide adequate protec- tion for the most sensitive devices. The energy effi- ciency of line-interactive storage systems is higher than that of on-line systems and becomes an impor- tant cost-saving advantage when protecting hundreds of kilowatts of critical loads. The on-line configuration (see Figure 4-3) provides the highest level of protection for critical loads. Off- line and line-interactive storage systems reduce the impact of transients, surges, and sags by either clip- ping the peaks, boosting power, or switching to stor- age backup. In contrast, on-line energy storage systems regenerate the sinewave and do not involve switching. The configuration protects against all util- ity disturbances because the system completely iso- lates the load from the utility supply at all times. Since on-line systems continuously condition input supply, they have relatively large parasitic losses. Figure 4-1. Off-Line Configuration of Energy Storage Systems. 4-1 TECHNOLOGY OPTIONS REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS UTILITY TRANSFER SWITCH VOLTAGE BOOST CONVERTER Figure 4-2. Line-Interactive Configuration of Energy Storage Systems. Each of these energy storage configurations for power quality applications has its advantages and disadvan- tages. Prior to selecting a solution, the electricity provider or end user needs to define the power quality events that are most prevalent at the location and must estimate the damages caused by the events. The different solutions, including the storage option, can then be assessed in order to determine the most cost- effective solution. To determine which device or combination of devices is appropriate, systematic monitoring of the facility, with the help of monitoring equipment and analysis of recorded data, is necessary. Matching the Power Quality Problem with the Technology Solutions Table 4-1 matches power quality events to the pre- ferred technology solution to mitigate that particular event. Thus if impulsive transients were the only type of power quality event that was experienced by an industrial facility, Table 4-1 would indicate that surge arrestors, filters, and isolation transformers are the technology options available to the customer to deal URGE UPPRESSOR POWER FACTOR CORRECTION/RECTIFIER/ CHARGER with the problem. Table 4-1 also lists the power quality events that only an energy storage system can address. These include interruptions, sags/swells, and over-/undervoltages. In each of these cases, supply of the electrical energy from external sources, such as a storage system, is required to deal with the problems. Often a mitigation technology can provide solutions to multiple power quality events. Table 4-2 illustrates this point by showing the different power quality events that can be handled by each of the technology options discussed in Table 4-1. An energy storage system is only essential when an external source of electrical energy is necessary to deal with the power quality event, such as with an interruption. However, the same energy storage system can also service all of the other power quality events shown in Table 4-2. Cost-Benefit Analysis Example For illustrative purposes, the cost-effectiveness of energy storage systems is analyzed using the loss es- timates given in Table 3-7 and the frequency of sup- ply disturbances obtained from the NPL survey and listed in Table 3-6. DYNAMIC BYPASS OPTION Figure 4-3. On-Line Configuration of Energy Storage Systems. 