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Development of Windgenerator Farms in Rural Alaska 1981
DEVELOPMENT OF WINDGENERATOR FARMS IN RURAL ALASKA by Mark A. Newell Wind Systems Engineer The Renewable Energy Group Anchorage, Alasak DEVELOPMENT OF WINDGENERATOR FARMS IN RURAL ALASKA by Mark A. Wind Systems Engineer The Renewable Energy Group Anchorage, Alaska ABSTRACT This paper discusses the use of multiple wind turbines genera- tors (windfarms) In remote Wrilages <n Al ask a. A background in windfarm develop- ment Outside Alaska Is built upon to relate some of the challenges and enticements for winagenerator use in the Last Frontier. In addition to identifying problem areas, solutions are presented which describe a rational approach to solving the energy dilemma in rural areas. 1. WINDFARMS IN ALASKA? A windfarm Is acluster of more than one windgenerator built for the purpose of generating electricity at a profit. In Alaska there are many parts of this state with high electri- city costs and high winds. This combination coupled with the Alaskan pioneering spirit would seemingly make a very attractive environment for windfarms. Yet not much Is happening with them in Alaska compared to the lower 48 and Hawall. Let's start our look at windfarms with a brief his- tory of their development. 2. WHY ARE WINDFARMS BEING BUILT? There is nothing new about windmills and their use to gen- erate electricity. Cheap, widely distributed, and government subsidized electric power drove the windgenerator manufacturers out of business In the 40's and 50's. in the late. 60*%s Ol! prices rose to the point that windgenerated electricity was becoming economic. With the advent of the solar tax credit, Windfall Profits Tax Act, and use of an investment tax credit a full 25% of a wind system can be written off on Federal taxes. The Public Utilities Regulatory Policy Act of 1978 (PURPA) paved the way for a windgenerator owner to be able to intertie with a utility and eliminate the need for batteries to store power. PURPA also opened the door to private entrepreneurs to build an array of windgenerators and become a "qualifying facility" under the law to sell power to a utility without having to be regulated as a utility. These entrepreneurs would put together an Investment package using wind- farms which would contain high rates of return and significant tax shelters. WINDFARMS HAWAII Be IN THE LOWER 48 AND Development of windfarms has added a new dimension to wind energy. Windfarms, Ltd., a San Francisco based firm has signed a contract to build a $300 million 80-megawatt (one megawatt equals 1000 kw) facility that when completed In late 1984, should provide 8% ot the electricity for Hawalilan Electrical Co. Windfarms, Ltd. has taken an aggressive lead In securing agreements with utilities. At the same time utilities are becoming active as well: o Southern California Edison has planned 370 megawatts of wind power for it's grid; o Bureau of Reclamation has finalized Its plans for a 100 megawatt farm at Medicine Bow, Wyoming, to intertie with its hydroelectric capacity; o Bonneville Power Authority has Installed three 2.5 mega- watt MOD-2 units, with plans for more installed capacity in the Columbia River Gorge. One of the first operational windfarms consists of twenty 30 kw turbines on Crotched Moun- tain, New Hampshire designed and built by U.S. Windpower, Inc. 4. ALASKAN WINDFARM EXPERIENCE The only operational windfarm In Alaska presently is in Unal- akleet. The three 10 kw array designed by Wind Systems Engi- neering (now The Renewable Energy Group) is providing about 5% of Unalakleet Valley Electrical Cooperative's energy needs. The Alaska Energy Center had planned a windfarm for Skagway, which was aban- doned when the Center was dismantled. 5. REASONS FOR DEVELOPMENT OF WINDFARMS IN ALASKA With a using dispursed grid diesel generators the cost of producing energy Is high enough for an economic return on an investment in a windgenerator. Since windgenerators compared to diesel systems are capitol Inten- sive with low operating costs they are well suited for the village environment. Presently the most sought after solution to rural energy problems Is hydroelectric generation. A drawback to hydroelectric Is the long lead time necessary for construction and the long trans- mission lines typically required. A windfarm requires very little lead time - on the order of two to three years compared to six to ten for' hydroelectric, and typi- cally transmission costs are comparitively low. The last strong reason for use of windfarms Is the coincidence of power avallable from the wind and demand for energy. Typically in Alaska the winds are strongest in the winter and since heat loss from structures is worst during windy cold days, good correlation exists between demand and supply. 6. CHALLENGES TO THE USE OF WINDGENERATORS IN REMOTE GRIDS The first problem encountered is lack of sufficient data on both the winds and the amount of ener- gy demanded at a given point in time (ie. verification of coinci- dence of supply and demand). The demand side is not as important as the wind resource data Infor- mation. Much of the Investment criteria Is developed around the amount of energy a windfarm will produce, which requires accurate wind data. Most wind systems rely on an electric grid system capable of handling a variable supply of power. This implies elther a large dispersed grid or some means of storing power - neIther of which Is descriptive of the village diesel grids. Since these wind systems rely on a grid being present, they are only as reliable as the grid is, thus they are not improving the utility's ability to deliver power. Because many of the remote systems are single generator grids there is usually no built In ability to match loads with power avalla- bility. |f a windfarm Is large enough to carry a significant portion of a load uncotrolled, the diesel unit may be forced to idle, which may save fuel but will harm the engine. A challenge over which one has no control is the severe weather and remoteness of many of the villages. The weather makes everthing that's going to go wrong happen at the worst time and the remoteness means you won't be able to get there when It does. To further complicate matters there Is presently a lack of trained installers, techni- clans, maintenance personnel and proffessionals to be responsible for the Installed wind systems. As Important as the people, the cost and availability of reli- able hardware has been a problem plaguing Alaska for years in the larger size wind- generator. 7. SOLUTIONS TO THE CHALLENGES The wind industry is expanding rapidly and despite some grow- ing pains Is now producing rellable hardware. It will take mass production to bring the price down however, the pros- pects for which look promising. The training problem is being addressed by Community Colleges, Universities, Trade Schools, and Manufacturers, as well as Inter- ested public service groups such as those which put the Alterna- tive Energy Conference together. The training and education may not be keeping up with the demand and need, but given time, it will. The dilemma of load/supply mismatch can be solved with todays technology. A load management system which turns on and off discretionary loads such as resistive water or space heating can effectively shave peaks, account for variable winds, (and with synchronous die- sels), operate the most efficient units for a given demand. The technology is solid state micro- computers which can make maintenance simpler with self- dlagnosis and automatic record keeping. If a utility is fortunate enough to have some hydroelectric capacity, such as in Skagway, it has a built-in storage system by using the reservoir to store power. The windgenerator re- cently installed on the City's Sewage Treatment Plant ties into the utility. The utility espe- cially in winter months must augment the limited hydro capacity with diesel power, thus the windgenerator is allowing them to burn less diesel fuel. A windfarm/hydro system may someday allow the utility to keep the diesels on standby and run the hydro at reduced flows on windy days for additional storage on nonwindy days. Intertiing villages opens up the load management possibilities as well as opening up windy terrains between villages making a wind- generator/transmission line tower possible. The lack of data however can only be solved with an aggres- sive information collection program and time. Much has been done to summarize the available wind power data base, but much more needs to be done to adequately assess the poten- tial before wide-spread use could be a reality. The most difficult problem to tackle though Is the remoteness of many of the communities. It Is difficult for private (or government) enterprise to function well and develop a network necessary to design, Install, operate, and maintain the systems developed. The only lasting network which will function in the village must have Incentives and not be based on subsidy, this point is often overlooked and is a key Issue to survival of any energy system. 8. CONCLUSIONS - A WINDY FUTURE? Winafarms are not the answer to the rural energy problem, yet they can be a very important step towards their solution. The challenges presented should be treated as such and the problems will be solved. A rational, logical approach Involving the villagers them- selves using the locally avallable resources will goa long way towards making renewable energy a reality. NEWSLETTERS/ JOURNALS WindBooks D ENERGY Report . = ewsletter of Wind Powe’ 16 pages Twelve Monthly Issues $115.00 Annually ISSN: 0162-8623 Wind Energy Report is a monthly newsletter devoted exclusively to providing thorough accounts of research activities, economic analyses, new technical developments and marketing opportunities in wind energy worldwide. Each month, the newsletter brings you 16 pages of concisely written, fact-filled, insightful articles on the technical, economic and political developments making wind energy the most promising solar-electric renewable technology available today. Wind Energy Report is the only publication which provides you with complete design specifications, cost estimates, operational characteristics and actual perform- ance results of experimental and commercially available wind energy systems—both large and small, vertical and horizontal axis. Wind Energy Report provides comprehensive technical descriptions of the wind turbine generators manufactured by Westinghouse, Hamilton Standard, Grumman, Boeing, General Electric, Bendix, ALCOA, WindBooks NEWSLETTERS/JOURNALS WIND ENERGY ABSTRACTS The International Wind Power Abstracts Journal Complementing Wind Energy Report is Wind Energy Abstracts. Each month, this new abstracts journal scans the literature of more than 250 scientific, technical and economic publications from universities, professional associations and societies, government agencies, companies and organizations actively involved in wind power development. Each abstract is written by a specialist who isknowledgeable about wind power to capture the essence of a book, article, study, report, or analysis in a short, yet concise, manner. Wind Energy Abstracts is divided into more than 30 categories covering:aerodynamics, economics, environment, generators, manufacturing, marketing, power conditioning, rotors, towers, utility integration, wakes & clusters, any many, many others to help you find information quickly and easily. The world’s wind power literature is at your fingertips each nth with As soon as you subscribe, you'll quickly find out how much energy their machines can produce, how much they cost, and how they are being financed and built. Only in the pages of Wind Energy Report can you find the details on the 80 MW Hawaiian wind farm, 320 MW array in northern California, plans for the San Gorgonio Pass, the world’s first SWECS wind array in New Hampshire, and other important wind power projects and activities throughout the world. Objective and complete, Wind Energy Report analyzes the prospects and the pro- blems, the successes and the failures, the opportunities and the challenges of wind power in a readable, non-technical format. Widely read and universally respected by wind energy professionals, government officials, executives, engineers and researchers around the globe, Wind Energy Report is your window on the world of contemporary wind power. DAF-Indal, Volund, Taylor Woodrow, Voith-Getriebe, Aerowatt, FIAT, MAN Neue Technologie, Messerschmitt-Bolkow- Blohm, Jacobs, Kaman, Enertech, and many, many more companies actively be- ginning to exploit a potential multi-billion dollar wind turbine marketplace. Special Bonus: Subscribe now to both Wind Energy Report and Wind Energy Abstracts and save $20.00 on the total cost of both publications. Subscribers to both publications are eligible for a combined 15% discount on all publica- tions in this Windbooks catalogue. A very limited number of complete back volumes are available: Volume 1 (1978) sixissues........... Volume 2 (1979) twelve issues . Volume 3 (1980) twelve issues .. . Volume 4 (1981) twelve issues CONFERENCE PROCEEDINGS Proceedings of the Vertical Axis Wind Turbine Design Technology Seminar for Industry Sandia National Laboratories, Albuquerque, NM April 1980 ISBN: 0-88016-007-1 WindBooks Developing Darrieus vertical axis wind turbine technology which can result in economical, mass- produced and commercially marketable wind energy systems was the theme of this important seminar. The emphasis of the 20 individual papers presented by America’s leading Darrieus experts is on cur- rent state-of-the-art Darrieus VAWT technical developments and on explaining, defining and testing readily available analytic and design tools. Topics covered in depth at the seminar include: current and future VAWT design characteristics; theoretical and performance analyses of the 17-meter, 100 kW Sandia/ALCOA Darrieus design; megawatt-scale VAWTs; aerodynamic performance prediction methods; structural, blade, rotor, drive train, guy cable and foundation design analyses; VAWT economic studies and optimization techniques; instrumentation and software programs and data collection and analysis. Papers include detailed technical drawings and specifications for the 17-meter, 100 kW Darrieus. Contents: Overview of the U.S. Department of Energy Vertical Axis Wind Turbine Pro- gram ¢ Design Characteristics of Current and Future VAWT Systems ¢ Structural Design of verti- cal axis systems ¢ Aerodynamic Performance of vertical axis systems * System Engineering and Economics ¢ Bibliography ISBN: 0-88016-007-1 1980 20 papers 334 pages Paper $65.00 Proceedings of the Second Conference on Wind Energy Technology University of Missouri-Columbia March 1981 Thirty five papers deal with a variety of current wind power research and development in the United States by leading scholars, scientists, manufacturers, consultants and wind resource experts. Papers deal with such topical technical, economic and institutional issues as: SWECS life-cycle costing * economic potential of wind systems in the northern U.S. ¢ wind energy economics for consumers ® wind turbine siting methodologies and techniques ¢ wind energy siting in urban and rural environments ¢ laminated wood blades * tower and foundation designs * vibration absorbers for wind turbines ¢ low cost, high performance rotors * wind turbine noise * WECS lightning hazards * wind turbine performance methods * WECS energy performance analyses * ducted wind turbines * hydrogen storage * flywheel and tethered balloon concepts ¢ SWECS standardiz- ed performance testing ® control systems ¢ 1981 35 papers paper $49.00 WindBooks CONFERENCE PROCEEDINGS Proceedings of the Third International Symposium on Wind Energy Systems ». Sponsored by BHRA Fluid Engineering and Danish Technical University Copenhagen, Denmark, August 1980. Pay Presented at the Third International Symposium, An excellent compendium of current economic and technical developments in hori- zontal axis, vertical axis and innovative wind power concepts from leading experts in Aus- tralia, Great Britain, Denmark, Sweden, Switzerland, Netherlands, France, West Ger- many, Argentina, Senegal, Canada, and the United States. Forty-three papers cover the design, con- struction and performance of wind systems under development by Taylor Woodrow (U.K.), Kaman Aerospace (U.S.A.), Messer- schmitt-Bolkow-Blohm (West Germany), Aerowatt (France), Saab-Scania (Sweden), Voith-Getriebe (West Germany), Karlskrona- varvet (Sweden), Bristol Aerospace Ltd. (Canada), and FDO Technische Adviseurs ISBN: 0-906085-47-0 (Netherlands). Papers deal with such topics as: offshore siting © wind resource assessments ® siting costs * blade design and fabrication * wind turbine power measurements ® maintenance policies for large wind systems © capacity credits ¢ wind-hydro integration ¢ low speed water pumping windmills ¢ wind power for space and water heating ¢ wind turbine wakes and clusters * simulation models. 1980 39 papers 580 pages Paper $90.00 co hagen Denmark August 1980 Proceedings of the Second International Symposium on Wind Energy Systems Sponsored by BHRA Fluid Engineering Amsterdam, Netherlands, 1978. Thirty-six papers cover a broad range of wind power research and development in Europe, North America, Africa and Asia. Wind energy projects in the Netherlands, Sweden, U.S.A., Den- mark, Canada, United Kingdom, Tanzania, Israel, and Iran are examined by leading scholars, scientists, and engineers in this seminal work on wind power. Typical of the many topics are: Darrieus and Savonius rotor configurations, articulated vertical axis, augmentors, cycloturbines, shrouded wind turbines, tipvane research, rotor aeroelastic stability, small-scale water-pumping windmills, wind generated heat applications, offshore wind systems, utility grid interconnection issues, clusters and wake interactions, and economics of large and small wind energy systems. Also important test results from the Saab-Scania 60 Kw, Gedser 200 kW, and DAF-Indal/NRC 230 kW. 1978 41 papers 750 pages 2 vols. Paper $55.00 ISBN: 0-906085-03-9 The Proceedings of the the First International Symposium on Wind Energy Systems. University of Cambridge, U.K 1977 21 Papers 498 pages Microfiche $53.00 ' CONFERENCE PROCEEDINGS Proceedings of the National ‘sdb American Wind Energy Association Summer 1980, Pittsburgh, PA More than 30 papers provide an insight into the multi-faceted and vibrant wind energy industry in the United States covering a variety of technical, economic, engineering and _insti- tutional issues. Papers detail significant develop- ments in the design and manufacture of the wind machines of ALCOA (300 kW, 500 kW), Carter Enterprises (25 kW), Grumman (25 kW), Bergey Windpower (650 Watt, 1 KW), and Enertech (1.5 kW). Papers cover the NASA and Rocky Flats ma- chine programs of the U.S. Department of En- ergy, federal commercialization activities, legal and institutional obstacles to wind power development, product liability insurance, im- plications of the Public Utility Regulatory Policies Act, and major wind power activities in Hawaii, New Hampshire, Texas, Pennsylvania, Oklahoma, Iowa, and Massachusetts. Recent studies on vertical wind profiles, lightning protection, SWECS reliability and grid in- tegration issues, vibration analyses, yaw dynamics, controlled velocity testing, aerodynamics, wind tunnel tests, performance testing and rating standards for small wind energy conversion systems and water and space heating applications are also presented. n o = a Ww lu o 3° ir a. 1980 32 papers 168 pages Paper $35.00 Earlier Proceedings: 1979, San Francisco, CA 32 papers 281 pages Paper $30.00 1978, Cape Cod, MA 28 papers 192 pages Paper $15.00 1977, Amarillo, TX 24 papers 184 pages Paper $15.00 Proceedings of the ISBN: 0-88016-008-X Wind Energy Conference Sponsored by the New York State Legislative Commission on Science & Technology SUNY Buffalo May 1980 The conference focused attention incorporating wind power in policy making to meet the energy needs of New York State. Problems associated with large, medium, and small-scale systems, regulatory, institutional, economic and legal barriers retarding wind power development in the state were examined in detail. Also discussed were research and development needs, the funding and the financing of wind system production, purchase and installation and commercializaton of wind systems. Presentations by the Public Service Commission, Hamilton Standard, General Electric, WTG Energy Systems, Grumman Energy Systems, Niagara Mohawk Power Corporation, Long Island Lighting Company, Power Authority of the State of New York, Rochester Gas & Electric, the New York State Energy Office and the New York Energy Research & Development Authority. 1980 96 pages Paper $10.00 REFERENCE BOOKS WINDPOWER: A Handbook on Wind Energy Conversion Systems by V. Daniel Hunt Director, The Energy Institute This reference Handbook provides a contem- porary, comprehensive collection and synthesis of wind power information which explores the achi- evements, problems and future potential of this important renewable energy resource. In a single volume, this handbook provides the fundamentals and basic data regarding the design, development and demonstration of wind energy conversion sys- tems. It features extensive coverage of the histori- cal development of wind power systems, character- istics of the wind, fundamental systems operation, characteristics of system design, water pumping and electricity producing systems, and U.S. and in- ternational views on the future of wind power. The Handbook is useful because it contains a skillfully edited compilation of many U.S. Wind Energy Program studies and analyses on both large and small wind energy systems. ISBN: 0-442-27389-4 Contents: Historical Development * Wind Characteristics and Their Impact * Fundamental Operation of Wind Energy Conversion Systems ¢ Applied Aerodynamics * Tower and Systems Installation ¢ Energy Conversion and Storage * Wind Energy Conversion Systems ® Applica- tions ¢ U.S. Wind Energy Program ¢ Commercialization ¢ Environmental and Legal Bar- riers ¢ International Development * The Future of Wind Power © Bibliography © Index © Glossary 1981 610 pages 413 illustrations Hardback $39.50 WIND MACHINES Second Edition — by Frank R. Eldridge 232 pages, 168 illustrations $19.95 Written by one of the world’s leading wind power experts, this comprehensive volume offers the his- tory of wind machines from their earliest uses in Pre-Christian Persia through twentieth century at- tempts to harness this almost unlimited natural energy source. Wind Machines examines the tech- nical, economic, environmental, sociological and institutional aspects of wind energy. The practic- ality of wind power, siting problems, design and performance characteristics are fully explored. Horizontal and vertical axis rotors, Darrieus ma- chines, and vortex generators are fully explained in terms the layperson can understand yet with suffi- cient technical data and detail to be useful to the engineer and scientist. Wind Machines is filled with more than 150 photographs, illustrations, charts and tables. Case reviews of wind machine experiments in the United States, Great Britain, Denmark, Sweden, Soviet Union, Germany, Netherlands, and France SMALL WIND SYSTEM SITING AIDS WindBooks A Siting Handbook for Small tS Wind Energy Conversion Systems by H.L. Wegley, J.V. Ramsdell, : M.M. Orgill, and R.L. Drake Battelle Memorial Institute Pacific Northwest Laboratories A small investment in locating the best available site for a wind energy system can easily yield savings of several thousands of dollars during its lifetime. Improper siting of a wind system is a prime cause of poor wind turbine performance but this can quickly be remedied by adhering to a few basic princi- ples about the wind found in the handbook. The Battelle Siting Handbook gives you easy-to-understand, practical advice on: how to analyze and select the best site for a wind system; how to measure and evaluate local wind data and conditions, how to estimate available power, what wind monitoring devices to use, how to avoid turbulence, wind shear and destructive terrain, how to maxim- ize energy output. The Battelle Siting Handbook is must reading for anyone seriously considering buy- ISBN: 0-88016-003-9 : ing or installing a small wind system. Contents: General Description of the Wind ¢ Siting in Flat Terrain ¢ Siting in Non-Flat Ter- rain ® Methods of Site Analysis © Wind Measurements ¢ Environmental Hazards for Wind System Operations * Sources and Uses of Wind Climatology ¢ Estimating Output Power from Annual Average Wind Speeds and Wind System Characteristics © Computation of Output Power from Wind Summaries 1980 5 Appendices 96 pages Paper $7.95 = MARKETI/FINANCIAL ANALYSES WindBooks A Market Analysis of the Potential for Wind Systems Use in Remote and Isolated Area Applications by Energy Resources Company, Cambridge, Massachusetts The analysis assesses the potential market for two million wind system installations in non-grid connected regions of the United States, Canada and the Caribbean. It is one of a handful of wind energy studies which quantifies the potential for sales of all sizes of wind machines in this lucrative, high energy cost marketplace. The Analysis examines exhaustively eight major segments of this market: telecommunications, isolated utilities, offshore oil and gas platforms, defense installations, onshore oil and gas pipelines, aircraft navigational aids and primary and secondary residences and farms (crop and livestock). It also surveys 14 other segments (fish farms, fertilizer, railroads, parks and cam- pgrounds, outdoor advertising, monitoring, logging, mining, police, highways, F.A.A., forestry, Indian reservations, and fish and game). The Analysis examines the attitudes of decision-makers within each market segment toward operational, maintenance, cost and reliability requirements of wind systems use. It also contains a wealth of data on remote power use and users, energy needs, conventional electric costs, costs of fuel, wind equipment specification factors, and marketing strategies for each of the eight major market segments. Appendix includes the names of individuals, utilities, agencies and companies contacted or interviewed in performing the analysis. Contents: Remote Power Uses and Users @ Market Size and Characteristics of Eight Major Seg- ments * Power and Energy Yields from Wind Turbine Generators * Cost of Conventional Elec- trical Systems ¢ Market Penetration Strategies ISBN: 0-88016-002-0 1979 36 Tables 26 Figures 180 pages Paper $95.00 GENERATION PLANNING MANUAL Wind Measurement Systems t & Wind Tunnel Evaluation of by J.V. Ramsdell & J.S. Wetzel Selected Instruments Battelle Memorial Institute ISBN: 0-88016-006-3 Pacific Northwest Laboratories Complementing the Battelle Siting Handbook is this Battelle survey of commercially available wind measuring systems. Battelle conducted wind tunnel tests of seven relatively inexpensive wind measurement systems to evaluate the accuracy and reliability of instruments for use in small wind energy conversion system siting studies. The report discusses wind measurement systems and documents the results of wind tunnel studies. Graphs and tables relate measuring system and system component performance to wind speed. The results describe the instrument’s performance under ideal, non-atmospheric, test conditions. Wind measurement systems examined: Natural Power A30-101 Wind Speed Compilator; WeatherMeasure W224 Recording Wind System, W300 Anemonitor, and 163 and W164 Contact Anemometers; Clean Energy Products Trade Wind II Anemometer/Odometer; and Wind Power Systems’ Windometer System. 1981 11 Tables 80 pages Paper $8.00 Planning Manual for Utility Application of Large Wind Energy Conversion Systems by Gerald L. Park, Otto Krauss, Jack Lawler and Jes Asmussen Division of Engineering Research Michigan State University, East Lansing, Michigan ISBN: 0-88016-005-5 The manual is a primer for utilities to help determine the feasibility of using wind energy as a electricity generation source. This manual aids utility managers, planners, engineers and con- sultants in evaluating the economics and feasibility of integrating wind energy systems with the utility grid by comparing wind power with conventional generation. A two-step planning and evaluation procedure is outlined, generally consistent with most utility power-source planning procedures. It requires the same input data including load forecasts, generation performance and cost data and information on utility operating policies. Sufficient in- formation and references are provided in the manual to enable planners to modify existing pro- cedures to include wind energy systems. Examples and a case study, work sheets and tables are provided. Among the topics covered are: siting investigation and effects of site features on wind velocity; land economics; wind generator availability; legal, regulatory and environmental constraints; siz- ing individual wind energy systems and choosing an array configuration; reserve, reliability and availability considerations; stability and operating problems peculiar to wind energy systems. 1979 bibliography Sappendices 1Stables 243 pages paper $49.50 INTERNATIONAL STUDIES WIND ENERGY: An Assessment of the Technical and Economic WindBooks This is an important International Energy Agen- cy study which helped shape West German policy jaf> on wind energy. It contains new results in the Potential: A Case Study technical and economic assessment of wind for the Federal Republic energy within West Germany and comparable of Germany. countries. The supply of wind energy fluctuates strongly and irregularly, while the electric power demand exhibits regular daily and seasonal variations. For an economic optimum the power delivered from the conventional power supply system must be adapted at all times to the momentary wind 1981 energy supply and the total demand, taking into account the composition and the control char- 122 figures, 230 pages acteristics of the existing system of power sta- Cloth tions and storage. This leads to an assessment of $45.00 the fossil fuel savings and the savings in conven- tional power plant capacity. The savings are evaluated with cost projections used by the util- ities and allow the determination of the break- ISBN: 3-540-10362-7 even cost of wind power. Contents: The Possible Position of Wind Power within the future energy supply of West Germany ¢ Determinants of Wind Power Utilization * Research Goals of the Study * Conver- sion of Kinetic Energy into electrical energy * The Conventional Energy Supply Sys- tem ¢ SWING: A Simulation Model for the Integration of Wind Power into the National Grid ¢ Fuel Saving Through the Use of Wind Power Plants * Displacement of Power Plant Capacity by Wind Power Plants (Capacity Credit) Wind Power in the United Kingdom The first seminar devoted to wind energy in the United Kingdom was held in Londotain July 1978. In addition to a wide-ranging discussion of wind power’s potential in the United Kingdom, ten papers covering a wide spectrum of technical were presented on the following topics: vertical axis windmills ¢ wind systems for heating © single bladed windmill designs ¢ small wind systems for telecommunications and other high reliability systems © electric controls for windmills ¢ wind power research at the Central Electricity Generating Board © prospects for wind power in the United Kingdom 1979 107 pages 10 papers illustrated paper $29.00 by L. Jarass, L. Hoffmann, A. Jarass, & G. Obermair University of Regensburg, West Germany. Proceedings of the Third British Wind Energy Association Wind Energy Conference Cranfield Institute of Technology, April 1981 An excellent overview of current wind energy activities in the United Kingdom. More than twenty papers cover such diverse topics as large and small wind machine design, construction and per- formance; offshore wind energy systems; economics and system integration and aerodynamics. Among the topics examined: the Musgrove vertical axis wind turbine; wind power and pumped storage; interpretation of wind turbine wake data; transmission systems; economics of wind pumps; and wind research at Napier College, The Open University, Reading University, the Cen- tral Electricity Research-Laboratory and the Central Electricity Generating Board. Projects cur- rently underway at Taylor Woodrow, North of Scotland Hydro Board, McAlpine and Aircraft Designs Bembridge, Hamilton Standard, Howden & Co., NEI Clarke Chapman Engineering, and the Intermediate Technology Development Group are also discussed. 1981 22 papers Paper $36.00 SMALL WIND SYSTEMS OPERATIONS HANDBOOK Handbook of the Operation of Small Wind Turbines on a Utility Distribution System by David Curtice and James Patton Systems Control, Inc. As more and more kilowatt-scale wind energy systems are being installed by customers, new and challenging technical problems are being created for utility personnel responsible for linemen safe- ty, for grid protection and for the ability of ex- isting distribution systems to accommodate vary- ing sizes and models of customer-owned wind tur- bines. For example, utilities are likely to be held liable by customers if a wind turbine continues isolated operation causing equipment damage due to fre- quency and voltage excursions outside normal limits. The large magnetizing inrush of current from wind turbines may cause intolerable light flicker for other customers connected on the same distribution transformer. Wind turbines may in- crease the number of voltage regulator operations, increasing equipment maintenance and cost. The Handbook addresses these and many other important technical issues affecting the safe and reliable operation of a network when large num- bers of kilowatt-size wind generators are feeding a.c. power directly or d.c. power fed through a ISBN: 0-88016-009-8 commutated inverter into the distribution system. Designed to provide immediate help to utilities regardless of grid size, here are just a few of the topics covered in the Handbook: © safety assessment © distribution operations assessment ¢ protection equipment and coor- dination © voltage regulation and line losses * continuous fault current * voltage decay of wind turbines ¢ and recloser operations Sponsored by the U.S. Department of Energy’s Small Wind Systems Program, the Handbook is the first systematic study of these critical issues from the utility perspective: personnel safety, reac- tive power, power output fluctuations, voltage flicker, distribution protection equipment, wind turbines as negative loads, feeder voltage and regulation equipment, line losses, load frequency control problems, substation power factor, disconnect options, and many other pertinent technical issues. The Systems Control Handbook examines in detail the characteristics of the induction generator, the self-and line commutated inverter and the synchronous generator and their impact on three- and four-wire distribution systems. The consequences of wind turbine penetration levels (5%, 20% and 50%) are also discussed. Among other techniques, the Handbook develdps a method to analyze utility load-frequency control problems with load patterns produced by customer demand and the wind turbine’s inter- mittent power output. It provides guidelines for line crew safety and wind turbine disconnect pro- cedures. Contents: Safety Assessment © Distribution Operations Assessment * Protection Equipment and Coordination * Voltage Regulation and Line Losses * Bulk Generation Operations Assessment ® Load Variations of Small Wind Systems ¢ Aggregate Wind Turbine Power Out- put Oscillations ¢ Electrical Characteristics of Wind Turbines ¢ Availability of Wind Turbine Data ISBN: 0-88016-009-8 1981 192 pages 48 figures 18 tables $49.50 OE OO ee ee WINDBOOKS ORDER FORM Quantity Description Price Total Wind Energy Report $115.00 Wind Energy Abstracts $95.00 Both Wind Energy Report and Wind Energy Abstracts $190.00 Siting Handbook for Large WECS $59.50 A Market Analysis of the Potential for - WECS in Remote and Isolated Areas $95.00 Planning Manual for Utility Applications of Large Wind Energy Conversion Systems $49.50 Handbook of the Operation of Small Wind Turbines on a Utility Distribution System $45.00 | Windpower: A Handbook $39.50 Wind Machines: Second Edition $19.95 Siting Handbook for Small ae Wind Energy Conversion Systems $ 7.95 Wind Measurement Systems $ 8.00 na Wind Energy: A Case Study of West Germany $45.00 Wind Power in the United Kingdom $29.00 Proceedings: Third B.W.E.A. Conference $36.00 Proceedings: American Wind Energy Association 1980— Pittsburgh ae $35.00 ‘ 1979—San Francisco i psaaon 1978—Cape Cod $15.00 1977—Amarillo $15.00 Proceedings: BHRA Fluid Engineering 1980—Third Symposium—Copenhagen $90.00 1978—Second Symposium—Amsterdam $55.00 1976—First Symposium—Cambridge, U.K. $53.00 Proceedings: Vertical Axis Wind Turbine Design Technology Seminar for Industry $65.00 Proceedings: New York State Wind Energy Conference $10.00 Proceedings: 2nd U. of Missouri Conference on Wind Energy Technology $49.00 Sub-total: Subtract 10% or 15% subscriber discount: N.Y. State residents add 7% sales tax: en Shipping: Add estimated shipping: (see opposite page) O _Non-U.S. surface mail, add 15% to subtotal: O Non-US. air mail (A.O.), add 25% to subtotal: Total: Mail order to: WindBooks, P.O. Box 14, Rockville Centre, NY 11571 Ship to: Name Company/institution Address City State Zip NOTE: Payment by cash, check or money order must be received before shipment is made. = LARGE WECS SITING HANDBOOK WindBooks Siting Handbook for Large Wind Energy Systems x by T.R. Hiester and W.T. Pennell Battelle Memorial Institute Pacific Northwest Laboratories This handbook focuses on the meteorologi- cal aspects of siting wind turbines with rated capacity greater than 100 kW. The Battelle Siting Handbook outlines the elements of a comprehensive siting strategy which will help identify the most favorable wind energy sites for any region and which will provide suffi- cient wind data to make responsible eco- nomic evaluations of the site’s wind resource possible. The data needs of utility resource planners and large wind farm developers are the primary focus of the siting strategies detailed in the handbook. These strategies and techniques are designed to minimize the chances of poor site selection by providing current knowledge on the most critical as- pects of wind prospecting: spatial and tem- poral wind variability, diurnal and annual wind fluctuations, wind speed and direction, vertical wind shear, turbulence, and flow separation. The chapter on wind arrays is particularly useful because it presents state-of-the-art knowledge for understanding the influence of prevailing wind direction and rotor diameter spacing formulas for maximizing electricity output from large numbers of wind machines ISBN: 0-88016-004-7 at a central site. The Battelle Siting Handbook is a careful synthesis of several years of wind resource research in- to the methodology of successful site selection by Battelle Pacific Northwest Laboratories, the U.S. Department of Energy’s principal wind research center. The handbook complements existing Battelle research and is indispensable to serious wind energy site selection. The Battelle Siting Handbook is essential reading for utility technical personnel, wind farm dev- elopers, engineering consultants, meteorologists, wind turbine designers and anyone seeking com- prehensive understanding of wind behavior and its relationship to turbine siting and performance. Contents: Strategies for Wind Turbine Siting * Numerical Modeling * Physical Model- ing * Topographical Indicators of Wind Power Potential * Biological Indicators of Wind Power Potential © Geomorphological Indicators of Wind Power Potential * Social and Cultural In- dicators of Wind Power Potential ¢ Wind Turbine Wakes and Cluster Design * Measurements and Instrumentation * Regional Wind Resource Assessment * The Variability of the Wind Re- source * Glossary * Bibliography 1981 17 Tables 4 Appendices 514 pages Paper $59.50 Special Bonus: Subscribers to both Wind Energy Report and Wind Energy Abstracts—the world’s leading publications on wind power—save $20.00 on _ the total cost of both subscriptions. Subscribers to either publication are eligi- ble for 10% off any book. But subscribers to both publications can take a Leen The world’s leading publisher WindBooks of books on wind energy. Cover: An Enertech 1.5 kW wind system (foreground) appears to over- shadow the world’s largest wind turbine, the 350-foot MOD-2, manufac- tured by Boeing Engineering & Construction of Seattle. Both machines are located at Goodnoe Hills, Washington, above the Columbia River Gorge—the site of the world’s first large wind machine wind array. HOW TO ORDER FROM WINDBOOKS Mail orders to: P.O. Box 14, Rockville Centre, NY 11571 Minimum Order: The minimum order is $15.00 Payment with Order: All purchases must be paid in full (including ship- ping/handling) prior to shipment by check, bank draft or U.S. Postal Money Order. All orders are shipped within 48 hours of receipt of payment and ship- ping charges. Prices in this catalog are subject to change without notice. Postage and Handling Charges: All U.S. orders are shipped book rate (fourth class) unless other rates are requested and paid for in advance. Please add the following postal charges to your order: $15.00 - $19.99... . $1.50 $40.00 - $59.99... . $3.50 $20.00 - $39.99 . . . . $2.50 $60.00 - $99.99... . . $5.00 $100.00+.. . ...< add 5% to total. United Parcel Service shipping is available at a slight extra charge. Free Shipping: On individual domestic U.S. orders totalling more than $300.00, WindBooks will pay all surface shipping/postage costs. Subscriber Discounts: Subscribers to Wind Energy Report or Wind Energy Abstracts can deduct 10% from the price of books, proceedings, manuals, handbooks, and market studies. Subscribers to both newsletters can deduct 15%. Substantial quantity discounts are available for bulk orders. Please write for details. Tax: New York State residents please add 7% local sales tax. Foreign Orders: All non-U.S orders must be paid in U.S. currency on a U.S. bank or by International Postal Money Order. Developing nations deduct 20% from total. 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Start an account with a minimum of $300.00 and draw against it for immediate, same day shipment of any publication from WindBooks currently in stock. A fully itemized statement, showing current balance, is pro- vided with each order. 189 Sunrise Hgwy. ¢ P.O. Box 14 € “PM oN My indBooks Rockville Centre, NY 11571 ¢ 7 Mark A. Newell 2 Wind Systems Engineering 1551 EF. Tudor Road Anchorage, AK 99502 pm et FALL 1981 CATALOG W.I.N.D. Editor: Donald Marier ABOUT THIS ISSUE U.S. Windpower Will Install 100 Systems ............. 1 Wind Division Board Elections................ Industry’s First Anti-Trust SORES Yen he lnc mae 38 RFP’s for 20 Anemometer Installations Issued ........ Two New SWECS Manufacturers............ Mehrkam Development Co. REGO oor o's wns Lockable Disconnects Required mMiniesota.... 3.0.2.5: Denmark Developing Wind Systems................. Liability Insurance and Hold- Harmless Clauses Will Be Required. 3 orcs con sas ceo Independent Energy Systems Ceases Manufacturing ..... . Hummingbird Wind Power COMinc ees ata Aerotherm Now in Production..............+ 5 Test Site For Wind Machines. . .5 Publications Received........ Wind Industry News Digest Copyright ©1981 by Alternative Sources of Energy, Inc. No part of this publication may be reprinted, reproduced, transmitted, or electronically stored in a data base system without written permission from the publisher. Editor: Donald Marier W.I.N.D. is published monthly by Alterna- tive Sources of Energy, Inc., 107 S. Central Ave., Milaca, MN 56353. (612) 983-6892. Subscriptions: U.S., Canada and Mexico ~ First Class Mail — One Year $36; Two Years $65. All Other Countries — Air Mail — One Year $45; Two Years $81. Wind Industry News Digest WIND SYSTEMS PUBLISHED® CPO UUW EES ES OF This is the Model 56-50 wind turbine that U.S. Windpower, Inc., will use on the “wind farm” it will develop in the Altamont Pass area of eastern Alameda County, about 50 miles east of San Francisco. When fully developed, the facility will comprise 600 windmills that will produce an estimated 90 million kilowatt-hours a year. U.S. Windpower Will Install 100 Wind Systems in the Altamont Pass area soon and a total of 600 systems will be installed within a few years. The wind farm will be located on the Walker Ranch just east of Livermore, California and north of Interstate 580 in Alameda County. It is about 50 miles northeast of San Francisco. Power generated will be purchased by Pacific Gas and Electric Company (PG&E) of San Francisco. Nolan Daines, Vice President of Planning and Research for PG&E called the pro- ject a “*. . . significant and welcome milestone in the development of alternative and sources.” US. Windpower, of Burlington, Massachusetts, will install its Model 56-50 wind systems at the site. The units will have a rated output of 50 kilowatts at 22 m.p.-h. The rotor is a 3-bladed, down-wind, and of fiber- glass construction. The first 100 units will generate an estimated 15 million kilowatt-hours per year. According to PG&E, this is equivalent to the annual electric consumption of 2,300 average homes in its service area. Or it is equivalent Continued on page 2 renewable energy Wind Inpustry News Dic to 24,000 barrels of oi! which would otherwise have to be burned in an oil- fired power plant to produce electri- city. When all 600 machines are installed, an .estimated 90 million kilowatt-hours of electricity will be generated yearly. The owner of the Walker Ranch, Hugh Walker, relates that winds are so strong in the area (averages exceed 17 m.ph.) that it is sometimes impossible to open doors on the west side of his home. “We'll finally be using the wind instead of swearing at it,” he remark- ed. The ranch will be continued to be used for cattle grazing and dryland farming after the wind units are in- stalled. US. Windpower began operation of a 20 unit wind farm at Crotched Mountain in New Hamshire in Jan- uary, 1981. The 30 kw units have 40 foot diameter rotors. These machines are being used as the prototypes for the Altamont Pass windfarm and other projects planned by U.S. Windpower. PG&E’s announcement of the Alta- mont Pass project follows closely its announcement in April, 1981 of the wind farm to be developed by Windfarms, Ltd in Solano County. In that project, Windfarms, Ltd will install 150 wind systems with a com- bined capacity of 350 megawatts in three stages by 1989. The com- bined output of the planned sixty- seven 500 kw and seventy-nine 4 mw units will be an estimated 1 billion kilowatt-hours per year. PG&E also plans to install a Boeing MOD-2 in Solano County near Fair- field, California in early 1982. The WECS Evaluator slide rule contains conversions for tower height (1/7th power law), wind power den- sity, and annual energy production (Rayleigh distribution), plus conver- sion factors. It should be useful for field estimates or for classes. The Evaluator is available from Regional Systems Services Group, Inc., 5680 South Syracuse Circle, Suite 514, Englewood, CO 80111. Wind Division Board Members of AS/ISES recently elected to the board include Dr. Irwin Vas of the Solar Energy Research Institute, Dr. C. G. Justus of Georgia Institute of Tech- nology, Dr. Marshal Merriam of the University of California, and Donald Marier of Alternative Sources of Energy, Inc. Dr. Pat Takahashi was elected Chairman of the Board, Dr. Vas as Vice-Chairman, and Donald Marier as Secretary-Treasurer. The Industry’s First Antitrust Suit has been initiated by Solargy Corpora- tion against Enertech Corporation. The following statement was issued by Solargy Corp. (17914 E. Warren Av, Detroit, MI 48224): “On June 25, 1981, Enertech Corporation of Norwich, Vermont, the major manufacturer of rural residential wind turbine induction gen- erators, was sued by its primary distri- butor, Solargy Corporation of Detroit, Michigan, for unfair competition and antitrust violations. In particular the suit, which was brought in the Federal Court for the Eastern District of Michigan, alleged that Enertech was imposing a tie in restriction on purchases of its ma- chines, whereby it required purchasers of its machines to also purchase from Enertech the towers which supported the wind generators. Solargy, which sells its own line of towers for wind turbine generators, has asked for a minimum recovery of $480,000.” RFP’s For 20 Anemometer Instal- lations are being issued by the Cali- fornia Office of Appropriate Tech- nology (1600 9th St, Sacramento, CA 95814) according to Remy Ceci, Cal OAT’s new Wind Technology Specialist. Remy, a graduate of the Red Wing (Minnesota) Vocational Technical Institute Wind Program, assumed the position in July, 1981. Cal OAT plans are to locate 20 anemo- meters at state owned facilities for one year. Facilities will include Parks, Recreation, and Forestry areas as well as Caltrans. Results of the siting pro- gram will help build the wind data base for California. In addition, ap- proximately 12 to 14 of the sites will be chosen for possible installation of wind systems to be purchased from manufacturers. Cal OAT is also conducting a feasi- bility study for possible installation of a wind system at the California Maritime Academy in the Carquinez Straits area. In another project, a wind system will be installed near the Half-Moon Bay airport south of San Fancisco. Wind power will be used for lighting the runway lights. Funding is being provided from a DOE A.T. small grant and from Cal- trans and San Mateo County. > OCTOBER, 1984 12 volt fluorescent from REC Spe cialties. REC Specialties (530 Constitution Av, Camarillo, CA 93010) makes 12 volt dc fluorescent lights for wind and photovoltaic applications. Units come in 8 to 32 watt sizes and have their own built-in inverters. Wind Engineering Consultants (3421 Adams Av., San Diego, CA 92116) offers a line of moderately priced wind siting instruments. W.E.C. makes a Windometer, a wind odo- meter; the Windplant Energy Simula- tor, an energy output simulator; and the Windlogger, a wind spectrum ana- lyzer.- The Windlogger stores wind speed data in a memory module and the module is mailed back to the com- pany for data processing periodically. Several months of data can be stored in the module. This makes for a low cost wind distribution analyzer sys- tem. Two New SWECS Manufacturers have entered the field. Bircher Ma- chine, Inc. (Box 97, Kanopolis, KS 67454) is manufacturing the BMI 671-WES with 15- foot diameter, 3-bladed prop, and 5 kw, 220 Volts ac generator. The WES.T. (Wind Energy Sys- tems Technology, 1835 W. Union No. 11, Englewood, CO 80110) 5 kw Swecs has a 20 foot diamter, 3-bladed prop of steel-reinforced fiberglass con- struction. An H.T.D. drive belt with 11:1 ratio turns a 115 or 230 volt synchronous generator. Propellor pitch is electronically controlled with a mechanical brake for backup. The WES.T. design utilizes a synchronous generator configuration. The control circuitry monitors the utility phase angle and adjusts the propellor pitch angle to maintain synchronization and a constant power factor. To date, WEST. units have been installed only in Colorado. Bob Gifford. Vice President of W.E.S.T., notes that the company is establishing a dealer net- work in nearby states. WIND INDUSTRY NEws DIGEST OCTOBER, 1981 Mehrkam Development Co. Is Re- grouping after experiencing several problems with runaway rotors and low outputs in low wind areas. “We’ve seen a lot of successes and failures” says Terry Mehrkam (Mehrkam Energy Development Co., 179 E. RD2, Ham- burg, PA 19526). A new 40 kw design is being licensed to a major agri- business company which will be build- ing units up to 300 Kw in size. The units have 4-bladed extruded alumi- num rotors and induction generators. Mehrkam units are presently planned for installation at wind farms near San Diego and in the San Gorgonio Pass although projects in the Pass have been delayed by environmental impact studies. Line noise in control circuits proved to be a problem on several of the machines Mehrkam first installed. The Kahua Ranch (Hawaii) machine had its blades fly off at 600 - 700 t.p.m. Mehrkam blames this on con- crete and water which got into the logic system during construction. The unit (originally purchased by the D.OE.) has been rebuilt and is now operated by the ranch owner. “We have installed English made air disk brakes on all new units” says Mehr- kam. Other Mehrkam units originally installed in Pennsylvania have been removed because of low power output. According to Mehrkam, the local winds proved to have only a 6 to 8 mph average instead of the 9 to 10 figure predicted by airport data. Problems with the first Mehrkam 2MW machine have not discouraged Mehrkam either. The unit, installed at the Reading Metal Plant in Red- ding, PA never ran on a day-to-day basis. A new unit is planned however, using a variable speed transmission to maintain constant power between 30 and 50 m.ph. Jim Schmidt has been appointed as instructor for wind technology courses at the Red Wing Area Voca- tional Technical Institute in Red Wing, Minnesota. Lockable Disconnects Are Required For Co-Generation Systems In Minne- sota according to John Quinn, Execu- tive Secretary of the State Board of Electricity for Minnesota. Quinn outlined the electrical requirements for wind systems and other co-genera- tion systems as specified by the Na- tional Electrical Code (N.E.C.) in a recent meeting for installers, manu- facturers, and utility representatives. He emphasized that the State Board did not intend to develop new re- quirements for wind systems but only to interpret the NEC. as it applies to such systems. Any changes to the N.EC. or local requirements would have to come through the nor- mal procedures, he stated. The main requirements oulined by the Board are for a lockable discon- nect switch to be placed between the co-generation system and utility power and that the co-generation system be listed by a recognized test- ing laboratory. The lockable dis- connect must be accessible by utility personnel. At the meeting, Alvin Tomford of Oakridge Windpower, Inc. expressed the concern that some customers may be bothered by the requirement and interpret it as a right for unlimited access to their premisses by utility personnel. Mar- cellus Jacobs of Jacobs Wind Electric noted .that the physical placement of the disconnect switch is important. Utility people would prefer that the switch be placed on or near the tower but this would requiré that the switch be wired between the generator and the control panel. Such an arrangement would not be acceptable in some systems, partic- ularly those using synchronous in- verters since the electronics could be damaged by opening the switch at the wrong time. Although the State Board will require laboratory certification of wind and other co- generation systems, manufacturer cer- tification will be accepted until laboratory facilities and standards are worked out. This amounts to the manufacturer being able to demon- strate that the system will discon- nect from utility power as soon as power is interrupted. In a memorandum entitled “Re- quirements for All Electrical Wir- ing, Apparatus and Equipment for Co-Generation Installations” Mr. Quinn summarized the requirements discussed at the meeting as follows: “Licensing and inspection is re- quired per Minnesota Statutes 326.242 and 326.244. The co-generation system shall be listed by a recognized testing laboratory, The listing shall detail the conditions under which the system shall operate. 3 Until such time as a listing ser- .Vice is available, the manufacturer is to certify that the wind generat- ing system will automatically cease generation when the utility serving the co-generation system ceases to provide an input - even though other co-generation systems are providing an input. The conductors from the genera- tor to the inverter and/or control unit must be protected by inherent design, fuses, breakers or other ac- ceptable means. Generator shall have a nameplate per National Electrical Code par. 445-3. A grounding conductor must be run between the tower and the control equipment and/or service entrance, except for separately derived systems grounded in accordance with National Electrical Code Section 250-5, 250-26 and 250-50. A lockable disconnecting means shall be provided between the co- generation equipment and utlity source.” fe, Integral wind generator, light and storage for various applications. Howe International’s (Nuffield In- dustrial Estante, Poole, Dorset, Eng- land) is offering a series of wind pow- ered lights for navigational use. A 5 watt wind-driven generator with inte- gral light and battery pack has pro- grammable electronics used to select different signalling combinations for ships and buoys (IALA and ISOC). Pictured is the LTWDSW model with 30 amp-hr battery. The unit is 1.3 meters high and weighs 40 kg. Winp INDustRY.NEws DIGE Denmark Has Been Developing Wind Systems longer than the US. and now Danish units are being im- ported into America. The Importer is Nielsen Iron Works (1500 N. Memo- rial Dr., Racine, WI 53401) which has just begun shipping SJ. Wind- Power (Suderbovej 4, 9900 Frede- rikshavn, Denmark) ~ units. Stan Spencer, engineer for Nielsen Iron Works, told us that they will soon be importing Wind-Matic and other systems from Denmark. Nielsen is no newcomer to the wind field, having already fabricated towers for Wind- works, Inc. in Wisconsin. Plans are to fabricate towers for all the import- ed units. The first SJ. Wind Power distrib- utor in the US. is T. Jensen Asso- ciates, Inc. (Rt 2, Cannon Falls, MN 55009). T. Jensen Vice President, John Cuddy, notes that the SJ. Wind-Power units will be installed primarily for space heating systems although 4 utility-connected package with synchronous inverter will be available. The SJ. unit has a 16-bladed, 22 foot diameter rotor with polyure- thane blades. The synchronous al- ternator provides 10 kw of power in 29 mph. (13 M/S) winds. Voltage options are for 220 volt single phase or 380, 220, or 150 volt 3 oa alternators. Gear ratio for the dhigst loaded gearbox is 30:1. The multi- bladed rotor self-stalls in high winds but an additional shut down is a hy- draulic control which folds the tail vane due to shaft overspeed or gener- ator over-voltage. John Cuddy notes that the installed cost of the space heating model will be approximately $18,000. For for- ced air heating systems, a 10 kw heat- ing unit is installed in the plenum or in the cold-air return of the furnace. For hot water systems, two 10 kw immersion heaters are installed in the tank. If the heating system does not need excess heat, the domestic hot water system can be activated by the controller circuitry. Cuddy stated that the first SJ. unit, installed in Cannon Falls, MN, survived two 75 m.p-h. winds and a hail storm im- mediately after being put up. S J. Windpower Specifications: Design Output - 10 kw at 13 M/S (29 mph) Rotor Configuration - Horizontal axis, fixed pitch, high torque, steel re- inforced high density urethane. Rotor Diameter - 22 feet Number of Blades - 16 Rotor Speed Control - Self Stalling Blades. Overspeed or overvoltage conditions activate hydraulic con- trols which turn the rotor parallel to the prevailing wind. : Generator - 380/220/150 volt, 3 phase or 220 volt single phase alternator. Gear Box - 30:1 ration, designed for thrust loads. Cut-in wind speed - 9 mph Overspeed control cut in - 29 mph Rated wind speed 10 kw at 29 mph (13 m/s) Survival wind d - 100 mph Output at 9 m/s (20 mph) - 4 kw Output at 12 m/x (27 mph) - 9.5 kw 4 OGTOBERM981, ~ Liability Insurance and Hold-Harm- less Clauses Will Be Required if rural electric cooperatives follow the sug- gestions of the National Rural Elec- tric Cooperative Association (NRECA, 1600 Massachusetts Ave NW, Wash- ington, DC 20036). This position was outlined by Lowell Endahl, NRECA Manager of Energy R&D at the Rocky Flats Wind P Woikahop in Boulder, CO in May, 1981. The hold-harmless clause is an agreement between the qualifying fa- cility (QF) and the utility to mutually indemnify and hold the other party harmless for injuries or damages caused by either the QF or the utility. “We must emphasize that rural electric systems cannot and will not be liberal about policies and practices that could jeopordize human lives.” states Endahl. He expressed further con- cerns about home-built wind or hydro- systems potentially causing line safety problems. A further recommendation of NRECA is that the QF be required to obtain general liability insurance to cover operations as an electrical generator. The recommended mini- mum coverage is $1,000,000. Such an insurance policy could cost anywhere from a modest fee up to several hun- dred dollars per year for an individual. Anticipating the charge that the rural coops are trying to stop the develop- ment of wind energy, Endahl outlined a series of recommendations in his paper entitled “REC Experiences and Winb ENpustry News DIGEST OCTOBER, 1981 Concerns With Interconnection of Small Wind Energy Systems”. These recommendations are summarized as follows: 1) The utilities should provide instrumentation for a reasonable num- ber of wind systems to get reliable data. 2) Wind system manufacturers and installers should work closely with utilities when planning instal- lations. “Utilities don’t like sur- prises.” 3) Cost of insurance could be a deterrent but manufacturers can de- velop their own insurance program. NRECA itself was originally formed to deal with insurance problems that coops originally had. 4) Utilities and manufacturers should develop a joint research pro- gram. Mr. Endahl called for further dialog between the utilities and manufacturers. “I have a feeling that maybe these (insurance requirements) aren’t going to be the big problems that we think they are right now. Utilities do need to monitor more wind machines to get the experience. We just don’t know enough about it at this time.” Rumors That Independent Energy Systems Has Ceased Manufacturing the Skyhawk wind systems are true. I.E.S. President, John D'Angelo blames high interest rates as the deciding factor in curtailing his sales. Meanwhile, another major wind system manufacturer will soon an- nounce its sale to a larger company. ~~~ Details will follow in W-EN-D> Hummingbird Wind Power Corp, a subsidiary of Power Group Interna- tional, is converting to a synchronous inverter design. The original Hum- mingbird design utilitzed a synchro- nous generator approach which proved to be unreliable in the field. This de- sign relied on a servo-controlled tail vane to regulate rotor speed and to allow the control circuitry to synchro- nize the generator with utility power. The response time of the circuitry and hardware proved to be too slow to properly synchronize during gusty conditions. This problem became apparent only after an agressive deal- er had sold dozens of units in Wis- consin, thus leaving many customers disgruntled. After much work, designer Chuck Syverson came up with a control circuit that would function but it proved to be too expensive, according to Syverson. Another negative factor was the reluctance on the part of utilities to accept a synchronous generator design in a SWECS, accord- ing to Syverson. It was at this point that the com- pany decided that the synchronous inverter design is most realistic at this time, according to Hummingbird Presi- dent Mario Gottfried. Speaking from his office in Mexico City, Gottfried stated that the company plans no fur- ther sales to the public until the design changes are proved in and all units previously sold are retrofitted. He emphasized that no major changes have been made to the wind generator hardware itself except for a change in the tower-mounted limit switch and a change from cast-iron to steel in the mounting pedestal. Aerotherm Is Now In Production with its 25 kw wind system which is designed as a stand-alone “wind fur- nace”. Four machines have been built and installed and 10 machines are being produced in September, 1981. Aerotherm (Box 574A, Len- hartsville, PA 10534) is betting that the use of wind energy for home heating will be a significant market since wind patterns match winter heating patterns well and since the utility interconnect problems are a- voided with such a design. Morgan Doughton, President of Aerotherm Corp., states that “Utilities are not interested in dealing with machines under 10 Kw for the average home- owner,” The first Aerotherm Units are now being manufactured and _ installed. The 33 foot diameter, 3 bladed rotor used on the Aerotherm design has a patented pitch control which varies the blade angle from 5 to 90 degrees at full feather. Startup is at 5 mph. and rated power of 25Kw is reached at about 26 mph. A 14:1 gearbox turns the alternator which supplies varying dc electricity to heating coils mounted in a heat storage tank in the home. The tower is a simple guyed steel pole design. 5 Aerotherm is using an insulated (R40) 1000 gallon plywood tank which is lined with rubber than can withstand temperatures up to 190 F. The tank system has been used widely in solar and wood heat systems. It is distributed by Sven Tjernaga’s Solar Systems Company of Mechanics- ville, PA. The Aerotherm system is expected to keep tank temperatures at 145° to 160° F in normal opera- tion. Aerotherm Vice President Art Troup stated that one of the first units installed is being used to drive a heat pump in a commercial applica- tion. The alternator output is recti- fied to drive a 3 to 12 volt variable voltage d.c. motor. A Test Site For Wind Machines is being established at the Golden Gate Energy Center (Building 1055, Fort Cronkhite, Sausalitor CA 94965). The Center is being established at the previously vacant Fort Cronkhite on the Marin Peninsula in the Golden Gate National Recreation Area. Fund- ing for the tax-exempt organization is being provided by private founda- tions. Executive Director Webb Otis comes to the Center from the Office of Small Scale Technology in Wash- inton, D.C. and Program Manager Tom Javits comes from the Integral Urban House Project of the Farallones Institute. Steve Mooney, Technical Program Coordinator, is establishing the wind machine test site. Mooney is moni- toring monthly wind data at the site and making the data available to prospective users. Presently, data is collected using an M.R.I. weather- station with strip chart recording and the data is then reduced on an Apple II computer. Monthly wind distribu- tions, a wind rose, and hourly averages for the month are printed out. Data collected to date show a 11.3 to 11.8 m.p.h. average, Mooney says. The site is located at an elevation of 880 feet above sea level and is only one mile from the Pacific Ocean so that marine corrosion effects can be tested at the site. Presently, a 500 watt Sencen- baugh for remote applications is being tested at the site. Prototypes from at least two de- signers are being readied also, accord- ing to Mooney. Experimenters May Be Interested in the Thermax model TC25G dc. generator. The permanent magnet generator produces 12 volts, 25 watts at low r.p.m.s. Plans available (Ther- mas Corp, One Mill St, Burlington, VT 05401) with the generator show how WIND INDustRY. News DIGEST “OCTOBER; 1981 to build a small wind, water, or pedal power unit. The Wind Power plans show how to build a 24x48 inc helical rotor from Lexan plastic. The rotor is v-belted to the p.m. generator. *PUBLICATIONS RECEIVED Wind Energy Activities in Africa, Alan Wyatt, Volunteers in Technical Assistance, 3706 Rhode Island Ave, Mt. Rainier, MD 20822, 35 pp. Presented at the Global Energy Challenge: African Perspectives and Business Opportunities conference in Houston, Texas, March 13, 1981, the paper presents a synopsis of wind energy activities in Africa. Included are data on organizations, availability of wind data, and water data. A bib- liography is included. Performance Summary _ Sheets, Rocky Flats Wind Systems Program, PO Box 464, Golden, CO 80401. A series of performance sum- mary sheets based on the SWECS testing program at Rocky Flats are now being made available. In some cases the summaries will be of limit- ed usefulness since the model has been discontinued or changed in the two years it has taken to get the data out. In some cases the power curve derived at Rocky Flats does not match that published by the manufacturer. In each case an explanation is given. For example, the American Wind Turbine model AWP-16 was not able to produce the manufacturer’s rated output because of two factors. They are - “The first factor was the use of manufacturer specified resistive load, rather than a submersible pump motor which the machine was designed to power. The second factor was the high start-up torque of the variable frequency ,; permanent magnet genera- tor.” Similarly, the Enertech model 1500 power output derived from con- trolled velocity testing at the De- partment of Transportation’s rail fac- ility in Pueble, CO was significantly lower than the manufacturer’s pub- lished data. The explanation given on the data sheet is that “It is impor- tant to note, however, that RF per- formance data are for a machine with tip brakes; while manufacturer specifications contained in this Per- formance Summary Sheet are for an earlier model without the tip brakes.” Preformance Summary Sheets are presently available for the following models: American Wind Turbine AWP-16; Aero Power SL1000; Jay Carter Model 25; Enertech 1500; and Whirlwind A 120. Fundamentals of Wind Energy, Paul Gipe, P.O. Box 539, Harrisburg, PA 17108a, $13.95, 85 pp. A looseleaf collection of writings on wind power suitable for either gen- eral reading or course work. Areas covered are hardware, power curves, payback, siting, and installation. Operation of Small Wind Tur- bines on a Distribution System, Final Report, March 1981, David Curtice, James Patton, Rockwell International Corporation, RFP-3177-2-UC-60, NT1S., 5285 Port Royal Road, Springfield, VA 22161, $12.00, 158 Pp. This report discusses theoretical models for the impact of SWECS on the utility grid. Factors such as penetration, load variations, voltage regulation, and impact on protection equipment are covered. The authors conclude that both frequency and voltage sensing relays are recommend- ed to disconnect SWECS from the grid. The authors begin with the assumption that certain safety prob- lems exist without questioning those assumptions and whether they can exist under real conditions. Never- theless, the report contains useful technical data for the evaluation of wind system-to-grid interface require- ments. WIND ENERGY RESOURCE ATLAS: VOL. | to 12, Pacific Northwest Laboratory, % U.S. Government Printing Office, Superintendent of Docu- ments, Washington, DC 20402. Twelve of the 13 volume Wind Energy Resource Atlas series, which was prepared by the Pacific Northwest Labs, are now available. Each volume cov- ers a different geographic region and includes extensive wind and geographic data for that area. Included are topographical maps, power density maps, wind speed frequency data, and seasonal variations. Anyone involved in the business of siting wind systems should obtain copies of the appropriate vol- ume for their region. We need more and better wind data but these volumes represent the best data available at this time. They do not subplant the need for local listings however. Title, price, and order numbers for each volume is as follows: Wind Energy Resource Atlas: Volume | - The North- west Region (Idaho, Montana, Oregon, Washington, and Wyoming) Wind Energy Resource Atlas: Volume 2 - The North Central Region (Iowa, Minnesota, Nebraska, North Dakota, and South Dakota) Wind Energy Resource Atlas: Volume 3 - The Great Lakes Region (Illinois, Indiana, Michigan, Ohio and Wisconsin) Wind Energy Resource Atles: Volume 4 - The North- east Region (Connecticut, Maine, Massachusetts, New 06 1-000-00446-7 ($6.50) 061-000-00529-3 ($6.00) 06 1-000-00528-5 ($6.00) 06 1-000-00486-6 ($6.50) Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont) Wind Energy Resource Atlas: Volume 5 - The East Central Region (Delaware, Kentucky, Maryland, 061-000-00502-1 ($6.50) North Carolina, Tennessee, Virginia, and West Virginia) Wind Energy Resource Atlas: Volume 6 - The South east Region (Alabama, Florida, Georgia, Mississippi, and South Carolina) Wind Energy Resource Atlas: Volume 7 - The South Central Region (Arkansas, Kansas, Louisiana, Mis- souri, Oklahoma, and Texas) Wind Energy Resource Atlas: Volume 8 - The South- ern Rocky Mountain Region (Arizona, Colorado, New Mexico and Utah) Wind Energy Resource Atlas: Volume 9 - The South- west Region (California and Nevada) Wind Energy Resource Atlas: Volume 10 - Alaska Wind Energy Resource Atlas: Volume 11 - Hawaii and U.S. Pacific Trust Territories Wind Energy Resource Atlas: Volume 12 - Puerto Rico and US. Virgin Islands 061-000-00530-7 ($6.00) 061-000-00533-1 ($6.50) 061-000-00534-0 ($6.00) 06 1-000-00509-9 ($5.00) 061-000-00527-7 ($6.00) 06 1-000-00536-6 ($4.75) 061-000-00535-8 ($4.50) Wind Energy Resource Atlas: Volume 13 - United States and its Territories (Synthesis of Regional Atlases) 6 m7 Winb INDUsTRY NEws DIGEST OBER, 1981 HERE IS YOUR SAMPLE COPY! As a member of the wind energy community, you need a timely newsletter which covers all aspects of the wind energy field. I am confident you will find that WIND INDUSTRY NEWS DIGEST fits the need. Future issues of WIND INDUSTRY NEWS DIGEST will offer the news as it happens*: ©@ Ground-breaking research-innovative systems @ Developments in siting @ Field Experiences - what the installers say. @ News of the manufacturers - new machines and installations @ The components market - new products and applications @ Business news - wind farms © Legislative and policy activities - PURPA, NEPA, NEC, Zoning ® Publications - books, reports, abstracts @ Calendar announcements - conferences, call for paper WIND INDUSTRY NEWS DIGEST is edited by Don Marier. Don is the Director of Alternative Sources of Energy, Inc. and the Executive Editor of ALTERNATIVE SOURCES OF ENERGY MAGAZINE. He is a member of the Board of Directors of the Wind Division of the Solar Energy Society, American Section (AS/ISES), he is author of WIND POWER FOR THE HOMEOWNER (Rodale Press, 1981) and has published numerous articles on wind power. Besides having a masters degree in Electrical Engi- neering, Don has 10 years of experience in the field. *Of course, ALTERNATIVE SOURCES OF ENERGY Magazine will continue to run feature-length articles on wind energy in each issue as well as updates in the “‘Wind Focus” section. COMING EVENTS Fifth Biennial Wind Energy Conference & Work- shop (WWV). October 5-7, 1981. Washington, D.C., Sheraton Washington Hotel, 2660 Woodley Road at Connecticut Av., NW, Wash., D.C. 20008. (202) 328-2000. Sponsored by S.E.R.I. and D.O.E. Wind Division Registration fee: $80.00. In a last minute development - booths for product displays have been eliminated and replaced by poster sessions. For registration information, contact: S.E.R.I. Confer- ences Group, Attn: Jeanna Finch, 1617 Cole Blvd., Golden, CO 80401, (303) 231-1026. Make checks payable to: Alternative Sources of Energy, Inc. Subscriptions: U.S., Canada, and Mexico - First Class Mail - One Year, $36; Two Years - $65. All Other Countries - Air Mail - One Year - $45; Two Years, $81. Wind/Solar Energy Technology Conference. April 5-7, 1982. Kansas City, MO. Sponsored by Univer- sity of Missouri-Columbia, American Society of Civil Engineers, American Wind Energy Association, Department of Energy, and Missouri Department of Natural Resources. 500 word abstracts on reaearclr and applications in solar and/or wind energy are due by October 15, 1981. Contact: G.H. Stickney, College of Engineering, University of Missouri- Columbia, Columbia, MO 65211. Wind Industry News Digest Non-profit 107 S. Central Av. organization Milaca, MN 56353 | U.S. POSTAGE PAID Milaca, MN Permit No. 115 a & WS. S. Sx & a Ce ss york Newell _sineerings 1” oe wand aree te or Road gy * 1551 1 ¥ anchorage aK 995° » INC. 1551 East Tudor er ANCHORAGE, ALASKA 99507 WIND ENERGY Report The International Newsletter of Wind Power JUNE 1981 Mod-2 damaged during BPA testing Ten days after the world’s first large wind machine array was formally dedicated, one of three Boeing/NASA MOD-2s was exten- sively damaged while undergoing a planned shutdown routine at its test site in Goodnoe Hills, Washington. The No. 1 MOD-2—the first unit install- ed at the Goodnoe Hills, cluster—failed to feather during a scheduled fast shutdown test on June 8. The test called for the elec- trical load to be removed and the blade tips to feather the machine to a halt. However, the blades tips failed to feather properly allowing the rotor to accelerate 60.% be- yond its normal rotational speed. The over- speeding MOD-2 burned out the generator and damaged the quill shaft and drive train in the process. Immediately after the incident, the No. 2 and No. 3 MOD-2s were shut down pending a detailed investigation by NASA, Boeing and Bonneville Power Administration of- ficials. No one was hurt during the episode. By the end of the month, details of the causes of the overspeed condition were still not fully available, although speculation centers on a possible hydraulic failure or an electronic control malfunction which caus- Inside W.E.R. In the news Carter wind farm in Montana MOD-2 damaged Calendar Three 100 kW Darrieus operational . . BuRec seeks Wyoming funding Medicine Bow wind farm study New publications ISSN: 0162-8623 ed the blades to delay feathering. According to BPA sources, the following scenario led to the overspeed condition of the 300-foot rotor diameter MOD-2: “When the [shutdown] test began, the 180,000 pound rotor was rotating smoothly in a 28 mph wind at its rated wind speed of 17.5 rpm. A button was pushed to start the fast shutdown. The [blade] tips were in a plus 3° position. The blade tips are design- ed to feather at the rate of about 4 °per se- cond during a fast shutdown. In this in- stance, they began to feather at the rate of 1° per second, which is typical for a nor- mal, slower shutdown. After about 2 sec- onds, the tips for some unknown reason stopped feathering. They were then in a 5 °degree position.”’ Both blades were designed to feather simultaneously. But, according to Boeing, just one fully feathered blade is necessary to stop the machine. The outer 30% of the blade, rotatable through 100° is used for pitch control. Hydraulic pitch governs both rpm and power. The hydraulic pitch change mechanism of both blades did not respond quickly enough to signals from the unit’s micropro- cessor, located in the MOD-2’s nacelle. Continues BPA: ‘‘Two and a half sec- onds after the button was pushed, a trip command, functioning as designed, remov- ed the electrical load from the generator. With the load gone from the generator, the rotor began to spin more freely. Within 28 seconds, it had accelerated and was spin- ning at the rate of 28 rpm. It was then that centrifugal forces caused the rotor windings in the generator to dislodge. “The tips then feathered and the long blades slowed to a stop in five more revolu- tions. It has not been explained why the rotor tips began to feather at a slower than (Continued on page 4) Reclamation seeks Medicine Bow funding The Bureau of Reclamation has finalized plans for its 100 MW wind farm at Medi- cine Bow, Wyoming, and is asking Con- gress to authorize $189,000,000 to build the wind-hydro project. If funds are approved by Congress, the Medicine Bow wind farm is expected to be completed by 1990. So far, it is the largest federal wind energy project to have reached the stage where it can ask for significant funding. In a combined economic feasibility and environmental assessment study released this month, the agency details its plans by examining two 100 megawatt wind farm op- tions: one using 25 Hamilton Standard 4 MW WTS-4 units and the other employing 40 Boeing Engineering & Construction MOD.-2s. Total project costs for each op- tion are $185,370,000 and $275,250,000, respectively. Importantly, both figures are calculated in October 1980 dollars. These figures include interest charges of 7 3/8% during a seven-year construction period and 82% carrying charges throughout the pro- ject’s 30-year lifetime. Based on estimated performance of the two machines, the Hamilton Standard wind array could produce 298 million kWh and the Boeing configuration 351 million kWh annually. This translates into an annual oil saving of 537,000 and 632,000 barrels, res- pectively for the WTS-4 and MOD-2. At $35/barrel, the net fossil fuel cost savings are $18,795,000 and $22,120,000. Importantly, more than two-thirds of the electricity generated by either machine will occur during the winter and during onpeak periods. While actual procurement will be done by competitive bidding, the agency is basing its funding request on the economics of using the Hamilton Standard option ‘‘for the purpose of establishing the congressional authorized ceiling,” according to B.E. = (Continued on page 6) Wind Energy Report Inthe news... WECS Industry Wind Engineering of Lubbock, Texas, says that it plans to re- enter the wind turbine manufacturing business shortly, after having obtained sufficient additional financing to continue development of a 25 kW three-bladed horizontal-axis prototype. “We spent a lot of money and encountered a whole multitude of problems when we first started this project”’ in 1977 says Coy Har- ris, president of the firm. The chief problem, apparently, was lack of operating capital. That plight prompted Bendix Corporation to make an offer for the company last year. The acquisition didn’t materialize, according to one Bendix official, because the timing was bad. It was to be acquired by a Bendix subsidiary heavily in- volved in supplying parts to the flagging automobile industry. Diversifying in the face of sagging automobile sales was not seen as a wise investment. Nevertheless, Wind Engineering has been able to raise an unspecified amount of investment capital, enough at least to make some predictions about its own future production and speculate on the size of the wind turbine market. Harris says the Company ex- pects to build about 20 to 30 machines a month, once full produc- tion begins, sometime later this year. Purchase price of the machine is approximately $24,000, including installation. Harris anticipates that the company could be making about 250 machines annually. The potential market, he says, could be as large as 800,000 machines. The turbine itself features a variable pitch, downwind rotor, employing three fiberglass fabric blades impregnated with silicone laid over an aluminum frame. A 230/460 V, 3-phase AC induction motor is located about a third of the way down a Rohn 60-foot lat- tice tower and connected to the gearbox through a shaft. According to Wind Engineering, the turbine achieves rated 25 kW in 25 mph winds. The operating range is between 10 and 45 rpm, at which point the blades pitch to feather the machine. For further information, contact: Coy Harris, Wind Engineer- ing, Airport Industrial Area, P.O. Box 5936, Lubbock, TX 79417. (806) 763-3182. Although Bendix decided not to acquire Wind Engineering, the multi-billion dollar automotive-electronics-aerospace corporation did solidify its stake in Enertech, a manufacturer of 1.8 kW, 4 kW and a 15 kW prototype. Bendix announced this month that it has acquired a 30% equity position in the Norwich, Vermont, company by converting an existing $750,000 loan into shares of Enertech stock. According to Bendix, the company can make further loans to Enertech—for as much as $2 million—and has the option to ac- quire additional shares of Enertech stock in the future. ‘‘We believe there is promising business potential in the residential and agricultural markets Enertech serves,”’ says William C. Purple, President of the Bendix Aerospace-Electronics Group. ‘‘Bendix plans to work closely with Enertech in the further development of Enertech product technology.’’ By acquiring nearly a third of Enertech—which the Wall Street Journal says had sales of $1.5 million in the fiscal year ended September 30, 1980—Bendix will eventually reap the benefits of more than $1,032,000 through two Department of Energy research and development contracts to design three-bladed 1-2 kW ‘‘high reliability’? ($318,000) and 15 kW machines ($714,000). Enertech claims to be the largest U.S. manufacturer of small wind machines. The company says it has more than 500 1.5 kW and 1.8 kW systems installed worldwide ($3,950 F.O.B., less tower and installation). It is reported to be testing as many as 50 new 4 kW systems. The 15 kW prototype, now in final stages of fabrication for DOE, is expected to become a commercially rated 20 kW in the near future. June 1981 Meanwhile, one disgruntled distributor of Enertech machines in Michigan is suing the company, alleging ‘‘unfair competition and anti-trust violations.’’ Solargy, a Detroit, Michigan, manufacturer of SWECS towers alleges that Enertech is requiring purchasers of its systems to buy Enertech towers as well. Solargy is suing in U.S. District Court for Eastern Michigan, asking ‘‘for a minimum recovery of $480,000.”’ For more information, contact: Enertech, P.O. Box 420, Nor- wich, VT 05055. (802) 649-1145. The chemical process industry appears poised to become a major supplier of materials to the wind power industry. At least that’s the conclusion of an article and an editorial in the May 13 issue of Chemical Week, a trade publication of the chemical process industry. The publication is read by more than 50,000 readers and its editors provided The industry sees wind power as a potential source of power for its own energy intensive processing but mainly as an opportunity to supply WECS manufacturers and component suppliers with a variety of end-products such as resins, glass fibers and nonferrous metals for turbine blades. Interest in wind energy by the process chemical industry is being stimulated by prospects of a huge market for wind turbines and by a number of major capital projects already announced: Windfarms Ltd. 350 MW California and 80 MW Hawaii projects, SCE’s 25 MW in Palm Springs, and Reclamation’s Medicine Bow plans. By the year 2000, says Edward Z. Gray of Bendix’s Aerospace Elec- tronics Group, the WECS market could be valued at $30 billion. Carter administration estimates of 1.7 quads (28,900 MW installed) predicted from wind power by the end of the century and Canada’s commitment to a megawatt-scale Darrieus have pricked more than idle curiosity. These developments are cited by Chemical Week as evidence that supplying the emerging wind energy industry with materials and composites could be a profitable endeavor, indeed. That observation is reinforced by two chemical industry com- panies already involved in wind power. Dow Chemical is supplying “‘significant amounts’’ of epoxy resin to Gougeon Brothers, a Bay City, Michigan, fabricator of wood blades. Four sets of 62-foot blades have already been built for NASA and will be installed on all four MOD-0As. (See Wind Energy Report, July 1980, p. 10). Gougeon will supply shorter epoxy impregnated wood blades to Energy Sciences, Inc., Boulder, Colorado, for a 50 kW two-bladed, horizontal-axis machine. Dow is also investigating the feasibility of using magnesium in blades. Hamilton Standard, perhaps the most aggressive of all large WECS manufacturers, will ship its first 127-foot fiberglass blade to Maglarp, Sweden, next month. The 27,000 Ib. blade is 65% glass fiber and 35% epoxy resin. Hamilton Standard is preparing to break ground on two additional blade winding plants in East Granby, Connecticut. Robert Fulmer, a market development manager at Owens- Corning Fiberglas in Granville, Ohio, ‘‘estimates that by 1988, some 9 million Ibs. of glass fiber and 4.5 milllion Ibs. of epoxy resin will be needed for U.S. [wind energy] projects.” The market for aluminum is also perceived to be large, though not yet fully quantified. Aluminum blades are being used for the McDonnell Douglas/Valley Industries 40 kW, the ALCOA 100, 300, and 500 kW, and for the proposed Free-Wing Turbine project at Point of the Mountain, Utah. (See Wind Energy Report, December 1980, pp. 8-9.) ALCOA has announced its willingness to sell aluminum extrusions to anyone who’ll pay for them—including competing wind system manufacturers. SRI International is reported to be experimenting with glass-fiber-reinforced concrete (Continued on next page) Wind Energy Report June 1981 Inthe news... Utilities Atlantic City Electric Co. has become the first municipal utility to offer cash incentives to customers who install wind energy sys- tems. This month, the New Jersey coastal utility will begin a pro- gram to pay $500 to the first one hundred customers who install “tapproved’’ wind machines by September 1983. The main reason for providing a financial incentive, says the utility, is to control the growth of peak demand for electricity and, thereby, avoid the necessity of constructing new power plants. To be eligible for the cash incentive, customers installing wind machines must agree to sign a contract to sell any excess power to the utility for 4.873 cents/kWh. Moreover, Atlantic Electric will bill each wind machine owner a $5.08 monthly service charge. The systems will not be sold by the utility but will have to conform to standards set by the state’s Department of Energy and Atlantic Electric. Wind turbines will require utility inspection of installation plans and an automatic cut-off capability should utility generated power be interrupted. According to Atlantic Electric, there are cur- rently six to nine owners of wind machines among its 380,000 customers. They are located mostly in coastal Cape May county. For further information, contact: Howard Mcllvaine, Atlantic City Electric Company, 1600 Pacific Avenue, Atlantic City, NJ 08404. (609) 645-4193. The Coos-Curry Electric Cooperative has begun program to site five more anemometers in its service area to determine the feasibili- ty of wind-generated electricity from small and intermediate size wind machines. ‘‘Coos-Curry is particularly interested in studying the winds between Brookings and the mouth of the Rogue River,”’ according to Conservation Supervisor Don Floyd. Several anemometers are already up and operating between Langlois and Gold Beach. ‘‘But we need some more data from Cape Ferrelo, Cape Sebastian and the Carpenterville area.’’ The utility is par- ticipating the Bonneville Power Administration’s anemometer loan program whereby wind data is collected and then shared with the region’s major power producer. Carter wind farm planned in Montana Livingston, Montana—Considered one of the windiest regions of the country—this southern Montana city will soon be operating the nation’s first municipally-owned wind farm, comprised of four Jay W. Carter Enterprises 25 kW machines. The Livingston City Council is expected to approve a proposal shortly to purchase the four wind machines, install them on municipal property and provide power to the city’s sewage treat- ment plant. A Carter 25 kW machine has been operating at the site as part of a demonstration project jointly funded by Montana Power Com- pany, Montana Energy Research & Development Institute (MER- DI) and the state’s Department of Natural Resources and Conser- vation (DNR). According to test data from the recently completed demonstra- tion project, the 100 kW wind farm could generate 250,000 kilo- watt-hours annually. Surplus power will be fed to Montana Power Company’s grid. The Livingston wind farm could be operating as early as August. The municipal wind farm will be funded by a $220,000 renewable energy grant from DNR. Funding for Montana renewable energy ‘projects comes from a 30.5% state severance tax on coal. Estimated cost of the four machines is $110,000 with an additional $70,000 going to a Butte engineering firm, Multi-Tech, Inc. to design the project and maintain the turbines for one year. The direct result of a successful 10-month long demonstration project using the Carter two-bladed, horizontal axis machine which convinced local officials to pursue wind power with greater vigor. With the installation of four additional Livingston machines, the state will have five Carter machines operating. A sixth Carter 25 kW wind machine in Montana before the end of the year is another possibility. The Montana Energy and MHD Research and Development Institute in Butte has submitted a $69,300 grant proposal to the state’s Department of Natural Resources and Conservation to install a Carter wind turbine on “weather hill’? just south of a mining smelter owned and operated by Anaconda Copper Co. Anaconda estimates that the average wind velocity at this site is 16.25 mph, slightly higher than the 15.8 mph in Livingston. Electricity from this machine will also be fed in- to Montana Power Company lines and an anticipated $1,600 in utility revenue passed along to Anaconda-Deer Lodge County which will operate the project after a six-month MERDI monitor- ing period is completed. The Livingston area has been identified by the U.S. Department of Energy as an exceptionally windy region. Pacific Northwest Laboratories is currently monitoring winds at one Livingston site for the Department of Energy’s candidate site program. Prelimin- ary data from wind measurements at three locations in the region show annual average wind speeds ranging from 10.6 to 15.81 mph. The Carter machine is being widely considered for a number of wind farm projects. The largest such project, 120 units in Califor- nia, is being undertaken by AeroVironment of Pasadena. WECS Industry Inthe news... (Continued from preceding page) blades—claimed to be cheaper and lighter than other materials—for machines no greater than 130 feet in diameter. Chemical Week may well be too optimistic on the WECS in- dustry’s demand for processed chemicals. Structural Composite In- dustries and Kaman, both fabricators of fiberglass blades for DOE/NASA, are ‘‘thought’’ by the publication to be capable of making one blade a week. Both companies have no immediate plans for mass production. In fact, SCI is out of the wind power business entirely as a direct consequence of the cut-off of federal wind energy funds for a 4 kW prototype. (SCI, incidentally, plann- ed to use fiberglass for the prototype’s tower.) Kaman has built a 40 kW prototype and is testing it at Rocky Flats. But the company has not committed itself any further in wind energy. Similarly, Chemical Week overstates its ‘‘biggest hope’’ for aluminum: the Free Wing Turbine. The 11 tetrahedron-shaped cars made of aluminum tubing running on a half-mile circular track has yet to be built or even tested experimentally. While the results are not yet in on which material—wood, fiberglass, aluminum or steel—are best suited for blades on dif- ferent size machines operating in diverse environments, ‘‘wind power,’’ says Chemical Week, ‘‘is worth a long look.”’ WIND ENERGY REPORT® Copyright © 1981. Wind Publishing Corporation. All rights reserved by the copyright owners. Wind Energy Report” is published monthly. No portion of this publication may be reprinted, reproduced, stored in a computer-based re- trieval system or otherwise transmitted whole or in part without the express, written permission of the publisher. Printed in U.S.A. ISSN: 0162-8623. Subscriptions: $115. annually (USA); $125. annually (Canada & Mexico); $145. annually (foreign airmail). Two-year subscriptions: $215. (USA); $230. (Canada- Mexico); $290. (foreign airmail). Editorial offices are loceted at: 189 Sunrise Highway, Rockville Centre, NY 11570. Mailing address for all correspondence: P.O. Box 14, Rockville Centre. NY 11571. (516) 678-1230. Wind Energy Report June 1981 MOD-2 damaged during BPA testing (Continued from front page) expected rate, stopped feathering, and then completed the feather- ing operation.”’ “Initial inspections showed that the generator and the drive train quill shaft were badly damaged. The rotor also appears to be damaged. Lesser damage was inflicted on the [Stal-Laval] gearbox, its mountings, and peripheral equipment. The gearbox will have to be disassembled and examined before its condition can be assessed. There was no visible damage to the tower or nacelle. “‘The rotor and nacelle are being removed to facilitate repairs. Boeing expects the repairs to take several months to a year.’’ Boeing appears truly mystified by the entire incident. ‘‘We’ve tried the same thing a dozen times before,’’ says Howard Woody, Boeing’s site manager, ‘‘and there hadn’t been any problems. But this is a test system, after all, and I guess you have to expect this kind of thing.’’ Boeing’s official reaction came from Joe Holmes, director of public relations and advertising: ‘‘This certainly wasn’t routine, but I wouldn’t call it serious.”’ = BPA officials emphasize, however, that the three machines are still undergoing acceptance tests and have not yet been turned over to BPA for operation, maintenance and evaluation. So far, the MOD-2s have cost an estimated $37 million. There are no estimates of how much it will cost or how long it will take to repair the damage components until a firm cause is established for the overspeed failure. During the time the No. 1 unit first delivered power to a Klickitat County PUD 69 kV transmission line on December 22, 1980, it operated for 107 clock hours (84 synchronized hours) and generated 99,400 kWh. Unit No. 2, installed on April 7, generated 138,000 kWh during 113.5 hours of synchronized operation. Boeing, as part of its contract requirements to NASA/DOE, an- ticipated a number of overspeed scenarios in a Failure Modes Ef- Sects Analyses completed in July 1979. More than 860 failure modes were analyzed with special attention to catastrophic pro- blems, including the inability of one blade tip to feather properly. According to Boeing, a normal shutdown calls for the blade tips to feather at 1° per second, dropping the load at 125 kW. In an emergency shutdown, the load is dropped and the blades are to feather at 4° per second for six seconds and 1° per second thereafter. The Boeing report examined the possibility that, with the machine loaded, the control system signal to both pitch actuators could drive the blade tips to zero pitch. In this event, emergency shutdown is triggered by generator output and shutdown occurs before damaging overspeed. NASA and Boeing engineers, however, didn’t consider the possibility of both blades being unable to feather in an unloaded condition. So far, 1981 has been a particularly cruel year for the U.S. wind energy program. In January, the troubled MOD-1, plagued by complaints of noise and television interference from local residents, was severely damaged when two bolts connnecting the shaft to the rotor failed. The 2000 kW machine has not been operating since the incident. Estimates of the cost of repairing the MOD-1 range from $500,000 to $1 million. The failure of the MOD-2—the wind turbine conceived and built to convince utilities of the technical maturity of wind turbine technology—is an acute embarrassment to NASA, DOE and, of course, to Boeing Engineering & Construction. Damage to both machines could not come at a worse time. There is no funding in the DOE Wind budget to initiate repairs for either wind turbine. Moreover, the Reagan Administration is recom- mending only $19.2 million for FY82 and resisting Congressional pressure for an additional $20 million for MOD-5 development. The FY82 money is barely enough to keep existing wind programs functioning without the added expense of repairs and replacement components for the two machines. According to DOE, there are no current plans for repairing the machines until Congress passes the FY82 DOE budget and submits it to the president, presumably in late September. According to DOE Wind System Branch officials, if faced with a choice, DOE would prefer to repair the MOD-2 rather than refurbish the MOD-1. Once the cause of the failure of the MOD-2 has been firmly determined and rectified, DOE says it wants toput the other two turbines back into operation. Meetings, Conferences, Symposia The Alternative Energy Resources Organization will hold a Nor- thern Great Plains Wind Conference in Billings, Montana, on Saturday, October 24th, 1981. Topics to be covered during during the one-day conference include: wind energy economics, choosing and operating a wind energy system, types and characteristics of wind power electricity generators and wind power site analysis and wind monitoring. A discussion of the possibility of large arrays of wind turbines on farms and ranches to provide electricity for sales to utilities will also be held. Registration fees is $35.00. For further information, contact: AERO, 424 Stapleton Building, Billings, MT 59101. (406) 259-1958. * * * The Second AIAA Terrestrial Energy Systems Conference will be held in Colorado Springs, Colorado, December 1-3, 1981. Several Papers on wind energy are planned. For further information, contact: Dr. Irwin Vas, Solar Energy Research Institute, 1617 Cole Blvd., Golden, CO 80401. (303) 231-1935. * * * The Fourth Miami International Conference on Alternative Energy Sources will be held December 14-16, 1981 in Miami Beach, Florida. Among the papers discussing wind energy will be: The Development of a 5-meter Darrieus Wind Turbine—Design & Technology, Chen Chi-Min, People’s Republic of China; Model- ling Wind Speeds and Wind Energy Production for the Grid Operating Strategy, W. Dub and H. Pape, West Germany; A Few Innovations Utilizing Wind Energy; Wind Energy to Beat Drought; Utilization of Wind Energy for Irrigation in India and Some Preliminary Methods to Site Windy Locations, A. Jagadeesh, et al., India; Optimal Design of a Wind Power System, Les Frair; Analysis of Site Economics for WECS Selection, George Biro, Gibbs & Hill; and Performance of a Wind Generator with a Subop- timal State Feedback Excitation Control, 1.M. El Amin and A.H.M.A. Rahim, Saudi Arabia. For further information, contact: Clean Energy Research In- stitute, University of Miami, P.O. Box 248294, Coral Gables, FL 33124. (305) 284-4666. * * * The University of Missouri-Columbia will hold a conference, Wind and Solar Energy Technology, April 5-7, 1982 at Kansas Ci- ty, Missouri. Parallel sessions on wind energy and wind and solar energy combinations are planned. For further information, contact: G. H. Stickney, College of Engineering, University of Missouri-Columbia, Columbia, MO 65211. Wind Energy Report Three 100 kW Darrieus now operational The third ALCOA-built, DOE-funded 17-meter Darrieus proto- type was installed early this month at the Tisbury, Massachusetts, municipal landfill site near Vineyard Haven on Cape Cod. Elec- trical output from the 100 kW VAWT will be used to power the Sanford water pumping station of the Tisbury Water Department. Excess electricity will be sold to Commonwealth Edison. After ap- proximately one month of operation, the utility will take over for the duration of the test period. Two other 100 kW Darrieus prototypes are already operating. The first was erected in August 1980 at DOE’s Small Wind Systems Test Facility at Rocky Flats, Colorado. The second began opera- tion in March at the Department of Agriculture’s Test Station in Bushland, Texas. A fourth machine may never be installed. It is a casualty of Reagan Administration cuts in the DOE FY81 wind energy budget. The Tisbury and Bushland machines are modified versions of the Rocky Flats machine. The Rocky Flats test machine has survived violent storms with wind gusts in excess of 120 mph. The service brake on both the Bushland and Rocky Flats machines has failed due to rust. And these machines have also required minor software adjustments. The three installations will provide operating data on how well the Darrieus 17-meter machine performs under varying en- vironmental and climatic conditions. According to Sandia’s Bill Sullivan, who is responsible for initial on-site testing at Tisbury and for training of Commonwealth Edison employees, the Vineyard Haven VAWT is the most important site because it is the first unit installed near sea level and close to the ocean. ‘‘We really don’t know what kind of corrosion problems to expect. And we are also June 1981 unsure of what will happen in an area like this prone to gale force winds.”” Unlike ALCOA’s 82-meter, three bladed design, the 17-meter turbine is a two bladed configuration rated at 95 kW in a 30 mph (measured at 30 feet). According to ALCOA’s Paul Vosburgh, the machine’s peak power output can reach 100 kW at 33 mph ‘‘and perhaps a bit higher, depending on local wind conditions.”’ The fabrication and installation of the three VAWTs prototypes is part of a DOE program to determine the economic and technical feasibility of commercial manufacture of this size VAWT. Sandia National Laboratories, DOE’s Darrieus program manager, con- tends that the 100 kW unit is commercially viable—less than $100,000 per unit—in quantity production. Although ALCOA Laboratories performed the research and development work for Sandia, the company apparently is not too keen on manufacturing the 100 kW, concentrating instead on the larger 300-500 kW, 82-foot diameter machines. But two other com- panies say they are seriously interested in manufacturing the 100 kW Darrieus based on the ALCOA/Sandia design. U.S Turbine Corporation, headed by a former ALCOA employee responsible for manufacturing its VAWTSs, is currently attempting to raise $1.5 million to build a facility to mass produce the 17-meter machine. Flow Industries of Kent, Washington, is also interested. Both com- panies indicate that they plan to make some changes in the basic ALCOA/Sandia design. For further information: contact: Dr. Richard Braasch, Division 4715, Sandia National Laboratories, Albuquerque, NM 87185. Dr. Y.H. (Michael Pao), Flow Industries, 21414 68th Avenue South, Kent, WA 98031. (206) 872-8500. Tom Logan, U.S. Turbine Cor- poration, Olde Courthouse Bldg., Canfield, OH 44406. (216) 533-3979. Rotor Number of blades .. . Axial height ... . -25.3m 83.0ft. Overall height (a.g.t -.28.9m 94.9 Ft. Centerline height .. . --15.1m 49.7 ft. eatacer (at coritertine)' .-- 2.2... 5 5.2.5.6. . 55.0 ft. un a ee eee Rotation direction -clockwise Guy wires . . . .3 steel cane eee 2,915 feet? Blade Length (total) . . . E . 