4-2 REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS TECHNOLOGY OPTIONS Table 4-1. Individual Solutions to Single-Category Power Quality Events* Method Of Power Quality Event Category Characterization Cause Solution Impulsive Magnitude, Lightning, Surge arrestors, filters, Transients Duration load switching isolation transformers Oscillatory Waveforms Lightning, line/cable Surge arrestors, filters, Transients switching, capacitor isolation transformers switching, transformer switching, load switching Sags/Swells Waveforms, Remote faults Constant voltage trans- RMS vs. Time former, storage systems Undervoltages/ RMS vs. Time Motor starting, Dynamic voltage Overvoltages load changes, restorer, constant compensation changes voltage transformer, storage systems Interruptions Duration Breaker operation/fault Backup generator, clearing, equipment failure, storage systems maintenance Harmonic Distortions Waveforms, Nonlinear loads, Filters, Harmonic Spectrums system response characteristic isolation transformer (zero sequence) Voltage Flicker Magnitude, Intermittent loads, arcing Static Var system, Frequency of loads, motor starting series caps Modulation Noise Coupling Method, Frequency Power electronic switching, arcing, electromagnetic ra- diation * Source: Power Quality Assessment Procedures, EPRI CU-7529 (December 1991). Wiring and grounding im- provement, chokes, filters, shielding Table 4-3 shows the benefit an energy storage system can bring to a large industrial customer if the storage system can handle both momentary outages and volt- age sags. Duke Power data show the average losses for these types of events to be $11,027 and $7,694 per event, respectively, while the power quality sur- vey data in Table 3-6 indicate that the median number of momentary outages was | per month and the me- dian number of voltage sags/swells was 4.1 per month. Systems based on batteries or on superconducting magnetic energy storage that protect megawatt-scale loads for durations in seconds are now commercially available at a cost of $1 to $2 million. With an annual avoided cost of $500,000 dollars and a payback period of 2 to 4 years, close to 50% of the large industrial customers (described earlier under “Estimation of National Cost of Poor Power Quality’’) in the U.S. may find storage systems economically attractive. 4-3 REVIEW OF POWER QUALITY APPLICATIONS OF TECHNOLOGY OPTIONS ENERGY STORAGE SYSTEMS Table 4-2. Power Quality Solutions and Their Ability to Protect against Events in Multiple Power Quality Categories Power Quality Categories Impul- Oscil- Under- sive latory voltages/ Tran- Tran- Sags/ Over- Inter- Harmonic Voltage sients sients Swells voltages ruptions Distortions Flicker Noise Power Quality Solutions Surge Arrestors v v Filters* v v v v lsolation Transformers v v v Constant Voltage v v Transformers Dynamic Voltage v v Restorer Backup Generator v Energy Storage” - Off-line v v v v v v v - Line-interactive v v v v v v v - On-line v v v v v 7 v v * Different kinds of filters will be required to mitigate the different power quality problems. > For sags/swells, under-/overvoltages, and interruptions, the level of protection increases from off-line to line-interactive to on-line. Table 4-3. Competitiveness of Energy Storage Systems for Power Quality Applications BENEFIT: ANNUAL AVOIDED COST Momentary Outage: Avoided Cost (1 event per month * 12 months * $11,027) $132,000 Voltage Sags: Avoided Cost (4.1 events per month * 12 months * $7,694) $377, 000 Total benefits per year $509,000 COST: CAPITAL COST OF EQUIPMENT Cost of commercially available 1-MW energy storage system capa- ble of providing protection for a few seconds $1 million (1 MW = $1M) SIMPLE PAYBACK PERIOD ~2 years 4-4 REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS CONCLUSIONS 5. Conclusions Power quality issues have come to the forefront re- cently mainly because of the increased use of sophis- ticated microprocessor-controlled equipment in industrial processes. Systems with loads that are highly sensitive and interconnected in extensive net- works are vulnerable