101 ft. Airfoil NACA 0015 troposkein profile Chord 609.6mm 24in. Thickness .. -92.40mm 3.65in. Material ... -extruded aluminum Pieces Struts Torque Tube Material .. . aluminum DIINO oon ou oie anioiacetnce nisi oinin v = 5 & wT aT Me 091m 3.0 feet Tower Height (agl.) . Ground clearance ALCOA/Sandia 100 kW Darrieus Vertical Axis Wind Turbine Specifications Transmission TYME eet eee eet Ratio ..2..:. i Input speed . . . Output speed Generator/Motor TRIS no ocr Horsepower . Voltage 460V, three phase pe eee ee eee ee (1000) 1200 rpm IIE sree sie 5 O6 6.55 0k Senos ve ce wawiemn sed (50Hz) 60Hz Performance Rated power... 22... 2... eee eee 95 kW at 30 mph 100 kW at 33 mph Wind speed at 30 feet Start-up Cut-in . - 13.0 mph Rated - -37.0mph 16.5m/s Cut-out -45.0mph 20.1 m/s Maximum desig! 58.1 m/s Annual Power Output (Estimated) I oe owes Peeters cee ab ee 102,000 kWh 14 mph* - 164,000 kWh 16 mph* . 227,000 kWh 18 mph* . . . 285,000 kWh “measured at 30-feet or 94 meters Wind Energy Report Reclamation seeks Medicine Bow funds (Continued front front page) Martin, the agency’s regional director. In its economic analysis, the agency says that the Hamilton Stan- dard array ‘‘will require approximately 67.3 mills per kWh to repay the reimbursable costs.’’ Electricity from the Boeing array will have to be valued at 84.9 mills per kWh. Both options include $16.08 per kilowatt-year for firming capacity. Among its other observations, the study reveals that large WECS are going to be initially more expensive per installed kilowatt of rated capacity than at first thought. For instance, $250,000,000 will be required to procure 40 MOD-2s, or approximately $6.25 million each. Twenty-five Hamilton Standard 4 MW units will cost $6.8 million per machine. WECS hardware costs are 91.7% and 90.8% of total project cost for Hamilton Standard and Boeing, respective- ly. “Based on present prototype turbine costs,’’ notes Reclamation, “both wind field alternatives indicate marginal economic feasibili- ty.’’ The agency recognizes that the capital cost of each unit could be reduced, principally through mass production. ‘‘Megawatt-size turbine costs are expected to stabilize with full-scale commercial production while energy costs continue to increase.’’ The Hamilton Standard option is considered by the agency to have a better cost- benefit ratio. Among the study’s principle economic conclusions: © Wind data collected confirm a high wind regime velocity which will produce high energy output. ¢ High average wind velocities during midday (peak demand period) and winter months are favorable characteristics for integra- tion with federal hydrosystem. © Based upon the hydroelectric operation studies of the Col- orado River Storage Project, the 100 MW of wind field capacity can be physically integrated with substantial monetary benefits and without adverse effects. ¢ From an engineering and technological development and testing standpoint, large megawatt-size wind turbines have advanc- ed rapidly in the past several years and now appear ready for im- plementation and commercialization. ¢ Wind fields at both sites are financially feasible. The energy produced can be marketed at rates that will result in full reimburse- ment of costs plus interest over a period of 30 years. ¢ Western Area Power Administration, the marketing agency, is in agreement that the wind field energy output can be integrated in- to the federal hydrosystem and that a feasible marketing plan can be developed. The financial obligation of the wind energy develop- ment would be independent of any other project. Environmental Considerations Bureau of Reclamation does not consider the proposed wind farm a ‘‘major federal action having significant impacts on the natural and human environment.’ As a result, it was able to avoid a lengthy environmental impact statement and a full explanation of alternatives to the project required by the National Environmental Policy Act. The Medicine Bow wind-hydro project has virtually no known adverse environmental consequences on land or wildlife. The agen- cy also contends that the project will not have any untoward effects on local habitat and will not preclude other existing land uses or any future exploitation of mineral resources. The configuration us- ing the Hamilton Standard machines requires 324 acres while the Boeing array will need 705 acres. ‘‘Permanent loss of land due to construction is minimal at both sites, 266 acres at A (Hamilton June 1981 Standard) and 472 acres at C (Boeing).”” “The newness of wind turbine technology and the uncertainty of environmental impacts,’’ says Reclamation, have prompted a monitoring program for wildlife and noise. During a three-year period, a bald eagle, high on the list of endangered species, was spotted but it was considered on its way somewhere else and not a permanent resident. The agency, however, recognizes some impact on wildlife and is willing to request funding from Congress for a ‘wildlife mitigation plan’’ if the need arises. The agency is also planning to monitor noise and sound emis- sions from the WECS. Mercifully, there are no homes within a one- mile radius of either the Boeing or Hamilton Standard site. The Bureau of Reclamation will sponsor a study to measure ambient noise and noise during operation of the machines to determine its impact on wildlife, domestic animals and residents. Among the study’s conclusions about environment impacts: ¢ The wind field will not affect recreational use of the project area. There will be no restrictions on hunting, etc. ¢ The manpower required for construction will not have long- term impacts upon the local economy or public services. A resident staff to operate the wind field will not exceed ten persons. © The irreversible and irretrievable commitment of resources will consist of the materials needed for the wind turbines and fuels ex- pended during construction. * * * Medicine Bow wind farm feasibility study The Executive Summary, Feasibility Report and Environmental Assessment, contained in a 212-page report entitled Wind- Hydroelectric Energy Project, Wyoming,(June 1981), are available from: Larry Nelson, Project Director, U.S Department of Interior, Bureau of Reclamation, Lower Missouri Region, Building 20, Denver Federal Center, P.O. Box 25247, Denver, CO 80225. In addition to a thorough description of the Medicine Bow pro- ject, the report contains some very useful information on the the wind resource at Medicine Bow, the project’s financing, the prices of large wind systems, and operation and maintenance cost estimates expressed in late 1980 dollars. Appearing below is an edited, highly condensed version of the report: : Bureau of Reclamation (Reclamation) personnel developed a concept for integrating wind power with hydroelectric power systems in 1976. Sup- ported by growing national interest, the Congress appropriated funds in fiscal year 1978, for a special study to expedite early field investigations and provide funds for the construction and testing of onsite prototype wind tur- bines (system verification units). Feasibility investigations for the Wind- Hydroelectric Energy Project were authorized in October 1980. The focus of national interest is development of a new sources of depend- able energy, which are non-polluting and renewable. Wind energy can make a valuable contribution to this goal. The Medicine Bow area ex- periences some of the country’s best power producing winds. The winds are strong, stable, and directional. The wind generation patterns coincide with the daily peak power demands and the winter seasonal maximun power production complements the annual summer water inflows into the hydroelectric systems. Thus, it is possible to develop an integrated plan for wind energy that blends the favorable characteristics of wind and water resources. From both a technological and economic standpoint, the large-scale harvest of energy from the wind appears ready for implementation and commercialization to help meet the nation’s long-range energy re- quirements and lessens depletion of our fossil fuels and dependency on foreign oil. Proposed Development Integration of wind energy with the federal hydrosystem is ideal because the Teservoirs can serve as storage and the existing installed hydrogeneration Wind Energy Report June 1981 Medicine Bow wind farm feasibility study (Continued from previous page) can provide the firming capacity. The ability of hydrounits to start up quickly, make rapid adjustment in power output and use efficiency, whether used for an hour or for several hours, is another advantage. The Medicine Bow site is geographically located in the Western Division of the Pick-Sloan Missouri Basin Program area. This system is interconnected and operations are coordinated with the Colorado River Storage Project (CRSP) which is also interconnected to the Parker-Davis Project. Reclama- tion operates the reservoirs and hydroelectric plants and Western Area Power Administration (Western) administers the power transmission and marketing. The Western Division does not have sufficient installed generating capacity to integrate the total wind field. However, since the CRSP system is a much larger system, has the operational flexibility to ac- commodate 100 megawatts (MW), markets power in the Western Division area, and schedules between the two systems are coordinated by Western to optimize the federal power sales, the CRSP system would be used opera- tionally to firm up the wind turbine generation. The combined capacity in the Western Division, CRSP, and Parker- Davis Project systems is about 2,300 MW installed in 25 hydroplants. The Western Division has 540 MW, CRSP has 1,487 MW, and Parker-Davis Project has 360 MW. The integrated Western Division, CRSP, and Parker- Davis systems are defined as the federal hydrosystem for purposes of transmission and marketing of power. It should be noted that the integra- tion of wind energy with the CRSP system would not include financial in- tegration. The wind energy development is considered to be financially in- dependent of any other project. The proposed development will consist of a wind turbine field with generation capacity of 100 MW. Three different plans were studied at two potential sites. These included wind field plans for 25 4 MW [Hamilton Standard] wind turbine units at site A (alternative 1), 25 - 4 MW [Hamilton Standard] units at site C (alternative 2), and 40 2.5 MW [Boeing MOD-2}units at site C (alternative 3). Alternatives 1 and 3 were selected for presentation in this report because they best represent the trade-off com- parisons necessary for testing engineering design, field layout variations, and economic, financial, and environmental feasibility. Either alternative could be implemented if authorized. Alternatives Feature 1 (site A) 3 (site3) Generation capacity 100 MW 100 MW Wind turbines 25-4 MW 40-2.5 MW Graded gravel road (miles) 19.7 38.7 Overhead 115-kV transmission line (miles) 71 33.8 Underground 34.5-kV transmission line (miles) 20.0 38.6 Restricted development area (acres) 16,320 35,360 Permanent easement (acres) 420 893 The costs associated with the wind turbine field include design, construc- tion, construction supervision, archeological and historical, and annual operation, maintenance, and replacement costs. The total construction cost, including contingencies, for the 25-and 40-unit wind field alternatives with a 100-megawatt generation capacity will by $185,370,000 and $275,250,000, respectively. The following tabulation is a breakdown of these costs, based on October 1980 prices: Construction Costs ($1,000) Feature Site A Site C 25 units 40 units Turbine generators $170,000 $250,000 Transmission lines 3,500 8,500 Substations, transformers, switches 5,000 5,600 Roads 3,200 6,200 Buildings & equipment 1,350 1,350 Lands and rights-of-ways 620 1,300 Remote contro! equipment 1,500 2,100 Subtotal $185,170 $275,050 Archeological & historical 200 200 Total $185,370° $275,250" “does not mclude pre-authorization costs of $17,428,000. The wind turbine and field development costs should decline over the next decade or so in response to improved design, production techniques, reduced space requirements, and competitive pressures. If present inflation rates continue much of the early cost decreases may be offset. If wind energy from large wind turbines becomes a viable industry, the unit costs may show actual declines. Annual OM&R Costs Feature Site A Site C 25 units 40 units Turbine generators $480,000 $760,000 Transmission lines 2,734 13,064 Substations, transformers, switches 62,050 72,250 Roads 5,900 11,500 Buildings 19,300 19,300 Remote control equipment 59,000 82,000 Total $628,984 $958,114 Power Production and Marketing Annual wind energy produced at sites A and C is estimated to be 298 and 351 million kilowatt-hours per year. At each site, the ratio of onpeak to off- peak generation will be approximately 69 % onpeak and 31% offpeak. A major part of the wind energy production will occur during the winter and onpeak periods. These two wind energy characteristics are ideal for integra- tion with hydropower. Wind turbine energy production will be electrically interconnected to the existing federal power grid through the substation at Medicine Bow which will provide the pathway for direct integration with the existing federal hydrosystem. The wind/hydro integration will increase the available energy to more nearly match the load factor by providing additional energy from a renewable resource with minimum environmental impacts. Since a greater percentage of the wind generation occurs during onpeak hours, a variety of marketing plans can be designed, including peaking plans, to accomodate the customer’s needs. Although a capacity credit is not being claimed for the installed wind tur- bine capacity when the wind turbines are operating, it is expected that the displaced capacity in the hydrosystem will then be used for reserves, emergencies, or short-term sales that will result in additional revenue, thus enhancing the hydrosystem. The federal projects have made large energy purchases in recent years and future upstream water depletions may reduce the average annual hydroenergy. The wind energy could be used to offset the potential future energy deficiencies in the hydrosystem now obligated in sales contracts. The CRSP power load, hydrologic operations, and integration of wind energy from the proposed project were analyzed to determine acceptability and potential impacts. Fourteen combinations of low, nominal, and max- imum wind years with low, nominal, and maximum water years were simulated in a computer model and measured against the projected power loads. The results showed that wind energy can be integrated into the hydrosystem with significant monetary benefits without adverse hydrologic impacts. However, the wind energy could not be fully utilized during the maximum water wind years. The financial reasibility of integrating wind energy into the hydrosystem is highly dependent on design of the marketing plan. The financial obliga- tions of the Wind-Hydroelectric Energy Project would be independent of any other project. Western markets power from all the resources developed ($1,000s) Annual benefits Alternative 1 Alternative 2 Onpeak power 18,450 21,645 Offpeak power 4,185 4,973 CRSP capacity -1,608 -1,608 Net annual benefits 21,027 25,010 Annual costs Construction & IDC costs 17,196 25,506 Operation, maintenance & replacement 629 958 Net annual costs 17,825 26,464 Benefit-cost ratio = 12to1 0.9 to1 Wind Energy Report Medicine Bow wind farm (Continued from previous page) by Reclamation and will develop the final marketing plan and define the marketing area for the Medicine Bow wind field. Economic Analysis Economic benefits for wind power are difficult to determine because of the unusual character- istics of the energy resource and lack of true alternatives. Thefefore, an analysis based on ‘willingness to pay’’ was developed. Based on information from the Department of Energy and Western, it was assumed that 90 mills per kilowatt-hour would represent the ‘‘willingness to pay”’ for onpeak power, and 45 mills per kilo- watt-hour for offpeak power, based on the estimated power values in the 1990 time frame. The wind turbines will produce the energy and the dependable capacity will be supplied by the CRSP hydrosystem. That system can provide the dependable capacity at a present reimbursable cost of $16.08 per kilowatt per year because that capacity has been marketed without energy. Project costs consist of construction costs of the wind turbines facilities, interest during con- struction (IDC), archeological and_ historical, preauthorization investigation costs including the system verification units, and annual opera- tion, maintenance, and replacement costs. In- terest during construction was calculated at a 7-3/8% interest rate over a 7-year construction period. Construction costs, IDC, and archeo- logical and historical costs were discounted to annual equivalent values at 7-3/8% over the 30-year life of the project. The preauthorization investigation costs, including the system verifica- tion units, are not included in the economic eval- uation as they are considered sunk costs. The analysis of the annual benefits and costs associated with the wind field at sites A and C are shown on the preceding page. It is estimated that the alternative 1 [25 Hamilton Standard 4 MW units] wind field will produce 298,000,000 kWh annually. If the wind- power is marketed at a uniform rate over 30 years, it will require appoximately 67.3 mills per kilowatt-hour to repay the reimbursable costs in- cluding an allowance for firming capacity of $16.08 per kilowatt-year. Based on information provided by Western, alternatives 1 or 3 should be marketable at these rates by the time produc- tion begins. The alternative 3 [40 Boeing MOD-2 2.5 MW units] wind field will produce 351,000,000 kWh annually. A uniform rate of 84.9 mills per kilo- watt-hour will be required to repay the costs in- cluding an allowance for firming hydrocapacity. The regional impacts from wind field develop- ment will be relatively small, since a high percen- tage of the capital investment will be spent for manufacturing and fabrication of the wind tur- bines at a location other than the project area. The regional impacts resulting from develop- ment of the wind field at either site A or C will be minimal and identical. The net income to the loc- al area as a result of constructing the wind tur- bines will be $770,000. Employment gains from project construction wil be 199 employee-years lasting over a period of 7 years. Long-term employment gains for operation and mainten- ance of the wind turbines will be 10 employees. Environmental Assessment The collection of environmental data in the area of Medicine Bow, Wyoming, has been on- aa Wore LOCATION MAP (SITE A) ron | wp TURBINE GENERATORS |. ALTERNATIVE "1 June 1981 going since 1976 independent of our program. The environmental studies were jointly scoped by Reclamation, Fish and Wildlife Service (FWS), and the Wyoming Game and Fish Department (WGFD) and consisted of population and nest- ing surveys for birds of prey. Those surveys have continued and additional data has been collected for antelope, sage grouse, passerine birds, water- fowl, small mammals, and endagered species, as well as vegetation. In each case, FWS and WGEFD have been consulted for input as to the scope and methodologies to be used in the envir- onmental studies. The permanent loss of habitat will be about 600 acres at both sites A and C. Minor reductions in antelope, raptor, and sage grouse populations can be expected due to habitat loss. Some dis- placement is also likely as a result of construc- tion. The displacement will probably be tempor- ary since no land use changes are anticipated and the wind turbines will be spaced widely enough to permit easy traverse of the area by wildlife. As soon as construction is completed, any displaced wildlife should return to the area. The wind field will be monitored to evaluate operational impacts of the wind turbines upon the environment. The turbines, transmission lines, and other facilities are being designed to restrict and protect wildlife. Anti-perching de- vices will be placed on the transmission poles and the lines spaced to avoid accidental electrocution of raptors. Existing roads will be used where possible and disturbed areas revegetated as ap- propriate. These protective measures will be monitored to evaluate their success. Wildlife will be monitored to ascertain res- ponse to wind turbine operation. It is possible that raptors could collide with the rotating tur- bine blades or utilize the wind turbine generators as a hunting/resting perch. Antelope may res- pond negatively to the turbine operation and va- cate portions of their present range. These types of potential environmental impacts will be monitored and mitigated, if necessary. A bald eagle was observed on site C (Septem- ber 1980). This was the only sighting of an en- dangered species in the area after approximately three years of surveys. It is likely that the eagle observed was migrating. There is a potential for mortality for bald eagles colliding with wind tur- bines at site C. The possibility appears remote since only one has been seen in three years. There are not reported collisions of raptors with the ex- isting turbines constructed by the National Aeronautics and Space Administration at other locations. General Plan of Development The plan of development is to integrate a 100-megawatt wind turbine field with the existing hydroelectric facilities of the CRSP. Three alter- native wind turbine field configurations were evaluated, one at site A and two at site C and are as follows: Alternative | - 25—4-MW units at site A Alternative 2 - 25—4-MW units at site C Alternative 3 - 40—2.5-MW units at site C Alternative 2 was not considered in the project analysis because alternatives | and 3 best repre- sent the trade-off comparisons necessary for test- ing engineering design, field layout variations, and economic, financial, and environmental feasibility. Wind Energy Report The wind turbines, evaluated for this report, was based on a series of prototype turbine de- signs being developed with the assistance of NASA. The turbine designs used for project for- mulation and evaluation were a 2.5-megawatt unit designated as the MOD-2 and a 4-megawatt unit designated as the WTS-4. There are many other wind turbines of differ- ent designs and configurations, such as the verti- cal axis, i.e., Darrieus design. The use of the MOD-2 and WTS-4 designs will not constrain possible future equipment selection. Final design and construction of the wind turbines for Re- clamation’s wind projects will be based on com- petitive bids within the 2-5 megawatt range. The optimum size of wind turbine units is evolving as more experience is gained. Determination of the wind turbine spacing is important in developing the most economical wind field. The allowable spacing to avoid mut- ual interference between wind turbines has not been accurately determined. Preliminary re- search results indicate that a spacing of 15-blade diameters with a staggered pattern between tur- bines is required to avoid interference. Research underway will further define spacing require- ments. . Wind Field Alternatives Alternative 1—Site A [Hamilton Standard] Twenty-five WTS-4 units will be constructed at site A. Site A has the following characteristics: (1) a well-maintained county road 5 miles from Medicine Bow; U.S. Highway 30/287; and the Union Pacific Railroad, (2) the Medicine Bow substation is located 4.4. miles away, and (3) a 115-kV transmission line for the SVU will al- The overhead transmission lines will form a loop with two lines proceeding from the substa- tion near Medicine Bow. One additional line will be added to the line under construction for the SVU. With a 50-foot-wide right-of-way, the area for the overhead transmission lines will be 43 acres. There will be five cluster groups. Each cluster group will have terminal structure that will occu- Py approximately one acre. Each terminal struc- ture interconnects the underground lines from the units to the overhead lines. Ground disturb- ance for the 20 miles of underground transmis- sion lines will be approximately 6 feet wide, a total area of 15 acres. The substation will require five acres and each WTS-4 unit will require 4.5 acres. The 16,320-acre restricted development area was determined by rounding off a distance of 15-blade diameters (3,855 feet) to the nearest quarter section around the field area. Alternative 3—Site C [Boeing Engineering & Construction] Forty 2.5-MW units with a blade diameter of 300 feet will be erected at site C. The impacted area for the graded gravel roads will be 281 acres. The area for the overhead transmission line will be 205 acres. There will be six cluster groups. Ground disturbance for the 38.6 miles of under- ground transmission line will be approximately 6 feet wide, requiring a total area of 28 acres. The 35,360-acre restricted development area was determined by rounding off a distance of 15 blade diameters (4,500 feet) to the nearest quar- ter section around the field area. The wind turbine fields (sites A and C) are June 1981 located in the area under the administration of the Pick-Sloan Missouri Basin Program (P-SMBP), Western Division with hydroelectric facilities located in eastern Wyoming and north- ern Colorado. However, federal hydroelectric power is marketed to preference customers from two different federal projects in this area. The two projects are the P-SMBP, Western Division, and the CRSP. Although the Western Division hydroplants are located near the Medicine Bow wind area and have about 540 MW of installed capacity the system has insufficient capacity and reservoir flexibility to firm up 100 MW of wind turbine capacity. Since Western markets the power from the three federal hydroprojects in the area and optimizes the power production, the 1,487 MW of capacity in the CRSP system and its flexibility are more than sufficient to firm up 100 MW of wind turbine capapcity. Both Medicine Bow wind turbine fields are located adjacent to the Western Division trans- mission system and either could be intercon- nected to the existing Medicine Bow Substation. The Medicine Bow location is adjacent to two ex- isting federal 115-kW transmission facilities con- structed to deliver power from the Wyoming hy- droelectric projects. Western plans to upgrade one or both of these lines Yor increased system capacity, whether or not the wind turbines are installed. This enhance- ment would provide sufficient transmission ca- pacity to integrate the Medicine Bow wind tur- bines and deliver the power to distant load centers. The Medicine Bow Substation will be enlarged to tie the wind energy into the existing federal hydroelectric power system. Reclamation’s Cas- i ae TT | = — | | (nermcre® SCVELOMOnT ame LOCATION MAP (SITE C) pes eer ome Pearse Ct re | ———_ meron courrr mons WIND TURBINE GENERATORS: ton ALTERNATIVES Wind Energy Report June 1981 Medicine Bow wind farm feasibility study (Continued from previous page) per Control Center will provide monitoring and control for remote opera- tion of the turbines. Generation data from the wind field could be tele- metered to the federal system dispatching office in Montrose, Colorado, or future dispatching office between Fort Collins and Loveland, Colorado, for regulation and automatic generation control. System Verification Early in the investigations, it was determined that in order to evaluate fully the wind/hydro concept and environmental impacts, installation of prototype wind turbine generators or SVU’s in the 2-to 5-megawatt size would be desirable. In July 1979, Reclamation issued a request for pro- posals to construct an SVU at site A. Site A was selected as the location for the SVU because it is close to the existing Medicine Bow Substation for utility-grid tie-in and it is convenient to the Union Pacific Railroad line for economical hardware transportation. After site selection for the SVU, the meteorological tower was constructed upwind from the site. Procurement of the SVU unit was accomplished through open market competitive bid contract procedures. This SVU is being installed to analyze performance, determine operation and maintenance requirements, verify manufacturer’s design criteria, assess public reaction and acceptance, and monitor and analyze environmental effects. The first SVU unit contract for a 4-megawatt wind turbine generator, designated as a WTS-4 unit, was awarded to the Hamilton Standard Com- pany of Windsor Locks, Connecticut, on February 1, 1980. The unit is scheduled for installation at site A in the fall of 1981. (Ed Note: Installation of the WTS-4 is delayed until Spring 1981). The procurement of the second SVU, a Boeing Company MOD-2, is be- ing provided for under a three-party agreement among DOE, NASA, and Reclamation. This unit will be a 2.5 megawatt turbine, which is also scheduled for completion in the fall of 1981. NASA has provided technical assistance in the procurement of the SVU’s and training of Reclamation’s engineers in the evaluation of wind turbine designs and performance. The contractor will furnish additional training in the operation and maintenance of the unit. This training will provide Reclamation personnel with the necessary skills to evaluate future designs and for the operation and maintenance of large wind turbine fields. Alternative Energy Sources Small wind turbines are in various operational/development stages. These turbines are very cost effective for special or small energy applica- tions such as remote cabins and farm use. However, these small units can- not produce low cost commerical blocks of energy. The various alternatives for commercial power highlight the difficulty in formulating plans comparable with the potential wind field. Traditional fossil fuels are not comparable when examining the pattern of output, fuel versus no fuel, and air pollution . . . Since windpower is a unique and unusual energy resource and lacks a true alternative, the benefit analysis. . . is based on a ‘‘willingness to pay’’ and not on the ‘‘most likely alternative’ concept. Feature WTS-4 MOD-2 Rated power 4000 kW 2500 KW Rotor diameter 257 feet 300 feet Rotor type Teetered-free yaw Teetered Rotor blade material filament-wound fiber- _ all welded steel glass Rotor orientation downwind upwind Rated wind speed 36.7 mph 31 mph Cut-out wind speed 60.4 50 mph Rotor tip speed 404 ft/sec 275 ftisec Rotor rpm 30 17.5 Generator rpm 1800 1800 Generator type synchronous synchronous Gear box step-up ratio 1:60 1:102.8 Gear box type 2-stage planetary 3-stage planetary Hub height 262 feet 200 feet Tower hollow steel steel (sheel) Total weight 782,000 Ibs 580,000 Ibs 10 Medicine Bow, Wyoming Summary of Wind Data Average Annual Windspeed (mph) Western Scientific University of Wyoming Services, Inc. Height Site A Site C Site A (feet) 2/78-1179 = 10/79-9/80 =. 2/78-1/79— 10/79-9/80_11/78-10/79 3/10-10/80* 12.75 *12.5° 13.12 *12.5° *13.0° 13.67 *13.0° 32.8 15.0 148 14.8 15.2 *15.0° *13.9° 140.0 *18.6" 190.0 *19.3° 200.0 20.4 20.4 20.4 21.0 19.5 °17.3° 262.0 21.3 215 #215 22.1 18.3 350.0 "18.6" + only 8 months data * measured data The mean windspeed at sites A and C for the three-year period 1978-1980, was also compared with the same time period at Casper. Site A data shown ?s a composite of data from UW and WSSI anemometers. The long-term average windspeed at the Casper airport is displayed and repeated for each 1-year period. The average available windpower was next calculated from the projected turbine hub heights using data collected by UW for the period February 1978 to January 1979. The estimated available power for site A at 262 feet was 965 and for site C at 200 feet was 772 watts per square meter, respec- tively. Before a power system can make a long-term obligation to sell wind energy as a wholesale power supply, there is a need to determine the long- term patterns and average annual generation that can be expected at a given generating site. Depending on the specific geographic area, it requires about 25 years of wind data to establish annual patterns of wind, verify weather extremes, and derive an estimate of long-term average annual wind conditions. The combined data in the Medicine Bow area are insufficient to determine long-term wind patterns and average annual windspeeds. Casper, Wyoming, which is 80 miles north of Medicine Bow, is the closest wheather station with 25 or more years of suitable wind data. The data collected at Medicine Bow was compared with the Casper long term record, and the period February 1, 1978 to January 31, 1979 tracks the same period at Casper and the long-term monthly data reasonably well. For the purpose of this study, this year was selected as being representative of the long-term period. Since it is impossible to capture all available energy from the wind, a specific wind turbine generator and design must be used to estimate the wind energy output. Windpower output was computed on an hourly basis using ‘‘windspeed versus power curves’’ for 2.5-and 4-megawatt wind tur- bine units. For example, on a typical winter day, the wind speeds remain below the WTS-4 rated speed of 15.9 mph at hub height until about 9 a.m.; then the wind speed increases above 15.9 mph and averages 18 mph for the first hour, generating about 300 kW (computed from the WTS-4 rating curve). The wind speed further increases to 28 mph for the period from 10 a.m. to 1 p.m. and generates about 2 MW each hours. The remainder of the daily generation is computed in the same manner and the computer sum- mates [sic] the total generation for the day. Each hour’s generation was computed for both turbines at each site for an entire year, Feburary 1, 1978 to January 31, 1979... These figures demonstrate that wind turbine power output will be signficantly greater in the winter than in summer, which-complements power production from the CRSP hydrosystem. Wind data were also analyzed to determine the prevailing wind direction at sites A and C. Both sites have almost the same prevailing wind. Almost all the energy will be generated from the west-southwest at a bearing angle of about 250 degrees. In summary, studies to date indicate that the Medicine Bow area has one of the highest values for average available windpower in the country with about 90% of the consistent power-producing winds coming from the west- southwest. A daily peak in energy generation, as well as a strong seasonal variation in wind, was observed. The high winter windspeeds and the strong afternoon winds coincide reasonably well with peak power demands. Wind Energy Report New Publications, Reports, Studies Mod-0A 200 kW Wind Turbine Generator Design and Analysis Report by T.S. Anderson, C.A. Bodenschatz, A.G. Eggers, P.S. Hughes, R.F. Lampe, M.H. Lipner, and J.R. Schornhorst, Westinghouse Corporation, Advanced Energy Systems Division. Prepared for NASA Lewis Research Center, Cleveland, OH. August 1980. DOE/NASA/0163-2, NASA CRJ}165128, AESD-TME-3052. This report documents the design, analysis, testing, installation, and in- itial operating performance of the MOD-0A 200 kW wind turbine generator installed at Clayton, NM. The MOD-O0A wind turbine was designed and built by the NASA Lewis Research Center for the U.S. Department of Energy as part of the Federal Wind Energy Program. The objective of the MOD-0A project is to obtain early operation and perfor- mance data and experience with horizontal-axis wind turbines in utility en- vironments. This report covers the effort from the formation of the MOD- OA project in 1975 to March 1978, and when the first MOD-0A wind tur- bine was released to the Town of Clayton Light and Water Plant for utility operation. This report contains the NASA project requirements and approach, system description and design requirements, design and analysis, system tests and installation, safety considerations, failure modes and effects analysis, data acquisition, and initial operating performance for the MOD- OA wind turbine. The system description provides an overview of the mechanical and electrical components. The system design requirements provide the basis for the design. The design and analysis section of the report includes the requirements, approach, selected design, and supporting analytical results for the com- ponents and systems. These components and systems are the rotor and ptich change mechanism, drive train, nacelle equipment, yaw drive mechanism and brake, tower and foundation, electrical system and com- ponents, and the control systems. The rotor consists of the blades, hub, pitch change mechanism, and its hydraulic system. The drive train includes the low speed shaft, speed increaser, high speed shaft, belt drive, fluid coupling, and rotor brake. The section on the tower and foundation also describes the service stand and the equipment and personnel hoist. The elec- trical system and components are the generator, switchgear, transformer, utility connection, and slip rings. The control systems are the blade pitch, yaw, and generator control, and the safety system. The methods and equip- ment used for manual control, automatic control, and remote control and monitoring are described. The results of system dynamic loads analyses and fatigue analyses are presented. System tests were performed at NASA and at the site. The engineering data acquisition system includes the instrumentation, remote multiplexer units, mobile data system, and a stand alone instrument recorder. Finally, the initial operating performance from November 1977 through March 1978 is reported. From the design, analysis, and initial operation (prior to its release for utility operation) of the MOD-OA at Clayton, the following principal con- clusions are reached. General agreement is shown between predictions and initial operational measurements for the power output as a function of wind speed and for the structural performance. Satisfactory initial operating characteristics in a utility environment are demonstrated. Several conclusions were drawn by the NASA Lewis Research Center from the design, analysis, and initial operation (prior to its release for op- eration by the utility) of the Clayton MOD-0A 200 kW wind turbine. These conclusions are categorized into the following: machine performance, structural performance, and utility interface. In the machine performance area, general agreement was shown between the predicted and measured values for power output as a function of wind speed. The measured drive train efficiency varied with output power and exceeded the design value as the power approached 200 kW. The average cyclic power varied less than +20 kW, due to tower shadow and wind shear effects. An ice detector was found to be necessary for safe operation during potential icing conditions. The structural performance was generally as predicted. Dynamic blade loads measured during initial operation were in good agreement with loads calculated using the MOSTAB computer code. Cyclic loads caused by tower shadow and wind shear were found to be significant and could cause local wear and fatigue damage in the blades and hub. Close monitoring of the blade loads and structural conditon, as well as hub clearances, is re- quired to insure structural integrity. June 1981] With regard to utility interface, satisfactory operating characteristics in a utility environment during initial tests from November 1977 to March 1978 were demonstrated. The wind turbine was successfully synchronized to the utility network in an unattended mode. The instantaneous frequency was controlled within a peak-to-peak variation of _ 1 Hz about the nominal. The wind turbine exhibits a natural mode oscillation at 1.33 Hz, which is twice the speed of the rotor. Oscillations at this frequency are caused by tower shadow and wind shear effects. Since the dominant frequency of oscillation of the Clayton system is 3 Hz, the wind turine does not excite the system. As a result of training, utility personnel were able to operate the MOD.-0A for the purpose of experimentally supplying power on their utility network. A Case Study Evaluating The Potential For Small Wind Energy Conversion Systems (SWECS) As An Integral Part Of The Generating Mix For A Regional Utility—The Kansas Gas And Electric Company; Final Report by Mark T. Jong, and Gary C. Thomann, Wind Energy Laboratory, College of Engineering, Wichita State University, Wichita, KS. Prepared for Mid- American Solar Energy Complex, 8140 26th Avenue South, Minneapolis, MN. (No Date). Available: MASEC. The potential of small wind energy conversion systems (SWECS) in a regional utility was investigated. Kansas Gas and Electric Company (KG&E), an investor-owned company with 1800-MW generating capacity, served as the case study subject. Eight previous studies that evaluated SWECS as an integral part of the generating mix of a utility system were reviewed and summarized. A wind characteristics analysis was performed for the KG&E service ter- ritory. A hypothetical wind machine with a cut-in velocity of 8 mi/hr anda rated velocity of 25 mi/hr was selected and analyzed in the Wichita wind regime. Using wind data from 1970 to 1975 this machine had an annual energy output of from 1793 to 1926 kWh/kW. The SWECS output was compared to KG&E load demand. On a yearly basis, there was poor cor- relation between SWECS output and load. The load peaks in the summer when SWECS output is low and the SWECS output peaks in the spring when power demand is low. On a daily basis there was some correlation between SWECS output and load during summer. In the winter the wind and load were out of phase on their diurnal cycle. Five years of concurrent wind/load data was used to simulate 15 years of KG&E system operation with an without SWECS. The KG&E system simu- lation computer programs were used to model hour-by-hour operation and to generate fuel requirements, production costs, and other reports. For the fifteen year study, the average present worthed production cost savings in 1980 dollars for a 3% SWECS penetration were found to be 13.2 mills/kWh for 6% spinning reserve, 9.6 mills/kWh for 7% spinning re- serve, and 6.4 mills/kWh for 8% spinning reserve. Spinning reserve of 6% is the normally used value of KG&E. For 6% penetration the values were 13.6, 10.1, and 6.2 mills/kWh for 6, 8, and 10% spinning reserve respec- tively. A program was developed to calculate the system ‘‘loss-of-load pro- bability’’ (LOLP) index, from which the effective SWECS capacity was determined. Based on the LOLP level of .1 days/year, it was found that 56-MW (3% penetration) of the selected wind machine could displace 14-MW of an existing coal fired conventional plant which had a forced outage rate of 8% and could displace 18 MW of the 136-MW coal unit to be added to the system in 1983. The capacity values for 6% SWECS penetra- tion were essentially double that found for 3% penetration. In the ‘‘fuel-saving’’ mode (SWECS used to displace energy but not capacity), it was found that at the 2% O&M level and with no spinning reserve penalties imposed on the SWECS, the breakeven cost was about $330/kW (in 1980 dollars) for 3% SWECS penetration, and $320/kW for 6% penetration. The SWECS were assumed to have 10% forced outage rate in arriving at these cost estimates. When the 15% investment credit allowed against the federal income tax was added to the savings, the breakeven cost would be about $470/kW for 3% penetraton with the same O&M and spinning reserve conditions. The increase in SWECS allowable installed cost due to capacity credit is difficult to estimate. To determine capacity credit it must be decided which future conventional unit is to be displaced and how much of this capacity can be displaced by the SWECS in order to maintain the sam LOLP level. Then, to determine savings, the installed cost of the future plant must be estimated and the system-simulation program must be run to determine sav- ings, the installed cost of the future plant must be estimated and the system Wind Energy Report simulation program must be run to determine the changes in production cost savings which occur when this conventional capacity is displaced by SWECS. it was found that when the future conventional capacity is displac- ed a large loss in production cost savings occurs. This is because more ex- pensive oil/gas fired units pick up part of the energy generated by the dis- placed capacity which uses fairly cheap coal or nuclear fuel. For example, when 56 MW of SWECS were used to displace part of the coal fired unit to be added to the system in 1983 the allowable cost for the SWECS was found to be about $535/kW under the same operation conditions which resulted in an allowable installed cost of $470/kW considering only fuel savings. SWECS were also used to displace coal fired unit tentatively planned for 1991. With 3% penetration, the allowable SWECS cost would be about $600/kW in this case using an installed cost of $1000/kW (in 1980 dollars) for the new coal fired unit. These capacity credit values were calculated from a thin data base and it is believed additional examples need to be done. A load management technique was postulated to cycle air conditioner compressors off 7.5 minutes each half hour during peaking periods and to shift water heater loads to off-peak periods. Using the historical wind/load data for six years from 1970 to 1975 and the 1979 annual peak, the postu- lated load management would reduce energy requirement by 11.5 GWH an- nually on the average at 3% SWECS peneatration, and 9.78 GWH at 6% SWECS penetration. At the 0.1 day/yr LOLP level, the 3% SWECS pene- tration plus the postulated load management could displace about 50 MW of conventional generating units in the existing system, and the 6% SWECS penetration could displace about 60 MW of conventional capacity. * * * Icing On Wind Energy Systems by Thomas Hoffer, Tony Reale, and Ashraf Elfigi, Desert Research Institute, Atmospheric Sciences Center, University fo Nevada System, P.O. Box 60220, Reno, NV. January, 1981. DOE/ET/23170-80/1 (DE81023942). Meteorlogical studies to determine wind availability and the feasibility of installing a wind energy system in certain areas are being pursued. However, in determining such a feasibility, the availability of wind is not the only aspect to be considered. An assessment of nature’s erosive forces and the stresses and strains that a system is likely to encounter during operation must also be determined. A particularly important aspect to consider prior to the installation of a wind energy system is the potential for atmospheric icing. Destructive win- ter icing occurs in many areas of the continental United States and riming is particularly common at the higher evelations. When accompanied by strong winds, excessive ice build-up on a wind turbine and its supporting structure will incapacitate it and can cause structural failure if such condi- tions were not anticipated. A study of atmospheric icing, however, is not a straightforward task since the observation and reporting of icing are not routine. A limited record of such measurements is available for the more severe ice storms occurring in the vicinity of urban areas, however. The de- pendability of such measurements is questionable. Very few measurements are published for mountain locations where the availability of wind is often optimum for a wind system installation. Unless field measurements are done at the proposed site of a wind energy system, an analysis of the icing potential must necessarily be based on other existing data. A source of such data is the network of meteorological recording stations within the continental United States which collect meteorological measurements both at the surface and aloft. This report presents pro- cedures for analyzing this data to determine the maximum possible icing to be expected at specified locations. Although atmospheric icing can result from wide range of meteorological conditions, icing due to widespread freezing rain (i.e., glaze) and icing due to riming are specifically discussed as these conditions are most commonly observed. Since the physical processes are different, the procedures for predicting maximum glaze ice and rime are presented in separate sections. The icing associated with glaze storms is computed using the hourly rainfall data co- incident with documented reports of severe glaze storm occurrences. Re- ported ice thicknesses are not depended upon but instead are estimated through the rainfall data. This is a unique approach for the study of icing associated with glaze storms and avoids the subjective aspect of the thickness measurements reported. Icing due to rime is analyzed for a moun- tian site using meteorological sounding data for the atmospheric layer up to and including the 10,000 foot level. The sounding data used are for a site ty- pically upwind from the mountain location. Rime is predicted for condi- 12 June 1981 tions of orographic lifting and cloud formation at subfreezing tempera- tures. The extent of riming is computed from the cloud water content. Models developed to simulate the maximum possible ice buildup on an exposed surface using the rainfall and cloud water data as input are also presented. Two models are considered, one for the static case, namely a sta- tionary collection surface, and one for the dynamic case, namely a rotating collection surface. In both cases, all of the water (i.e., supercooled water) available for icing is assumed to accrete an ice and, therefore, no further ice buildup can be attained. In addition to the maximal dynamic and static icing loads, comparative icing values based on an attempt to simulate actual field conditions are also shown. Included are assumptions of droplet splashing and water drainage for the glaze cases and atmospheric mixing during orographic lifting for rime cases. This study has been directed towards outlining procedures and presenting preliminary findings regarding the total mass of ice that a wind energy structure would have to be capable of encountering during a glazing or rim- ing episode. Regarding the dynamic case for rime, the blades will certainly not accu- mulate as much ice as the dynamic model predicts since they would stop rotating. The importance of dynamic linear model lies in predicting the mass of ice/unit time that the blades must indeed be capable of shedding if the windmill is to continue operating in the normal mode. Any ice ac- cumulation on the blades will have deleterious effect, either in decreased ef- ficiency or in an imbalance that can be transmitted through the entire system as mechanical shock. Thus, to reiterate the numbers predicted by the dynamic model represent the maximum mass of ice that the blades will have to shed per unit time. The maximal load as calculated by the static model, most applicable to glaze icing and tower icing during riming, may actually be smaller than the computed value for several reasons. Specifically, the ice may fracture and fall from the structure due to stresses, the shape of the collection surface will change with time (particularly with riming) causing changes in the col- lection efficiency and as has been discussed the iifting and ice accretion models utilized indicated maximal icing conditions. With respect to the maximal ice load values projected in this study, the results for glaze storms seem to reflect typical maximal values to be expect- ed. Glaze storm intensity and duration, form which icing values are de- rived, agree with comparative findings. A maximal icing rate of 10 kg/m*hr and a maximal load of 40 kg/m’ (8 Ibs/ft?) were determined. Projected maximal loads for riming (static case) where much greater with maximal ic- ing rates exceeding 100 kg/m*hr and maximal loads ranging from 170 kg/m? (35 Ibs/ft?) at sustained 5 mph winds to 1,700 kg/m? (350 Ibs/ft*) at 50 mph winds. Although these loads will rarely be attained, such cases can be encountered. * * * A Review of Remote-Sensor Potential for Wind Energy Studies by William H. Hooke, Wave Propagation Laboratory, Environmental Research Lab- oratories, National Oceanic and Atmospheric Administration, Boulder, CO. March, 1981. DOE/ET/23151-80/1. This report evaluates a number of remote-sensing systems such as radars, lidars, and acoustic echo sounders which are potential alternatives to the cup and propeller anemometers routinely used in wind energy siting. The high cost and demanding operational requirements of these sensors current- ly preclude their use in the early stages of a multi-phase wind energy siting strategy such as that recently articulated by Hiester and Pennell (See Wind Energy Report, March 1981). Instead, these systems can be used most ef- fectively in the lattermost stages of the siting process—what Hiester and Pennell refer to as the ‘‘site development phase,’’ necessary only for the siting of large wind-energy conversion systems (WECS) or WECS clusters. Even for this particular application only four techniques should provide the data sets currently considered adequate for wind-energy siting purposes. They are in rough order of increasing expense and operating demands: op- tical tranverse wind sensors; acoustic Doppler sounders; time-of-flight and continuous wave (CW), Doppler lidar; and frequency-modulated, con- tinuous wave (FM-CW), Doppler radar. Not all these instruments are presently commercially available. While the first two are, the latter two are not. Nor can such instruments necessarily be operated as simply, as reliably, or as economically as their in situ counter- parts. Although in some instances this is the case. For the most part, these remote sensors are more expensive and demanding in their operating re- Wind Energy Report June 1981 quirements than the most rudimentary in situ capability for this siting phase (which for purposes of discussion can be taken to be a single tall tower with three anemometers, mounted respectively at the bottom of the rotor disk, at hub height, and at the top of the rotor disk). Neither will the data sets obtained by these instruments necessarily be entirely free of shortcomings. In some cases, it is possible that the data may be biased as a result of varia- tions in system performance under different meteorological conditions. However, it appears that these shortcomings could be tolerated in siting studies. Despite these caveats, the use of remote-sensing systems in wind-energy applications may be viable in the next five years, if not now. Some of the in- struments can operate virtually unattended for extended periods. The cost of their operation, while sometimes high, often falls within the rather large dollar limits determined by cost-benefit analyses to be available for site sur- veys, particulary for the larger WECS systems and WECS clusters. In addi- tion, remote-sensing systems may prove quite useful, perhaps essential, in the development of certain specialized data sets for WECS design and for the advancement of WECS technology generally. As user requirements on wind-energy data sets become more stringent, as inflation increases the cost of conventional siting methods, and as improved technology reduces the cost of remote sensing alternatives, these should continue to look increas- ingly attractive. This report summarizes these findings by describing the principles under- lying the operations of remote-sensing systems and discusses their advan- tages and limitations for wind-energy applications. The emphasis is on siting but some material on design work is included. Future data needs for wind-energy siting and design are projected and compared with the capabilities of the new instruments. Some lines of research and develop- ment that could be fruitfully pursued in order to increase the effectiveness of remote-sensing systems in wind-energy applications are indicated. * * * Assessment of Wind Turbine Wake-Effects in the Proposed “*Markerward”’ Wind/Hydro Project by P.E.J. Vermeulen, P.J.H. Built- jes, J.B.A. Vijge and L. De Smet, Organization for Industrial Researsch, TNO, 7300 AH Apeldoorn, Netherlands. October 1980. 