because they are dependent on the most sensitive device in the system when a distur- bance occurs. Surveys conducted by the electric util- ity industry demonstrate that manufacturers incur large losses as a result of poor power quality. Power quality problems arise from a variety of events. There are a number of technology options that electricity suppliers as well as end users can use to mitigate power quality problems. It is imperative that careful investigation of the frequency of events and their economic impacts be undertaken. Often it would be most cost-effective to implement solutions only for those power quality problems that have severe eco- nomic impacts rather than installing systems capable of dealing with all power quality events. Data on the frequency of system disturbances and their economic impacts can be obtained through sys- tematic monitoring at end-user sites. Several such studies have been conducted; however, most of the results are considered to be proprietary and are thus not available in the public domain. Summaries of some of these surveys have been published that con- tain enough information to permit tentative conclu- sions to be drawn regarding the nature and frequency of power quality disturbances and the role energy storage systems can play in mitigating them. The sur- vey data suggest that storage systems are well suited to handle problems arising from unscheduled momen- tary outages. These types of events, although less frequent, cause the most severe economic impact. An energy storage system installed to handle outages can also reduce the impacts of voltage sags, under- voltages, and other disturbances. On-line storage systems are capable of eliminating all power quality- related problems, but such a comprehensive solution may be justified only for the more critical processes. Preliminary estimates based on both the NPL and Duke Power surveys indicate that a 2-to-4-yr payback period for commercially available energy storage systems is feasible for the industrial customer experi- encing typical disturbances. The data from these two surveys were used to obtain a rough estimate of $150 billion as the annual losses incurred nationally by the industrial sector because of momentary outages and voltage sags, two events for which storage systems are the primary solution. This number is between the $25 billion estimate made in an IEEE publication and the $400 billion estimate made in an EPRI publica- tion. This study suggests that the accrued national benefit from mitigating power quality losses is very large. This conclusion is supported by studies conducted by EPRI and other entities. However, it is important to note that the numerical estimates of the benefits de- veloped in this study are based on limited data and on extrapolation from the available information. The numerical estimates therefore serve only to establish an order of magnitude of the accrued benefits of miti- gating power quality problems. To establish more precise estimates, it would be necessary to further refine the analysis with better, more complete data obtained through more detailed surveying or through greater access to surveys already conducted by elec- tric utilities. 5-1 REVIEW OF POWER QUALITY APPLICATIONS OF CONCLUSIONS ENERGY STORAGE SYSTEMS Intentionally Left Blank Graphical Illustration of Power Quality Events REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS APPENDIX A Appendix A Graphical Illustration Of Power Quality Events IDEAL SUPPLY WAVEFORM TRANSIENTS e VOLTAGE SAG E VOLTAGE SWELL 1. IDEAL SUPPLY WAVEFORM: An ideal supply waveform is a pure sinusoidal waveform with a constant amplitude and frequency. 