80-012082. The choice of an optimal mutual distance between the wind turbines is clearly not only determined by aerodynamic arguments. The objective of this study is therefore to support, from the aerodynamic viewpoint, the determination of the optimal mutual distance between the wind turbines. The results are presented in such a way that the aerodynamic consequences of a certain choice of mutual distance can be easily recognized. The present study is intended to be useful, not only for the “‘Markerwaard”’ project itself, but also for other wind farms where the wind turbines are placed on one or more concentric circles. Computer calculations have been made concerning wake-interaction ef- fects between wind turbines situated on the edge of an otherwise empty area. This study gives results for: the power caused by wind-depletion ef- fects; and the maximum additional velocity differences experienced by wind turbines in the array. The following conclusions can be drawn: For large arrays (greater than 50 km?) the power loss caused by interaction ef- fects is independent of the wind turbine diameter and of the size of the ar- ray itself. Graphs are presented which correlate the total power loss with the mutual distance between the wind turbines: For arrays consisting of wind turbines situated on one single circle this total power loss is relatively small: only 10% at a spacing of 4 diameters. At such small spacings, however, the additional velocity differences can be as high as 50% of the undisturbed approach flow, causing large aerodynamic loads. The closest spacing between the wind turbines that can be used is therefore believed to be determined by these additonal loads. * * * Residual Streses in Darrieus Vertical Axis Wind Turbine Blades by Paul Veers, Sandia National Laboratories, Albuquerque, NM. April, 1981. Sand81-0923. The new blade extrusion technology has made it possible to produce ver- tical axis blades relatively inexpensively. The cold forming process used to bend the straight extrusion into the troposkien or approximate troposkien shape used on VAWTs induces residual stresses that may reduce fatigue life. Based on a knowledge of vertical axis wind turbine dynamic stress and the use of a Goodman Diagram, acceptable levels of residual stresses can be determined. The need to calculate the residual stresses in many different VAWT blade 13 configurations led to the development of the computer code, RESID. With a knowledge of the blade geometry and material properties, the RESID user can calculate residual stresses accurately with a minimum of input. Material properties that affect residual stress magnitude are yield strength and strain hardening slope. Increasing strain hardening slope (E,) results in decreasing residual stress. Residual stresses increase almost linear- ly with increasing yield stress. Analysis of some blade configurations now in use reveals that some blades on rotors with a height to diameter ratio of 1.0 have residual stresses near two thirds of the yield stress. A larger height to diameter ratio results in less blade curvature and lower residual stresses. A method of forming the blades by bending them back into the desired shape, significantly reduces one residual stress local maxium but has little effect on the other, larger, local maximum. The combination of material nonlinearities and complex geometries makes a general statement about residual stress levels difficult to form- ulate. However, the RESID code provides a means for quick and accurate residual stress assessments for a general class of VAWT blades which are fabricated by the bending process. A numerical package called RESID has been assembled to calculate the residual stresses in VAWT blades induced during cold forming. Using a strength of materials—elementary beam theory approach, RESID modes the material response with a bi-linear stress-strain curve, and the cross- sectional geometry with an array of ‘area increments.’ Through an iterative solution procedure residual stresses are predicted for a specified final radius of curvature or applied bending moment. RESID results are compared to theoretical solutions for simple geometries and with MARC Finite element results for VAWT blade geometries. Calculating residual stress levels, determining acceptable residual stress levels, and a method of reducing residual stresses are discussed. A complete listing and sample run are in- cluded in the appendicies. * * * Dynamic Analysis of Darrieus Vertical Axis Wind Turbine Rotors by Don W. Lobitz, Sandia National Laboratories, Applied Mechanics Division, Albuquerque, NM. May, 1981. SAND80-2820. The dynamic response characteristics of the VAWT rotor are important factors governing the safety and fatigue life of VAWT systems. The prin- cipal problems are the determination of critical rotor speeds (resonances) and the assessment of forced vibration response amplitudes. The solution to these problems is complicated by centrifugal and Coriolis effects which can have substanial influence on rotor resonant frequencies and mode shapes. This paper describes and discusses the primary tools now in use at Sandia National Laboratories for rotor analysis. These tools include a lumped spring-mass model (VAWTDYN) and also finite-element based ap- proaches. The discussion centers on the accuracy and completeness of cur- rent capabilities and plans for future research. This paper is meant primarily to provide an overview, much of the detail is omitted and will be presented in a follow-on report. The sophistication of dynamic analysis methods for VAWTs has undergone steady improvement at Sandia, according to the author. The current method provides a means to predict straightforwardly the spectral characteristics of rotating turbines which have a significant degree of struc- tural complexity. Verification tests have shown the accuracy of the method to be quite satisfactory. After completion of the planned activities inden- tified in the previous section, a strong capability for dynamic assessment of VAWTs should be available. This should be achieved with the current calendar year (1981) and will significantly improve the capability to design, structurally, advanced VAWT systems. * * * Advanced And Innovative Wind Energy Concept Development: Dynamic Inducer System by P.B.S. Lissaman, A.D. Zalay and B.H. Hibbs. AeroVironment, Inc., Pasadena, CA, for Solar Energy Research Institute, Golden, CO. May, 1981. SERI/TR-8085-1-T2 (DE81024090) The performance benefits of the dynamic inducer tip vane system have been experimentally demonstrated for the first time. Tow-tests conducted on a three-bladed, 3.6-meter diameter rotor have shown that a dynamic in- ducer can achieve a power coefficient (based upon power blade swept area) of 0.5, which exceeds that of a plain rotor by about 35%. Wind tunnel tests conducted on a one-third scale model of the dynamic inducer achieved a power coefficient of 9.62 which exceeded that of a plain rotor by about ‘ . Wind Energy Report June 1981 70%. The dynamic inducer substantially improves the performance of con- ventional rotors and indications are that higher power coefficients can be achieved through additional aerodynamic optimization. It is noted that the wind turbine system used as a baseline unit is the Kedco 1200, a conven- tional propeller-type wind turbine with power blades designed for optimum performance without tip vane augmentation. In addition, the tip vane utilized a standard conventional NACA airfoil selected on conservative grounds to guarantee acceptable performance. More advanced high lift-to- drag airfoil sectons are expected to improve the tip vane effectiveness. The analytical and experimental development efforts summarized in this report suggest that the dynamic inducer can play a major role in future tur- bine technology. A new method for calculating wind tunnel corrections for augmented wind turbines is developed. This shows that corrections are very significant. For example, with a blockage of 16%, the corrected power coefficient is about 20% lower than that actually measured. Comparison of the results of the field tests with the wind tunnel tests is good qualitatively, but has differences in magnitude of power coefficient. It is believed these differences are attributable to scale effect, calibration, geometrical infidelities between model and actual turbine and various ran- dom factors associated with field testing. The field tests demonstrated tip vane effectiveness. More extensive testing with a better optimized tip vane will result in further improvements. It is noted that optimization of a tip speed ratio 1.33 times higher will permit a 33% reduction in tip vane span. It is recognized that the power coefficients observed during the tow tests of the basic Kedco turbine, Cc, greater than 0.5, are higher than correspon- ding measurements published by Rocky Flats. The reason for this ment is not clear. However, the absolute value of the power coefficient for the baseline rotor is of secondary importance. The purpose of the tow tests was to compare the incremental performance of the baseline rotor com- pared to the dynamic inducer. The tests demonstrated that the dynamic in- ducer significantly improves the performance of the rotor. The differences observed between the existing tow test measurements and the Rocky Flats measurements should be addressed in a separate program. The conclusions of this study are: the dynamic inducer system can substanially increase the power output of a conventional rotor system; wind tunnel corrections are very important for augmented turbine systems; and the performance benefits of the dynamic inducer system are likely to be higher for optimized configurations. The favorable results obtained in this program suggest that the dynamic inducer system can play a major role in future WECS technology. * * * A Parallel-Anemometric Approach to Windmill Siting by Douglas A. Halperin and Ralph A. Beckman, Aeolian Kinetics, Providence, RI. Paper presented at the /98/ Annual Meeting of the American Section/Interna- tional Solar Energy Society, Philadelphia, PA. Two volumes, $150. Available: AS/ISES Headquarters, Research Institute for Advanced Technology, U.S. Highway 190 West, Killeen, TX 76541. As more people turn to the use of small-scale wind energy systems, the need to develop a reliable short-term method for windmill siting becomes critical. The parallel-anemometric by direction (PAD) approach to siting is one attempt at such a method. Measurements of speed and direction for a three month period at both a prospective wind energy site and a site with known wind characteristics are taken. Data is divided into sets by direction and correlations between the two sites are computed for each set. The Weibull distribution is applied to these correlations in order to extrapolate the short-term data to a long-term prediction of available power at the pro- spective site. Many prospective small-scale WECS users find that the demand for a full year’s data collection prior to making any assessment of the wind’s available energy expensive and time consuming. Use of a method which is compatible in cost and practibility to such a user will better assure that a WECS erected will successfully operate. The PAD approach is one method; it has been used by the authors in several locations in the country. The ap- proach and similar ones must be confirmed in their viability and validity as predictive techniques before their wide scale application will result. Wind Energy Activities Within the Department of Defense by William J. Barattino, Air Force Energy Liaison Office, Albuquerque, NM. Paper presented at the /98/ Annual Meeting of the American Section/Interna- tional Solar Energy Society, Philadelphia, PA. Two volumes, $150. Available: AS/ISES Headquarters, Research Institute for Advanced Technology, U.S. Highway 190 West. Killeen, TX 76541. 14 The Department of Defense, the largest single consumer of energy within the U.S., has a significant number of bases in good wind resource areas. Past activities in wind energy have focused primarily on determination of the adaptability of commercially available machines for military bases. Military engineers share the same operational and maintenance concerns as their counterparts in the private sector. There are, however, some unique Department of Defense (DOD) concerns that must be considered as well. Future DOD activities in wind energy are aimed at developing a good wind resource data base, identifying the electromagnetic effects of wind turbines on communication-electronics equipment, developing siting procedures for small and large WECS on military bases, and continuing to gain O&M ex- perience with small wind turbines at selected locations. The military services will continue to gain experience with purchase of small turbine systems over the next several years. Base engineers from in- stallations in California, Texas, Hawaii, Alaska, and other locations have indicated their intent to purchase small WECS in the near term. In loca- tions where wind farms can meet or exceed electricity costs of local utilities, third party entrepreneurs will find a receptive audience at most military in- stallations. With the passage of the Wind Energy Systems Act of 1980, the DOD began organizing to play a major role in the implementation of the federal buy portion of the bill. While the future of such a program remains in doubt at this time in light of recent budgetary cuts, selected organizations within the DOD will continue to press for the use of wind energy as a viable source for meeting the year 2000 goal of 20% solar. The key to how large the DOD involvement will be in wind energy, lies with the ability of the WECS to provide reliable electrical energy at a price competitive with the local utility. * * * SOLSTOR Description and User’s Guide by Eugene A. Aronson, David L. Caskey and Bill C. Caskey, Sandia National Laboratories. March, 1981. SAND79-2330 This report describes the computer simulation code SOLSTOR. The code simulates energy systems in which electricity is generated by either a photovoltaic (PV) system or a wind turbine generator (WTG). Storage may or may not be present. Backup electricity, if needed, is provided either from a utility grid or from a fuel-burning generator. SOLSTOR minimizes the life cycle cost of providing energy by choosing the optimal solar or wind system component sizes. Rates for electricity purchased from the grid can include time-of-day (TOD) energy charges as well as time-of-day peak de- mand changes. Sell-back to the grid of excess collected energy is also con- sidered. Planetary Boundary Layer Wind Model Evaluation at a Mid-Atlantic Coastal Site by H.W. Tieleman, Virginia Polytechnic Institute and State University, Blacksburg, VA. October, 1980. DOE/ET/23007-80/1 (DE8 1024093). Detailed measurements of the mean flow and turbulence have been made with the use of a micrometeorological facility consisting of an instrumented 76-m tall tower located within a 100-m distance from the Atlantic Ocean at Wallops Island, Virginia. An interpretation of the experimental results demonstrates that under moderately strong wind conditions (hourly mean wind speed between 10 m/s and 20 m/s at a height of 10m), the popular neutral boundary-layer flow model fails to provide an adequate description of the actual flow. For daytime westerly winds the convective boundary layer, which has been previously observed at sites on the continent, provides an adequate model for the surface flow at the Wallops Island site. However variations from this model have been observed for certain wind directions and under certain atmospheric conditions such as low altitude cloud cover combined with precipitation. The observed low-frequency velocity fluctuations give rise to increased turbulent intensities and larger turbulence integral scales. These low-frequency fluctuations also occur in the surface layer where the observed mean velocity profiles generally fit the logarithmic law quite well. For on-shore winds the surface flow is complicated as the result of the development of an internal boundary layer (IBL) as the air crossing the beach generally experiences a change in surface roughness and surface temperature. The internal boundary layer has a height between 15 m and 30 m at the tower location depending on wind direction and change in surface conditions. For southerly winds the warmer air flows over the cooler water allowing the existence of a surface-based inversion of variable depth. Under these conditions a low-altitude maximum velocity (surface jet), occasional- . Wind Energy Report ly below the highest observation level of 76 m, has been observed. Under extreme stable conditions at hourly mean velocities in excess of 10 m/s the turbulence has been observed to vanish completely. In addition, low- frequency internal gravity waves have been observed to co-exist with the turbulence. In addition to detailed flow information for all wind directions, averages of the important flow parameters used for design such as vertical distribu- tion of mean velocity, turbulence intensities and turbulence integral scales have been presented for wind-direction sectors with near-uniform upstream terrain. Power spectra of the three velocity components for the prevailing northwesterly and southerly winds are presented and discussed in detail. The experimental results indicate clearly that the non-uniformity of the upstream surface conditions, the non-neutral thermal stratification and the presence of appreciable low-frequency velocity fluctuations have a pro- nounced effect on the surface flow. Consequently it is impossible to find a simple and single PBL model to describe the flow at this site even under moderately strong wind conditions. Moreover, there is no evidence that under still stronger wind conditions (hourly mean wind speed z = 10 m over 20 m/s) the surface flow will alter sufficiently as to conform to the neutral boundary-layer model whose turbulence is of purely mechanical origin. Balloon Measurements of Upper Level Wind Speeds by Gary L.. Johnson, Associate Professor, Electrical Engineering, Kansas State University, Manhattan, KS. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. The intelligent deployment of large wind turbines requires a good knowledge of the wind speed variation between 20 and 120 meters in eleva- tion, although most wind speed data are recorded at about 10 m. One way of dealing with this problem is to sample wind speeds at these heights with weather balloons. The paper describes a balloon launch program at KSU. Distinct differences in the wind profiles for daytime and night have been observed with the wind speed increasing more rapidly with height after dark. Wind resources may be seriously underestimated by simply using sur- face wind data and extrapolating upward with average power law ex- ponents. * . . Wind Energy Potential in a Typhoon Environment by Henry Liu, Visiting Professor, Civil Engineering, University of Melbourne, Australia; Pro- fessor, Civil Engineering, University of Missouri-Columbia. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. Taiwan experiences an average of four typhoons per year, often bringing with each high winds and heavy rains. Can conventional windmills with- stand the fierce forces generated by the typhoon wind? The question can be answered intelligently only when typhoon wind intensity associated with a given occurrence probability or recurrence interval is known and when the survival wind velocity of the windmills are given. A study has been launch- ed to answer this question. The paper presents statistical data on both the annual average wind speed and the probability of extreme winds at various places in Taiwan and its satellite islands. Some unique features of the data will be pointed out. The wind energy potential of these places will be discussed. Experience in using wind energy and plans for increased tapping of this resource in Taiwan also will be discussed. * . . Height Variation in Diurnal Wind Patterns by Charles Stearns, Lorne Kuf- fel, Madison, WI. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. Presents an improved description of the wind energy resource in the Midwest. The analysis indicates 1) much more available wind energy aloft than normally estimated with most of the additional energy occurring at night and, 2) the seasonal variation of winter highs and summer lows in available wind energy can be evened out with an increase in height above the surface. These results suggest that an increase in the height of a wind energy conversion system will be much more beneficial than previously estimated in the midwest. 15 June 1981 Annual Energy Production from Fixed-Pitch, Constant-Speed Rotors by C. Wayne Martin, University of Nebraska. Presented at The Second Con- ference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. Extensive aerodynamic calculations have been performed for horizontal axis wind turbines which have fixed-pitch, fixed-speed, and three blades. One objective was to determine the blade incidence angles and rotational speeds which result in maximum annual energy production. A second ob- jective was to determine the fraction of energy lost by fixed-speed opera- tion. A third objective was to determine the influence of shut-down speed and power absorbing capacity or ‘‘generator size’’ on annual energy pro- duction. For turbines with optimum blade incidence angle and rotational speed, the parameter which most strongly affected annual energy produc- tion was ability to absorb power when available, or ‘‘generator size.”” The calculated annual energy production of optimum constant-speed, fixed- pitch rotors with untwisted, constant-chord blades is a high percentage of the energy achievable with more complex turbines. It is expected, of course, that they would be much less expensive to build than variable-pitch turbines having blades with nonlinear twist and taper. * * * Small Wind Turbines Operating in Utility Distribution Systems by David Curtice, Systems Control, Inc., Palo Alto, CA. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. The study’s intent was to define possible problems created by small wind turbines (WTs) connected on utility distribution systems and to develop solutions. The specific objectives included analysis of: utility personnel safety; distribution system and WT protection equipment; WT’s effects on feeder voltage profiles, regulation and line losses; and development of a technique to analyze utility load-frequency control problems with various penetrations of WTs dispersed throughout its service area. * . * Approaches to Wind Energy Siting in Urban and Rural Environments by Richard A. Rothstein, CCM, TRC, Weathersfield, CT. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. This paper reviews some generic meteorological siting problems and pit- falls and site analysis methodologies for wind energy assessment studies in urban and rural areas. Considerations presented are more germane to small WECS users (less than 100 kw) such as industrial facilities located in urban environments and farms or private users in rural areas. Discussions and ex- amples of site survey evaluations, basis and use of various wind measure- ment instrumentation systems, and approaches for performing statistical correlations between off-site and on-site data and wind power calculations are presented. . . . Lightning: Hazard to Wind Turbines by J.G. Smith, et al. Southern Illinois University, Carbondale. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Col- umbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. The risks and dangers to wind turbines from lightning activity are detail- ed. Components that are vulnerable include blades, bearings, generators, electronic controls, sensor, and computers. The danger to humans and animals at the wind turbine site is examined as are the methods of estimating the probability of a wind turbine being struck by lightning. Ac- tual lightning strike damage to wind turbines is reported. . * * Siting a Wind Turbine Generator for an Industrial Facility in an Urban Area by James J. Binder, P.E., TRC, Weathersfield, CT. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. Siting, or more specifically, evaluating the feasibility of operating a wind turbine generator in an urban environment has received only limited atten- tion in the wind energy community. Yet, it is precisely such areas, par- Wind Energy Report ticularly in the Northeast, that are heavily dependent on oil and represent prime candidate locations for alternative energy applications, including wind energy. Siting in an urban area is complex in that there is normally limited available space, little or no representative wind data, and it is im- perative to account for wind channeling, wind turbulence, and wind blockage from buildings to accurately assess site specific wind potential. In addition, one must address more restrictive environmental and institutional issues in an urban vs. a rural environment. The paper discusses one ap- proach and the data utilized for siting a WTG at an industrial facility in Jersey City, New Jersey. Actual field data is presented and discussed as ap- propriate. * * * Siting for Wind Energy Within the Tennessee Valley Region by B. Owens, Project Manager, Solar Applications Branch, TVA, and D. Cromack, et al., University of Massachusetts. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. This effort consisted of topographical and field studies to identify pro- mising sites for the early installation of wind systems. These sites have been identified as the most promising based on the wind resource, potential ap- plication, environmental impact and user interest and are expected to be the locations of the first wind machines to be installed. One site is described in detail including descriptions of two possible wind energy systems as an ex- ample for possible installations. Plans for incorporating wind energy systems in to TVA region are also discussed. * * * The Design, Fabrication and Testing of a 72’ Ducted Wind Turbine by Oliver C. Eckel, P.E. Delray Beach, FL. Presented at The Second Con- ference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. The ducted wind turbine is radically different from conventional horizontal and vertical axis wind turbines. Work on the ducted wind tur- bine is directed toward a prototype for a line of turbines that will be com- mercially produced for generating power for emergency use, for storage or as a supplemental source. Design, fabrication and testing of the DWT is described. * * * Measurement and Assessment of the Noise Produced by Small Wind Energy Systems (SWECS) by A.C. Hansen, Wind Systems Program, Rockwell International, Golden, CO. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. This paper presents results of measurements of noise levels around four SWECS at the DOE Rocky Flats Small Wind Systems Test and Develop- ment Center. The noise measurements are interpreted in terms of probable community response to SWECS installations. It is shown that normally operating SWECS generate noise levels comparable to common community noises. Noise levels range from 40 to 60 dBA depending upon the particular SWECS, the distance to the observer and the wind speed. The paper notes that background wind noise levels near trees are of a similar magnitude. It is concluded that SWECS noise will often be indistinguishable from other background noises. Situations may arise however, where persons sensitive to any noise disturbance may be annoyed by the proximity of SWECS in relatively quiet suburban or rural neighborhoods. The probability of noise complaints will also be heightened if there is a public perception of a risk of physical danger near SWECS. * * * Design and Development of SWECS for Small Tropical Islands by Edgar Werner, Ph.D., Office of Energy, Puerto Rico. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. While the well established concepts of economy of scale, and centralized generation for grid distribution are effective methods for massive alter- native energy systems in the continental U.S., this same technology is ill- adapted for transfer to Third World countries and small tropical islands. 16 June 1981 Not only do these areas lack even modest distribution grids, but in general no economy could support a substantial scale-up of wind turbines to any appreciable size. The development of alternative energy systems for small tropical islands must essentially follow patterns appropriate for the ex- ploitation of other natural resources in similar situations. A concept, to be useful and acceptable, for tropical isand SWECS must be of manageable size, technologically simple, low cost (but cost effective) and site specific. Each of these parameters is considered in detail. * * * Wind Site Survey Methodologies for U.S. Air Force Installations by Lt. Col. Thomas E. Kullgren, U.S. Air Force Academy. Presented at The Se- cond Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. Section 11 of the 1980 Wind Energy Systems Act directs the Secretary of Energy to ‘‘conduct a federal application study for wind energy systems, cooperatively with appropriate Federal agencies to determine the potential for the use of wind systems at specific Federal facilities."” The Air Force mission depends heavily upon the operation of aerospace vehicles within or through the earth’s atmosphere. Characteristics of the atmosphere, namely weather conditions, have been recorded for many years at locations with flying activities and represent a sizable data base which can provide a star- ting point for wind site surveys. Three organized methodologies are presented for rank-ordering potential wind sites from among all Air Force bases in the continental United States. A key feature of these methodologies is the early introduction of economic factors which are critical to any selection criteria applied to potential Air Force candidate sites. Variable Inertia Flywheel Concept by Edward N. Kuznetsov and Henrique L.M. dos Reis, University of Illinois at Urbana-Champaign.Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. A new type of variable inertia flywheel is proposed to reduce the transmissions requirements of flywheel energy storage systems. The con- cept is based on a passive control (mechanical feedback) of the rotating mass inertia. This is achieved by synthesizing a composite structural com- ponent possessing a prescribed force-displacement diagram and using it as the flywheel rim. In operation, energy is accumulated or delivered mainly at the expense of flywheel inertia variation rather than due to a change in its angular velocity which remains nearly constant. * * * The Economic Potential for Wind Turbine Generating Systems Across the Northern United States by Martin K. Goldenblatt, JBF Scientific Corp., Wilmington, MA.Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Columbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. The Department of Energy and the Solar Energy Research Institute are sponsoring a series of six regional assessment studies (covering the entire country) aimed at identifying both the potential for solar electric technologies and applications that represent the best potential markets with opportunities for early commercialization. One of the solar electric technologies showing the earliest promise is wind. This paper is based on work done for the three assessment studies which covered the northern tier of the United States (28 states) and focuses on the results obtained for the utility application of large central station wind turbine generators. Siting for Small Wind Systems: A Review of 30 Installations by Steve Blake, Oskaloosa, KS. Presented at The Second Conference on Wind Energy Technology, March 16-17, 1981, at the University of Missouri, Col- umbia. Proceedings are available for $49.00 prepaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. A methodology for projecting wind electric system output based on mean wind speed data is presented. This methodology in turn enables the use of inexpensive wind-run anemometers in the site evaluation of small wind elec- tric systems. a WIND bulletin New Zephyr - PO Box 3627. Arlington, Va.22203 November 6, 1981 FEDERAL BUDGET UPDATE The Senate Appropriations Committee has approved $30.2 million in fund- ing for the federal wind program during fiscal year 1982. This fig- ure is $9 million less than that approved by the House of Represen- tatives, but $11 million more than requested by President Reagan. The 1982 fiscal year has already begun (it runs from October 1, 1981, through Sept. 30, 1982), but Congress did not pass the energy (and other) appropriations in time. Until actual appropriations are made, the federal wind program is operating on a budget matching the Reagan Ad- ministration's original request -- $19.2 million. The House-approved budget funds the $19.2 million in the Administration plan, plus $18 million for develop- ment of the Mod-5 large wind turbine and $2 million for wind resource assessment. The Senate committee has not specified where the $9 mil- lion difference between its version and the House budget would come from. The full Senate was scheduled to vote on the energy budget figures sometime this week. A joint House- Senate conference would meet soon after that to resolve the differ- ences. According to congressional observers, the final outcome of the conference is anybody's guess. Number 16 NEW CALIFORNIA WIND FARM PROJECT Unique Investments, an energy devel- opment firm located in San Francisco, is hoping to complete negotiations soon on a $5-million, 3-megawatt wind farm project to be located in north- ern California. According to Ron Blauer, head of the company's wind operations, they are negotiating for a final site in Solano County in the Carquinez Straits area or near Altamont Pass. The firm has an option on the wind equipment, but Blauer declined to name the manufacturer (to avoid at- tracting interest that might upset Unique Investment's option agreement). He did say, however, that the indi- vidual units are larger than the Jay Carter 25-kW model. Blauer said the recent Reagan Admin- istration proposal to repeal the energy tax credits has not caused any problems for their financing ne- gotiations. Interested investors have had some hesitancy, he noted, but are not convinced that any changes will actually be enacted. “It has scared them, but not scared them off." Unique Investments expects to see its wind farm up by the middle of next year. the WIND bulletin 11-6-81 p2 BOOKS... Alaskan Wind Energy Handbook, by Matt Reckard and Mark Newell, Alaska Department of Transporta- tion and Public Facilities, 1981. The "Alaskan Wind Energy Handbook" is a useful source for anyone about to enter the wind energy field, whether as a consumer, dealer, in- staller, or engineer. It covers almost every detail of successful operation of a wind generating ‘sys- tem, and handles even technical concepts in clear, understandable language. The book, 144 pages total, is the second wind energy publication by the Alaska DOTPF. The first, the “Alaska Wind Power User's Manual" by Dr. Tunis Wentink, was published in August, 1980. The "Handbook" is described in the preface as an expansion on the earlier publica- tion. It explains: how wind power is cap- tured by wind turbines; the princi- ples of siting; the various types of wind generators; how wind equip- ment components fit (or don't fit) together; how to figure electrical demand; how to decide among machines; how to calculate the costs; and how to safely install and maintain a machine. The book also includes several useful lists in its appendices -- figures on energy use for various electric appliances, a glossary, and an annotated bibliography. The Handbook makes wind systems more understandable to potential consumers, but it doesn't make them sound easy -- good reading for people who assume wind power can automatically end their utility bills forever. Available from Alaska Dept. of Trans- portation and Public Facilities, Division of Planning and Programming, Research Section, 2310 Peger Road, Fairbanks, AK 99701; free as long as copies are available. Fall 1981 Catalog, WindBooks, PO Box 14, Rockville Centre, NY 11571. A listing of 24 technical and econom- ic studies on wind energy, available from the publisher of Wind Energy Report. Includes proceedings from several American and international conferences as well. PURPA UPDATE The challenge to the Public Utility Regulatory Policies Act (PURPA) -- the 1978 law requiring utilities to buy electricity from small power producers such as windmill owners -- is expected to be argued before the Supreme Court sometime early next year (January or February). The court case arises from a ruling by a Mississippi federal judge that sections of PURPA are unconstitu- tional infringements on state au- thority. The Justice Dept. is appealing that decision. Despite the pending court case, the WIND bulletin 11-6-81 every state except Georgia has gone forward in implementing PURPA -- but the process has been fairly slow. According to observers, some of the slowness is due simply to the newness of the issues in- volved. Another factor, however, is the fact that the Federal Energy Regulatory Commission (FERC), the agency responsible for implementing PURPA, has not been aggressively enforcing it while the court case is pending. : PURPA is important to the econom- ics of wind energy, both for home- owners who want to interconnect their wind machine with the utility grid, and for wind farm developers who plan to sell large amounts of wind-generated electricity to the utility. CALIFORNIA WIND ASSN, FORMED A state wind industry association has recently formed in California, primarily in response to problems encountered with local governments. According to Mario Agnello, head of Aero Power, the association was formed this past summer. Its mem- bership now numbers 75, and growing. Agnello, a manufacturer, and Neil Holbrook and Joe Richardson, both dealers-installers, are the founders of the new industry group. The association has two types of membership: voting, for individuals who make their living in the wind in- dustry; and non-voting, for wind power users and supporters. Dues range from $10-15 for non-voting members, and from $35-600 for voting membership. p3 Although they are including non- industry members, Agnello emphasized that the group is "essentially an in- dustry association." Currently the association has 3 di- rectors and 3 officers, elected tem- porarily until its first annual meet- ing in January in Sacramento. At the state level in California, "a very rosy picture is painted for wind energy," Agnello said. "But both large wind farm developers and indi- vidual owners are running into prob- lems with counties and localities." He said the new association's purpose is to provide "legitimate industry input" to these local governments and help reduce such problems. For more information, contact Agnello at 2390 Fourth St., Berkelet, CA 94710, 415/848-2710. NOTES . « .. . . .Van Nostrand Reinhold (135 W. 50 St., NY NY 10020) has announced pub- lication of a new edition of Putnam's Power from the Wind, the account of the 1941 multi-megawatt wind turbine installed on Grandpa's Knob, VT. The revised edition also includes details about current large-wind projects. Available in November for $27.50. ... TMAC (680 Beach St., Ste. 428, San Francisco, CA 94109) is handling ex- hibits for the Solar Technologies Conference & International Exposition (June 1-5, 1982, in Houston). The con- ference is the annual meeting of the American Section of the International Solar Energy Society. Contact TMAC at 415/474-3000 or 800/227-3477. . .. The Delaware River and Bay Authority has issued a request for proposal to provide wind-generated electricity Tecaticaed on next page) Ze9€ XOG Od UNeIING GWIM uy > = = 2 - ° # < a) LS) LS) iS) ° @ L0S66 Ay abeuoyouy LLOMAN y4RW peoy wopn] 4se9 [SST Bulusautbuz swazshs pul ew Snseuiog the WIND bulletin 11-6-81 p4 Notes (cont. from p3) _ for the Cape May and Lewes Ferry ter- minals. Contact Paul Gipe & Asso- ciates, 717/233-3996 by January 1, 1982. CALENDAR. . . Nov 21 (Sat.) Pittsfield, MA: Wind Workshop, at Berkshire Community College, 10 amto 4 pm. A general course for people interested in using wind energy to produce electricity, sponsored by the Center for Ecological Technology. It will cover the history and theory of wind energy, types of machines, site selection, electricity storage, economics, and utility inter- face. Cost is $45. For more information, contact Alan Silverstein, Center for Ecological Technology, 74 North St.,Rm. 610, Pittsfield, MA 01201,413/445-4556. Feb 23-24 (Tues-Wed) Washington Solar Under Reagan, at the Ram nO %- naissance Hotel, 1143 New Hampshire Ave., NW, 8:30 am to 5:30 pm, 9 am to 11:45 am. The seminar, sponsored by Solar Energy Intelligence Report, is subtitled "How to Survive and Win Through Better Marketing" and is de- signed for solar manufacturers, engi- neers, contractors/builders, dealers and distributors. Sessions cover gen- eral outlook for solar businesses Plus specific review of individual technologies, including wind. Speakers include industry, government, and trade association representatives. SEIR subscribers receive a registra- tion discount: $180 by 12/2/81; $205 after. Fee for non- -subscribers is $220. Contact Oyez Seminars, 2031 Florida Ave., Washington, DC 20009, 202/332-0380. 1551 Past Toler ‘Road ANCHORAGE, ALASKA 9950 WIND ENERGY Report The International Newsletter of Wind Power MAY 1981 MOD-2 wind farm dedicated in northwest The world’s first large wind turbine array began generating electricity this month as three Boeing MOD-2 machines were form- ally dedicated at Goodnoe Hills, Washing- ton, on the Columbia River Gorge. The ceremony contained the obligatory thetorical flourishes about the huge poten- tial of wind power, the dire nature of the energy crisis, and how politicians, contrac- tors and government officials admire one another. Boeing Engineering & Construction Pres- ident Fred W. Maxwell admitted that there were plenty of skeptics four years ago about wind energy in his company. ‘‘Now our top management is a believer in wind energy and fully supports our efforts to become a major supplier of these systems.”’ BPA Administrator Peter Johnson estimated that ‘“‘with a good effort, the region can capture more than 250 average annual megawatts” by 1990. For his part, Senator Jackson used the occasion to criticize Reagan Administration proposals to reduce the FY82 federal wind energy budget to $19 million. ‘Today the danger comes, not from OPEC, but from those who would abandon government par- Inside W.E.R. Wr the ROWS... ccc cecccccserce 2 | USWP’s Altamont wind farm........ 3 Fayette’s California wind farm ...... 4 | Aerotherm to bulld UMASS 50 kW ...5 COMORGM oo cs iste cscs cieccncee 6 Battery storage a wind option ....... 6 | MOD-2 dedicated In northwest ..... 10 Investing In wind power ISSN: 0162-8623 ticipation and cooperation in energy research, development and demonstration projects and would, instead, leave everything to the private sector and the marketplace.”’ A $19 million budget for next year would make it virtually impossible for his impor- tant industrial constituent, Boeing, to ob- tain funding to build the MOD-5 Nevertheless, the dedication is the cul- mination of an intensive government/in- dustry collaboration. More importantly, perhaps, the three MOD-2s represent the materialization of the major underlying premise of the federal wind energy pro- gram: in mass production, multi-megawatt wind energy systems can produce cheap, utility grade electricity but only after reliability and performance are satisfactori- ly demonstrated. The Department of Energy commitment to the MOD-2 program, including research, development, construction and manag- ment, totals $35 million. That doesn’t in- clude an additional $3,623,227 contract awarded to Boeing this month for analysis, operation and maintenance for a two-year test period. The first unit cost $6 million. The second and third cost $5.3 million each for con- struction and installation. Power from-the MOD-2 costs approximately 10 cents/kWh. Boeing estimates that if the MOD-2 were mass-produced, electricity from the 100th unit would cost 4-5 cents/kWh ($1977). To defray part of the cost of the demon- stration, the Bonneville Power Administra- tion will pay DOE 2.5 cents for each kilowatt-hour generated. The BPA says it has already contributed $2 million toward the project for site acquisition and develop- ment costs, bringing the total cost of the project to slightly more than $40 million. (Continued on page 6) USWP to build Altamont Pass wind farm U.S. Wind Power Inc. has received the final go-ahead from Alameda County of- ficials to build a five megawatt wind farm in California’s Altamont Pass. Construction of the company’s second wind farm—to be located on the Walker Ranch 50 miles east of San Francisco—is expected to begin in July and be completed before the end of the year. Initially, the wind farm will deploy 100 newer 50 kW three bladed wind machines. But plans call for the wind array to double in size to 200 machines eventually. In March, the Alameda County Board of Supervisors voted to allow wind machines on land zoned for agricultural use and, subsequently, the county zoning admini- strator granted approval to a conditional use permit. According to U.S. Wind Power’s the ar- rangement with the Walker family, cattle grazing and dry farming of barley, wheat and hay will continue uninterrupted during construction and operation of the wind farm. Wind studies sponsored by the California Energy Commission indicate that the roll- ing hills of the Altamont region, near Liver- more, receive most of its powerful westerly winds during the summer months, generally from 10 P.M. to 6 A.M. One totalizing anemometer close to the 585-acre Walker ranch yielded a 17 mph mean average annual wind speed. During the months of June, July and August, wind velocities were measured at 24.1, 23.5 and 26.1 mph respectively. Power generated by the five megawatt wind farm will be sold to Pacific Gas & Electric and the California Department of Water Resources. According to Alvin Duskin, who’s res- ponsible for site selection, leasing and power contracts for U.S. Wind Power, the 200 machine wind array could produce 40 million kWh annually. U.S. Wind Power does not plan to install (Continued on page 3) Wind Energy Report In the news. i : Pennsylvania Power & Light Co. has announced that it has re- ceived state regulatory approval for a “‘pioneer’’ rate schedule per- mitting the utility to pay 6 cents/kWh for electricity generated from wind energy systems and other small power producers. Until the new rate takes effect in June, PP&L will continue to pay 1.9 cents/kWh for wind generated electricity. According to Robert Ro- mancheck, the utility’s manager of rate administration, there are no reliability requirements for wind energy equipment. But PP&L may require that the user pay for interconnection costs and meter- ing to measure the turbine’s output. Data from PP&L’s rate sub- mission to the state’s PUC reveals that the utility doesn’t think the six cent/kwh will cause it to lose much revenue from wind energy systems. The utility anticipates that 250 wind power installations will provide only 625 kW of capacity and generate a mere 500,000 kWh annually by 1990. (Contact: Romancheck, (215) 770-5534). Pacific Gas & Electric will start paying small power producers the highest buy-back rate in the nation beginning this month and con- tinuing for June and July. For electricity purchased during on- peak, 7.783 cents/kWh, for partial peak, 7.487 cents/kWh; for offpeak, 6.446 cents/kWh. 6.85 cents/kWh is the average buy- back rate. The new rate surpasses the 7.7 cents/kWh mandated by New Hampshire. Central Hudson Gas & Electric Corporationwill be spending $50,000 beginning next month in a year-long effort to determine potential wind power locations in the mid-Hudson region. Sixteen sites in Central Hudson’s service territory will be initially surveyed and eight will be selected for a three-month wind characteristics study. Three of the eight sites showing the greatest potential will be studied further for one year. Ultimately, a single site, ‘‘capable of economically producing electricity,’ will be selected for the in- stallation of a demonstration wind turbine The Atmospheric Sciences Research Center at the State Universi- ty of New York at Albany will interpret the wind data. Flowpower, Inc., of Huntington, a meteorological consulting firm will perform computer simulations of various wind machines at the primary can- didate sites. The project is jointly funded with the state’s Energy Research & Development Authority. Tri-State Generation and Transmission Association will spend $58,800 during the next year to collect and analyze wind resource data from four sites now under consideration for final selection. Wind sensors will record wind speed and direction at 15-minute in- tervals to provide the utility’s planners with sufficient information to determine power duration curves and statistics for calculating generating capacity. Tri-state is a consumer-owned power supplier to 25 member distribution systems in rural areas of Colorado, Nebraska and Wyoming. Clarence Colyn, Tri-State Resource Planning Depart- ment Manager, will coordinate the project from the association’s Thornton, Colorado, headquarters. (303) 452-6111. A Bonneville Power Administration draft study of the potential for small wind energy systems in a segment of its service territory indicates that if 4% of the households in good wind areas install wind systems, 97,200 MWh could be saved by 1985. By the year 2000, 1,120,000 MWh are “‘technically feasible,”” assuming a 40% saturation rate. ‘Potentially achievable’’ projections, assuming saturation rates just one half of the technically feasible range, show that savings range from 48,600 MWh in 1985 to 560,000 MWh by the year 2000. The BPA figures are based on a forecast of households in its West Group Area, using ‘‘an average generator size of 4 kW in a 12 mph average wind regime and an annual energy May 1981 output of 9,000 kWh from each system.’’ (Contact: BPA, Division of Power Requirements, (503) 234-3361). As Congress prepares to decide finally on the Department of Energy’s budget for FY82, the American Wind Energy Association is recommending that a $55 million funding level for wind energy conversion systems be adopted. ‘‘The momentum created by federal assistance for the design, manufacture, and operation of (large and small) systems has brought them to the brink of commer- cial competitiveness and must be maintained.’’ The association is seeking a deferral of work on the MOD-6 but is asking for $20.7 million for continued work on the MOD-5. AWEA also wants more emphasis on the development of wind machines appropriate to agricultural applications. ‘‘A balance must be maintained bet- ween work on both large and small-scale wind turbines, since no clear sizing advantage has yet been demonstrated—or is likely, in light of the diversity of potential wind applications.’”’ (Contact: Tom Gray. (202) 667-9137). The Citizens’ Energy Project has launched an investigation of the role of big business involvement in the development of wind energy, The Washington-based ‘‘advocacy’’ organization is inter- ested in the possible problems of competition experienced by small firms as a result of the involvement of large businesses and utilities in the wind energy market.’’ Securing government contracts and grants, acquiring patent rights and franchises for wind energy pro- ducts, utility rate structures, utility buy-back policies and wind energy commercialization are a few of the topics the organization is examining. (Contact: Brian Gallagher, (202) 387-8998). The Solar Energy Research Institute (SERI) has awarded $97,364 to Washington University Technology Associates, an affiliate of St. Louis’ Washington University, for development of a passive pitch change mechanism for two-bladed, horizontal-axis wind energy conversion systems. The mechanism is intended to help alleviate the stress placed on the rotor during operation and otherwise reduce structural engineering requirements in wind turbines of all sizes. (Contact: Dr. Kurt Hohenemser, (314) 889-6143) . . SERI has also awarded $200,000 to JBF Scientific Corporation, Wilmington, MA, to continue its study of the potential of wind energy system applications at federal facilities. The study, mandated by the Wind Energy Systems Act of 1980, will identify federally owned sites where electrical demand profiles could make wind generated power economically attractive. Results of the study are expected to be re- leased in the Fall by DOE. (Contact: Ed Johanson, (617) 657-4170. NASA’a Lewis Research Center in Cleveland, Ohio, has award- ed a $1,593,037 contract to Boeing Engineering and Construction to build a MOD-2 wind turbine at Medicine Bow, Wyoming, for the Interior Department’s Water and Power Resources Service. The contract calls for Boeing to buy or build all of the materials and components necessary to build the wind turbine generator and erect the tower. An optional part of the contract, valued at an additional $2,137,729, calls for complete installation and acceptance testing of the machine and training of operating personnel. More than four years after it was originally installed, a Grum- man Windstream 25, 15 kW three-bladed machine, has been quietly removed from its demonstration site on the McKnight Farm in Hopkinton, New York. The Windstream 25 was shut down in July 1979 after two years of sporadic operation. Apparently, it hasn’t functioned since. The precise problems associated with the machine remain something of a mystery. The New York State Energy Research and Development Authority, which spent more than $250,000 on the project, has yet to release any details on the problems causing the (Continued on page 4) Wind Energy Report May 1981 USWP to build Altamont Pass wind farm (Continued from front page) the 30 kW machines now operating intermittently on an experimen- tal basis at its Crotched Mountain, New Hampshire, wind farm. (See Wind Energy Report, January 1981). Rather, the company will manufacture an uprated, slightly modified version of the New Hampshire wind turbine: 50 kW, three-bladed downwind machine with a 56-foot rotor diameter. The generator, rotor and transmission will be placed on a 65-foot high steel tripod tower, again similar to the New Hampshire tower. The 50 kW design features a new curved cuff airfoil, similar to the Carter Enterprises 25 kW blade. U.S. Wind Power says that the new airfoil will be more efficient than the tapered, 18-foot blade currently be used on the 30 kW machine. The 50 kW machine is rated at 22- 25 mph while the smaller machine reaches peak power at 27 mph. . Like the 40-foot diameter 30 kW, the new 28-foot blades of the 50 kW will also be made of fiberglass. Tillotson-Pearson, Inc. of Warren, Rhode Island, which made the 28-foot blades will also fabricate the 50 kW blades. Apple computers located in the machine’s hub assembly will monitor wind speed and direction and Pitch the blades. U.S Wind Power plans to dismantle two or more of the 30 kW machines at Crotched Mountain and test the 50 kW model before shipment to California. New Hampshire Facility Dedicated During dedication ceremonies in New Hampshire last month, U.S. Wind Power Chairman Stan Charren couldn’t resist the op- portunity to compare the economics of nuclear and wind power in the presence of the governor, local officials and Public Service of New Hampshire executives. He told William Tallman, chairman of the board of the investor-owned utility, ‘‘to forget about Seabrook now that these windmills are up.’ Charren boasted ‘‘how much cheaper the windmills are, in all respects, over any other source of power—nuclear, coal, or anything else.”’ “It takes over five years of full operation for a nuclear plant to generate the amount of energy that is used up in building it,” said Charren, ‘‘it is three or four years before a large coal plant pays back its energy costs. But each windmill replaces the amount of energy used in only one year.” Graciously, Tallman said the project ‘‘is precisely the type of engineering ingenuity that’s going to help America solve its energy problems.”’ Wind power may well be cheaper over the long haul, thanks to energy tax credits and a beneficent federal and state regulatory climate. Whether the economics of an experimental wind farm are the basis of challenging a technology whose costs are fairly well established (and well publicized) remains to be documented by long-term experience. No one has accused U.S. Wind Power of being overly candid about the project’s true cost. In January, USWP President Norm Moore said the cost of the project was ‘‘around $1 million.”’ By the April dedication, the cost was being publicized at $1.2 million. For competitive reasons, says Charren, U.S. Wind Power is reluctant to telease detailed figures of the costs of the project. Meanwhile, Stan Charren is despairing. Or at least that’s the im- pression he gave the Boston Globe in an interview earlier this month. He’s afraid that the general public regards the Crotched Mountain wind farm as ‘‘a tinkerer’s toy, a tourist attraction.” (Oddly, the Crotched Mountain facility now has a new tour guide who shuts the farm down during uninformative walking tours.) Preferably, U.S. Wind Power wants tourists willing to come, see and, then, invest in its projects. Nevertheless, U.S. Wind Power is not thinking small, except in wind machine size. Says Charren: ‘‘A 50 kW windmill has approximately the same weight and mechanical complexity as an automobile, and the potential demand on the nation’s supply of materials and labor for a large scale implementation of a windmill production program is a small fraction of the current resource demands of the automobile industry .. . it would take an industry 10% of the size of our automotive industry only six years to build and install the six million windmills that would enable us to eliminate all oil imports.” “*In a day, a single windmill produces the power of one barrel of oil. That means six million windmills can produce the same amount of energy as six million barrels of oil . . . Currently, the price of oil determines the value of wind power, but in the not too distant future the cost of wind power may dictate the price at which oil can be sold.” Six million wind machines are going to require a large amount of land. “‘If only 2% of our land was covered with windmills, our en- tire energy needs could be met,’’ says Charren, ‘‘and since 2% of the land would have to be very windy and, therefore, at high altitudes, it would be relatively underpopulated.”’ According to Duskin, the company has already secured wind (Continued on next page) 7 U.S. Wind Power, Inc. 50 kW Wind Turbine Wind Energy Report In the news... (Continued from page 2) machine to perform poorly—when it performed at all. Unconfirm- ed reports place the blame on a malfunctioning Gemini syn- chronous inverter. The inverter, manufactured by Windworks of Mukwonago, Wisconsin, permitted the Windstream 25 to be inter- connected with Niagara Mohawk Power Company’s grid. But other experiments with the Windstream 25, notably a DC-battery application for the U.S. Department of Agriculture in Iowa, sug- gest that a wide range of design problems afflict the Windstream 25. Among them are safety control, proper yawing, and adequate operation of the blade pitch control system. Nevertheless, Clarkson College’s Engineering Department, which monitored the project for NYSERDA, has declared the four- year experiment a success: ‘‘The project was a complete success in that it quickly pinpointed the problems with the Gemini,” Clarkson’s Dr. Edward Kear told a local newspaper this month. If any structural or design problems developed during its intermittent operation at the farm, no one at NYSERDA seems to know. Clarkson and Grumman Energy Systems have tentative plans to install an improved version of the Windstream, a 33-foot diameter, 18 kW (at 28 mph). This Windstream 33 is the result of a research and development contract awarded to Grumman in 1978 to develop an 8 kW (at 20 mph) machine. Unlike its experimental predecessor, the Windstream 33 features an induction generator, thus obviating the need for a synchronous inverter. Whether a Grumman machine is reinstalled at the McKnight farm is subject to much speculation. It is one of several machines ordered by the Department of Energy for its Field Evaluation Pro- gram. But money for the program was cut drastically earlier this year and it is questionable whether DOE will have the funds to in- stall the machine. USWP to build Altamont Pass wind farm (Continued from preceding page) rights to 20,000 acres of land, mainly in sparsely inhabited areas of the West. One USWP project beginning to receive attention is a proposed 90 megawatt, 1,800 machine wind farm on 5,000 acres of ranchland in Montana. According to Bob Fitzgerald, the company’s local agent, ‘‘we’re looking at a capital investment of $180 million and long-term support for 45 people.’” U.S. Wind Power has already negotiated wind rights with four ranchers owning land along the benchlands east of Livingston, con- sidered by many knowledgeable wind resource experts to be one of the windiest regions of the country (16 mph, 24 hours a day, 365 days a year). Each rancher is will receive a few hundred dollars plus 2% of all the revenues generated by wind farms on their property. U.S. Wind Power is said to be getting the use of up to 5% of each ranch ‘‘plus the right to convert all of the wind resources of the property.”’ Says Fitzgerald: ‘‘It’s like an oil exploration lease, only we know the wind’s there.’’ (U.S. Wind Power, incidentally, will pay the Crotched Mountain Foundation 5% of the anticipated $150,000 annual revenues from the project plus an unspecified amount in local taxes). U.S. Wind Power’s approach is virtually risk-free: obtain wind rights for choice land parcels first and worry about the buy back rate later. If the energy price is not attractive enough to the com- pany, the four Montana ranchers have worthless lease agreements. The Montana utility regulatory agency will determine the buy-back May 1981 rate sometime this fall. According to U.S. Wind Power, “‘the pric- ing decision in Montana will have a major impact on our plans there.”’ The company is also exploring wind farm projects on the Knapp Ranch near Cape Blanco, Oregon; the Columbia River Gorge in - Washington, site of the MOD-2 installation; Medicine Bow, ‘Wyoming; Massachusetts and Hawaii. Fayette wind farm for Altamont Pass? A second wind farm may be built in the Altamont Pass region if plans by Pennsylvania small wind systems manufacturer and a local land developer materialize. Joseph J. Jess, owner of a 593-acre ranch in the pass, has formal- ly applied to the Alameda County Planning Commission to install 300 ‘‘20 kW’’ wind systems manufactured by Fayette Manufactur- ing Corporation of Clearfield, Pennsylvania. According to Jess, the wind array—dubbed the Rafter-JJJ Wind Farm—will be operated by the Great Falls Wind Energy Corpora- tion, also of Clearfield. Jess will lease the land to the corporation. The financial aspects of the lease arrangement are not available. Fayette ‘20 kw”’ In a 20-page promotional brochure, Fayette devotes barely one page to describing the machine’s design and operating characteristics. Nineteen pages, however, explain in much detail the tax incentives, depreciation and general tax shelter advantages of wind machine ownership. The Fayette machine, called the Windway 20-30-80, is a three- bladed, downwind horizontal axis machine on a recommended guyed 80-foot tower. It has two induction generators of 10 kW each and uses the company’s ‘‘unique controls that improve perfor- mance and output.” Its three blades, says Fayette, are ‘“‘made with a massive steel spar, an expanded and reinforced foam cover, and a durable fiberglass skin . . . Tip speed governors are deployed to ‘‘prevent the blades from overspeeding in gale force winds.” The machine reaches it rated 20 kW in a 50 mph wind, a wind speed when most wind machines are shut down or in the process of doing so. At 20 mph, the machine generates 7.3 kW. Nevertheless, Fayette claims that its machine ‘‘converts about 60% of this [wind] potential to electricity at the low windspeeds that are most frequent (9-15 mph) and a somewhat smaller percen- tage at the less frequent, higher windspeeds.”’ It is even willing to guarantee ‘‘in advance in writing how may kilowatt-hours our machine will produce at your site.” According to Fayette, the machine sells for $29,000 F.O.B. plus additional for delivery and installation which could bring the total cost to $32,000. Fayette says that it will finance 50% of the purchase price of the machine (at 10% simple interest) for buyers in proven high wind- speed areas. For further information, contact: Fayette Manufacturing, 712 River Street, P.O. Box 567, Clearfield, PA 16830. (800) 458-3632. In Pennsylvania, (814) 765-1631. Copyright © 1981. Wind Publishing Corporation. All rights reserved by the copyright owners. Wind Energy Report® is published monthly. No portion of this publication may be reprinted, reproduced, stored in a computer-based re- trieval system or otherwise transmitted whole or in part without the express, written permission of the publisher. Printed in U.S.A. ISSN: 0162-8623. Subscriptions: $115. annually (USA); $125. annually (Canada & Mexico); $145. annually (foreign airmail). Two-year subscriptions: $215. (USA); $230. (Canada- Mexico); $290. (foreign airmail). Editorial offices are loceted at: 189 Sunrise Highway, Rockville Centre, NY 11570. Mailing address for all correspondence: P.O. Box 14, Rockville Centre, NY 11571. (516) 678-1230. Wind Energy Report May 1981 Aerotherm to build UMASS Wind Furnace With the exception of a half dozen manufacturers of water- pumping windmills, nearly all small wind energy systems manufac- tured today in the United States produce AC electricity by means of an induction generator or synchronous inverter. There are, of course, a number of DC battery/inverter applications for remote sites. But the trend appears to be toward induction generators de- livering utility compatible electricity for sale or storage in the grid. Few manufacturers have attempted to use AC output for thermal storage for direct space and hot water heating. And, perhaps, for good reason. Much of the focus of the economics of small wind energy systems has been on the regulatory fact-of-life requiring utilities to buy excess electricity from small power producers. Estimates of future price of this excess power loom large in payback calculations. Nevertheless, one company—soon to manufacture a three- bladed, 33-foot diameter machine—argues that the prime use for wind energy systems in the northern United States and Canada should be for heating, rather than back feeding surplus power to a local grid. It is cheaper for a wind system to produce unsynchroniz- ed, non-grid quality electricity, says the company. To back up its claims, Aerotherm, Inc. of Macungie, Penn- sylvania, says it plans to build a commercial version of the Univer- sity of Massachusetts 25 kW Wind Furnace and use the electricity in a heat storage mode. Researchers at the university’s Mechanical Engineering Depart- ment have been persistent champions of thermal storage applica- tions of wind energy. And so it is not surprising that Aerotherm is relying heavily on University of Massachusetts research into both the storage concept and the wind generator. The key to the economics of the Wind Furnace concept is the ef- ficiency of its thermal storage as much as its wind- electric machine. According the Aerotherm, the 25 kW Wind Furnace creates elec- tricity which is fed directly to a thermal storage mass by means of resistance heating elements. This mass may be a tank of water or oil, or it may be rock, sand or masonry, or even a combination of liquid and solid media. A fan or pump is used to move air or water through a heat exchanger in the storage medium into the parts of a building requiring heat. This approach allows the Wind Furnace to share the same storage medium as Trombe walls, flat plate collectors and massive masonry chimneys. It also makes possible combined direct solar and wind energy systems: the sun shines brightly on calm days but cloudy days are often associated with high wind periods. Importantly, says Aerotherm, a properly insulated water storage system can maintain 1,000 gallons or more at 170° to 180° with losses of approximately 1%, ‘‘much better than the 40% conver- sion losses which are common with battery/inverter systems.”’ Aerotherm contends that a direct thermal application is less cost- ly to build and maintain, causes fewer problems with the local utili- ty and delivers greater energy value for every dollar of invested capital than the prevalent grid-connected approach. Aerotherm argues its case simply: ‘‘Meeting [utility] require- ments involves substantial added expense for equipment and for the marketing time required to obtain utility acceptance. Wind tur- bines designed only to produce electricity for heat don’t require such acceptance. “There is a close seasonal match between the output of a wind turbine (in the northern U.S. and Canada) and the coldness of the weather. The colder the month, the stronger the winds blow. This means that the turbine is producing best in cold weather . . . usual- Aerotherm Corporation 25 kW Wind Furnace Rotor Diameter . . . 33 feet (10.1 meters) Blade Length. . ....16 feet (4.9 meters) Swept Area... . 855 feet? (79.5 meters?) Tower Helght ... . ..60 feet (18.3 meters) Start-up Speed...... . .5 mph (2.2 meters/sec)) Rated Wind Speed .. . ..26 mph (11.6 meters/sec) Cut-out Speed...... . .-52 mph (23.3 meters/sec) Weight above tower .................... 1,500 Ibs. (680 kilograms) Estimated Annual Energy Gaiputiet 9mpl) ..... 2... 2. ccc cceweeseees 20,000 kWh Source: Aerotherm, Inc. ly ten times as much output in a winter month than in a summer month . . . Anyone buying a wind turbine to take care of other [non-thermal] electrical loads that do not vary with the seasons will soon discover that the turbine produces too little for the load ir the summer and helps best in the winter.”’ Using data provided by the University of Massachusetts, Aerotherm points out that 65.7% of the 31,544 kWh hours that could be generated by its own experimental Wind Furnace would be delivered between December and March, traditionally the coldest months in New England. “Storage is considerably easier, less costly and more efficient when one is storing BTUs to be used as heat instead of electricity. Aerotherm discounts the notion that selling utility compatible ex- cess output to a utility is worthwhile: ‘‘you sell energy to your utili- ty at wholesale rates, and buy it from it at retail rates.’”” Why pay more for a wind turbine, whose output is utility compatible, con- tends Aerotherm, ‘‘if you can use all the output for space and water heating anyway simply by storing the output as hot water?’’ But just how economical is the thermal storage approach? Aerotherm assumes that its Wind Furnace will be sited where it can generate 25,000 kWh annually (‘‘any wind regime averaging above 9 mph at 30 feet’’). Calculations at the UMASS Habitat in- dicate that the Wind Furnace ‘‘will produce 30,000 kWh per year at a site with a mean annual wind speed of 10 mph.” In 1981 dollars, energy value is calculated to be 7 cents/kWh or $1.50 per gallon of heating oil. Assuming an annual energy infla- tion rate of 10% ‘‘payback’’ is six to seven years (after subtracting federal tax credits). In 20 years, ‘‘the Wind Furnace will bring sav- ings equal to about six times its original costs.” That prices the 25 kW Wind Furnace at $17,000 (including 1,000 gallon heat storage tank). Prospective purchasers will have to put $7,000 up front and be liable for increased costs of components “dollar for dollar” until delivery. The buyer will also have to cer- tify to Aerotherm that his site has a minimum 9 mph wind regime at 30 feet. Estimated costs for installation range from $1,650-$4,000 depending on transportation, cabling, foundation, etc. Using wind generated electricity to supply heat, says Aerotherm, “leaves to the utilities the market they serve best (electricity of high quality and reliability for appliances, etc.). It focuses the turbine’s commercial and residential use on the market growing fastest in cost (oil heat especially) and in which an inexpensive wind turbine design can best compete... .” For further information, contact: Aerotherm, 40 West Main Street, Macungie, PA 18062. (215) 966-2468. For details of the wind furnace con- cept: A Preliminary Investigation of Three Advanced Wind Furnace Systems for Residential and Farm Applications: 2 Volumes. by Paul H. Sarkisian and Jon G. McGowan, Mechanical Engineering Dept, University of Massachusetts, Amherst, MA 01003. RFP-3059/67025/3533/80/4-1&2. Available: National Technical Information Service, Springfield, VA. Wind Energy Report Meetings, Conferences, Symposia A three-day DOE/NASA Workshop on Large Horizontal Axis Wind Turbines will be held on July 28-30, 1981 in Cleveland, Ohio. Co-sponsored with Cleveland State University and Oregon State University, the workshop will be held at the Bond Court Hotel,Cleveland. Planned reports on design, operation and data will will focus on the following topical areas: tests data from the MOD-0 experimen- tal wind turbine; operating data from DOE/NASA wind turbines located at utility sites; design of advanced systems; electric utility experience and future plans; and rotor blade design data. For further information, contact: Dr. David A. Spera, Workshop Chairman, NASA-Lewis Research Center, Mail Stop 500-202, Cleveland, OH. 44135. (216) 433-4000, ext. 6629. The British Wind Energy Association will hold a one day Inter- national Colloquium on Wind Energy on Thursday, August 27, 1981 at the Solar World Forum Congress and Exhibition in Brighton, England. The Colloquium will present a forum for discussing the current status and future plans of national programs as well as a wide range of topics in wind energy utilization. Papers will include the follow- ing topics: large and small wind turbines, wind data and meteorology, power system integration and economics, control systems, offshore potential, wakes and clusters, materials and structural problems, measurement techniques and environmental aspects. Invited speakers include: Dr. Freddy Clarke, UK Department of Energy; Dr. Louis Divone, US Department of Energy; Dr. Peter Musgrove; Chairman, British Wind Energy Association; and Dr. Horst Selzer, ERNO, West Germany. For further information, contact: Dr. Leslie F. Jesch, Chairman, Organizing Committee, Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, England. Tel.: 021-472-1301. Wind Workshop V, the Fifth Biennial Conference on wind energy conversion systems, will be held in Washington, DC, October 4-7. Further details can be obtained from: Conferences and Staff Development Branch, Solar Energy Research Institute, 1617 Cole Blvd, Golden, CO 80401. (303) 231-7361. The Second AIAA Terrestrial Energy Systems Conference will be held in Colorado Springs, Colorado, December 1-3, 1981. Several papers on wind energy are planned. For further information, contact: Dr. Irwin Vas, Solar Energy Research Institute, 1617 Cole Blvd., Golden, CO 80401. (303) 231-1935. BHRA Fluid Engineering, in conjunction with the Swedish Board for Energy Source Development, will hold the 4th International Conference on Wind Energy Systems from September 14-17, 1982, in Sweden. Further details of the conference can be obtained from: The Conference Organizer, BHRA Fluid Engineering, Cranfield, Bed- ford, MK43 OAJ, England. Tel: (0234) 750422. May 1981 Battery storage a wind-electric option? Currently, ‘battery storage of wind-generated electricity is being used chiefly for non-grid connected, remote and isolated residential applications where utility lines are usually not available. For wind electric applications where a utility transmission line is readily available, battery storage is not seen as economical nor ad- visable when induction generators and synchronous inverters make interconnection and back feeding of electricity possible. Moreover, batteries aren’t cheap and to store appreciable amounts of electrici- ty for later use still requires a significant capital outlay. But some utility customers in the future may find it profitable to store electricity on site using battery systems, according to a feasibility study recently completed by Battelle’s Columbus (Ohio) Laboratories. Although the study did not address itself specifically to wind-electric storage, it does raise some intriguing possibilities for energy storage, once technical, regulatory and institutional issues are resolved. Typically, a wind farm delivering electricity to a commercial or industrial establishment, for example, in a region where the wind is energetic between midnight and 7 a.m., say, could store its electrici- ty in batteries. After consuming a portion of the stored electricity for its own needs, it could then sell the excess power to a utility dur- ing peak demand periods when the buy-back rate is higher. (By the same token, electricity could be purchased from the utility during off peak and sold back during on-peak periods.) The Battelle study indicates that moderate-size commercial and industrial utility customers are most receptive to battery storage but uncertainty about changing regulatory policies, rate structures and schedules are still important disincentives to widespread use. An economic analysis by the Battelle researchers found battery storage to be viable for some electric utility customers with high de- mand charges or large on-peak to off-peak differentials. The Bat- telle study found three important factors influencing economic viability: how much utilities charge customers during their peak de- mand period, the length of the battery discharge period and the cost of the battery storage system itself. Cost estimates used by Bat- telle for battery systems were based on projected ‘‘commercializa- tion levels of production,’’ presumably when such systems would be attractive capital investments. (Contact: F.. Jere Bates, (614) 424-6424). MOD-2 wind farm dedicated in northwest (Continued from front page) By mid-March, Unit No. One, which first began operation last December, had already generated more than 75,000 kWh during 80 hours of pre-acceptance testing. DOE is thus entitled to an im- mediate $1,875 return on its investment. . . . Editor’s Note: Although much has already been said and written about the MOD-2 design, a brief review of the machine’s major design features can provide useful background information. Addi- tionally, the ‘‘real world’’ testing phase now underway will confirm or deny a number of important and controversial design assump- tions made by the federal large wind program. According to NASA, four major innovations over the MOD-OA and the MOD-1 are important to the MOD-2 design: controlling the load on the blades by feathering the tips only; the ‘‘soft’’ steel (Continued on next page) Wind Energy Report May 1981 MOD-2 cluster dedicated (Continued from preceeding page) shell tower; the compact, light gearbox; and teetering the rotor to reduce loads on the turbine. ‘ Briefly, the MOD-2 consists of a 193-foot tower, a 37-foot long nacelle containing the gearbox, generator, and other major pieces of equipment, and a 300-foot long rotor. The MOD-2stands 350-feet tall with the blade in the vertical position. It weighs 628,500 pounds. Rotor: The hollow steel shell rotor is built as a single continuous piece rather than two separate blades. This, according to Boeing, greatly increases its strength and resistance to fatigue. Each rotor was fabri- cated in five welded sections—two tips, two midsections, and a hub—which were bolted together at the site. The rotor also teeters on its hub up to 6% degrees off the vertical axis, balancing out the effects of different windspeeds at differ- ent heights above ground, and erratic wind gusts. This reduces the physical stresses or loads on the rotor and other components. The outer 45 feet of each blade changes its pitch hydraulically to as much as 100 degrees to control the response of the wind turbine to the wind. When the machine is operating, the tips are continually adjusted to extract as much energy from the wind as possible. To shut the machine down, the tips are fully feathered. As the wind turns the rotor at a constant 17% rpm, two teeter bearings in the hub transfer the rotation to the low-speed shaft, which takes the energy into the nacelle. An important part of the low-speed shaft as- sembly is the quill shaft, a flexible steel tube which absorbs vibrations and oscillations from the blades’ rotation, reducing stress on the gearbox. Gearbox: From the low-speed shaft, the energy goes into the gearbox which in- creases the shaft rotation speed from 17% to 1800 rpm. The gearbox, manufactured by Stal-Laval of Sweden, is smaller, lighter, less expensive, and claimed to be more effi- cient than an ordinary parallel shaft gear- box with a similar rating. It is also said to be more tolerant of the extraneous twisting and bending which occur along with the 7 rotation of the blades. Generator: From the gearbox, the mech- anical energy goes into the generator, where it is transformed into electrical energy at 4.2 kilovolts. The generator is an AC, syn- chronous design working at a constant rpm. The electrical energy from the generator travels through cables down the inside of the tower where it then runs underground from the tower base to a ‘‘bus tie contactor unit’’ and transformer contained in a small box 100 feet from the base of each unit. There, the energy is connected (or discon- nected) from the power system and is transformed from 4.2 kV to 12.5 kV. The power continues underground to the Good- noe Hills substation, where it is trans- formed up to 69 kV and sent to the Nor- thwest power system. Tower: The 193-foot steel tower supports the nacelle (housing the generator, trans- mission, yaw drive) and rotor through the yaw bearing. The top 150 feet of the tower consist of a 10-foot-diameter cylinder. The lower section flares to a 21-foot diameter base, which is secured to the ground with (Continued on next page) Wind Energy Report MOD-2 cluster dedicated (Continued from preceding page) 400 cubic yards of concrete in an octagonal underground pad. 72 anchor bolts reach 29 feet below the base of the foundation into solid rock. The rotor is mounted to the low-speed shaft seven feet above the top of the tower, so the rotor hub is located 200 feet above ground. Operation: The MOD-2 is designed to be completely computer operated. Sensors on each machine detect wind speed and direc- tion and other details such as ice loading and potential metal fatigue. This information is feed into a micropro- cessor in the nacelle. The microprocessor automatically keeps the blades turned into the wind, starts and stops the machine, and changes the ptich of the tips of the blades to maximize power output under varying wind conditions. Should any part of the wind turbine suf- fer damage or malfunction, the micropro- cessor will immediately shut the machine down. The entire system is monitored from BPA’s system control center in Vancouver, Washington. Technicians there can restart the machine after an automatic shutdown, or dispatch maintenance crews if on-site in- spection or maintenance is needed. Moni- tors are also available in the substation, the base of the tower, and at the microproces- sor itself. The MOD-2 starts generating power in 14 mph winds and produces power in increas- ing amounts up to 27 mph. At this point, the microprocessor maintains a steady out- put of 2.5 megawatts by feathering the tips of the blades and ‘‘dumping”’ wind eenrgy. At windspeeds greater than 45 mph, the MOD-2 shuts down completely. Gusts of wind faster than 45 mph which last no long- er than 20 seconds do not affect the MOD-2’s operation. Wind Power Laboratory: To make the most of the research opportunities afforded by the MOD-2s, each machine has been as- signed a separate primary test function, while still working as part of the multi-unit wind farm. Unit 1, nearest the visitor’s center, will be kept in operation whenever possible. It will be quickly brought back on line by Boeing or BPA crews in the area when it shuts down to determine the maximum energy yield which can be produced by the MOD-2 at the Goodnoe Hills site. Unit 3, nearest the road, will run under “real world”’ utility conditions. When the machine shuts down and requires inspec- tion, crews from BPA substations will be scheduled to work on it. This will give utilities an idea of the staff commitment necessary to maintain a wind turbine and the energy production achievable under routine operating conditions. Unit 2, farthest from the road, is the machine where ideas for improving the de- sign or operating limits on the MOD-2 will first be tested. Machine Spacing: One important aspect of wind turbine operations will be the ef- fect, if any, of wake interference. The wind in the wake of each blade contains less energy and slows down. If the turbines are too close together, downstream machines could produce less energy than they should. They could also be subject to higher fatigue stresses due to air turbulence caused by the blades cutting through the air. The three machines are purposely posi- tioned at the corners of an irregular triangle whose sides are five, seven and ten blade diameters long (1,500, 2,100, and 3,000 feet respectively). This will allow researchers to test the effects of the machines on one another at different spacings. Data Collection: Two meteorological towers—a 200-foot BPA tower and a Bat- telle Northwest Laboratory 350-foot tower—will collect wind speed and direc- tion and other atmospheric data. On the wind turbines themselves, internal sensors record the stresses, vibrations, and other movements of critical pieces of equip- ment, particularly those which are new to the MOD-2, such as the teeter bearings and May 1981 the high and low-speed shafts. Overall movement of the nacelle is also recorded. Sensors on the MOD-2 blade skin will shut the machine down should a crack or hole appear, or if ice loads or wind loads exceed design ratings. Temperature gauges on the gearbox and generator or other sensors recording rota- tion speeds would also shut the machine down should any part overheat or rotate too quickly. Acceptance Tests: Boeing is responsible for checking the machine out under all nor- mal operating conditions, to prove no part will vibrate more than it should, heat up higher than design ratings, or simply not work. The machine starts up, runs, and shuts down many times in this test mode, both with and without integration with the power system. During the two-year test period, Boeing will experiment with its wind turbine design to see if the MOD-2 can be made to work safely and cost-effectively in windspeeds lower than 14 mph or higher than 45 mph to increase energy production. DOE/NASA will also be interested in possible design changes to the MOD-2 and will use the site as a place to test new ideas, such as wooden blades tips, or possibly a two-speed generator. After the two-year test period is ended, BPA may continue to operate the machines and feed their electricity into the Northwest power grid. No firm contractual basis for this eventuality has been fixed between BPA, NASA, DOE and Boeing. From the utility perspective, BPA is in- Goodnoe Hills Wind Electric Generating Station ro Kacsiat County PUD | cow tarenmcnte | Note: Site is located in Section 33 18E, T4N, W.M. Klickitat County, Washington Wind Energy Report terested in both power quality and the variation in the quantity of electricity from momemt to moment due to wind speed fluctuations. Data from the MOD-2 cluster will provide useful information for utility generation planners on a monthly and an- nual basis. Environmental concerns: Earlier NASA/DOE machines, particularly the MOD-1, caused pulsing noises as its down- wind rotors passed behind the support towers. This noise occurred both at audible levels and at low ‘‘infrasound’’ frequen- cies—inaudible to the ear but irritating nonetheless to local Boone, North Caro- lina, residents. Infrasound has not been a problem for the brief period of testing, so far, perhaps because of the MOD-2’s soft, modular steel tube tower. No infrasound pulsations have been recorded. The MOD-2 in operation, according to BPA, sounds like a strong steady wind ‘“‘blowing through fir trees.” No one lives very near the Goodnoe Hills site, but a cable television company did have an air pick-up antenna nearby. BPA paid the company to move its antenna to Portland, Oregon, and to microwave its transmission to its Goodnoe Hills transmit- ter relay station. So far, there have been no May 1981 reports of TV interference The Solar Energy Research Institute and BPA are using the old cable TV antenna to measure signal interference near the site, with one, two or three machines in opera- tion under different wind speeds and direc- tions, to determine the extent of television interference. SERI will also conduct a number of en- vironmental studies of the effects of wind turbine operation on wildlife, microclimate and flora. Perhaps the most noticeable environmen- tal impact of the MOD-2 will be is effect on the landscape. Boeing Engineering & Construction/NASA/DOE : 2.5 Megawatt Rotor Newtber-of blades... 220 ccc cc cscccscecccccvcccscgsns 2 CHRPULOUOOE oo ac 5 ones oie oso oe ont ep ees 1800 rpm Diameter ....... -300 feet MR cerita soar ce -17.5rpm Generator Rotation direction (looking upwind) counterclockwise Mat ina erence See celee ees Synchronous AC Location, relative to tower .........--..-.002-00- upwind Woe oa cowias ete coco ce cl costes ere 3125 kVA TSMR CRID hoe aaa wis init ie wee eislneise sie 6 teetered I ON aoc aoe ta nl clon aioe aol altace 08 Method of power regulation . variable tip pitch control Voltage ..... 4160V (three phase) CR OIING eos asi iors oe cassie soeo's aiele ner tetas sia o° SO rss iaie ono srots erastominnieicisaicial- oie ae ee 1800 rpm MEME ei cis ieee sch n oe leic ose Ramin © cle e csie o:<\ vinta 2° PRCDIIGY cicoite a)-)ete oss Sie soe op wos soleus stewie 60 Hz Blade Orientation Drive REMIND): clo tees cenit ante nee ee cecnce 147 feet WYRG eiacscen tiene sere neces internal tooth ring gear WI oo noe o> oo e0 viele win) ele 0816 64s le'winle Sivisiswivinieis oo) 6 feet Yaw rate... -0.25 degrees/second MINE 5 556 «, 0.0 01010. <ia\otewialninlnisleinivivinielo= wisloivvisinsis seis’ steel NAME CHIOD Sete oe ane wre eee ciara loieis store ciaites ares hydraulic Weight/total . . 112,000 Ibs. Airfoil ...... "NACA 230XX Control System SRM 113 ore <seyi cic aiats'o Bie tio dinje) a(eieitie Ome ne ee REA 8.0° td ate te Re RS Pa ee Pee Oe SEG Microprocessor ND ere oe an ois ain ce ininsoiala = vies ais aie ketene 4.7 feet SD GU MOUMON, 6... 5.0 oop 010s 05605 ong ae Hydraulic SEMIS CIRIIO oin:<10's/cidicigicin sien is «Wipe eeiele > oan 3:1 Overspeed control ...........-..2- eee ee eens blade pitch TEN FS on. cinta snes e ot ee oe 275 feet/second/188 mph Performance Nacelle Ried poet. eS 2500 kilowatts DMEM pac nfcis a) cintnyaisintn Sloe eis a een iotere -roisaie atin steel Wind speed at hub Dimensions: Me cece tahmlieae 5 Wailea vier oa ena ee ee 14.0 mph WME ter cleer seni see eee ene ener 37 feet Rated ... , Oe eee ec cee ocr sien oasiecers ciceisagil 9 feet Cut-out Tower Weight (MMR Grric eo ete eee cylindrical with flared base Rotor (including blades) .................... 201,000 Ibs. Height ..... 193 feet PM crearsia wo oslo otal - 112,000 Ibs. Height at hub ... -200 feet ee -87,000 Ibs. WHOM orcs sor raisisinio <ieforsioislcia loins olsieini easels 427: 5 tons Nacelle subassembly - -90,600 Ibs. Tower diameter: GemBOx .. 0.52. . -37,000 Ibs. Be ore ee cee glee eitee ese ose eee eae ee 21 feet Generator ... . . 18,500 Ibs. atthe hub .... - 10 feet Above tower ... .377,000 Ibs. Tower material .... “welded steel Tower .... . 251,000 Ibs. Ground clearance . . -- -50 feet Tra ME pee bees tee ccc a 628,500 Ibs. Erection technique ...........-...-0> 240-foot gin pole Foundation ................--- concrete, 400 cubic yards System Design Life eee seen se eee ee eeG nate caee eee 30 years Transmission Tower ....... 30 years VINO she eo se eee eee . - three-stage planetary Transmission 30 years Rating, horsepower . . 3700 Generator ....... 30 years Input speed ............-- cece e ee eee cece eee 17.5rpm CORO SY SCSI os orci sciclarasosh ie tinaloicls clone ealo are ott 30 years Wind Energy Report May 1981 Editor’s Note: California is leading the nation in efforts to Stimulate the development of wind power. Not only does the state have an excellent wind resource, but its public officials have recognized the importance of creating an attractive investment climate conducive to financing wind power projects. Excerpted befow are portions of Wind Energy: Investing in Our Energy Future, prepared by the California Energy Commission for the wind energy conference in Palm Springs last month. It serves as a succinct introduction to the financial incentives available for in- vestments in wind energy projects and can be applied to a number of states which already have enacted favorable tax legislation. * * * The increasing monetary and environmental costs of nonrenew- able energy resources make production of electricity from wind en- ergy one of the most attractive and cost effective generation tech- nologies currently available. The average cost of electrical energy in California has more than doubled since 1977. Further increases in excess of inflation are expected in the future. . . ‘ Recent changes in state and federal laws have created attractive investment opportunities in various alternative energy technologies, especially wind. A public utility is now required to purchase wind- generated electricity at the high avoided cost rates. State and fed- eral tax credits are available to return up to 50 % of investment in wind energy systems after the first year. Other special provisions al- low accelerated depreciation of those investments. Moreover, wind turbines can be installed in a fraction of the time required for con- struction of a large conventional power plant. Investing in wind makes sound economic sense, is good for our environment, and is essential in our efforts to reduce national dependence on foreign oil. Virtually anyone can invest in wind energy. In California, the development of major wind energy projects has been initiated by investor-owned and municipal utilities, by individuals and by private developers. The wind farm concept has been the focus of most recent interest in wind energy development. A wind farm consists of numerous wind turbine generators clustered in an area of strong and persis- tent winds. Wind farms are now being planned and developed by California utilities and many private development companies and will produce a substantial supply of electricity in the very near future... In general, investing in wind energy is best for individuals and business that can take advantage of the substantial tax credits and depreciation allowances provided by state and federal law. As mass production of wind turbines accelerates, the production of electrici- ty with wind energy will become economical even without the help of tax credits. The purchase of wind generation equipment is a sub- stantial capital investment. Economics will be the primary con- sideraton of any company considering a venture in wind energy production. There are economic advantages and other incentives that should be considered in reaching a decision. Guaranteed Market for Wind-Generated Electricity Utilities are seeking new, renewable and reliable soucres of elec- tricity. Even though a utility may develop and operate its own wind project, it must purchase wind-generated electricity from wind farm developers or other private sources as required by federal and state regulations. These regulations require the utility to pay the cost of generating the same amount of electricity or the cost of pur- chasing it from another utility. When generating electricity, a utility brings its cheapest source last (often an older, oil-fired power plant). The cost of bringing the last, most expensive source on line 10 is called the ‘‘marginal’’ cost by economists and the ‘‘avoided’’ cost by utilities. A utility is required to pay its avoided cost for wind generated electricity. Therefore, a private wind developer will re- ceive a relatively high price for wind-generated electricity. This price will rise with increases in the cost of oil. California’s major utilities currently pay as much as 8 cents per kilowatt-hour to produce electricity during periods of peak de- mand. In many cases, the strongest winds in California occur dur- ing summer afternoons when utilities are operating their most ex- pensive peaking plants. Therefore, utilities must pay these peak load prices for wind-generated electricity which is purchased from private firms. The price paid for wind electricity varies with the utility so that it may be advantageous for a private wind developer to sell electricity to a distant utility at a higher price. The federal government utilities—such as the Western Area Power Administration and the Bonneville Power Administration—are eager to purchase wind- generated electricity and may compete with local utilities by offer- ing a better price. However, a private developer may need to pay the cost of ‘‘wheeling’’ or transmitting the power through the transmission lines of intermediate utilities between buyer and seller for distant electricity sales. The high price that a utility will pay for wind-generated electrici- ty is a powerful incentive to encourage private investment in wind energy. In addition, this price will continue to rise with the cost of oil burned in conventional oil-fired generation plants. Few invest- ments give this assurance. Moreover, government experts, manu- facturers, utilities, and private wind development firms foresee substantial reductions in the cost of wind hardware as manufac- turers move into mass production. These anticipated cost reduc- tions wil make the future cost of producing electricity from wind far cheaper than producing it from oil. State and federal financial incentives have been developed to help stimulate rapid development of wind industry. Incentives are now available to offset today’s higher pre-mass production equip- ment costs and make wind energy an attractive investment opportu- nity that will yield a quick return on investment today. Many financial incentives are currently available to investors in wind energy. These incentives make a wind investment an especially good tax shelter. An investor who installs wind equipment in a commercial project is eligible for a 10% Federal Investment Tax Credit. He is also eligible for an additional 15% Energy Property Investment Tax Credit provided by the Windfall Profits Tax Act of 1980. This new credit applies to all hardware except the transmis- sion lines from a windfarm to the utilities’ existing transmission lines. If an investor has California state tax liability, the project will be eligible for a 25% Solar Tax Credit in addition to the federal tax credits. The tax savings produced by the state credit are reduced somewhat because the amount of any state credit is treated as fed- eral taxable income. Even so, the state tax credit is a valuable incen- tive which may be carried forward to future years. The federal cred- its can be carried backwards and forward. A utility investing in wind energy is not eligible for the 15% federal tax credit provided by the Windfall Profits Tax Act, but it may claim the 10% Business Investment Tax Credit and the 25% California Solar Tax Credit. All business and utilities are allowed to depreciate wind invest- ments. The IRS has not yet established a class life for a wind tur- bine as it has for other types of power plants. Many private wind developers believe, however, that they will be able to depreciate their investment over as little as seven years for federal tax pur- poses. If wind turbines are treated as new Section 1245 property, Wind Energy Report wind investments could be depreciated using the double declining balance method. For California state tax purposes, a wind investment may be de- preciated over even shorter periods. State law permits depreciation in 1, 3 or 5 years in lieu of the 25% state tax credit. It is also poss- ible to claim the state credit and depreciate all cost above the amount of the credit within three years using the double declining balance... There are many possible ways to structure a wind investment. Under state and federal regulations wind projects are classified as small power producers which are exempt from state and federal regulation as utilities. They are also exempt from utility reporting requirements of the Federal Securities and Exchange Commission. Below are examples of wind investments. ¢ A profit-making business which is a large consumer of electrici- ty may choose to develop wind energy to supply part of its own en- ergy requirements. The output of a wind project can be used to off- set the most expensive blocks of electricity that would otherwise be purchased from a utility. oe A business may be established for the sole purpose of produc- ing wind-generated electricity. The local utility will be required to purchase the electricity generated, or it may be sold to a distant util- ity or to another company which needs the electricity. A wind elec- tricity producer can be set up as a corporation. partnership, or cooperative. © Joint ventures may be arranged between a producer and a consumer of wind-generated electricity, or between a producer and a utility. In the latter case, the utility could supply a portion of the capital, help acquire land for the project, and assist in operating and maintaining the wind farm. As long as the utility ownership is less than 50%, the project is not regulated as a utility. Joint ven- tures involving a private developer, an equipment manufacturer, a project contractor and a utility have also been proposed. For an established business, traditional sources of capital invest- ment may be best for financing a wind project. Several investment and commercial banks have been working with prospective wind May 1981 farm developers to secure private market financing. Projects involving the most cost-effective machines may even provide acceptable returns on vested capital without debt financing once the tax credits and other write-offs are considered. Investors who are unable to take full advantage of the existing state and federal tax credits and depreciation may consider financ- ing a wind project through a leveraged lease. This arrangment will permit the tax benefits to be transferred through the parties who can use them, while reducing the investor’s costs accordingly. Numerous government programs are potential sources of finan- cial assistance. The assistance may be in the form of loans, tax-ex- empt bonds, loan guarantees, grants, or even technical assistance. (A complete listing of these programs is available from the Califor- nia Energy Commission publication ‘‘Guide to Financial Assistance for Wind Energy.’’ Several programs are of particular interest to prospective wind farm developers.) The newly created California Alternative Energy Authority will make low-interest loans available by selling tax-exempt revenue bonds repayable from the revenues earned by a wind energy facili- ty. In reviewing an application, the Authority will consider: © Technical feasibility; ¢ Economic soundness; and © Contribution to displacing the use of fossil fuels. The Authority will be issuing up to $200 million in bonds over the next several years. Individual projects are limited to $10 million. The newly created California Business and Industrial Develop- ment Corporation (SAFE-BIDCO) will also issue loans for wind energy projects and for manufacturers and suppliers of wind hard- ware. Funding levels for this program are not high, but projects to receive loans will also receive loan guarantees from agencies such as the Small Business Administration. The pro forma cash flow analysis below was constructed for a tax shelter partnership in which the individual partners have sufficient income to take advantage of their share of the tax credits and tax deductions. Pro Forma Cash Flow Analysis (All amounts are expressed in $ per $100 of investment.) Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year7 A. Income from electricity sales ....... 10.35 11.85 13.50 15.15 17.40 20.10 22.80 B. Expenses (operations, maintenance insurance & prop. taxes) .......... 3.70 3.95 4.22 4.50 4.81 5.14 5.50 C. Debt Service (principal & interest) ... 7.99 7.99 7.99 7.99 7.99 7.99 7.99 D. Tax Credit—Federal..............- 21.25 E. Tax Credit—State..... ...6.020.54. 22.50 F. Cash Flow Before Taxes (ABE+O+ 8) -...........5..20. 42.41 ( 0.09) 1.29 2.66 4.60 6.97 9.31 G. Depreciation—Federal 17.00 13.60 10.88 8.70 6.96 5.57 4.46 H. Depreciation—State ......... os 48.33 16.11 5.37 |. Interest Portion of Debt Service ..... 7.50 7.43 7.34 7.25 7.13 7.01 6.86 J. Income Tax Liability or (Refund) —Federal (A-B + E-G-l) x 50% ...... 2.33 ( 6.57) ( 4.97) ( 2.65) ( 0.76) 1.20 3.00 K. Income Tax Liability or (Refund) —State (A-B-H-l) x 11% ..........- ( 5.41) ( 1.72) ( 0.38) 0.37 0.60 0.87 1.15 L. Net Tax Adjusted Gain on Sale of Project after year7............-.. 35.74 M. Net Cash Flow After Taxes (F-J-K+ L) 45.49 8.20 6.14 4.94 4.76 4.90 40.90 For the above case, the internal rate of return on the investor's equity after taxes is 33.8% and the payback period is slightly more than one year. This case assumed that the machines installed are capable of producing 1,500 kilowatt-hours of electricity per year per $1,000 of capital cost. This is equivalent to a machine costing approximately $2,000 per kilowatt of installed capacity operating with a 34% capacity factor. A loan for 50% of capital cost at 15% interest fully amortized over 20 years is also assumed and the project is sold at the end of the minimum federal tax credit holding period of sever years for 129% of its original cost. Source: California Energy Commission Wind Energy Report May 1981 NEW PUBLICATIONS, REPORTS, STUDIES The following four studies are the result of several years of investigation of the potential for agricultural uses of wind energy conducted by the U.S. Department of Agriculture and funded by the U.S. Department of Energy. The reports were released this month. The date of the report represents the date the contractor submitted his draft to the USDA/DOE. * * . Economic Analysis of Wind-Powered Refrigeration Cooling/Water Heating Systems in Food Processing: Final Report.By W.S. Garling, M.R. Harper, L. Merchant-Geuder, and M. Welch Tetra Tech, Inc. Arlington, VA. March 1980. DOE/SEA-1109-20401/81/1. Available: National Technical Information Service, Spingfield, VA. Potential applications of wind energy include not only large central turbines that can be utilized by utilities but also dispersed systems for farms and other applications. The U.S. Department of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored ina simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyz- ed the economic feasibility of wind power in refrigeration cooling and water heating systems in food processing plants. Type of plants included were meat and poultry, dairy, fruit and vegetable, and aquaculture. The methodology for this study involved (1) making an inventory of food-processing plants by state; (2) describing equipment and processes, and describing or estimating energy requirements; (3) analyzing wind pat- terns, and comparing plant locations with available wind power; and (4) performing an economic analysis. The economic analysis determined breakeven costs of small wind energy conversion systems (SWECS) re- quired to economically supplement or replace present energy sources, estimated payback periods, and compared breakeven costs with projected SWECS costs. With the projected costs and energy prices assumed, SWECS (under 100 kilowatts) were found to be economically viable for some processing plants operating year-round, if wind power averaged at least 200 watts per square meter. Seasonal plants operating for less than 6 months annually probably could not install SWECS economically. Wind systems in most cases prob- ably would be used as supplemental power sources because of the intermit- tent nature of the wind and the high temperatures required in some process- ing operations. Payback periods estimated were fairly long—8 to 12 years—even if breakeven costs were met. * * * On-Farm U.S. Irrigation Pumping Plants: Final Report. By James R. Gilley, Southwest Research and Development Company, Las Cruces, New Mexico. April 1980. DOE/SEA-7315-20741/81/1. Available: National Technical Information Service, Springfield, VA. Land irrigated with the aid of pumping plants in the United States reach- ed approximately 44 million acres in 1979. This report summarizes the size distribution of some 473,000 pumping plants supplying water to this area, the energy sources used, the water supply source and the duration of seasonal operation. These estimates include the entire country, and are sub- divided by farm production regions, individual states, and in some cases, selected subareas within a state. Because wind power varies greatly within the U.S., the pumping plants are further classified by areas having similar average wind power during the primary irrigation season. More than 473,000 on-farm pumping plants are being used to pump and deliver irrigation water in the United States. The distribution of these units by geographic regions and potential wind power zones was determined. More than 60% of the pumping units in the U.S. are smaller than 37.3 kw (50 horsepower) in size and only 9.4% of the units are larger than 74.6 kw in size (100 horsepower). More than 49% of these pumps (231,440) are located in the six Great Plains States of Colorado, Kansas, Nebraska, New Mexico, Oklahoma and Texas. This area also has the largest potential wind power in the U.S. during the primary irrigation season. More than 51% of the pumping units are located in wind zones having a potential average wind power greater than 250 W/m? at 50 meters). However, only 6.5% of the units are located in the largest potential average wind power zone (greater than 400 W/m? at 50 meters). In general, those areas which have greater potential wind power have larger sized pumping units. 12 Economic Analysis of Wind-Powered Farmhouse and Farm Building Heating Systems: Final Report. By R.W. Stafford, F.J. Greeg, M.F. Smith, C. Des Chenes, and N.L. Weaver, Regional Systems Services Group, Inc., Englewood, CO, January 1981. DOE/SEA-3408-20691/81/1. Available: National Technical Information Service, Springfield, VA. The study evaluated the break-even values of wind energy for selected farmhouses and farm buildings focusing on the effects of ther- mal stoarge on the use of WECS production and value. Farmhouse structural models include three types derived from a national survey: an older, a more modern, and a passive solar structure. The eight farm builing applications analyzed include: poultry-layers, poultry- brooding/layers, poultry-broilers, poultry-turkeys, swine-farrowing, swine-growing/finishing, dairy, and lambing. These farm buildings Tepresent the spectrum of animal types, heating energy use, and major contributions to national agricultural economic values. All energy analyses were based on hour-by-hour computations which allowed for growth of animals, sensible and latent heat production, and ventilation requirements. Hourly or three-hourly weather data obtained from the National Climatic Center was used. Use of thermal storarge was found to significantly enhance wind energy uses ‘and its value for all applications. Thermal storage increas- ed the break-even value of WECS energy for farmhouse by more than 50%—to more than 4 cents/kwh for electric resistance and LP heating, to more than 3 cents/kwh for fuel oil heating, and to more than 2 cents/kwh for natural gas fuels. Use of thermal storage for farm building heating applications showed break-even values of energy fall- ing between .8 and 6.3 cents/kwh for electricity, .8 and 4.6 cents/kwh for natural gas, .9 and 4.9 cents/kwh for LP gas, and .8 and 4.1 cents/kwh for fuel oil heating. The study also evaluated the added value to the WECS production if the WECS output was also used for thermal storage for space heating and water heating, appliances and machinery, and sell-back to the local utility. State-by-state average wholesale electric rates for rural electric cooperatives were used as a basis for the value of WECS production sold to the local utility. It is noted that for this study farmhouses were defined as any rural home reported by the 1970 Census of Housing, rather than assuming that one farmhouse would be associated with each farm operation reported by the Census of Agriculture. This definition of the farmhouse is believed to more completely represent the number of farmhouses located in rural areas which could accomodate the type of wind energy conversion systems (WECS) considered with this study. * * * Economic Analysis of Wind-Powered Crop Drying: Final Report. By W.S. Garling, M.R. Harper, L. Merchant-Geuder, and M. Welch, Tetra Tech, Inc., Arlington, VA. March 1980. DOE/SEA-1109-2040/81/2. Available: National Technical Information Service, Springfield, VA. Potential applications of wind energy include not only large central tur- bines that can be utilized by utilities, but also dispersed systems for farms and other applications. Agricultural applications include production of hot water for rural sanitation, heating and cooling of rural structures and pro- ducts, drying agricultural products, and irrigation. This study analyzed the economic feasibility of wind power in crop drying. Drying of corn, soy- beans, rice, peanuts, tobacco, and dehydrated alfalfa were addressed. The economic analysis included a determination of the breakeven costs of small wind energy conversion systems required to economically supple- ment or replace present energy sources, as estimation of payback periods, and comparison of breakeven costs with projected wind systems costs. A major conclusion of the study was that the economics currently are not favorable if wind systems are operated only for crop drying, since drying is a. seasonal activity often occurring for only 6 to 8 weeks in the fall. Breakeven costs would not be achieved if currently projected wind system costs are assumed. However, if these systems were to supply electricity for farm uses other than crop drying, their installation seems economically viable. They should find the greatest use in low-temperature drying of grains and peanuts, where dryers are operated over relatively long periods; of time but require little heat. Even if breakeven costs were to be achieved, the payback periods estimated were fairly long—between 9 and 12 years. Assessing the Local Windfield with Instrumentation by T.G. Zambrano, Aerovironment, Inc., Pasadena, CA. Battelle Pacific Northwest Wind Energy Report Laboratories, Richland, WA. October 1980. PNL-3622. Available: Na- tional Technical Information Service. This report concerns the development and testing of a technique for the initial screening and evaluation of potential sites for wind-energy conver- sion systems (WECS). The methodology was developed through a siting ex- ercise involving measurements of winds along the surface and winds aloft using a relatively new instrument system, the Tethered Aerodynamic Lif- ting Anemometer (TALA) kite. Notation of ecological factors such as vegetation flagging, soil erosion and site exposure, and verification of an area best suited for wind-energy development by establishing and maintain- ing a wind monitoring network were also employed. The siting exercise was carried out in an approximately 100-square mile region of the Tehachapi Mountains of Southern California. The results showed that a comprehen- sive site survey involving field measurements, ecological survey and wind- monitoring can be an effective tool for preliminary evaluation of WECS sites. The first step involved preliminary screening of the site using available data and a tour of the area. Of the 100 square miles comprising the study region, only a 20-square mile area containing major ridgelines was con- sidered suitable for WECS investigation. The preliminary site investigation showed that in this remaining 20 square miles there would most probably be one orographic feature per square mile which would make a local area suitable for WECS siting. The second step involved investigating 16 candidate sites in a detailed field assessment survey. The survey was conducted during a one-week period when winds were from the dominant northwest direction. The goal of the survey was to use various wind-energy assessment techniques to judge the merits and disadvantages of wind-monitoring at each respective site. For each wind-energy assessment technique—namely, ecological features, short-term anemometry, and serviceability—each site was ranked with respect to the other 15 in order of merit. This ranking was a preliminary wind-energy assessment criterion. The final result was a com- bination of the three sets of rankings into a matrix to obtain, from best to worst, the most suitable sites for installing wind-monitoring stations. Many of the techniques used in this second step were novel to wind-ener- gy assessment. The TALA kites proved to be versatile field instruments (but not without design flaws) and continually indicated a more uniform vertical profile of wind speed than would be obtained from a 1/7 power law. The vegetation survey involved the development of a deformation index for California oak, which will be refined when annual wind speed statistics for the data are obtained. Portable, modular 10-m wind-monitoring stations specifically designed for study application were shown to be satisfactory low-cost field instruments. In the third step, nine sites of the original 16 candidates were equipped with 10-m wind-monitoring stations. Wind speed and wind-direction were continuously recorded during a six-month period. Two stations out of nine had wind-direction monitoring capabilities. For future surveys, however, it is recommended that wind direction data be taken at all wind-monitoring locations. Presently, an additional six months of wind-monitoring is being performed with support from the California Energy Commission. The wind-field analysis identified four basic wind-flow patterns in the study region—summer northwest, winter northwest, summer southeast, and Santa Ana flow—and their respective diurnal patterns, frequency, and wind speed distribution. In general, it was seen that-during the summer and early fall, northwest flow can be enhanced by a channeled northwest flow up the axis of the San Joaquin Valley. The study region is located at the ter- minus of the valley and is recipient of the up-valley flow. At other times during summer and early fall, an inversion layer caps the San Joaquin Valley and inhibits the flow of air over the study region. During late even- ing, the high ridges of the study area were exposed to upper-level flows. Periods of high winds on these ridges corresponded to strong upper-level wind associated with weather fronts and active upper-level atmospheric cir- culation. These winds tend to be the strongest during the winter and spr- ing seasons when the atmospheric circulation is most active. The wind-speed distributions for each of the 9 wind-monitoring sites were determined and the wind-energy flux obtained on a seasonal (summer and fall) and annual (estimated) basis. There is a ridgeline running approx- imately 7 miles in an area referred to as LaLiebre, where the annual estimated wind-energy flux exceeds 400 watts/m’, corresponding to a cons- tant steady energy wind of about 9m/sec (20 mph) at the 50-m level, with some areas showing a seasonal wind-energy flux in excess of 500 watts/m’ (a steady energy wind of 22 mph). The energy wind is defined as the con- tinuous wind which would have the same energy as the actual wind distribu- 13 May 1981 tion. Most other regions that were investigated showed an estimated seasonal wind energy flux rarely exceeding 200 watts/m? (a steady energy wind of 15 mph) at the 50-m level. Wind-energy distributions were applied to a hypothetical, large WECS, of which the Boeing design for the MOD-2, 2500 kW rated, 100-m rotor diameter propeller-type unit is a typical example. In the most promising regions of the study area such a single unit would produced 5.7 x 10° kW-hr per year, corresponding to an annual average power of 0.65 MW. Based upon simplified single-line design with a two-rotor-diameter spacing bet- ween hubs and an assumed 90 percent land availability, an array of 56 units located in the most promising ridgelines could produce 320 x 10° kW-hr per year, corresponding to an average power of 36.4 MW. Array modifications and optimum turbine sizing and selection were not considered in the initial survey. Comparisons of recorded six-month data to the results of the field assess- ment survey showed that the wind-energy assessment techniques used were able to identify sites which were most immediate and reliable for WECS development, and also those with marginal development potential. Data analysis showed a need to refine initial relationships concerning the mechanics of tree deformation. The insights gained during the course of this program are the basis of the author’s conclusion that, with improvement of the vegetation indices and further field experience with the TALA systems, this program for assessing local wind fields constitutes a reliable cost effective technique for WECS siting in complex terrain. a * * Assessing the Local Wind Field at Sierra Grande Mountain in New Mexico with Instrumentation by K.M. Barnett and R.D. Reynolds, Physical Science Laboratory, New Mexico State University, Las Cruces, NM 88003, Prepared for Battelle Pacific Northwest Laboratory, Richland, WA. May 1981. PNL-3623. Available: National Technical Information Service, Spr- ingfield, VA. This report is intended for electric utility engineers and meteorologists who wish to find the best location for large wind energy conversion systems (WECS) at mountainous sites where the wind energy potential is already considered good by vegetation indications, preliminary wind measurements, physical modeling, numerical modeling, or by other indica- tions. It is assumed that the sites would be ranked by the amount of their mean annual wind power density and that the velocity variability characteristics would be important secondary factors. No account is taken here of the important non-wind factors of accessibility, installation costs, nearness to existing power lines, etc. An assessment was made of the concept to measure wind speed and direc- ton directly at several spots on a mountain to obtain data for deciding on a WECS location. An evaluation was made of the methodology by operating a specific type of wind measuring system for 6 months. Six systems were installed on top of Sierra Grande, a nearly symmetrical mountain in New Mexico about halfway between Raton and Clayton, with a peak of 2659 meters (8720 ft. msl) standing over a wide mesa of approx- imately 1829 meters (6000 ft msl). Two systems were on the peak, one at 10 meters (33 ft) above the surface and the other at 20 meters (66 ft) because the peak is often the most probable spot for the greatest wind energy. The two levels were needed to measure variations of speed with height. Four other systems with instruments at 10-m (33 ft) were located roughly north, east, south, and west from the center on secondary ridge lines to measure certain horizontal variations of the wind. These four were within 110 to 230 meters of the center to encompass a radius of 1 to 2.5 diameters of a large WECS—a minimum area to be dedicated to a single large WECS. The wind direction and speed were measured every six minutes, a time interval con- siderably shorter than the traditional one hour but long enough so that all WECS power outputs are expected to resond to these wind speed varia- tions. All six systems were operated for a period of six months between 6 June 1979 and 5 December 1979. The major results were: © The wind speed change with height from the 10- to 20-m levels on the central tower varied considerably and appeared to be a function of speed magnitude, direction, and time of day. © For 10-m towers, the use of wooden poles was the least expensive, approximately one order of magnitude cheaper than the erection of 10-m metal towers on cement bases. Taller towers become much more expensive to install. The expense of erecting towers to hub heights of 30 m to 60 m in remote mountain locations may be very large. Wind Energy Report © The methodology of instrumenting an isolated peak and leaving the equipment unattended for a month at a time proved feasible. © The wind-measuring equipment, after recommended improvements, should prove to be a cost-effective way to obtain wind data for proposed WECS sites, except for the uncertainties of extrapolating wind conditions to a higher altitude in mountainous areas. © This type of equipment manufacturing is a very competitive field so better equipment and even a relative decrease in cost should be expected. © Difficulties with direction sensors and timing devices did not allow any significant use of the time series capabilities of the four sensors sur- rounding the peak to study WECS stoppage due to yaw error, wind shear or convergence. e The maximum mean wind speed for six months (6 June-S5 December) was 18.8 mph at 10 m with a mean power density of 542 W/m’. The estimated annual values are 19.7 and 680 W/m’. The estimated annual values are 19.7 mph and 680 W/m’, respectively. © During this six-month investigation the peak of the mountain did not provide the greatest wind energy. A slightly greater maximum, about 11% more, was east of the peak. © The winds over Sierra Grande had a diurnal maximum at night, usually between 2 and 4 a.m. ; . © The estimated energy output of a MOD-2, if installed at the peak, for 6 months (6 June-5 Dec) was calculated to be 4.5 x 10° kwh. This assumed that the wind increased above 20 m by the 1/7 power law. * * * Accelerometer Measurements of Aerodynamic Torque on the DOE/Sandia 17-m Vertical Axis Wind Turbine, By Gerald M. McNerney, Sandia Na- tional Laboratories, Albuquerque, NM 87185. April 1981. SAND80-2776. Available: National Technical Information Service. The wide variations in aerodynamic torque that are characteristic of ver- tical axis wind turbines will damage any drive train that has not been pro- perly designed. Consequently, the DOE/Sandia 17-meter VAWT was designed with a “‘soft”’ drive train, including flexible couplings to filter out torque variations at high frequencies. The torque sensor between the flexi- ble couplings measures the torque applied to the shaft. We can use these measurements to determine the average torque, such as in aerodynamic per- formance. However, when more detailed information is needed, we must use a different technique to measure aerodynamic torque. This latter technique consists of using blade accelerometer measurements in conjun- tion with those from the torque sensor to deduce actual aerodynamic tor- que. Sandia used this technique for this experiment. The experiment was a success in its primary objective of providing previously unavailable infor- mation on the detailed function of aerodynamic forcing. The information is the first concrete evidence of the dynamic stall phenomenon and is now being used to fix constants in the new aerodynamic models. A secondary objective of the experiment was to see if this method was a valid experimental technique to determine aerodynamic torque and to model improvements in second-generation tests. The following is recommended for future testing of aerodynamic torque with accelerometers and a torque sensor: © Devise a refined technique to mount the accelerometers on the blades. This would help reduce the largest fixed-error source encountered. © Records should be taken for up to at least 1 min. Our records were all for 30 s, which limited the pool of cycles from which to average cycles at any given windspeed. © Instruments chosen should more closely match the phenomenon range of interest and the analog range of the digitizer. A judicious selection could reduce digitization and instrument sensitivity to 1/3 the error of this experi- ment. Guy Cable Design and Damping for Vertical Axis Wind Turbines,by Thomas G. Carne, Sandia National Laboratories, Albuquerque, NM 87185. May 1981. SAND80-2669. Available: National Technical Informa- tion Service, Springfield, VA. Guy cables are frequently used to support vertical axis wind turbines since guying the turbine reduces some of the structural requirements on the tower. The guys must be designed to provide both the required strength and the required stiffness at the top of the turbine. The axial load which the guys apply to the tower, bearings, and foundations is an undesirable conse- quence of using guys to support the turbine. Limiting the axial load so that it does not significantly affect the cost of the turbine is an important object- 14 May 1981 ive of the cable design. The lateral vibration of the cables is another feature of the cable design which needs to be considered. These aspects of the cable design are discussed in this paper. A technique for damping cable vibra- tions is mathematically analyzed and demonstrated with experimental data. * * * Survey of Long-Term Durability of Fiberglass-Reinforced Plastic Struc- tures by Seymour Lieblein, Technical Report Services. Prepared for Na- tional Aeronautics and Space Administraton, Lewis Research Center. May 1981. DOE/NASA/9549-1, NASA CR-165320. Available: jNational Technical Information Service, Springfield, VA. A survey has been conducted of the long-term strength properties of fiberglass-reinforced plastic structures. Included in the survey were data from fluid containment vessels, marine structures, and aircraft radomes with up to 19 years of service. Correlations were obtained for the variations of static fatigue strength, cyclic fatigue strength, and burst strength of pressure vessels. The relationship between static fatigue strength and residual burst strength was explored. The effects of moisture on strength retention for both stressed and unstressed materials were examined and implications for testing and design aplication were discussed. Strength retention for gasoline storage tanks after many years of service was documented and analyzed. Examination of the change in strength properties with time for large size composite structures indicated that the structures that were exposed to a high moisture environment in the absence of weathering and ultraviolet radiation could sustain their strength for long periods of time. However, when exposure to weathering and ultraviolet is present, appropriate surface protection appears to be required for long-term durability. * * * Application of Statistical Techniques to Wind Characteristics at Potential Wind Energy Conversion Sités: Final Report for the Period October 1, 1978-September 30, 1979. By Ross B. Corotis, Department of Civil Engineering, Northwestern University, Evanston, IL. May 1980. DOE/ET/20283-2. Handbook—DOE/ET/20283-3 Both available: Na- tional Technical Information Service, Springfield, VA. In this report a number of new statistical techniques and mathematical models are developed to analyze wind data collected at a potential wind energy conversion site. Data to develop and verify the models have come principally from the National Climatic Center (NCC) hourly data tapes from about three dozen sites in the continental United States. A companion handbook has been developed to describe basic application of the methods. The Rayleigh distribution is often used for the probability of hourly wind speed. Inherent in the derivation of the Rayleigh are the assumptions that the horizontal vector components of wind speed are zero-mean, identically distributed, independent, normal random variables. Herein, the assump- tions of independence and equal variance are relaxed and the resulting wind speed distribution is derived in summation form. A parameter sensitivity analysis indicates that for practical purposes the resulting distribution is well modelled by the Rayleigh. Two separate 24-hour records consisting of continuous data were made at a site in northeastern Illinois. These records were digitized with one 20-second average every twenty seconds. These records were then used to study the sensitivity of derived statistics as a function of various averaging times and sampling rates. The mean and variance of wind speed were seen to be relatively insensitive to sampling variations of practical interest. A distinct increase in the autocorrelation function for a given lag time as a function of increasing averaging time was observed, as well as an increase in the wind speed persistence (run duration) with decreasing sampling rate. A simple approximate procedure was derived for the time series simula- tion of hourly wind speed at a site. The procedure was based on the Weibull distribution for wind speed and used conditional parameters updated each hour as a function of the wind speed simulated for the previous hour and the value of the autocorrelation function for a one-hour lag. The model is an exact procedure for a normally-distributed random variable. The im- plicit assumption that the autocorrelation function was a decaying ex- ponential is found to be satisfied with actual site data. A related procedure is developed for the time series simulation of total hourly power generated by a regional array of wind turbines. Here the normal assumption can be substantiated, but an equivalent linear wind turbine operating characteristic curve is required. Autocorrelation as well as spatial correla- tion was included in the approach. The simulated results for three different regions and six different wind turbines (ranging from 45 kW to 2.5 MW) a Wind Energy Report were compared with observed data and with a different simulation model. The means and variances of power were seen to agree well with the actual observed data. Histograms of array power from the simulated model agreed reasonably well with the observed data, except for some disagree- ment in the extreme ranges. Array power autocorrelation from the simula- tion and observed data matched very well in form, although there were some quantitative discrepancies at long lag times (fortunately, the agree- ment was very good at the important initial few hours of lag). Mean run durations also compared very favorably between the simulation and the observed data, although there were substantial differences in isolated cases. Bayesian statistics were applied for the wind speed probability density function. Sampling uncertainty due to finite duration of site data collection was reflected through a gamma prior distribution for the site mean wind speed. Inherent uncertainty was included with a Rayleigh distribution. The resulting Bayesian distribution must be tested further, but it appears that sampling uncertainty is strongly dominated by inherent variability for a year or more of field data. Additional NCC data generally confirm the applicability of previously derived procedures and lead to new regression curves for calibration of the wind persistence model. A Review of Wind Turbine Wake Effects; Final Report By James J. Riley, Edward W. Geller, Max D. Coon, John C. Schedvin, Flow Research Com- pany, Inc. Kent, WA. January 1980. DOE/ET/23160-80/1. Available: Na- tional Technical Information Service, Springfield, VA. For wind energy to have a significant impact on U.S. electrical power production, wind turbines will have to be grouped together into arrays, or wind farms. This grouping together can introduce possible detrimental ef- fects on both the power output and structure of the turbines, due to down- wind turbines being in the wakes of upwind turbines. The issues critical to treating wake effects can be categorized into two groups: first, how a wake affects the performance and structure of a down- wind machine; and second, the characteristics of the wake of single units and of multiple units in arrays. The wakes of upwind units can affect the performance of downwind units through (i) intercepting ambient wind energy and thus decreasing the energy flux to the downwind unit, (ii) generating gradients in the mean wind, (iii) generating turbulence, and (iv) producing discrete flow structures such as tip vortices. The structure of the downwind unit can be affected by (i) induced wind shear, (ii) fluctuating loads due to wake turbulence, and (iii) specific flow structures such as tip vortices. The wake characteristics needed are thus the mean wind speed, wake turbulence characteristics and specific flow structures. These should be known as functions of ambient wind conditions and characteristics of the particular turbvne under consideration. In addition, when wind tur- bines are placed in arrays, these wake characteristics are needed as a func- tion of the configuration of the array. Several theoretical models have been developed to treat the effects of wind turbine wakes. The model furthest developed, and possessing the most potential for future applications, is due to Lissaman (1979). It calculates the reduction in velocity in the wake of a wind turbine by using a semi-empirical model based upon the analogy of wind turbine wakes to jet- type flows. It then uses linear superposition of these velocity defects from upstream turbines to calculate the kinetic energy flux intercepted by a downstream turbine in order to determine the reduction in power caused by the wake environment. It can be used for arbitrary array configurations and accounts for most major influences. However, this model needs valida- tion because of many simplifying assumptions made in developing it. A second theoretical approach has been direct numerical calculations us- ing the governing primitive equations of motion. Although fewer assump- tions are needed here than with Lissaman’s model, this approach is more difficult to use, and cannot easily be extened from single units to arrays. Theoretical techniques have been borrowed from aeronautics for a third approach, which computes the behavior of the shed vortices in the near field behind the turbine. While probably applicable in the near field (less than about 3 diameters), these techniques do not apply to the mid to far field. Other methods have been developed to treat arrays using boundary layer similarity theory (e.g., Templin, 1974). However, because of the ex- tensive assumptions made in developing these models, only very qualitative results can be obtained from them. Another approach to modeling wind turbine wake is physical, or laboratory, modeling. Approximately scaled models of horizontal-and vertical-axis turbines have been used. Although this approach has much 15 May 1981 potential, confidence-levels in the technique need to be estabilished since all the similarity requirements cannot be met. In particular, because of the small size of the models (roughly 20 to 30 cm diameter), the Reynolds number is not duplicated. Some experiments have been carried out with larger models (roughly 2 m) in aeronautics wind tunnels, where scaling ef- fects appear to be much less significant. However, these tests are limited to structural and near-wake studies, and are incapable of treating the mid to far wake. Greatly simplified (e.g., porous disc) models have also been used in wind tunnel studies. Because of the small size (about 7cm) and simplicity of the models, they can be used in array studies. However, in additon to the scal- ing problems mentioned above, these models also suffer from no power be- ing extracted from the flow. They are obviously poor models in the near field, realistic operating curves cannot generally be matched, and their ef- fect on the ambient wind is probably erroneous. The knowledge of wind turbine wake effects has been advanced using the mathematical and physical models as well as by carrying out field ex- periments. However, little reliable quantitative information has been ob- tained, because of difficulties inherent in carrying out field programs and the uncertainties of the mathematical and physical models. There is, though, a considerable amount of qualitative information now available. For example, estimates have been made of the dependence of power output in arrays on array spacing. Ambient and wake turbulence have been found to profoundly influence wake recovery rates. And the relative effects of varying such parameters as the tip speed has been determined. But it is clear that much more needs to be known. With regard to wake turbulence effects on performance of downwind machines, some estimates of wake turbulence intensities and frequencies have been made from the laboratory studies. It appears that in the range of 5 to 10 diameters downwind of a turbine, wake turbulence can be com- parable with or greater than the ambient turbulence. The frequencies of the wake turbulence appear to be much higher than in the ambient turbulence. Although a little work has been done to estimate the effects of ambient tur- bulence on turbine performance (using both mathematical and physical modeling), the results are ambiguous and cannot be extended to determine the effects of wake turbulence. No work has directly addressed wake tur- bulence effects. No work has been done to estimate the effects of wake tur- bulence on structures. However, computer programs have recently been developed which can probably address this problem. . . * Test Evaluation of a Laminated Wood Turbine Blade Concept. By James R. Faddoul, National Aeronautics and Space Administration, Lewis Research Center. May 1981. DOE/NASA/20320-30. Available: National Technical Information Service, Springfield, VA. This report presents the results of a series of tests conducted on a root end section of a laminated wood wind turbine blade fabricated by Gougeon Brothers, Bay City, Michigan. The blade-to-hub transition of wood blade uses steel studs cast into the wood ‘‘D’’ spar with a filled epoxy. Because of the high stiffness and fatigue strength of wood (as compared to density) along with the low cost manufacturing techniques available, a laminated wood wind turbine blade application has been studied. This report presents the results of the testing performed on elements of the wood blade-to-hub transition section which uses steel studs cast into a laminated wood spar with a filled expoxy. Individual stud samples were tested for both ultimate load carrying capability and fatigue strength. A one-time pull-out load of 78,000 Ib was achieved for a 15 in. long stud with a diameter of 1 in. Tension-tension fatigue indicated that peak loads on the order of 40% of ultimate could be maintained as an endurance limit (mean load = 20,000 Ib, cyclic load = + 15,000 Ib(. Following the individual stud testing, a full-scale inboard blade section (20 ft. in length) was tested. One million load cycles were imposed on the test section at each of three load levels, representing the rated wind condition (40x10* cycles over 30 yr.), the cut-out wind conditon( 10” cycles), and 25%eabove the cut out wind con- dition. This was followed by 670,000 load cycles to a peak moment of 210,000 ft-Ib which represents the emergency shutdown load condition ( 1000 cycles) at which point fatigue failure occurred at a stress concentra- tion in the stud. No evidence of distress to the wood, the epoxy, or the epoxy-to-steel bond was found. Based upon the results of this testing, two sets of wind turbine blades have been built and are operating on MOD-0A (200 kQ 14 ft diam rotor) wind turbines at Kahuka, Hawaii and Block Island, Rhode Island. In addi- tion, a set of 40 ft long inner blade sections have been fabricated for a tip . Wind Energy Report controlled wind mu-bine, MOD-0 (100 kW, 125 ft diam rotor), at Sandusky, Ohio. Results indicate that the bonded stud concept is more than adequate for both the 30-yar-life fatigue loads and for the high wind or hurricane gust loads. Issues and Examples of Developing Utility Interconnection Guidelines for Small Power Production: Technical Memorandum. By C. Lawless- Butterfield, J.V. Guerrero, K. Pykkonen and L. States, Rockwell Energy Systems Group, Rocky Flats Plant, Golden, CO, January 1981. TM- IP/81-5. Available: National Technical Information Service, Springfield, VA. Although interconnecting with an electric utility is only one method of installing a SWECS, the cost competitiveness of interconnection appears to be better than stand-alone installations. The additional-costs of energy storage or backup systems can make stand-alone SWECS installations more expensive except in remote areas not serviced by convential electric utilities. Consumers interested in interconnecting SWECS are concerned about interconnection requirements and associated costs. If these costs are higher than the amount a small power producer may expect to realize in selling electricity back to the utility, a prospective customer may be deterred from investing in SWECS. This report summarizes what several states are doing to establish inter- connection guidelines under the Public Utilities Regulatory Policies Act rules for small producers, in particular Small (under 100 kW) Wind Energy Conversion Systems (SWECS). The emphasis of the report is to discuss issues relevant to interconnecting SWECS. No effort is made to establish either a model interconnection policy or a definitive procedure for develop- ing SWECS interconnection policies. * * * Controlled Velocity Testing of Small Wind Energy Conversion Systems: An Evaluation of a Technique. By J.C. Balcerak, Rockwell Energy Systems Group, Rocky Flats Plant, Golden, CO. November 1980. RFP-3189. Available: National Technical Information Service, Springfield, VA. Tests of a SWECS mounted on a rail flatcar were performed at the Department of Transportation Test Center in Pueblo, Colorado, to deter- mine the merits of such a facility. Specifically, tests were performed to verify the usefulness of data gathered by such methods. Parameters ex- amined in these initial tests were: 1) power and other performance curves of test machine, 2) wind velocity profile above the flatcar, 3) the accelera- tion/deceleration forces imposed on the support system, 4) the effects of non-tracking on rotor performance, and 5) the feasibility of wake measurements and flow visualization studies using this test method. This report discusses the results of these tests and provides conclusions and recommendations regarding the use of controlled velocity testing to provide additional capabilities to meet anticipated SWECS industry growth. * * * Early Results From The SWECS Rotor Wake Measurement Project: Technical Memorandum. By A.C. Hansen, Rockwell Energy Systems Group, Rocky Flats Plant, Golden, CO. September 1980. TM-TD/81-4.Available: National Technical Information Service, Spr- ingfield, VA. Measurements were taken in August, 1980 at the Department of Transportation Rail Test Facility in Pueblo, Colorado, using Controlled Velocity Tests to quantitatively measure the nature and extent of the wake around a horizontal-axis wind machine and to pravide data necessary to validate rotor wake models. Early results are presented here and show that the mean velocity wake at the center line is detectable 14 diameters from the rotor. The interdependence of the wake strength and SWECS power coeffi- cient were also measured. Data presented give the mean speed recovery, lateral growth, and behavior with mean wind speed of the wake of an Aero Power SL1000 rotor. The data provide necessary and sufficient wake characteristics for selec- ting optimum rotor spacing at a wind farm site with a known wind regime. Proper spacing requires calculation of the energy loss due to rotor in- terference. This energy loss is a function of rotor spacing, the site wind speed (or rotor loading) and direction distributions, and the rotor wake strength and extent. Simple computer programs could be written or modified to account for all significant effects in selecting optimum spacing. The reader is strongly cautioned against using only the wake decay infor- mation as a basis for a rotor spacing decision. 16 May 1981 A great deal of data has been collected that is not presented in this memo. Wind direction data are available in the wake and extensive analog data are available from which three-component turbulence information will be ex- tracted eventually. . . . A Practical Method for Estimating Wind Characteristics at Potential Wind Energy Conversion Sites. By R.M. Endlich, F.L. Ludwig, C.M. Bhumralkar, and M.A. Estoque, SRI International, Menlo Park, CA. [No Date]. PNL-3808A vailable: National Technical Information Service, Spr- ingfield, VA. i Terrain features and variations in the depth of the atmosphereic boun- dary layer produce local variations in wind and these variations are not depicted well by standard weather reports. The authors have developed a method to compute local winds for use in estimating the wind energy available at any potential site for a wind turbine. The method uses the ter- rain heights for an area surrounding the site and a series of wind and pressure reports from the nearest four or five National Weather Service sta- tions. An initial estimate of the winds in the atmospheric boundary layer is made, then these winds are adjusted to satisfy the continuity equation. In this manner the flow is made to reflect the influences of the terrain and the shape of the boundary-layer top. The author has applied the method to seven sites in the United States for 1977. For four of the sites, the windflow model was “‘tuned”’ by altering its adjustable features and comparing the corresponding wind simulations to wind measurements that were made at the sites under the auspices of the Pacific Northwest Laboratory (PNL). For the other three sites, simulations were made without tuning the model. This report describes in detail the methodology and results and provides descriptions of the computer pro- grams, instructions for using them, and complete program listings. . . . Aerodynamic Characteristics of Seven Symmetrical Airfoil Sections through 180-Degree Angle of Attack for Use in Aerodynamic Analysis of Vertical Axis Wind Turbines. By Robert E. Sheldahl and Paul C. Klimas, Sandia National Laboratories, Albuquerque, NM. March 1981. SAND80-2114. Available: National Technical Information Service, Spr- ingfield, VA. The aerodynamic section data for four different symmetrical airfoil cross sections (NACA-0009, -0012, -0012H, and -0015) were obtained for angles of attach up to 180 degrees at nominal Reynolds numbers of 0.36 x 10*, 9.50 x 10°. In addition, experimental section coefficients were obtained for the NACA-0012 airfoil with a larger chord length at Reynolds numbers up to 1.76 x 10’. The data were obtained for use with vertical axis wind tur- bines performance prediction computer codes. The data was extended to a wider Reynolds number range (from 10* to 10’) and expanded to additional symmetrical airfoils (NACA-0018, -0021, and -0025) by the use of an airfoil section characteristics snythesizer computer code. These airfoil characteristics as used by the vertical axis wind turbine performance predic- tion codes appear to be adequately predicting VAWT performance. Cor-Ten Steel—Its Application and Limitations in Wind Systems Struc- tures: Technical Memorandum. By J.F. Boland, Rockwell Energy Systems Group, Rocky Flats Plant, Golden, Co. August 1980. TM-TD/80-4. Available: National Technical Information Service, Springfield, VA. This memorandum clairifies the properties of Cor-Ten steel so that the potential for misuse of this material can be reduced. There is a tendency to exaggerate the capabilities of this material which could lead to its inap- propriate use by designers of wind systems. Of particular interest to designers of small wind systems is the use of Cor-Ten steel for the support towers. Two such towers are installed at the Rocky Flats Wind Systems Test Center. High strength, low alloy steels, such as Cor-Ten offer the wind system designer the opportunity to improve the strength and atmospheric corro- sion resistance of steel components while decreasing the system weight. With proper attention to the choice of alloy and design of the component, the above advantages can be achieved at no increase in system cost. Careful thought must be given to the environmental conditions into which these alloys will be placed, because they will not necessarily retain excellent cor- rosion resistance and, in certain applications, will require the protection normally given to carbon steels. WIND ENERGY Report The International Newsletter of Wind Power APRIL 1981 PG&E, Windfarms Ltd. planning 350 MW project Pacific Gas & Electric and Windfarms, Limited have announced ‘‘an agreement to negotiate’ towards a purchase power con- tract which could result in the utility adding 350 MW of wind power to its grid by 1990. According to details released by the prin- cipals, PG&E and the California Depart- ment of Water Resources would buy the electricity generated by 67 500 kW and 79 four megawatt wind machines from wind arrays at PG&E-owned sites in Solano County, approximately 30 miles northeast of San Francisco. The joint announcement, made with much publicity in San Francisco (and a week later at a California Energy Commis- sion wind energy conference in Palm Spr- ings), came one day after another an- nouncement by Windfarms in Hawaii con- firming the long expected deal to buy 20 Hamilton Standard wind machines for its Kahuku Hills wind farm. According to a joint announcement, the “development would occur in three stages. Commercial operation of the first stage—51 machines with a combined generating capa- city of 92,000 kilowatts—will begin by the end of 1983 and will be completed by 1985. Inside W.E.R. ALCOA 500 kW crashes Fairfield to be small power producer . Calendar WENCO distributor in U.S. ......... 4 Volund to build 15 kW unit SCE/San Gorgonio wind farms SCE/Windfarms disagree on PURPA.10 ISSN: 0162-8623 On completion of the third stage in 1989, the development would include 146 wind- powered turbine generators with a capacity of 350,000 kilowatts. “The facility would produce almost one billion kilowatt-hours of electricity a year, equivalent to the annual electric consump- tion of about 150,000 typical northern and central California homes. Producing one billion kWh of electricity in a [PG&E] oil- burning power plant requires about 1.6 million barrels of oil.’