2. TRANSIENTS (Impulsive and Oscillatory): A tran- sient is a surge in voltage or current that can have ex- tremely short duration and high magnitude. Typically, surges are caused by switching operations or lightning. Surges can be generated by customers switching their own loads or may be caused by utility switching of capacitors, breakers, etc. Surges have always existed in power sys- tems, but it is only in recent years that they have received attention mainly because of the sensitivity of electronic devices like VCRs and personal computers. 3. VOLTAGE SAG: A momentary voltage dip that lasts for a fraction of a second or less is classified as a voltage sag. Voltage sags may be caused by faults on the transmis- sion or distribution system or by the switching of loads with large amounts of initial starting/inrush current. Volt- age sags may be sufficiently severe, especially in the case of faults, to cause sensitive loads to reset. 4. VOLTAGE SWELL: When a fault occurs on one phase of a 3-phase, 4-wire system, the other two phases rise in voltage relative to ground (about 20%). This steady-state rise in voltage is referred to as a swell. Voltage swells usu- ally have duration of a fraction of a second or less. A-] APPENDIX A REVIEW OF POWER QUALITY APPLICATIONS OF ENERGY STORAGE SYSTEMS UNDER/OVERVOLTAGE POWER OUTAGE HARMONICS 5. UNDER/OVERVOLTAGE (Voltage Drop): A cus- tomer who experiences a long-duration (several seconds or longer) service voltage less than the proper nominal operat- ing voltage limit can be considered to be experiencing an undervoltage situation. Similarly, a customer experiencing higher than nominal operating voltage can be considered to be experiencing overvoltage. Such a condition may be caused by a number of factors, such as overloaded or poor internal wiring, poor connections, compensation changes, and/or voltage drop/gain on the utility system. 6. INTERRUPTION (Power Outage): A power outage is a complete loss of voltage usually lasting from as short as a quarter cycle up to several hours, or in some cases even days. Outages are usually caused by the fault-induced operation of circuit breakers or fuses. Some of these inter- ruptions might be classified as permanent, while others may be classified as temporary. 7. HARMONICS: These are the nonfundamental frequency components of a distorted 60-Hz power wave. They have frequencies that are integral multiples of the 60-Hz funda- mental frequency. Harmonics are not generally produced by the utility but rather by the customer’s equipment. For ex- ample, a large nonlinear industrial load may produce har- monics that, if they are of sufficient magnitude, can travel back through the power system and affect other customers. ABB Power T&D Co., Inc. Attn: P. Danfors 16250 West Glendale Drive New Berlin, WI 53151 American Electric Power Service Corp. Attn: C. Shih 1 Riverside Plaza Columbus, OH 43215 Applied Power Corporation Attn: Tim Ball Solar Engineering 1210 Homann Drive, SE Lacey, WA 98503 Ascension Technology Attn: Edward Kern Post Office Box 6314 Lincoln Center, MA 01773 Anchorage Municipal Light & Power Attn: Meera Kohler 1200 East 1 Avenue Anchorage, AK 99501 Bechtel Corporation Attn: W. Stolte P.O. Box 193965 San Francisco, CA 94119-3965 Berliner Kraft und Licht (BEWAG) Attn: K. Kramer Stauffenbergstrasse 26 1000 Berlin 30 GERMANY Business Management Consulting Attn: S. Jabbour 24704 Voorhees Drive Los Altos Hills, CA 94022 C&D Charter Power Systems, Inc. (2) Attn: Dr. Sudhan S. Misra Attn: Dr. L. Holden Washington & Cherry Sts. Conshohocken, PA 19428 Distribution Argonne National Laboratories (2) Attn: W. DeLuca G. Henriksen CTD, Building 205 9700 South Cass Avenue Argonne, IL 60439 Arizona Public Service (2) Attn: R. Hobbs Herb Hayden 400 North Fifth Street P.O. Box 53999, MS-8931 Phoenix, AZ 85072-3999 AVO International Attn: Gary Markle 510 Township Line Rd. Blue Bell, PA 19422 Babcock & Wilcox Attn: Glenn Campbell P.O. Box 785 Lynchburg, VA 24505 California State Air Resources Board Attn: J. Holmes Research Division P.O. Box 2815 Sacramento, CA 95812 Calpine Corp. Attn: R. Boucher 50 W. San Fernando, Ste. 550 San Jose, CA 95113 Chugach Electric Association, Inc. (2) Attn: T. Lovas J. Cooley P.O. Box 196300 Anchorage, AK 99519-6300 Consolidated Edison (2) Attn: M. Lebow N. Tai 4 Irving Place New York, NY 10003 Corn Belt Electric Cooperative Attn: R. Stack P.O. Box 816 Bloomington, IL 61702 Delphi Energy and Engine Management Systems (3) Attn: J. Michael Hinga R. Galyen R. Rider P.O. Box 502650 Indianapolis, IN 46250 Alaska State Division Of Energy (3) Attn: P. Frisbey P. Crump B. Tiedeman 333 West Fourth Ave, Suite 220 Anchorage, AK 99501-2341 EA Technology, Ltd. Attn: J. Baker Chester CH1 6ES Capenhurst, England UNITED KINGDOM Eagle-Picher Industries Attn: J. DeGruson C & Porter Street Joplin, MO 64802 Electrosource Attn: Michael Dodge P.O. Box 7115 Loveland, CO 80537 Eltech Research Corporation Attn: Dr. E. Rudd 625 East Street Fairport Harbor, OH 44077 Energetics, Inc. (3) Attn: H. Lowitt P. Taylor L. Charles 7164 Gateway Drive Columbia, MD 21046 Energetics, Inc. (4) Attn: M. Farber R. Scheer J. Schilling P. DiPietro 501 School St. SW, Suite 500 Washington, DC 20024 Energy and Environmental Economics, Inc. Attn: Greg J. Ball 353 Sacramento St., Suite 1540 San Francisco, CA 94111 International Energy Systems, Ltd. Attn: G. Barker Chester High Road Nestor, South Wirral L64 UE UK UNITED KINGDOM East Penn Manufacturing Co., Inc. Attn: M. Stanton Deka Road Lyon Station, PA 19536 Electric Power Research Institute (3) Attn: S. Chapel S. Eckroad R. Schainker P. O. Box 10412 Palo Alto, CA 94303-0813 Electrochemical Engineering Consultants, Inc. Attn: P. Symons 1295 Kelly Park Circle Morgan Hill, CA 95037 Electrochemical Energy Storage Systems, Inc. Attn: D. Feder 35 Ridgedale Avenue Madison, NJ 07940 Energy Systems Consulting Attn: A. Pivec 41 Springbrook Road Livingston, NJ 07039 Firing Circuits, Inc. Attn: J. Mills P.O. Box 2007 Norwalk, CT 06852-2007 General Electric Company Attn: N. Miller Building 2, Room 605 1 River Road Schenectady, NY 12345 General Electric Drive Systems Attn: D. Daly 1501 Roanoke Blvd. Salem, VA 24153 GE Industrial & Power Services Attn: Bob Zrebiec 640 Freedom Business Center King of Prussia, PA 19046 Giner, Inc. Attn: A. LaConti 14 Spring Street Waltham, MA 02254-9147 Golden Valley Electric Association, Inc. Attn: S. Haagensen Box 71249 758 Illinois Street Fairbanks, AK 99701 GNB Technologies (3) Industrial Battery Company Attn: G. Hunt J. Szymborski R. Maresca Woodlake Corporate Park 829 Parkview Blvd. Lombard, IL 60148-3249 Lawrence Berkeley Laboratory (3) Attn: E. Cairns K. Kinoshita F. McLarnon University of California One Cyclotron Road Berkeley, CA 94720 Longitude 122 West Attn: S. Schoenung 1241 Hobart St. Menlo Park, CA 94025 Lucent Technologies Attn: C. Mak 3000 Skyline Drive Mesquite, TX 75149 Lucent Technologies, Inc. Attn: J. Morabito Director, Global Research and Development P.O. Box 636 600 Mountain Avenue Murray Hill, NJ 07974-0636 GNB Technologies World Headquarters Attn: S. Deshpande’ 375 Northridge Road Atlanta, GA 30350 Hawaii Electric Light Co. Attn: C. Nagata P.O. Box 1027 Hilo, HI 96720 ILZRO (3) Attn: J. Cole P. Moseley C. Parker P.O. Box 12036 Research Triangle Park, NC 27709 Imperial Oil Resources, Ltd. Attn: R. Myers 3535 Research Rd NW Calgary, Alberta CANADA T2L 2K8 Innovative Power Sources Attn: Ken Belfer 1419 Via Jon Jose Road Alamo, CA 94507 Metlakatla Power & Light Attn: H. Achenbach P.O. Box 359 Metlakatla, AK 99926 Micron Corporation Attn: D. Nowack 158 Orchard Lane Winchester, TN 37398 ZBB Technologies, LTD. Attn: Robert