* At this stage of negotiation, Windfarms plans to build, own and operate the wind farm. It would sell all of the electricity generated by the project to PG&E at a yet- to-be-determined price. Windfarms would use PG&E’s transmission lines to wheel power to the Department of Water Re- sources to help meet its pumping require- ments for the California state water project. The agency already has a wheeling agree- ment with PG&E and would buy the wind farm power at off-peak rates. The project is planned to be developed on the 1300-acre Ruth King Ranch and the 3400-acre Swett Ranch. Both ranches are contiguous and located within the triangle formed by Interstates 80, 680 and 780. The land is located approximately half-way bet- ween the City of Fairfield to the east and Vallejo to the west and roughly five miles north of the Sacramento River’s Carquinez Strait. PG&E owns the King Ranch where it plans to erect a Boeing MOD-2 and have it operating early next year. PG&E is in the process of purchasing the Swett Ranch for an unconfirmed price of $6 million. Initial- ly, Windfarms and the City of Fairfield at- tempted to acquire the Swett Ranch for a joint venture but, according to one source close to the actual negotiations, ‘‘couldn’t (Continued on page 3) SCE negotiating two wind farm projects Southern California Edison has an- nounced that it has signed letters of intent to negotiate purchase power agreements with two companies—a wind farm develop- er and a major WECS manufacturer—thus formally setting into motion wind projects totalling 25 megawatts. Hamilton Standard will provide five 4 MW two-bladed machines, accounting for 20 MW and WECS Tech Corporation of Gardena, California, will provide 5 MW consisting of fifty 100 kW sailwing machines. Both projects will be built near the Palm Springs-Whitewater area of Riverside County, commonly known as the San Gor- gonio Pass. William R. Gould, SCE chief executive officer, told participants at the utility’s an- nual stockholders’ meeting this month that “the signing for 25 megawatts plus the con- clusion of current negotiations for 200 MW more will go a long way toward Edison’s announced goal of 360 MW of wind power by 1990.”” Prospective sites have been selected but SCE is unwilling to reveal the details of the exact location of either one of the installa- tions, pending final negotiation between WECS Tech and a local landowner. Wind Energy Report, however, has learned that two sites for the five Hamilton Standard machines are under active consid- eration. The prime site is said to be ‘‘within a few yards’’ of anemometer No. 7 used as a wind data collection point for the Aero- Vironment study of the San Gorgonio- Whitewater region. The alternate site is said to be thetract of land adjacent to SCE’s 220/115 kV Devers substation and slightly southwest of the Bendix 3 MW horizontal- axis and ALCOA 500 kW vertical axis ma- chines. The site proper is located approxi- mately one mile north of Interstate 10 and three-quarters of a mile east of Highway 62. In 1979, SCE proposed, unsuccessfully, the same site as a potential location for the (Continued on page 7) ‘Wind Ene;gy Report ALCOA 500 KW VAWT crashes in California The world’s largest Darrieus vertical axis wind turbine collapsed and partially destroyed itself early this month while undergoing testing at Southern California Edison’s wind test facility in the San Gorgonio Pass. An 82-foot diameter Aluminum Company of America 500 kW research unit responding to gusts in excess of 40 mph went into an overspeed condition and toppled to the ground 39 seconds later. The collapse occurred when one of its three, 4,169 Ib. blades broke a bolt connecting the bottom section of the blade to one of two mini-struts holding the blade to the torque tube. When the blade separated from the strut, it flared upward, cutting one of the five guy wires fastening the machine to its concrete foundation. It then began spinning out of control and crashed to the ground. While the three blades themselves were destroyed beyond reclamation and the torque tube was bent at a joint, Alcoa indicates that the generator and the transmission might be salvaged for use in another machine. According to ALCOA, the unit was undergoing the fourth in a series of monitored test runs as part of pre-acceptance testing for Southern California Edison. The 123-foot tall unit was installed in February and began its first operation on March 17. Since installa- tion, the machine had run for less than three hours. A second, iden- tical unit has been operating without incident since December of last year at Agate Beach, Oregon. ALCOA officials ordered the Oregon machine to stop operation until a detailed examination of the causes of the failure are determined and corrective measures undertaken. According to ALCOA, the sequence of events leading to the machine’s collapse is as follows: “‘During startup, a service brake shutdown was initiated when the windspeed exceeded the pre-set operating threshold of 40 mph. Simultaneous with the initiation of the shutdown, the rotor reached its normal 29 rpm crossover point at which time power was automatically switched from the [25-30 kW] starter motor to the [500 kW] motor/generator. An excessive voltage drop of approx- imately 25% due to inrush current to the generator momentarily shut down the controller, disconnecting the generator and causing the application of the emergency brakes and release of the service brake. “‘The restoration of voltage allowed the controller to resume the previously initiated service stop sequence thus releasing the emergency brakes and reapplying the service brakes. Then the con- troller, sensing the previous emergency brake event, released the service brakes and reapplied the emergency brakes. This control se- quence took approximately 4 seconds. An additional 10 seconds were required for the emergency brakes to develop maximum brak- ing torque. During this time period, the rotor speed increased from 29 to 49 rpm. The time required to reach maximum braking torque and the maximum level of torque developed were inconsistent with design criteria and previous test runs. “‘At the same time the emergency brakes developed their max- imum torque, the wind speed dropped to 25 mph and the rotor started to decelerate. The deceleration continued until the rotor speed was 45 rpm. At this time, the brakes started fading and the wind speed started increasing. The rotor then started to accelerate until failure occured at 60 rpm when the aerodynamic and cen- trifugal forces on the blade end connections were at least 22 times that of normal operating loads.’’ Most of the wreckage was contained within the area fenced off for the experimental project, a few hundred feet from the Bendix 3 April 1981 MW. One blade did, however, hit the perimeter fence, damaging it. No one was injured during the episode. But one of three Alcoa engineers who witnessed the entire incident from a nearby control shed said there were some anxious moments during the incident when he did not know whether to leave the shed for safety or stand- by and watch. He watched. By the end of the month, ALCOA wind program manager Frank Townsend confirmed that the cause of the accident was due to a software error in the programming for the microprocessor. Among other functions, the electronics governs the critical phases of the start-up and shutdown routines for the machine. On the brighter side, says ALCOA’s marketing manager Paul Vosburgh, the accident proves that there are no structural defects in the machine’s design. Vosburgh points out that there were no vi- brations at 50% overspeed, or 60 rpm. ‘‘No single part of it let us down,”’ he says, ‘‘the blades never shook. It worked far better than anybody expected it to.’’ Vibrations in the overspeed mode were the cause of the failure of a 57-60 kW unit last March at the com- pany’s Pittsburgh area testing facility. The central torque tube of (Continued on page 5) Looking southeasterly, two of the three ALCOA Darrieus blades and the torque tube lie on the ground. Not shown is the third blade which hit the fence. A portion of SCE’s Devers substation can be seen in the ex- treme upper right hand corner. Just below is the rear portion of the Ben- dix megawatt machine Photo: Courtesy ALCOA. ' Wind Energy Report April 1981 350 MW Windfarm project in N. California (Continued from front page) come up with the financial guarantees needed to seal the deal. PG&E wanted it badly and has the money.”’ The land is currently being used for cattle grazing, a use that will be continued with the wind arrays in place. PG&E/Windfarms Limited Project Timetable Phase Number of WTGs Total Rated Annual 4MW 500 kW Capacity (kW) Energy (kWh) 1 - 1983-85 19 32 92,000 270 million Il - 1985-87 30 9 124,500 347 million Il - 1987-89 30 26 134,000 326 million Total 79 67 350,000 963 million PG&E’s acquisition of the land in a prime wind resource area will, no doubt, make for an interesting round of negotiations. Windfarms has until November 1 to reach a formal arrangement with PG&E on the project. ‘‘Our plans for the Solano project may require adjustment as we go forward to take advantage of improv- ing technology, special regulatory requirements and lessons all of the partners learn,’’ according to Ivan Gold, Windfarms vice presi- dent and counsel. Meanwhile, Windfarms is facing some formidable capital forma- tion problems. It must raise $350 million to finance the Kahuku project and several hundred million more to finance the Solano project (rumored to cost $750 million) and other announced pro- jects in California and Hawaii. And while the avoided cost formula worked out by the California Public Utilities Commission is an at- tractive starting point, (7.783 cents/kWh for May-July), no one ex- pects PG&E to agree to full avoided cost when it is allowing its own land to be used for the site. Solano County has been identified as one of four California regions where the wind resource is substantial enough to attract serious wind farm development. In 1979, the California Energy Commission and PG&E jointly conducted an 11-month field study at a number of sites in Alameda and Solano Counties. Within the triangular study area, PG&E meteorologists Earl Davis and Ron Nierenberg stationed three wind run measuring devices and one anemometer (S-04) capable of measuring wind speed and direction. (Davis has since become Windfarms Limited’s meteorologist.) Results of the study, Wind Prospecting in Alameda and Solano Counties, May 1980, reveal that the area around the S-04 has a mean annual average wind speed of 18.5 mph with a high of 28.1 mph during August. Mean wind speeds range between 18.1 mph and 28.1 mph from April through October. Peak energy producing winds range between 18.5 and 23.6 from 3 P.M. through midnight. A PG&E wind turbine generator simulation analysis indicates (Continued on page 7) Maximum Wind Turbine Generator Performance Hamilton Boeing Bendix Standard ALCOA 2.5 MW 3.0 MW 5.0 MW 500 kw Hours below cut-in 39% 39% 42% 39% Hours at capacity 25% 6% 9% 11% Hours above cut-out 1% 0% 0% 0% Calculated energy (millions kWh) 69 48 85 1.2 Normal. annual en- ergy output-18.6 mph (millions/kWh) 9.0 63 W141 16 Capacity factor 41% 24% 25% 34% F ZB 10: S-07 * Cordelia Junction ZB $-13 a a4 os at Ce LST Ral ? SES Source: CEC/PG&E Municipality to be wind small power producer? Windfarms Limited and PG&E aren’t the only ones interested in exploiting the wind potential of the Fairfield-Vallejo-Benicia triangle in Solano County. The City of Fairfield, which gets all of its electricity from PG&E, may become the first municipality to become a small power pro- ducer using wind machines to generate electricity for sale to PG&E. Fairfield first became interested in wind-electricity about a year ago, says Joseph Shilts, the city’s public works director, when a much sought-after industry opted to locate near Seattle because it feared that PG&E’s power reserves are uncomfortably slim. Accor- ding to Shilts, during peak summer periods, PG&E’s reserve margin is a meagre 4-5%. At that point, says Shilts, ‘‘we decided that we wanted to be part of the solution and not the problem.’”’ Soon after, the city then began looking at wind power in earnest. The: California Energy Commission had already completed the Alameda and Solano County wind prospecting study and had funds for a small wind system demonstration project. Fairfield, with wind sites in excess of 18 mph, was looking for a machine. The California Energy Commission subsequently awarded the City of Fairfield a $93,000 grant to erect a two-bladed 25 kW Jay W. Carter Enterprises machine for a two-year test and demonstra- tion project. The machine is expected to be installed next month on the Red Top Dairy hill just west of Interstate 80, overlooking Cor- delia Junction. The PG&E/CEC study indicated that the rolling hills in and around Fairfield have a potential for 50 to 100 MW of wind- (Continued on page 7) Wind Energy Report Meetings/Conferences Solar Rising, the annual meeting of the American Section, Inter- national Solar Energy Society, will be held at the Philadelphia Civic Center, Philadelphia, PA, May 26-30, 1981. The meeting will have only one session on wind power, Wind Commercialization, which will be held on Saturday, May 30, at 10:40 A.M. For more information, contact: AS/ISES, Research Institute for Advanced Technology, U.S. Highway 190 West, Killeen, TX 76541. (817) 526-1300 or (215) 545-2150. * * * A one-day seminar, Wind & Wave Energy for Electricity Genera- tion, will be held on May 27 in London. Organized by the Heliotechnic Associates International, the seminar will focus on current United Kingdom developments and applications of wind and wave energy systems. The following papers/presentations will be given: Large Scale Application of Wind Turbines Onland and Off- shore, Dr. D. Swift-Hook, C.E.G.B.; Wind Energy System In- tegration, Dr. P. Musgrove, Univ. of Reading; Horizontal Axis Wind Turbine Programme on Orkney, Dr. D. Lindley, Taylor Woodrow Construction, Ltd.; Towards a Wind Energy Market, William Grylls, Univ. of Exeter; Cost Benefit of Renewable Energy, J. Shapiro, Cierva Rotorcraft Ltd.; Historic Development of Windmills in Greece and their Potential for Electricity Genera- tion, Costis Stambolis and Peter Vastardis, Heliotechnic Associates; Overview of Wind Energy Program, Louis V. Divone, U.S. Dept. of Energy; and A Review of Wind Energy Applications in Sweden, Holland, and Denmark, William Grylls, Exeter Univ. Fee for the conference is slightly in excess of $200.00. For further information, contact: Organizers, The Institute of Directors, Heliotechnic Educational, 5 Dryden St., Covent Garden, London WC2E 9NW, United Kingdom. 01-240-2430, 602-2657. Telex 299533. * * * A three-day DOE/NASA Workshop on Large Horizontal Axis Wind Turbines will be held on July 28-30, 1981 in Cleveland, Ohio. Co-sponsored with Cleveland State University and Oregon State University, the workshop will be held on the Campus of Cleveland State University with lodging in the adjacent Downtown Holiday Inn. Planned reports on design, operation and data will will focus on the following topical areas: tests data from the MOD-O experimen- tal wind turbine; operating data from DOE/NASA wind turbines located at utility sites; design of advanced systems; electric utility. experience and future plans; and rotor blade design data. For further information, contact: Dr. David A. Spera, Workshop Chairman, NASA-Lewis Research Center, Mail Stop 500-202, Cleveland, OH. 44135. (216) 433-4000, ext. 6629. * * * The Von Karman Institute Lecture Series on Wind Energy Devices, will be held June 1-5, 1981, in Belgium. For further information, contact: Von Karman Institute for Fluid Dynamics, Chaussee de Waterloo 72, B-1640 Rhode-St. Genese, Belgium. * * *. The British Wind Energy Association will hold a one day Inter- national Colloquium on Wind Energy on Thursday, August 27, 1981 at the Solar World Forum Congress and Exhibition in April 1981 Brighton, England. The Colloquium will present a forum for discussing the current status and future plans of national programs as well as a wide range of topics in wind energy utilization. Papers will include the follow- ing topics: large and small wind turbines, wind data and meteorology, power system integration and economics, control systems, offshore potential, wakes and clusters, materials and structural problems, measurement techniques and environmental aspects. Invited speakers include: Dr. Freddy Clarke, UK Department of Energy; Dr. Louis Divone, US Department of Energy; Dr. Peter Musgrove; Chairman, British Wind Energy Association; and Dr. Horst Selzer, ERNO, West Germany. For further information, contact: Dr. Leslie F. Jesch, Chairman, Organizing Committee, Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, England. Tel.: 021-472-1301. * * * Wind Workshop V, the Fifth Biennial Conference on wind energy conversion systems, will be held in Washington, DC, October 4-7. Further details can be obtained from: Conferences and Staff Development Branch, Solar Energy Research Institute, 1617 Cole Blvd, Golden, CO 80401. (303) 231-7361. * * * The Second AIAA Terrestrial Energy Systems Conference will be held in Colorado Springs, Colorado, December 1-3, 1981. Several papers on wind energy are planned. For further information, contact: Dr. Irwin Vas, Solar Energy Research Institute, 1617 Cole Blvd., Golden, CO 80401. (303) 231-1935. * * * WINDTEX to build 50 kW Swiss WECS in U.S. A Fort Worth, Texas, company has been named to manufacture and sell a 50 kW, two-bladed wind machine developed by the Wind Energy Corporation (WENCO S.A.) of Biasca, Switzerland. WINDTEX, Inc. has been granted a U.S. license to build and market the machine, very similar in design to the Aerowatt 4 kW model 4100. The 50 kW machine, Model W 15050, features two aluminum alloy extrusion blades with a rotor diameter of 49.2 feet. Rated at 24 mph, the machine generates 2.5 kW at 9 mph and produces power up to 54 mph at which speed, says WENCO,it will automatically or manually stall. An upwind machine, it features a marine plywood tail vane which is positioned at an angle from the nacelle. The vane extends slightly beyond the radius of the rotor. The machine is mounted on a tubular steel tower and fastened by four guy wires. According to its Swiss manufacturer, the machine can produce 100,000 kWh annually in a wind regime of 24 mph. WENCO says that it plans to install a 25-meter diameter, 200 kW machine at its Biasca test facility. Late last year, the WENCO signed a licensing agreement with an Italian company, ENEO, covering Italy and the North African countries of Egypt, Libya, Tunisia and Algeria. The Italian com- pany subsequently installed the 50 kW unit in Berceto, Parma, claiming that the unit is the largest operating wind system in the country. For further information, contact: Willis F. Brown, WINDTEX, Inc., 200 Rupert St., P.O. Box 9380, Fort Worth, TX 76107 (817) 332-6352 or Emilio Bianchi, Via Lavizzari, P.O. Box 248, CH-6850 Mendrisio, Switzerland. (091) 46 58 35. Wind Energy Report April 1981 ALCOA VAWT crashes in S. California (Continued from page 2) that machine buckled in 40-50 mph winds (see Wind Energy Report, June 1980). The collapse occurred at approximately 4:30 p.m. (E.S.T) on Friday, April 3, a few days before the start of a major con- ference, Wind Energy: Investing in Our Energy Future, sponsored by the California Energy Commission in nearby Palm Springs. Southern California Edison was quick to point out that the machine was undergoing ‘‘pre-acceptance tests’’ and that it was not liable for any damage, or repair, to the unit. ALCOA will be responsible for cleaning up the wreckage. SCE officials, however, were just as quick in their comments both publically and privately to demonstrate their undaunted en- thusiasm for the demonstration project. Robert Scheffler, SCE project manger, was philosophical about the whole incident. ‘‘It’s discouraging in one sense, but it points out the fact that even though we don’t like to see it, these things happen and you can’t tule them out when you’re doing research.’’ Larry Papay, SCE vice president for R&D, reassured the more than 500 people attending the conference that failures are not unex- pected in a research project, openly expressing confidence in ALCOA’s ability to design and build a reliable wind machine. Nevertheless, it was a painful experience for ALCOA officials to explain the failure to technically unsophisticated delegates to the conference—many of whom might be potential purchasers. Town- send narrated a videotape of the entire incident before a hushed au- dience comprised largely of local landowners, public officials, financiers and wind farm developers. He received a warm round of applause for his candid explanation of the accident. And the next day, SCE officials gamely tried to explain what had happened to the machine totwo busloads of conference delegates viewing the wreckage and an inoperable Bendix horizontal axis machine. Embarassing though it was, both ALCOA and SCE are anxious to rebuild the machine and are now discussing terms and timetables. The software programming error may prove to be an expensive lesson for ALCOA. The machine itself cost $350,000 plus an estimated $125,000-$150,000 for installation. In addition, ALCOA had five employees at the site monitoring the machine.The total cost of the entire project may be as high as $750,000. ALCOA indicates that the incident will delay any further in- stallations of its line of Darrieus turbines, possibly for as long as six months. It had negotiated a deal with Windfarms Limited for a six unit cluster in Hawaii and had several other prospective sales. Vosburgh and Townsend still exude confidence in the company’s ability to weather this setback. But what worries Townsend and Vosburgh are the unexpected problems that may still arise in subse- quent testing of the machines. ‘‘How often can we go to manage- ment and continue asking for support,’’ says Townsend, ‘‘when we can’t tell them for sure that there are no other technical unknowns that could cause another accident like this again. It gives the naysayers [within ALCOA] ammunition to shoot at us.” * * * Bendix 3 MW HAWT not operating either SCE’s other experimental wind machine—a three-bladed, three megawatt upwind machine designed by Charles Schachle of Moses Lake, Washington, and licensed to Bendix—was not operating either. It was formally dedicated last December but hasn’t met SCE acceptance requirements by generating 300 kW for one hour. This is partly due to lack of energy producing winds and partly due to a number of key systems failures. In mid-February, the main bearing failed. There have been a number of unconfirmed reports of pro- blems with the turbine’s hydraulic systems.Bendix, attempting to get its machine operating in time for the Palm Springs wind con- ference, burned out the generator just a few hours after the ALCOA machine collapsed. * * * GAO report evaluates wind energy program As the Reagan administration prepares to abort active federal in- volvement in the commercialization of wind power, the General Accounting Office released results of a survey indicating that, as far as commercialization is concerned, the utility industry is not very optimistic about the near term deployment of large numbers of wind energy systems. The survey of 50 utilities from a DOE-supplied list of more than 150 utilities ‘‘interested‘‘ in wind energy concludes that utilities “‘generally agree with DOE’s basic strategy for developing wind energy.’’ But that agreement, however, is not without some criticism of specific elements of the program. Most of the 50 utilities queried believe that the cost, energy and commercialization goals of the wind energy program are ‘‘ad- mirable and ambitious,’’ but most believe these goals are unattain- able by 1988, the year set to achieve 800 MW of installed wind capacity established by the Wind Energy Systems Act of 1980. Im- portantly, the utilities surveyed were critical of the act’s manage- ment plan currently being put together by DOE’s wind systems branch. ‘‘Only a limited effort is being expended to obtain the views of electric utilities.’ That criticism may well be a mute point in light of the Reagan’s administration’s efforts to repeal the act. Regardless, one fear expressed by these utilities was that congres- sionally mandated commercialization goals may ‘‘result in the in- stallation of many wind machines which are not market-ready.’’ As a consequence say some utilities, the ‘‘credibility of wind energy may be lost by pushing machines which are uneconomical, not reliable, unsuitable for utility use, and otherwise unattractive to potential buyers and users.’” According to the GAO survey, ‘‘almost half of the utilities stated that a successful demonstration of a large wind machine is the most important step DOE can take to advance the use of wind energy.” Moreover, ‘‘once wind energy is demonstrated to be cost-competi- tive with conventional power sources . . . other problems impeding the use of wind energy would be attacked by the utilities with more vigor.’” Although the utilities questioned—14 investor-owned, 14 rural electric coops, and 12 municipals—generally supported large, megawatt-size machines such as the MOD-2, several utilities ex- pressed concern that the wind machines currently being built under DOE’s program are too complex and sophisticated for widespread use. That sentiment came mainly from the rural electric coops and the smaller municipals, according to Don Weisheit of the GAO’s Cleveland office which conducted the survey. Nevertheless, the GAO did discover that the majority of the utilities surveyed were unhappy about the usefulness of the wind resource assessment program managed by Battelle Pacific Nor- thwest Laboratories. Rather than wide area ‘‘atlases,’’ utilities in- dicated they wanted site-specific studies of the wind resource. ‘‘The [Battelle] assessment activity will not provide the specific wind resource data they need,”’ notes the survey. ‘‘ Funds could be better spent by supporting site specific wind surveys for those utilities that (Continued on next page) Wind Energy Report Volund to begin manufacturing 15 kW SWECS Windtechnic A/S, a subsidiary of the Danish manufacturer Vo- lund A/S, has announced that it plans to start manufacturing this summer a two-bladed, downwind 15 kW horizontal axis wind machine. The machine is a high tip speed ratio, variable speed device pro- ducing full rated power at 142 rpm. It is designed for 135,000 hours of continuous operation, or a lifetime of 15 years. No price has yet been announced for the unit. The blades are fiberglass, reinforced polyester with a laminar profile. Rotor diameter is 8 meters ( feet). Rotor speed is controlled aerodynamically by blade pitch feathering which enables the machine to shut itself down at 170 rpm. The 8-meter diameter wind machine will also stop in the event of excessive vibration and loss of control. The machine has no slip rings and automatically shuts down after six twists of the main cable. After each shutdown, however, the machine must be reset manually. The generator is a direct drive, permanent magnet alternator which achieves full rated 15 kW at 142 rpm. Volund says that the entire machine, including a 60-foot tubular steel tower, can be erec- ted and lowered by two men using an A-frame and a winch. It is kept in place by four steel guy wires attached to the tower approxi- mately 45 feet from its concrete base and imbedded in four con- crete pads. The machine cuts-in at 3.5 m/s (8 mph). Windtechnic/Volund says that the machine can withstand wind velocities of 70 m/s (157 mph). Depending on actual wind speeds at a specific site, the 15 kW can generate 25,000-30,000 kWh annually, according to Windtech- nic/Volund product literature. * *. * GAO report evaluates wind energy program (Continued from preceding page) express interest in investigating the potential of wind energy in their respective service areas.”’ Nearly all of the utilities said that DOE could improve its wind energy information dissemination program. ‘‘Many stated that they were not receiving the type of information needed to make in- vestment decisions on wind energy . . . and that much of the infor- mation they were receiving was ‘“‘too technical, not timely, and does not include sufficient performance and operating data.’’ The survey was to be part of a much larger examination of the federal wind energy effort but administration plans to trim the FY82 budget substantially resulted in a scaled-down effort This amounted to a five-page letter from GAO’s Energy and Minerals Division head J. Dexter Peach to DOE Secretary Edwards. A complete copy of the GAO report, Electric Utilities Concerns with the Department of Energy’s Wind Energy Program (EMD-81-77) April 21, 1981, can be obtained from: Energy and Minerals Division, U.S. General Accounting Office, Washington, DC 20548. (202) 275-3567. WIND ENERGY REPORT® Copyright © 1981. Wind Publishing Corporation. All rights reserved by the copyright owners. Wind Energy Report® is published monthly. No portion of this publication may be reprinted, reproduced, stored in a computer-based re- trieval system or otherwise transmitted whole or in part without the express, written permission of the publisher. Printed in U.S.A. ISSN: 0162-8623. Subscriptions: $115. annually (USA); $125. annually (Canada & Mexico); $145. annually (foreign airmail). Two-year subscriptions: $215. (USA); $230. (Canada- Mexico); $290. (foreign airmail). Editorial offices are located at: 189 Sunrise Highway, Rockville Centre, NY 11570. Mailing address for all correspondence: P.O. Box 14, Rockville Centre, NY 11571. (516) 678-1230. April 1981 Jan Haahr, in charge of the wind program in Volund’s fiberglass technology division, says the major ‘‘innovation’”’ of the machine is the absence of a gearbox. (The Windworks 10 kW, three-bladed wind system, incidentally, also uses a direct-drive, permanent magnet alternator which achieves full power output at 150 rpm.) Haahr contends that the major problem for small wind system designs during the past few years has been getting the gearbox to last. ‘‘There has been a rather large loss of output in the gearbox at lower performance than the rated [windspeed]. We have developed a low speed generator which is capable of turning the energy of the wind into electric energy at approximately 100 rpm.’’ He argues that this approach removes ‘‘a mechanical vulnerable’ from the unit. Haahr claims that, because the machine is equipped with per- manent magnetized poles, the generator does not have to use any of its output for magnetizing. ‘‘The lowest efficiency we have measured is 92%,’’ says Haahr, ‘‘This means that 92% of the mechanical energy is transferred to the generator from the blades which you get back as electric energy.”” Volund, one of Denmark’s leading exporters, has built one pro- totype machine and plans to continue testing it at its Viborg facility before actual production begins in July. The company is actively seeking an American manufacturer/licensee to fabricate and mar- ket its 15 kW and 265 kW, three-bladed design (see Wind Energy Report, October 1980) to the North American market. Haahr says that Volund/Windtechnic could provide the fiberglass blades and nacelle and certain other components while the actual fabrication could be done in the U.S. Towers and other components could be provided by domestic suppliers. For further information, contact: Volund Fibreglass and Windtechnic A/S, Marsk Stigsvej 4, DK-8800 Viborg, Denmark. Telephone: 45 6 62 34 99. Telex 66 225 volund dk. Wind Energy Report Municipality to be wind small power producer? (Continued from page 3) electricity. Not surprisingly, several wind farm developers became interested in helping Fairfield exploit its wind resource. U.S. Wind- power Inc., Windfarms Ltd., Wind Resources Company of San Francisco and the Free Wing Turbine Company of Salt Lake City are discussing wind projects with the city. Even a Danish WECS manufacturer, Volund A/S, is wants to install a demonstration 265 kW machine. So far, no formal project has materialized. But Fairfield officials are optimistic that some arrangement can be worked out. The CEC is providing $44,000 and the City of Fairfield is contributing an ad- ditional $100,000 toward the cost of an 18-month feasibility study to examine the prospects of a 10-50 MW wind farm within the city limits. Part of the funds will be used to study the wind resource and particularly promising sites more intensively. The city says it plans to install anemometers along the ridgeline running parallel to In- terstate 680 in early May. Within the triangle, the city of Fairfield has jurisdiction over 2-3 square miles southeasterly from the in- tersection of I-80 and I-680. A wind run device located at S-06 (18.0 mph annually) and an anemometer at S-04 (18.5 mph annually) are within Fairfield. (The Swett ranch, incidentally, is immediately ad- jacent to the city limits along the ridgeline.) If the feasibility study suggests a successful project, Fairfield of- ficials indicate that they could sell revenue bonds and use the money to build the project themselves. ‘‘With the revenues we could collect by selling electricity to PG&E,”’ says Joseph Shilts, the city’s public works director, ‘‘we can eventually pay back the costs.’’ He tentatively estimates the cost of a 10 MW project to range between $10-$15 million dollars. All of the electricity generated by the wind would be sold to PG&E at full avoided cost, making Fairfield the first municipality to become a small power producer utilitizing wind energy systems. Fairfield is still interested in a joint venture with a wind farm developer. Shilts indicates that while the city can’t take advantage of investment tax credits and other financial incentives available to private companies, it is willing to exchange the use of its land for a wind farm developer who could. “It would make a lot sense,’’ says Shilts, ‘‘to work a joint ar- rangement with ourselves, the third party and PG&E which allow the third party to get all the tax credits, the transmission facilities we would finance with tax-exempt municipal bonding.”’ Fairfield says that it already has an agreement with PG&E at full avoided cost, based on the formula worked out by the California Public Utility Commission. Beginning May 1, PG&E will pay Fair- field 7.783 cents/kWh for any electricity generated by the Carter machine. ‘‘We have had very good cooperation from PG&E on this,’’ says Shilts. Pacific Gas & Electric Cogenerator/Small Power Producer Energy Prices (cents/kWh) May 1980 through Aug. 1980 Nov. 1980 Feb 1981 May 1981 through through through Time of delivery: July 1980 Sep. 1980 Oct. 1980 Jan. 1981 Apr. 1981 July 1981 On-Peak 5675 «6.100 5.858 6.226 «= 6580 7.783 Partial-Peak 5.459 5.868 5.596 5.884 6.219 7.487 Off-Peak 4.700 5.052 4.943 5.254 5553 6.446, Average price: All kilowatt-hours: 4994 5.368 © «5.968 5.706 += 6.030 «6.850 On-peak: 12:30 p.m. to 6:30 p.m., Monday-Friday except holidays May 1-September 30; 4:30 p.m. to 8:30 p.m. October 1-April 30. Off-peak is 10:30 p.m. to 8:30 a.m. Monday-Saturday and all day Sunday and Holidays. Partial peak: all other times. April 1981 350 MW Windfarm project in N. California (Continued from page 3) that maximum energy possible from four machines range from 1.6 million kWh from an ALCOA Darrieus VAWT to 11.1 million kWh annually from the two-bladed, Hamilton Standard megawatt- scale WTG. Nevertheless, the announcement of a 350 MW wind project should provide some guidance to WECS manufacturers uncertain of just how large the third party market for wind energy systems could be. With the 20 four-megawatt Hamilton Standard machines committed to the Hawaii project, the 79 wind turbines announced by Windfarms brings the 1989 total to 99. Additionally, Windfarms has requested lease rights for 320 MW, or 80 machines, on BLM land in the San Gorgonio Pass region. The first phase of this pro- ject, if approved, will require 20 large machines in place by 1983. With the collapse of the ALCOA machine delaying its inter- mediate size VAWT program, only Westinghouse has the domestic manufacturing capability to supply the 500 kW machines in the near term. This may be the reason why Windfarms is also discuss- ing the prospect of designing a 500 kW horizontal-axis machine with WTG Energy Systems, Inc. of Buffalo, New York. WTG has a 200 kW three-bladed, horizontal-axis prototype on Cuttyhunk Island, off Cape Cod, and two machines at locations in Oregon and Canada. Three MOD-2s will be formally dedicated on May 29 at Goodnoe Hills, Washington. “, Wind Energy Report April 1981 SCE negotiating wind projects in San Gorgonio (Continued from front page) three Department of Energy MOD-2s. SCE is also reluctant to reveal the status of negotiations between the two companies. Both agreements will be negotiated during the next several months in a non-PURPA environment according to SCE. The Hamilton Standard project, which meets the minimum five megawatt total project size criteria set by Edison, does not involve a third party entrepreneur. The company refused to confirm or deny that its parent, United Technologies, will finance the project and collect the revenues from the electricity generated by it. At least one principal of WECS Tech is not new to wind farm development. Charles Gossett, mananger of product engineering, was involved with a vertical axis machine and the construction of a wind farm in the Texas Panhandle nearly two years ago. In early 1978, Alternate Energy Corpora- tion, comprising Barnes Engineering of Anaheim and Benchmark Corp. of Hunt- ington Beach, California, built a prototype “‘giromill.’’ Later that year, the company began erecting 132 30-foot steel towers with concrete foundations near Dalhart, Texas. By the spring of 1979, three vertical axis, fixed pitch, straight-bladed machines had been installed. In an atmosphere of great secrecy, the machines were tested and even- tually dismantled. Paul Gipe of the Center for Alternative Resources, Harrisburg, Pennsylvania, wit- nessed a portion of the erection and opera- tion of the facility and noticed that the machine had three, five-foot wide, 30-foot long blades with dacron cloth wrapped around the airfoil. Each blade was con- nected by a single strut. He estimates the machines to be in the 25-30 kW range but few reliable details are available about the wind machine, the project or its financial backers. The 132 towers are still standing and in Areas suitable for wind turbine dev I—excellent potential Il—good potential Il1l—fair potential IV—poor potential. Estimates based on average power density distribution. Some of Area I has a seasonal potential for greater than 1200 watts/meter?. All of Area I has an annual potential for 600 watts/meter?. Area II has greater than 300 watts/meter?. Area III has greater than 100 watts/meter?. Area IV has less than 100 watts/meter? [| Area I Area Il HH Area Ill elopment: recent weeks have been used for the testing of what appears to be a similar, though lar- ger, vertical axis machine. Meanwhile, Edison is evaluating propo- sals from more than a dozen prospective wind farm developers. Ventus Energy Com- pany of Covina says it has submitted a plan to Edison for 800 37.5 kW machines. No details are available on the machine itself or the location of the project. AeroVironment of Pasadena is reported to be proposing a $3 million project using the Carter Enter- prises 25 kW two-bladed wind turbine. Ac- cording to one estimate, that project could be as large as 800 machines. And Renew- able Energy Ventures of Palm Springs, Inc. has submitted a proposal for 20-30 MW of large kilowatt and megawatt-scale machines on a parcel of land slightly less than 200 acres and just one mile from the Devers substation. Additionally, six other projects on fed- eral and privately-owned land in the San Gorgonio region are in the offing which presumably would be interconnected with SCE’s grid. Area IV Source: California Energ Wind Energy Report Attractive wind energy property Sites in the San Gorgonio-Whitewater area are becoming some of the most coveted in all of California. And not without good reason. The Palm Springs-Whitewater section, situated 120 miles east of California’s largest load center (Los Angeles County), has one of the most energetic wind regimes in the state, if not the nation. The $355,000 AeroVironment study, funded jointly by the CEC and Southern California Edison, reveals that in the sec- tion approximately 7.5 miles east-west and 5 miles north-south, the annual wind energy flux exceeds 600 watts/meter’. This cor- responds to a constant average wind of 22.2 mph with some part of the region register- ing energy winds of 27.9 mph. The Califor- nia Energy Commission estimates that as much as 40% of all the energy extractable from California’s winds could conceivably come from the wind arrays in this region alone. And as the wind resource itself has be- ission/AeroVironment, 1980. come better understood and quantified, it is attracting a variety of wind projects. Three companies have publically an- nounced plans for wind arrays near the Whitewater River on land under the juris- diction of the Bureau of Land Management (BLM). The agency must approve lease ap- plications for the use of its land. Earlier this year, Windfarms Limited, the San Francisco firm planning an 80 MW cluster in Hawaii and 350 MW in northern California, proposed an initial large WECS array using 20 four megawatt machines. Ultimately, it wants to erect 80 machines generating 320 MW on 6,000 acres of land. U.S. Windpower Inc. of Burlington, Massachusetts, which constructed the world’s first small wind farm in New Hampshire late last year, has put forth in- itial plans to develop 400 acres by installing 200 of its own three-bladed, 50 kW mach- ines on 65-foot towers grouped in clusters of 20 generators producing 100 MW. Plans filed with BLM indicate the company wants 2,000 machines generating 1000 MW in 14 separate clusters on 9,000 acres of land. Smart & Company of Hermosa Beach, California, has proposed using 12 Mehrkam Energy Development Company “2 MW”’ machines on 70 acres. All three proposed projects are located on portions of Bureau of Land Manage- ment land near the Whitewater Region in the section near the Devers substation. At least two of the projects are competing for the same land. The land situation, in the words of one county official is ‘‘a real mess.”” These three projects alone, if fully im- plemented, could account for 1,345 MW on 15,000 acres of land. Wind Resource Company of San Fran- cisco is also proposing three projects of un- disclosed size on privately-owned land. An Oceanside company is proposing a wind farm using 36 small wind machines. The magnitude of the resource and the proposed projects, however, is creating a number of problems, principally over land use and environmental consequences. Wind plans have aroused local officials who see a stampede to the develop the area without consideration of the special needs of their communities. Most of the prime wind sites have been designated as scenic areas which attract thousands of tourists each year and millions of dollars in revenue. Wind energy exploitation in the San Gorgonio area will not be easy. The entire itself is a patchwork quilt of political jurisdictions, Indian reservations, public and private ownership. This situa- 9 April 1981 tion promises to enrich a host of lawyers long before any electricity is fed to the Edison grid. For the time being, all wind farm development has been halted pending the completion of a detailed environmental review now getting underway as a coopera- tive venture between BLM, the California Energy Commission and Riverside County. The environmental impact review is ex- pected to be completed by January 1982 with prospective wind farm developers pay- ing the cost. Balancing the requirements for adequate land use planning, protecting the rights of other land owers downwind of initial wind arrays, and addressing environmental con- cerns, such as noise and the impact of wind turbines on tourism will all have to be dealt with successfully. Already the battle lines are forming for what appears to be a protracted conflict over how the region will develop its wind resources. The first skirmishes took place at the Palm springs conference as local lan- downers publically criticized state and county officials for using the environmental review process as a way of delaying permits for individual machines and clusters. Several said they perceive a conspiracy in the entire process to allow Edison enough time to acquire choice wind properties at a fraction of their true value. Denying any conspiracy to control wind farm development through land acquistion, Edison officials privately concede that a more rational way of developing the region would require some form of ‘‘master plan- ning,’’ preferably at the county level. The Riverside Planning Department estimates that 70-80% of the prime wind array sites are within country jurisdiction. As each project gets underway, SCE will be faced with the formidable task of in- tegrating wind-generated electricity with its grid from dozens of wind farms and indivi- dually owned machines, both large and small. Little empirical knowledge presently ex- ists about the impact of individual large or small wind machines on grid stability and reliability, much less on large numbers of machines from various manufacturers with different operating characteristics feeding into a common substation. The issue of wind rights, ignored in many other regions of the country, may find its first test in the region. Public reaction an unknown How well the rapid installation of wind (Continued on next page) ” Wind Energy Report Edison, Windfarms Ltd. disagree on PURPA The selection of Hamilton Standard and WECS Tech is the first fruits of a controversial Wind Program Opportunity Notice (WPON) issued by SCE last October (see Wind Energy Report, December 1980). It proposed joint ventures with third parties pro- viding capital, equipment or both and SCE providing land, inter- connection, transmission and assistance with local permits. One key phrase in the WPON piqued the interest of several serious wind farm developers: ‘‘whatever the amount of participation by Edison, the combined total cost to Edison for the electrical energy produced will be an important evaluation criterion.”’ To some wind farm entrepreneurs this phrase was a signal that, while SCE may be bullish on wind power technology, it is decidedly unhappy with the prospect of having to deal with third parties using PURPA avoided cost formulations to determine purchase power contracts. Purchase power agreements based on full avoided cost are seen by many utilities as locking them into very disadvan- tageous long term arrangements. During the 15-month period from February 1980 through April 1981 alone, avoided cost for SCE rose from 4.0 cents/kWh to 6.6 cents/kWh, or 58.5%. Additionally, the California Energy Commission, in its rulemaking OIR No. 2, incorporated a capacity component ‘‘for a firm commitment by the Qualifying Facility which allow the utility to defer plant construc- tion.’’ A ten year contract beginning in 1981, for example, will cost SCE $66 per kilowatt per year. Both avoided cost and capacity credit are expected by both utilities and wind farm developers to rise annually, although perhaps not at this high rate. Edison has been attacked in some wind energy quarters as using the notice as a ploy to stall the more aggressive PURPA-oriented developers. Larry Papay, SCE head of Research & Development, emphatically denies this, stating to Wind Energy Report that the notice was merely to inform those who might be otherwise unaware of PURPA that SCE stood ready and willing to discuss joint wind projects with them. That prompted one wind farm developer, who refused to submit a WPON proposal, to comment acidly: ‘‘Any- body who needs Edison to inform them of PURPA better keep his money in saving bonds.’’ He argues that the WPON gives Edison an opportunity to select projects with favorable terms, issue letters of intent so the ventures can raise money, secure options on choice wind sites and allow Edison to tell the California PUC that it is fostering rapid wind development. ‘‘What guarantee do we have,” he says, “that SCE won’t select projects which are unrealistic technically, but wholly favorable to SCE on strictly financial grounds, to discredit legitimate projects with a sound piece of equipment and ‘real world’ financing.” Clearly, SCE wants to be in a better bargaining position with prospective windfarm developers. Papay told more than 500 at- tendees at a conference in Palm Springs, Wind Energy: Investing in Our Energy Future, early this month that the utility did not want to see third party entrepreneurs make ‘‘a financial killing,’’ presumably at the expense of SCE. Papay also indicated that the total cost of several proposals actively under consideration were based on substantially less than avoided cost. (At least one pro- posal, rumored to be by a company wanting to use Mehrkam Energy Development Compaay ‘‘2 MW”? wind turbines, came in at 65% of avoided cost.) The charge of making excessive profits was immediately countered by Wayne Van Dyck, President of Windfarms Limited, who pointed out that no one he knew could make a “‘killing”’ on wind farm projects because they are still technically and financially very risky. He openly ridiculed any project as being ‘‘unrealistically financed’’ at an avoided cost of 65%. 