J. Parry Managing Director 16 Emerald Tce. West Perth Western Australia 6005 National Renewable Energy Laboratory (6) Attn: L. Flowers J. Green S. Hock R. DeBlasio B. Stafford H. Thomas 1617 Cole Blvd. Golden, CO 80401-3393 New York Power Authority Attn: B. Chezar 1633 Broadway New York, NY 10019 NC Solar Center Attn: Bill Brooks Corner of Gorman and Western Box 7401 NCSU Raleigh, NC 27695-740 Northern States Power Attn: D. Zurn 414 Nicollet Mall Minneapolis, MN 55401 NPA Technology Attn: Jack Brown Suite 700, Two University Place Durham, NC 27707 Oak Ridge National Laboratory (3) Attn: B. Hawsey, Bldg. 3025, MS-6040 J. Stoval, Bldg. 3147, MS-6070 J. VanCoevering, Bldg. 3147, MS-6070 B. Kirby, Bldg. 3147, MS-6070 P.O. Box 2008 Oak Ridge, TN 37831 Public Service Company of New Mexico Attn: J. Neal Manager, Premium Power Services Alvarado Square MS-BA52 Albuquerque, NM 87158 PEPCO Attn: Brad Johnson 1900 Pennsylvania NW Washington, DC 20068 Oglethorpe Power Company Attn: C. Ward 2100 E. Exchange Place P.O. Box 1349 Tucker, GA 30085-1349 Chief Technology Officer Attn: Robert Wills Advanced Energy Systems Riverview Mill Post Office Box 262 Wilton, NH 0308 Omnion Power Engineering Corporation Attn: H. Meyer 2010 Energy Drive P.O. Box 879 East Troy, WI 53120 Orion Energy Corp. Attn: Doug Danley 10087 Tyler Place #5 Ijamsville, MD 21754 Public Service Company of New Mexico Attn: R. Flynn Senior Vice President Alvarado Square MS-2838 Albuquerque, NM 87158 International Business and Technology Services Inc. Attn: J. Neal Administrator Research and Development 9220 Tayloes Neck Rd. Nanjemoy, MD 20662 Gridwise Engineering Company Attn: B. Norris 121 Starlight Place Danville, CA 94526 Pacific Northwest Laboratory (2) Attn: J. DeSteese, K5-02 D. Brown Battelle Blvd. Richland, WA 99352 Power Technologies, Inc. Attn: P. Prabhakara 1482 Erie Blvd. P.O. Box 1058 Schenectady, NY 12301 Puerto Rico Electric Power Authority Attn: W. Torres G.P.O. Box 4267 San Juan, Puerto Rico 00936-426 Solar Electric Specialists Co. Mr. Jim Trotter 232-Anacapa St. Santa Barbara, CA 93101 ENERTEC Attn: D. Butler 349 Coronation Drive Auchenflower, Queensland, 4066 P.O. Box 1139 Milton BC Qld 4064 AUSTRALIA Southern Company Services, Inc. (2) Research and Environmental Affairs 14N-8195 Attn: B. R. Rauhe, Jr. K. Vakhshoorzadeh 600 North 18" Street P.O. Box 2625 Birmingham, Al 35202-2625 Trace Technologies (2) Attn: Michael Behnke W. Erdman 6952 Preston Avenue Livermore, CA 94550 TRACE Engineering Attn: B. Roppenecker President 5916 195" Northeast Arlington, Washington 98223 RMS Company Attn: K. Ferris 87 Martling Ave. Pleasantville, NY 10570 Powercell Corporation (2) Attn: Reznor I. Orr Rick Winter 10 Rogers Street Cambridge, MA 02142 Raytheon Engineers and Constructors Attn: A. Randall 700 South Ash St. P.O. Box 5888 Denver, CO 80217 Siemens Solar Attn: Clay Aldrich 4650 Adohn Lane Post Office Box 6032 Camarillo, CA 93011 R&D Associates Attn: J. Thompson 2100 Washington Blvd. Arlington, VA 22204-5706 California Energy Commission Attn: Jon Edwards 1516 Ninth Street, MS-46 Sacramento, CA 95814 Sentech, Inc. (2) Attn: R. Sen K. Klunder 4733 Bethesda Avenue, Suite 608 Bethesda, MD 20814 Sentech, Inc. Attn: Robert Reeves 9 Eaton Road Troy, NY 12180 Santa Clara University Attn: Charles Feinstein, Ph.D. Department of Decision and Information Sciences Leavey School of Business and Administration Santa Clara, CA 95053 SAFT Research & Dev. Ctr. Attn: Guy Chagnon 107 Beaver Court Cockeysville, MD 21030 Salt River Project (2) Attn: H. Lundstrom G.E. “Ernie” Palomino, P.E. MS PAB 357, Box 52025 Phoenix, AZ 85072-2025 Southern California Edison Attn: R. N. Schweinberg 6070 N. Irwindale Ave., Suite I Irwindale, CA 91702 Soft Switching Technologies Attn: D. Divan 2224 Evergreen Rd., Ste. 6 Middleton, WI 53562 Solarex Attn: G. Braun 630 Solarex Court Frederick, MD 21701 The Solar Connection Attn: Michael Orians P.O. Box 1138 Morro Bay, CA 93443 Trojan Battery Company Attn: Jim Drizos 12380-Clark Street Santa Fe Springs, CA 90670 U.S. Department of Energy Attn: C. Platt EE-12 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: K. Heitner Office of Transportation Technologies EE-32 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: R. Brewer EE-10 FORSTL Washington, DC 20585 SEIA Attn: S. Sklar 122 C Street NW 4" Floor Washington, DC 20001-2104 SRI International Attn: C. Seitz 333 Ravenswood Ave. Menlo Park, CA 94025 Stored Energy Engineering (2) Attn: George Zink J.R. Bish 7601 E. 88" Place Indianapolis, IN 46256 Stuart Kuritzky 347 Madison Avenue New York, NY 10017 Superconductivity, Inc. (2) Attn: Jennifer Billman Michael Gravely P.O. Box 56074 Madison, WI 53705-4374 Switch Technologies Attn: J. Hurwitch 4733 Bethesda Ave., Ste. 608 Bethesda, MD 20814 Trace Attn: Michael R. Behnke 6952 Precision Avenue Livermore, CA 94550 U.S. Department of Energy Attn: P. Patil Office of Transportation Technologies EE-32 FORSTL Washington, DC 20585 U.S. Department of Energy _ Attn: T. Duong EE-32 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: J. Daley EE-12 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: N. Rossmeissl EE-13 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: Jim Rannels Photovoltaic Program EE-11 FORSTL 1000 Independence Ave., S.W. Washington, DC 20585-0121 U.S. Department of Energy Attn: J. P. Archibald EE-90 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: M. B. Ginsberg EE-90 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: G. Buckingham Albuquerque Operations Office Technology Development Division P.O. Box 5400 Albuquerque, NM 87185 TU Electric R&D Programs Attn: James Fangue P.O. Box 970 Fort Worth, TX 76101 University of Missouri - Rolla Attn: M. Anderson 112 Electrical Engineering Building Rolla, MO 65401-0249 U.S. Department of Energy Attn: R. Eynon Nuclear and Electrical Analysis Branch EI-821 FORSTL Washington, DC 20585 R. Weaver 777 Wildwood Lane Palo Alto, CA 94303 U.S. Department of Energy Attn: A. Jelacic EE-12 FORSTL Washington, DC 20585 U.S. Navy Attn: Wayne Taylor Code 83B000D China Lake, CA 93555 U.S. Department of Energy Attn: A. G. Crawley EE-90 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: P. N. Overholt EE-11 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: J. Cadogan EE-11 FORSTL Washington, DC 20585 U.S. Department of Commerce Attn: Dr. Gerald P. Ceasar Building 101, Rm 623 Gaithersburg, MD 20899 Virginia Power Attn: Gary Verno Innsbrook Technical Center 5000 Dominion Boulevard Glen Ellen, VA 23233 Walt Disney World Design and Eng’g. Attn: Randy Bevin P.O. Box 10,000 Lake Buena Vista, FL 32830-1000 Yuasa, Inc. (3) Attn: N. Magnani F. Tarantino G. Cook P.O. Box 14145 2366 Bernville Road Reading, PA 19612-4145 U.S. Department of Energy Attn: A. Hoffman Office of Utility Technologies EE-10 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: R. Eaton Golden Field Office 1617 Cole Blvd. Building 17 Golden, CO 80401 Westinghouse Attn: Tom Matty P.O. Box 17230 Baltimore, MD 21023 Westinghouse STC Attn: H. Saunders 1310 Beulah Road Pittsburgh, PA 15235 W. R. Grace & Company Attn: S. Strzempko 62 Whittemore Avenue Cambridge, MA 02140 Yuasa-Exide, Inc. Attn: R. Kristiansen 35 Loch Lomond Lane Middleton, NY 10941-1421 Crescent EMC Attn: R. B. Sloan Executive Vice President P.O. Box 1831 Statesville, NC 28687 HL&P Energy Services Attn: George H. Nolin, CEM, P.E. Product Manager Premium Power Services P.O. Box 4300 Houston, TX 77210-4300 UFTO Attn: Edward Beardsworth 951 Lincoln Ave. Palo Alto, CA 94301-3041 The Technology Group, Inc. Attn: Tom Anyos 63 Linden Ave. Atherton, CA 94027-2161 ZBB Technologies, Inc. Attn: P. Eidler 11607 West Dearborn Wauwatosa, WI 53226-3961 ECG Consulting Group, Inc. Attn: Daniel R. Bruck Senior Associate 55-6 Woodlake Road Albany, NY 12203 Westinghouse Electric Corporation Attn: Gerald J. Keane Manager, Venture Development Energy Management Division 4400 Alafaya Trail Orlando, FL 32826-2399 The Brattle Group Attn: Thomas J. Jenkin 44 Brattle Street Cambridge, MA 02138-3736 Exide Electronics Attn: John Breckenridge Director, Federal Systems Division 8609 Six Forks Road Raleigh, NC 27615 Northern States Power Company Attn: Gary G. Karn, P.E. Consultant Electric Services 1518 Chestnut Avenue North Minneapolis, MN 55403 Frost & Sullivan (2) Attn: Steven Kraft Dave Coleman 2525 Charleston Road Mountain View, CA 94043 C&D Powercom Attn: Larry S. Meisner Manager Product Marketing 1400 Union Meeting Road P.O. Box 3053 Blue Bell, PA 19422-0858 Distributed Utility Associates Attn: Joseph Iannucci 1062 Concannon Blvd. Livermore, CA 94550 SAFT America, Inc. Attn: Ole Vigerstol National Sales Manager 711 Industrial Blvd. Valdosta, GA 13601 American Superconductor Corporation Attn: S. Amanda Chiu, P.E. Manager, Strategic Marketing Two Technology Drive Westborough, MA 01581 University of Texas at Austin Attn: John H. Price Research Associate Center for Electromechanics J. J. Pickel Research Campus Mail Code R7000 Austin, TX 78712 U.S. Department of Energy Attn: W. Butler PA-3 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: J. A. Mazer EE-11 FORSTL Washington, DC 20585 VEDCO Energy Attn: Rick Ubaldi 12 Agatha Lane Wayne, New Jersey 07470 Intercon Limited (2) Attn: David Warar 6865 Lincoln Avenue Lincolnwood, IL 60646 Utility PhotoVoltaic Group Attn: Steve Hester 1800 M Street, N.W. Washington, DC 20036-5802 U.S. Department of Energy Attn: P. Maupin ER-14 G-343/GTN Germantown, MD 20874-1290 Tampa Electric Company Attn: Terri Hensley, Engineer P.O. Box 111 Tampa, FL 33601-0111 U.S. Department of Energy Attn: R. J. King EE-11 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: A. O. Bulawka EE-11 FORSTL Washington, DC 20585 Southern California Edison Attn: N. Pinsky P.O. Box 800 2244 Walnut Grove Ave., Rm 418 Rosemead, CA 91770 U.S. Department of Energy Attn: D. T. Ton EE-11 FORSTL Washington, DC 20585 U.S. Department of Energy Attn: J. Galdo EE-10 FORSTL Washington, DC 20585 Queensland Department of Mines and Energy Attn: N. Lindsay Senior Project Officer Energy Planning Division GPO Box 194 Brisbane 4001, Qld. Australia Utility Power Group Attn: Mike Stern 9410-G DeSoto Avenue Chatsworth, CA 91311-4947 Amber Gray-Fenner 7204 Marigot Rd. NW Albuquerque, NM 87120 ABB Power T&D Company, Inc. Attn: H. Weinerich 1460 Livingston Avenue North Brunswick, New Jersey MS-0513, MS-0953, MS-0953, MS-0741, MS-0212, MS-0340, MS-0343, MS-0613, MS-0613, MS-0614, MS-0613, MS-0614, MS-0613, MS-0614, MS-0614, MS-0614, MS-0614, MS-0613, R. Eagan (1000) W.E. Alzheimer (1500) J.T. Cutchen (1501) S. Varnado (6200) A. Phillips, (10230) J. Braithwaite (1832) W. Cieslak (1832) A. Akhil (1525) D. Doughty (1521) E. Binasiewicz (1522) G. Corey (1525) G.P. Rodriguez, (1523) I. Francis (1525) J.T. Crow (1523) T. Unkelhaeuser (1523) D. Mitchell (1522) K. Grothaus (1523) N. Clark (1525) MS-0613 R. Jungst (1521) MS-0704, MS-0708, MS-0752, MS-0753, MS-0753, MS-0753, MS-0753, MS-1193, MS-0614, MS-0537, MS-0613, MS-9403, MS-0613, MS-0619, MS-0899, MS-9018, P.C. Klimas (6201) H. Dodd (6214) M. Tatro (6219) C. Cameron (6218) R. Bonn (6218) T. Hund (6218) W. Bower (6218) D. Rovang (9531) A Jimenez (1523) S. Atcitty (2314) J.D. Guillen (1525) Jim Wang (8713) P. Butler (1525) (20) Review & Approval Desk For DOE/OSTI (12690) (2) Technical Library (4916) (2) Central Technical Files (8940-2)