10 April 1981 These comments may be the opening round in a protracted negotiation period between Windfarms Limited and SCE. WFL has made application to the Bureau of Land Management for rights to use nearly 2000 acres of the agency-supervised land for a 320 MW wind project. Presumably, electricity generated by the wind farm would be sold to SCE or transmitted by its grid. * * * SCE negotiating projects in San Gorgonio (Continued from preceding page) farms in the PSWR region will be received by local residents re- mains to be seen. Already, some opposition is beginning to take shape. BLM, Riverside County and the CEC held two ‘‘scoping’’ meetings in Banning and Palm Springs a few days after the CEC conference to introduce the chief elements of wind farm develop- ment and the environmental review process. Criticism of the project came from Desert Hot Springs which fears that unregulated construction of wind farms just outside its city limits will adversely affect the community’s economic develop- ment. The mayor indicates that the city council may entertain a proposal to extend the municipality’s boundaries to include jurisdiction over many proposed wind farm sites. Southern California Edison is also concerned about public reac- tion to wind farm development. It is quietly conducting an ‘‘at- titude”’ survey among residents of the area to determine the issues affecting public acceptance of the projects. Wind Energy Specialist A Denver-based, fast-growing diversified company is seeking so- meone to direct their energy program who understands the poten- tial of wind as a renewable energy supply source. The successful candidate will be knowledgeable in the following areas: © Wind Resource Measurement and Siting: particular emphasis being placed on the ability to. identify a large number of sites and evaluate the most promising ones via an on-site data acquisition program. © Wind Turbine Technology: a thorough understanding of the merits of various rotor configurations, generator types and overall hardware reliability. © Economics: knowledge of wind systems hardware, land use issues, utility interface/interconnection and operating costs associated with large numbers of wind turbines generating electrici- ty simultaneously and in parallel with a utility grid. © Energy Production: experience in using wind data, wind speed frequency distributions and wind turbine power production curves to determine annual energy production. © Education: B.S. (M.S. preferred) in meteorology, physical sciences or engineering. Must include 3-5 years of increasingly responsible experience in energy research, modelling, or demonstration projects. Should be able to communicate effectively with policy makers and top-level executives in government and business. Salary, benefits, and professional working conditions are fully commensurate with your experience, education, and the impor- tance of this ground-floor position. To apply, send your resume, with salary requirements, in full confidence, to: Ms. Imogene Glassmeyer, Assistant to the Presi- dent, First Financial Management Corp., 444 Sherman St., Denver, Colorado 80203. (303) 744-7261. Equal Opportunity Employer. Wind Energy Report April 1981 NEW PUBLICATIONS, REPORTS, STUDIES Height Projection Methods and Sensitivity Study: Technical Report by A.S. Mikhail and C.G. Justus, Georgia Institute of Technology, Atlanta, GA. June 1979. DOE/ET/20355-T1. A vail- able: National Technical Information Service. A brief description is given of different techniques for height projection wind speed. One of these techniques, the similarity model, is based on Monin-Obukhov similarity theory. Other models examined are the em- Pirical velocity-dependent power law model (power law model) and the semi-empirical modified velocity-dependent power law model (modified power law model). A detailed description of the methodologies is given and example applications are illustrated with all necessary imput parameters to the models. A study was conducted on the sensitivity of the similarity model and modified power law model to different input parameters. The models are most sensitive to wind speed at anemometer level and to net radiation (at- mospheric stability) and are less sensitive to surface roughness length. For higher values of wind speeds, such as would be of interest in wind energy applications, the two models are less sensitive to wind speed and stability. Although the similarity model is theoretically more rigorous than the modified power law model, it is computationally more complicated. The analysis shows that the largest deviation between the two models occurs at low wind speeds and in very stable conditions. The magnitude of this varia- tion was judged after applying the two models to different data sets. The root-mean-square (rms) error between observed and predicted wind speed at hub height at Argonne is 0.30 m/s (4.7%) for the similarity model and 0.62 m/s (9.5%) for the modified power law model. For the Kennedy tower data, the rms error for the similarity model is 0.37 m/s (4.4%). For the modified power law model it is 0.61 m/s (7.3%). The similarity model provides a slightly more accurate prediction of the diurnal cycle at Argonne (nighttime and early morning wind speeds) than the modified power law model does. However, both models produce rms errors which are not large compared with the accuracy of wind speed measurement. While the rms er- ror of the modified power law model is slightly higher ( 10%), this model is less complicated and does not require stability input. Data from met towers at nine nuclear power plants, given in stability rose frequency format, presented a challenge to the models, because of the diversity of the topographic and climatic conditions at each site. The rms error between observed and predicted hub-height wind speeds, averaged over all sites, is 14% for the similarity model and 9% for the modified power law model. These results show that both models have successfully predicted the hub- height wind speed for meteorological towers at Argonne, Kennedy, and the nine nuclear power plant sites considered for this study. For the nuclear sites, there was a higher rms error associated with the similarity model com- pared to that for the modified power law model. The reverse was true for the Argonne and Kennedy tower data. Data were also studied from sites selected as candidates for installation of large DOE wind turbines. These candidate site data, given in wind speed frequency form at two or three altitudes, were used to test and compare dif- ferent empirical models with the power law and modified power law models. The models considered were the 1/7 power law model, the logarithmic model and the linear model suggested by Peterson and Hen- nessey. The model with the lowest rms deviation between the observed and predicted wind speeds, averaged over all the sites, was the modified power law (5.9%). The power law model showed the highest rms deviation (12.4%). Since the candidate sites have prevailing neutral conditions (con- sistently high wind speed regimes), the logarithmic model adequately predicted wind speed (rms error 6.8%). The rms error of the logarithmic model for predicting the average cube speed with 22.3%, while the rms er- ror for the modified power law was 16.6%. The logarithmic model is not expected to perform well under strongly varying stability conditions. The coefficients of the linear model were found to be site-specific and height- dependent, which renders the model of little practical significance, even when data are taken at two levels and a wind-speed extrapolation to a third level is required. The Monin-Obukhov similarity law is also site-specific and height-dependent, but in a way which is relatable to fairly well- understood physical parameters, such as surface roughness and Monin- Obukhov scale. Relationship to such physical parameters is lacking for the Peterson-Hennessey model. i After the tower data, the nuclear power plant site data and the candidate site data were used to verify the accuracy of the proposed models, the similarity and modified power law models were used on a set of National Weather Service time-series data. The maximum deviation between wind speeds at hub height predicted by the similarity and modified power law was on the order of 1 m/s. The similarity model consistently predicted a slightly higher nighttime and early morning wind speed. . * * Aerodynamic Interference Between Two Darrieus Wind Turbines by P.R. Schatzle, P.C. Klimas, and H.R. Spahr, Sandia National Laboratories, Albuquerque, NM. April 1981. SAND81-0896. Available: National Technical Information Service. Since its inception, the DOE Wind Energy Program has been largely con- cerned with the problems associated with individual wind turbines and systems. As the single turbine state-of-the-art has progressed, increasing at- tention is being given to the operation of turbines in multiple machine ar- rays. This attention is required because of the impact of turbine spacing on interconnect and land usage costs. Small separation distances work toward minimizing these as long as array members are not so close as to negatively interfere with each other aerodynamically. This report concerns itself with Sandia’s research on the problem of optimizing these separation distances. Darrieus turbine aerodynamics is different from and somewhat more complicated than that of most horizontal axis wind turbines. Blades nor- mally operate in both the linear and deep stall portions of the Cy vs. curve. Although the wake may be periodic, it is unsteady and unsym- metrical. The flowfield downstream of an advancing blade differs from that downstream of a retreating blade and the blades do not operate in- dependently of each other. There is always some degree of mutual interac- tion as blades cut wakes generated by those preceding. A mathematical representation which treats all of these effects is the vortex/lifting line model developed by Strickland, Webster, and Nguyen. In particular, it calculates a highly detailed wake. This wake is felt to be representative of actual turbine wakes within a few downwind diameters, i.e., before the non-included dissipative effects of atmospheric turbulence are no longer negligible. The model is viable and may be modified to treat simultaneously more than one turbine. As long as separation distances are small, the aerodynamic calculations may be considered realistic. The mutual aerodynamic interference between two 17-m diameter Dar- rieus wind turbines with a tower-to-tower separation distance of 1.5 diameter has been calculated using a vortex/lifting line model neglecting the effects of freestream turbulence. The calculations showed that, for the configurations examined, downstream turbine power reductions: are significant only when the two turbines were aligned with the ambient wind direction; increase with increasing tipspeed ratio for a fixed separation distance; and are due more to changes in downstream flow angularities than velocity deficits. The calculation of downstream turbine power decrements at separation distances greater than 1.5 diameter could be calculated if a suitable velocity deficit decay model were added to the basic vortex scheme. * * . Methods for Analysis of Wind Ripple in Wind Turbines by R.E. Akins, Virginia Polytechnic Institute, Blacksburg, VA. April 1981. Prepared for Sandia National Laboratories. SAND81-7006. Available: National Technical Information Service. Utilization of wind power and accurate design of wind energy conversion systems will require the ability to predict the effects fluctuations in the inci- dent wind will have both on the wind turbine structurally and on the quality of the output power. Currently, most methods of analysis concentrate on a steady incident wind. While such methods have been useful, they are not capable of addressing the question of the response of a wind turbine to a turbulent wind. In order to provide an estimate of some of the effects which a turbulent wind may have on a wind turbine, experimental techniques have been developed which allow analysis of full-scale performance of wind tur- bines with particular emphasis on the effects of turbulence in the incident wind. These techniques provide a means of separating these portions of the fluctuations in output of a wind turbine which are caused by incident at- mospheric turbulence from those which are caused by the aerodynamics of the wind turbine. Variations in output which would occur in a steady wind Soni Ene toon eve Sesn “ecm iorgue or power mpple. In an analogous manner, the floomuciems wich are essocizted with incident atmospheric turbulence bave Ses sel== wind ripple. In many cases the wind and torque ripple are incepenGent srt the torque ripple being much higher in frequency than the wine corie Siowever, as Larger turbines are designed, the ranges of frequences of wind and torque ripple may begin to overlap. Such a situa- tion cowlé -ssuit im a resonance at a mechanical mode of either the entire turbine or = mzjor component such as a blade. Obviously a resonance shoulc be aeniced in any design and therefore an understanding of wind Fipple is nperwe. Tris reper= presents four data-reduction techniques which may be ap- Plied to amainc= the wind ripple of a wind turbine. These techniques have been Gevweicm== =: a part of the vertical-axis-wind-turbine (VAWT) pro- gece spemser=< by DOE a Sandia Laboratories. Examples of their ap- Plicetion ar= provided using actual data records of the DOE/Sandia 1°-mecer V4 BT. While the Gevelopment of the technique has concentrated on the VAW7 eoplications, they in most cases are of a general nature and may be acriiie= to any wind turbine. Foor tectmicses have been proposed for use in evaluating the fluctuating outpat of 2 sind turbine. In particular techniques were sought which would allow the acourece assessmemt of the wind ripple or the contributions to the fluctuations in tarbine output caused by atmospheric turbulence. The four s=<=miques are an extension of the method of bins, long-time averages, spectral density or band pass filter concept, and a transfer func- tion berwe=n che input velocity and turbine output. The extension of the method of ims provides the standard deviation of output as a function of tip-spesd-caniio end the standard deviation of the incident wind. A signifi- camt Gsecuemege of the bins approach is the need to select an averaging period for =n= celculation of the standard deviations. A second disadvan- tage is thar m> formation is provided concerning the frequency content of the fincruazcioms. The long—ime average provides a single estimate of the standard devia- tion of ocursuz for an entire record. This estimate includes contributions from 2 wice range of frequencies and a range of tip-speed-ratios. *. . * Utility Cemcerns about Interconnected Small Wind Energy Conver- sion Systems Technical Memorandum. by W.E. Bawn, Jr., with assisance pom J.V. Guerrero, Rocky Flats Wind Systems Pro- gram, Rockwell International, Golden, CO. November 1980. TM- IP-81-2. 4 wcilable: Rocky Flats. Smal wimcd «ergy conversion systems interconnected in parallel to a utility network 2llow the utility to provide backup power during windless periods amc 10 accept amy excess energy the system might produce. Inter- connecting wind systems to utility systems is being tested and evaluated in a nureber of scetes through the Rocky Flats Field Evaluation Program. This Teport is 2 Giscession of the concerns which utilities have raised either about the propose= or actual installations of small wind systems on their systems. Among tie issues addressed in the report are: safety, self-excitation, manual Giscomnect systems, lability, power quality, power factor, voltage flicker, VAR. and voltage control. . * * Effects OF Guy-Wires On SWECS Tower Dynamics, Technical Memorandum, By C.P. Butterfield, K.R. Pykkonen and J.H. Sex- ton, Rock *=i] International Corporation, Rocky Flats Plant, Wind Sysems Program, Golden, CO, July 1980. TM-TD-81-1. Available> Rocky Flats. Testing a Rocky Flats has emphasized the importance of tower dynamics for sefe ope-ezion of small wind energy systems (SWECS). To select proper towers for x= machines, the SWECS community must have simple methods to Getermine tower dynamic characteristics. For some of the most common- ly used towers, test data can be published to aid in the decision. However, most Gecisicms must be besed on analyses often difficult to perform by those uxcrgzimed in dynamics. This pace: Gscusses some of the effects of improperly tensioned guy- wires oc grees towers. A 40 ft Rohn 45 GSR tower (four 10-ft sections) was tested. This tower has an equilateral triangular cross section with a side Jenghx of 145s im. The corner pieces are 1% in. solid steel rods which are connected t= ~ 16 in. solid steel bracing in a zigzag pattern. Three 3/8 in. 12 April 1981 Extra Heavy Strong (EHS) guy-wires of 41.7 ft. each were attached at a height of 29 ft. The tower had a top load weight of 590 Ibs. If guy tension was low, but not low enough to be affected by gravity, the tower bending frequency was substantially reduced from the predicted by linear dynamics. At high guy tension the tower bending frequency was relative unaffected. It was experimentally determined that the phenomenon obeyed an equation that accounts for guy wire added mass at the guy-wire attachment point. From experimental results it was found that if the guy fundamental frequency is 30% greater than the tower fundamental fre- quency, the system natural frequency would be within 90% of that predicted by linear structural dynamic model. *. * * Wind Machine Fatigue Analysis and Life Prediction, C.A. Waldon, DOE Rocky Flats, Wind Systems Program, Rockwell In- ternational Corporation, Golden, CO., April 1980., RFP-3135/3533/80-19. Available: Rocky Flats. Most SWECS experience at least one wind storm with 85 to 120 mph winds. The statistics indicated that the severe loading on SWECS com- ponents is sufficient to cause one or more failures. In some cases, the entire SWECS is lost due to a critical component failure. At least 40% of the SWECS tested at the Rocky Flats SWECS test site have experienced one or more fatigued-related failures. Of all the failures experienced, at least 65% were obvious fatigue. Since most of these were short term, high stress failures, those systems that survived conceivably contain parts with fatigue- related damage which degraded the materials to the point where failure could be imminent even though not apparent. Even though the Rocky Flats wind environment is severe, the ac- cumulative damage from lower wind speeds has also been sufficient to generate a fatigue caused failure. From the investigation of the failures the following causes have been identified: loading higher than expected; thin material was unsupported; sharp edges and threads caused stress risers; poor quality assurance on fabrication, welding, and handling; and’ no X-ray of cast parts to check for voids or cracks. This report is intended to show SWECS manufactureres how to perform an analysis of fatigue stresses and obtain a running compilation of cycles, reduction factors, and fatigue summation. Also, using an algorithm bet- ween stress and wind speed, the report gives the capability to estimate the fatigue life corresponding to the wind regime of the SWECS location. The work described is intended to be an aid to the SECS manufacturer in the conduct of fatigue tests and in making predictions about life expectan- cy. The computer programs are included to eliminate their development costs and several techniques are presented which will put the analysis effort within a wide range of budgets. This paper is not intended to give direction on fatigue design but does give the capability of determining if the design is adequate in real loading conditions. Also developed herein is a means of comparison between small wind systems which is based on life expectancy. *. . . SWECS Qualifications for State Programs: Final Report, by Theodore R. Kornreich and Dennis Devine, Science Applications, for Rockwell International Corporation, Rocky Flats Plat, Wind Systems Program, Golden, CO., July 1980. RFP-3127/05480/80-11. Available: National Technical Informa- tion Service. A number of states have adopted tax incentive programs to encourage the use of renewable resource energy systems. Many of these states have in- cluded small wind energy conversion systems (SWECS) in their incentive programs while others have decided not to include SWECS at present. It appears that the decisions not to include SWECS may have been due, at least in part, to the perceived absence of a credible basis upon which to ap- prove (and possibly monitor) residential SWECS installations. The purpose of this report is to assist in establishing the needed basis through the development of a range of ‘‘qualifications documents.” These documents address the most signficant issues relating to the residential SWECS aplications: performance validation, siting, adequacy of installa- tion, utility intertie, reliability, warranty provisions, safety, and en- vironmental concerns. Three prototypical qualifications documents are included in this report reflecting three levels of stringency: very demanding, moderately deman- ding, and relatively relaxed sets of requirements that may be placed upon Wind Energy Report April 1981 SWECS by the states. The basis for structuring these documents includes qualifications requirements already in effect in certain states as well as in- formation obtained from interviews with responsible officials in a selected sample of ten states. The officials interviewed were queried as to their perceptions and attitudes concerning residential SWECS applications. They were also asked general questions concerning their state’s political, fiscal and governmental processes which might impact the requirements to be im- posed on residential SWECS. This information was analyzed and a range of options for defining SWECS qualifications was established. It is anticipated that the three qualifications documents presented will serve as models for states to follow in structuring their own qualifications requirements for incorporating residential SWECS in tax incentive pro- grams. For example: a state may wish to directly adopt one of the model documents, or; a state may wish to implement a modified verson of one of the model documents, either using alternative qualifications presented in another of the model documents or alternatives developed by states themselves. In Section II the issues to be addressed in the qualifications documents are identified, a brief discourse on each issue is presented and the rationale for according consideration to each issue is established. Requirements that might be imposed upon the state organizational structure, as a result of ad- dressing these issues, are also described. Section III provides an overview of the three qualifications documents, including a chart which compares these documents. This information enables responsible state officials to rapidly compare the range of options available. These documents are structured in identical formats with issues and alter- native qualifications presented in the same sequence. A glossary of terms frequently used in dealing with SWECS installations and a list of states with tax incentive programs already in effect are included. Operations of Small Wind Turbines on a Distribution System: Final Report by David Curtice and James Patton, System Control, Inc., Palo Alto, CA for Rockwell International, Energy Systems Group, Rocky Flats Plant, Wind Systems Program, P.O. Box 464, Golden, CO 80401. Available: Rockwell at above address. This study has analyzed technical interconnection problems associated with the dispersed wind turbine (WT) application scenario: wind systems connected on distribution systems producing AC power directly or DC power fed into an inverter, without storage systems, feeding back surplus power whenever wind is blowing. Its specific objectives included analysis of: utility personnel safety; distribution system and wind system protection equipment; wind turbine effects on distribution feeder voltage and regula- tion equipment, and line losses; and development of a method to analyze utility load-frequency control problems with load patterns produced by customer demand and the WT’s intermittent power output. The primary safety issue for utility personnel is whether or not present work procedures are adequate for distribution systems with customer- owned wind systems electrically connected on circuits. Present procedures do not rely on generations control systems and require a disconnect for voltage-source wind energy systems (synchronous generation, self- commutated inverter). Although not specifically required by safety pro- cedures, a disconnect on voltage dependent WTs (induction generation, line-commutated inverter) is recommended to minimize any possibility of a self-excited wind turbine continuing to operate after a distribution line has been sectioned from the utility system. Isolating or ‘‘islanding”’ small wind turbines is a serious problem for utilities and their customers. Utilities are likely to be held liable by their customers if a wind system continues to operate isolated causing equipment damage due to frequency and/or voltage excursions outside normal limits. Voltage-source wind energy system will continue to operate after being separated from a utility, if their power output is sufficient to support the isolated section’s load. Voltage-dependent wind systems require both reac- tive power support and light load conditions to operate self-excited. Relays sensing abnormal frequency and voltage are recommended for automatical- ly disconnecting isolated wind energy systems. In general, radial feeder overcurrent protection equipment coordination was not found to be significantly affected by small wind energy conversion systems. Reverse fault current, contributed even by a high penetration of wind turbines is unlikely to disrupt a utility’s existing overcurrent protecton schemes, however, wind turbine protection equipment should be coor- dinated with utility practices. 13 Wind turbines’ power output reduces load and tends to decrease a feeder’s voltage drop. Existing feeder voltage regulation equipment can perform as planned with WTs, because even high wind system penetrations cause only small voltage changes. Utility engineers need experience with combinations of WT power output and load conditions to develop methods for adjusting equipment for optimum voltage control. However, small wind systems may increase the number of voltage regulator operations, in- creasing equipment maintenance and cost. Voltage flicker on secondary circuits will be a potential problem for in- duction generators larger than approximately seven horsepower (5 kW). The large magnetizing inrush current of the generators may cause intoler- able light flicker for other customers connected on the same distribution transformer. A method was developed to analyze possible utility load-frequency con- trol problems. Treated as negative load, second-by-second wind system power output was used in a technique to modify utility load curves input to an automatic generation control simulation. The method allows examina- tion of possible wind speed variation scenarios, their effect on a utility’s short-term load characteristics, and possible changes to load-frequency control performance. This study’s results must be understood in the light of the technique used to characterize the wind turbine’s variable power output effect on a utility’s load. It used a limited number of wind turbine power output data as a data base to represent a larger number of wind turbines. The technique produc- ed second-by-second power output records for various penetrations of wind turbines by adding together time-shifted samples taken from data recorded from four wind turbines. Because the sampling and adding process used each wind turbine’s real power output record thousands of times, it is not possible to conclude that load variations produced represent what actual operating wind turbines will do to the utility’s system load. What has been developed is a method to study the combined effects of customer demand and wind turbines power output fluctuations on a utility’s load-frequency control process. With better data from operating wind turbines and short-term wind speed patterns over a large land area, this method can be used effectively to define wind turbine penetrations that affect the load-frequency process, and develop new automatic generation control algorithms. A utility’s system response capability is limited. This study has examined two examples, 6 and 20 MW per minute. Control schemes are designed to regulate units to follow controllable load variations that are slower than the system’s response rate. Uncontrollable load variations, faster than the system’s response rate, cannot be compensated and show up as decreased system performance, e.g., higher ACE values, longer times between zero crossings, tie-line flows deviating from scheduled exchanges, etc. Small wind turbines have highly variable power output characteristics. Output variations, greater than 0.01 cycles per second, add a noise compo- nent to the load in the range that is likely to be uncontrollable. If the magnitude of these variations is great enough, then the quality of utility system performance is likely to decrease. The aggregate output variations of a large number of small wind turbines should be studied. If wind turbines can be treated as essentially indepen- dent, then simply adding the power output of a number of wind turbines is the correct approach to produce the aggregate output characteristics. The magnitude of these output variations may be approximated by multiplying the number of wind turbines by the standard deviation characteristic of a single wind turbine. Based on the examples presented in this study the high frequency variations are likely to add directly to the ACE values. Being able to characterize short-term wind speed changes over a large land area will also assist studies of this type. The approach used in this study attempted to simulate the effects wind speed changes have on a large number of wind turbines by imposing a sine wave oscillation on the wind turbines’ aggregate steady-state power output. Given better data on the wind speed rate-of-change across a large land area and the likelhood of these variations, suitable functions can be developed to vary the wind tur- bines’ power output. The combined data characterizing the wind turbines aggregate power output and wind speed rate-of-change based on the probability of oc- curence will allow development of new algorithms. These control schemes will then recognize the small wind turbine’s effect on load. If wind speed variations will affect a large number of wind turbines, then control algorithms can be developed to regulate units in response to load conditions while the operator adjusts the operating reserve to account for the possibili- ty of losing the wind turbines’ power output. If such wind speed variation April 1981 Wind Energy Report patterns are unlikely, then a control algorithm can be designed to ignore wind turbine imposed high-frequency load variations. . . * Issues and Examples of Developing Utility Interconnection Guidelines for Small Power Production: Technical Memorandum by C. Lawless-Butterfield, J.V. Guerrero, K. Pykkonen and L. States, Rockwell International Corporation, Rocky Flats Wind Systems Program, P.O. Box 464, Golden, CO 80401. January, 1981. Available: Rocky Flats. This report summarizes what several states are doing to establish inter- connection guidelines under The Public Utilities Regulatory Policy Act of 1978 (PURPA) rules for small power producers, in particular small (under 100 kW) wind energy conversion systems (SWECS). The emphasis of the report is to discuss issues relevant to interconnecting SWECS. No effort is made to establish either a model interconnection policy or a definitive pro- cedure for developing SWECS interconnection policies. In reviewing the numerous issues and problems that appear to be associated with interconnection, the burden of concerns and requirements seems overwhelming. Is interconnection really all that complicated and fraught with technical precautions? While it may appear so, at least one state public utility commission (California) is exploring how to minimize in- terconnection requirements for SWECS below a certain size (10 kW has been mentioned as a possible cutoff point) to reduce the burden of inter- connection costs on individuals. The basis of California’s perspective is that interconnection requirements and costs should be related to the size of a small power production facility and its potential effects on the utility system. Sections 201 and 210 of the PURPA, through rules developed by the Federal Energy Regulatory Commission (FERC), require state utility regulatory commissions to develop procedures permitting small power pro- ducers (less than 30 MW in size) to interconnect their qualifying facility (QF) to an electric utility network. Under this arrangement, the utility serves both as a source of electric energy for the QF and as a recipient of energy produced by the QF. The rates of payment for this energy transfer- red into the utility system must be ‘‘fair and reasonable,’’ ‘‘non- discriminatory,’’ and representative of the ‘‘avoided costs”’ a utility realizes by reducing its fuel or capacity costs, or both. While the fact that utilities will pay for energy produced by QFs may influence small power producers to make the investments in renewable energy production, buyback rates and the cost of actual interconnection (including any required interface equipment) will also influence these decisions. This is particularly the case for those QFs under 100 kW in generating capacity where investments may be marginal. Consequently, if the cost of interconnection appears to exceed the revenues expected from selling energy to the utilities over a reasonable payback period, small power producers may not elect to connect their qualifying facilities to utility networks. One of the problems facing public utility regulatory commissions (PUCs) in implementing PURPA is how to meet their responsibilities to provide for the safe and reliable operation of regulated utilities while at the same time encourage the development of small power production facilities using renewable energy resources. In theory, the two objectives should not be mutually exclusive. In practice, however, conflicts may exist, especially over the type and cost of equipment which may be required for interconnec- tion between a QF and the utility. Although interconnecting with an electric utility is only one method of installing a SWECS, the cost competitiveness of interconnection appear to be better than stand-alone installations. The additional costs of energy storage or backup systems can make stand-alone SWECS installations more expensive except in remote areas not serviced by conventional electric utilities. Consumers interested in interconnecting SWECS are concerned about interconnection requirements and associated costs. If these costs are higher than the amount a small power producer may expect to realize in selling electricity back to the utility, a prospective customer may be deterred from investing in SWECS. Factors that could influence that decision in- clude: © Federal and state incentives that could reduce the initial costs of equip- ment and installation. © Rates (determined by the state PUC for regulated utilities) for energy the customer would purchase from the utility (standby or backup energy) and for excess energy sold to the utility (buyback energy). © Interest rates for purchasing alternative energy devices. © Interconnection costs for interface and metering equipment plus the 14 services a utility can charge, e.g., 1or shutting off the power during installa- tion. ¢ Liability insurance and its related costs. Interconnection equipment is presently restricted largely to currently available hardware. A review of state-of-the-art development seems to in- dicate there is room for more research in this area. Continued examination of these developments as they relate to interconnection costs is required. PURPA states that a QF is obligated to pay all ‘‘responsible’’ intercon- nection costs. It is up to the public utilities regulatory commissions, in con- cert with regulated utilities, to develop safe and reliable interconnection policies that do not unnecessarily discourage consumer investment in SWECS. In addition to examining various technical and economic considerations of interconnection, the report compares interconnection policies of the Tennesee Valley Authority, Southern California Edison, the Rural Elec- trification Administration and Consumers Power Company of Michigan. The report also contains five useful appendices: Excerpt on metering op- tions from draft: Interim Recommendations for Interconnection Small Power Producers, Rural Electrification Administration; Excerpt from the California Public Utilities Commission Staff Report on Cogeneration and Small Power Production Standards for Operating Reliability (OIR No. 2); Excerpt from Cogeneration and Small Power Production Pricing Stan- dards Southern California Edison Company; TVA Proposed Policy on Dispersed Power Production and Interim Program Guidelines for Im- plementation; and Proposed requirements for paralleling customer's elec- tric generators (Consumers Power Company of Michigan). * * * The Hydraulic Windmill by James A. Browning, Browning Engineering Corporation, Hanover, NH. Presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, February 24-26. Com- plete Proceedings will be available from the National Technical Informa- tion Service in June, 1981. The hydraulic windmill pumps pressurized oil from rotor shaft level to the gound where a motor-generator produces electricity. Alternatively, the useful output may be heat. Rotor speed is governed by a flow valve. Over pressure, the result of high wind velocity, rotates the tail to move the rotor blades out-of-the-wind. Loss of oil pressure causes a brake to close as well as to swing the tail to its maximum distance from the rotor plane. Advantages of the hydraulic transmission principle lie in the simplicity of rotor speed control and the governing of power output in higher-than- design wind regimes. These functions can now be obtained at low cost and high reliability. Two prototype models of 16-ft. rotor blade diameter have been made and tested. Power outputs were determined by measuring oil flow and pressure. Specific power levels were sufficiently high to warrant the con- struction of a 71-foot, two-bladed, horizontal rotor axis machine presently undergoing tests on a high ridge in Lebanon, N.H. The design of the 71-foot hydraulic windmill has attempted to reduce costs while maximizing reliability. These considerations preclude the use of feathering blades, limit the number of blades to two, and reduce com- munication between rotating structures and the ground to the oil column itself. Judgement of the relative success of these design parameters must await results of the testing period which is only now commencing. * * * Passive Cyclic Pitch Control for Horizontal Axis Wind Turbines by Gerald W. Bottrell, Ventus Energy Corporation, La Crescenta, CA. Presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, February 24-26. Complete Proceedings will be available from the Na- tional Technical Information Service in June, 1981. A new flexible rotor concept, called the balanced-pitch rotor [Patent Pending], is described. The system provides passive adjustment of cyclic Pitch in response to unbalanced pitching moments across the rotor disk. The aerodynamically-balanced cyclic pitched rotor [balanced-pitch rotor] is analogous to the teetered hub. Its main function is to reduce vibratory loads and improve yaw performance of wind turbine rotors. This is ac- complished in the teetered hub by cyclic flapping in response to unbalanced thrust on the blades. In a similar manner, the balanced-pitch rotor pro- duces cyclic pitch changes as a result of unbalanced pitching moments Wind Energy Report across the rotor disk. Certain advantages of the new concept include reduced tower clearances, avoidance of cyclic speed variations, and superior survival characteristics. For two-bladed multi-megawatt wind turbines these features have been estimated to save some 15 to 25 percent of rotor cost and to increase reliability of the machine as a whole. * . * Vertical Axis Wind Turbine Drive Train Transient Dynamics by David B. Clauss and Thomas G. Carne, Sandia National Laboratories, Albuquerque, NM. Presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA- Lewis Research Center, Cleveland, OH, February 24-26. Complete Pro- ceedings will be available from the National Technical Information Service in June, 1981. Complete study is available as SAND80-2640, Sandia Na- tional Laboratories. Start-up of a vertical axis wind turbine causes transient torque oscilla- tions in the drive train with peak torques which may be over two and one- half times the rated torques of the turbine. These peak torques are of suffi- cient magnitude to damage the drive train, possibly. Safe and reliable operation requires that mechanical components be overdesigned to carry the peak torques caused by transient events. A computer code, DYDTA, based on a lumped parameter model of the drive train, has been developed and tested for the Low Cost 17-meter Darrieus VAWT. The results show excellent agreement with field data. The code has subsequently been used to predict the effect of a slip clutch on transient torque oscillations. It has been demonstrated that a slip clutch located between the motor and brake can reduce peak torques by 38%. DYDTA represents an initial step towards understanding and analyzing methods of controlling transient behavior in VAWT drive trains. Results for start-up in zero wind speed show exceptional agreement with ex- perimental records on the Low Cost 17-meter turbine, thus providing verification of modeling accuracy. DYDTA is currently being used to predict responses for several different transient operations and possible design modifications intended to reduce transient torque levels. It is ex- pected to become a versatile, easily implemented drive train design tool. * * * Kaman 40 kW Wind Turbine Generator-Control System Dynamics by Richmond Perley, Kaman Aerospace Corporation, Bloomfield, CT. Presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, February 24-26. Complete Proceedings will be available from the Na- tional Technical Information Service in June, 1981. The Kaman 40 kW Wind Turbine Generator design incorporates an in- duction generator for applications where a utility line is present and a syn- chronous generator for stand alone applications. A combination of feed forward and feedback control is used to achieve synchronous speed prior to connecting the generator to the load, and to control the power level once the generator is connected. The dynamics of the drive train affect several aspects of the system operation. These have been analyzed to arrive at the required shaft stiff- ness. The rotor parameters that affect the stability of the feedback control loop vary considerably over the wind speed range encountered. Therefore, the controller gain was made a function of wind speed in order to maintain consistent operation over the whole wind speed range. The velocity requirement for the pitch control mechanism is related to the nature of the wind gusts to be encountered, the dynamics of the system, and the acceptable power fluctuations and generator dropout rate. A model was developed that allows the probable dropout rate to be determined from a Statistical model of wind gusts and the various systems parameters, in- cluding the acceptable power fluctuation. Economics of Wind Energy for Irrigation Pumping: Final Report by R.R. Lansford, R.J. Supalla, J.R. Gilley, and D.L. Martin, Southwest Research & Development Co., Las Cruces, NM for the U.S. Department of Agriculture, Science and Education Ad- ministration, Agricultural Research. July 14, 1980. DOE/SEA-7315-2074!/81/2. Available: NTIS. How much can an irrigator afford to invest in a wind turbine system for pumping irrigation water? This study addresses some of the economic ques- April 1981 tions associated with wind power as an energy source for irrigation under different situations in seven regions of the nation. Three types of wind systems were considered for each of the seven regions. These regions were selected on the basis of the typical wind power available during the irrigation season and other factors, such as the length of the irrigation season and the quantity of irrigation water required. The regions were: A. Kansas, Oklahoma, High Plains of Texas, High Plains of New Mexico, and Eastern Colorado. B. Nebraska, South Dakota and North Dakota. C. South Texas (Edwards Plateau) and Pecos Valley of New Mexico. D. Southern Arizona and Southern California (primarily the Imperial Valley). E. Snake and Columbia River Basins in Idaho, Oregon, and Washington. F. Midwestern U.S.—lIllinois and Indiana. G. Southeastern U.S.—Florida and Georgia. The three types of wind powered irrigation systems evaluated for each region were: wind assist combustion engines (diesel, natural gas, propane pane), wind assist electric engines, with or without sale of surplus electrici- ty, and stand alone reservoir systems with gravity flow reservoirs. The wind assist units essentially consist of vertical axis turbines (DAF- Indal)connected to a conventional power source by means of an override » clutch . Convential fuel consumption would be reduced when wind power is used, but the system would retain its ability to function without wind power, if necessary. With the stand alone system, water would be pumped directly by wind into a reservoir for use when irrigation water was needed. Outflow from the reservoir would be gravity. The approach used in the study of wind assist systems was as follows: (1) estimates were made of the average monthly amount of energy that can be harvested by a wind turbine under average conditions; (2) estimates were made of the economic value of the energy saved and/or sold; and (3) assessments were made of what irrigators in selected situations could af- ford to pay for wind turbines of different sizes. A similar approach was us- ed for analyzing stand alone systems, with two addtional steps: various combinations of reservoir and turbine sizes necessary to meet water demands were calculated for selected situations, and reservoir construction costs were estimated. 7 The amount that one could afford to invest in wind turbines was estimated for average conditions in each wind region, under three energy price projections, for each major energy source, over a 20-year period. Dis- count rates of 7% & 10% were used in these analyses. The estimated amount of energy saved from assisting conventionally powered irrigation pumping units with wind turbines ranged from 13 kilowatt hours per square meter of turbine size (kWh/m*) in Region F to 117 kWh/m? in Region D. When the electricity that could be generated dur- ing non-irrigation periods was added to irrigation savings, total estimated energy saved ranged from 565 kWh/m? for Region A to 93 kWh/m? for Region G. Economic Results and Conclusions Results of the economic analysis for wind assist systems indicate that wind turbines may be a viable alternative for irrigators who are using diesel or LP gas pumps in Region A. At the high energy price scenario and, with a 10 percent discount rate, diesel users in Region A could afford to pay $132 per square meter before tax savings, if they could not shift to any other con- ventional fuel. When tax considerations are taken into account, a diesel user in the 25 % tax bracket in Region A could afford to invest $161 per m? by claiming the business energy and investment tax credits. When the addi- tional first-year depreciation and annual depreciation are included, the in- vestment for wind turbines could be increased to $192 per m?. LPG users in the same situation could afford to pay $106 per m? before the tax savings, and $154 when all tax credits are claimed. Estimated investment values for all other wind assist situations are much lower (all less than $75 per m’) at the medium energy price scenario. Thus, such systems would not be economically attractive unless production costs could be reduced well below the current cost of about $250 per m? for prototype units. Wind assist with sale of surplus electricity is more attractive economically than without it. Under this alternative, the investment per m? for a wind turbine under the high energy price scenario, with a 20% discount rate, ranged from $217 per m? in Region A to $21 per m? in Region G. With all tax credits claimed, the maximum investment per m? for wind turbines ranged from $315 in Region A to $31 in Region G for a person in the 25% federal income tax bracket. Under the medium energy price scenario, the investment ranged from (-)$146/m? in Region G to (-)$2/m? in Region A, and when federal tax credits were included, it ranged from $212/m’ in Region A to (-)$2/m? in Region G. Investment values appear to be high wi Wind Epergy Report . enough in Region A under both the high and medium energy price scenarios to merit serious considerations. In Region B, the investment values almost merit consideration under the 25% federal tax bracket, and they merit serious consideration under the 50% federal income tax bracket. In the other regions, the values do not appear high enough to merit serious con- sideration at this time. The amount that one could afford to invest in wind turbines for a stand alone system was estimated for average conditions in each wind region. Under the high‘energy price scenario, the fuel that would be replaced, the maximum before-tax investment value per m? and the corresponding wind turbine sizes for each region are as follows: Region A, diesel, $702/m?, 197 m’; Region B, diesel, $178/m?, 326 m’; Region C, natural gas, $45/m’, 694 m’; Region D, Electrcity, $129/m’, 830 m’; Region E, electricity $78/m’, 628 m’; Region F, gasoline, $91/m?’, 354 m? and Region G, diesel, $143/m?, 416 m’. Thus, when a high energy price scenario is assumed for irrigators in Regions A and B who cannot shift to electricity or natural gas, even when federal income tax deductions are not considered. When all federal incen- tives and taxes are deducted, stand alone wind systems appear to have reasonable potential for irrigators using diesel and LPG in Region A, even under the lower energy price scenario. If at least medium energy prices are expected, after tax, wind energy values look attractive for diesel and LPG users in Regions A and B. Under the high energy price scenario, after tax, wind energy values for the diesel user in Region G may also fall within the feasible range. Estimated investment values for all remaining situation are well below the current cost of about $250 per meter for prototype wind tur- bine units. ” * * Wind Response Characteristics of Horizontal Axis Wind Turbines by R.W. Thresher, W.E. Holley and N. Jafarey, Mechanical En- gineering Department, Oregon State University, Corvallis, OR. Presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, February 24-26. Complete Proceedings will be available from the Na- tional Technical Information Service in June, 1981. A statistical description of the wind input including all three wind com- ponents and allowing linear wind gradients across the rotor disk, was used together with quasi-static aerodynamic theory and an elementary structural model involving only a few degrees of freedom. The ideal was to keep the turbine model simple and show the benefits of this type of satistical wind representation before attempting to use a more complex turbine model. As far as possible, the analysis was kept in the simplest form, while still preser- ving key physical responses. From the onset of this work, it was felt that the results should be validated by comparison with test measurements. Due to the three-bladed rigid rotor used on the turbine and the limited degrees of freedom, com- parison with data from one of the small systems under test of Rocky Flats would provide the most realistic comparison. At this time, the experimental comparison is incomplete. On the basis of the work done in this study, the longitudinal turbulence input, Vy, and the two gradients, Vy,x and Xy,z are of equal importance when computing the dynamic response of wind systems, and these three in- puts together comprise the major excitation source for horizontal axis wind turbines. Because of the simplifying assumptions and approximations used in this analysis, it is imperative that the results and the technique be validated with experimental data, prior to use for design. * * * The Effect Of Delta 3 On A Yawing Hawt Blade And On Yaw Dynamics, Frederick W. Perkins and Robert Jones, Kaman Aero- space Corporation, Bloomfield, CT. Presented at the Second Depart- ment of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, February 24-26. Complete Proceedings will be available from the National Technical Information Ser- vice in June, 1981. A single degree of freedom aeroelastic computer model, WMSTAB3, has been employed to perform a parametric analysis of HAWT blade behavior during yaw maneuvers. Over 1,000 differenct combinations of Delta 3 and normal frequency was analyzed. The effect of Delta 3 and flapping stiffness on flapping frequency, phase, and magnitude are discussed. The moments transmitted to the fixed system during yaw maneuvers are calculated and reduced to time constants of 16 April 1981 response to step changes in wind direction. The significance of the time constants for the configurations considered relative to yaw response rate and lag angle is discussed, along with their possible significance for large HAWT. The incorporation of significant amounts of Delta 3 into a horizontal axis wind turbine blade greatly increases the options available to the designer. The Delta 3 hinge may be used to adjust magnitude or phase of the flapping response to either yaw rate or direction, thus controlling the mechanical and aerodynamic coupling with the fixed system degrees of freedom. The effect of Delta 3 on flapping frequency can also be exploited to optimize system dynamics. The reductions of the blade flapping data into yawing spring and damp- ing constants allows the estimations of response time to changes in wind direction. The data indicate that large wind turbines may suffer large lag angles if operated where winds vary in direction. This may be source of per- formance degradation previously overlooked. . . * Wind Turbulence Inputs For Horizontal Axis Wind Turbines by W.E. Holley, R.W. Thresher, and S.R. Lin, Department of Mech- anical Engineering, Oregon State University, Corvallis, OR. Presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, February 24-26. Complete Proceedings will be available from the Na- tional Technical Information Service in June, 1981. Fluctuations in the aerodynamic forces on a wind turbine blade are generated by the relative motions of the air with respect to the blade. These relative motions are comprised of two parts: the motions of the blade and the motions of the air. The motions of the air can further be divided into the undisturbed turbulent flow and the ‘induced flow’ due to the presence of the wind turbine wake. The terms comprising the undisturbed flow will be characterized in this paper. More precisely, for a horizontal axis wind turbine, the aerodynamic forces are determined by the instantaneous air velocity distribution along each of the turbine blades. These blades, in turn, are rotating through the turbulence field which is being convected past the turbine rotor disc. It is thus necessary to characterize the wind turbulence field by a three-dimensional velocity vector which varies randomly with time and with the position in space. A complete statistical description of this turublent velocity field requires the determination of all possible joint probability distributions between different velocity components at different times and positions in space. Clearly, such a description will not be possible without considerable simplification. The validity of the resulting simplified model will depend upon a comparison of the characteristics predicted by the model and those observed in the atmosphere and more importantly, those observed in actual wind turbine field tests. The authors describe the assumptions and the analytical steps used to arrive at the simplified model. In the accompaning paper the model is used to predict wind turbine response charactertistics. It is hoped that these results will be verified in the near future by direct com- parison with the results of actual field tests. The authors have formulated a theoretical model for the wind turbulence as it affects horizontal axis wind turbines. The model includes the effect of variations in the turbulent velocity across the rotor disc. An indication of the approximation error in the model has also been given. It is expected that the model will be useful for determining how important the different tur- bulence effects are for given machine responses. . . * Aerodynamic Potpourri by Robert E. Wilson,Department of Mechanical Engineering Oregon State University, Corvallis, OR. Presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, February 24-26. Complete Proceedings will be available from the Na- tional Technical Information Service in June, 1981. Aerodynamic developments for vertical axis and horizontal axis wind turbines are given that relate to the performance and aerodynamic loading of these machines. Included are: a fixed wake aerodynamic model of the Darrieus vertical axis wind turbine; Experimental results that suggest the existence of a laminar flow Darrieus vertical axis turbine; a simple aerodynamic model for the turbulent windmill/vortex ring state of horizon- tal axis rotors; and a yawing moment of a rigid hub horizontal axis wind turbine that is related to blade coning. WIND SYSTEMS 1551 East Tudor Road ANCHORAGE, ALASKA 9950° WIND ENERGY Report The International Newsletter of Wind Power February 1981 Reagan cutting federal wind energy program President Ronald Reagan submitted his solar energy budget to Congress late this month, confirming widespread apprehen- sion in the American wind energy commun- ity that massive cuts in the federal wind ef- fort are imminent. In submitting a $460.6 million revised solar budget for the remainder of this fiscal year ending September 30, the administra- tion is asking Congress to rescind $103.4 million, or 18% of funds already ap- propriated by the Carter Administration, for several solar energy technologies. Ap- proximately a quarter of the solar budget cuts, $26.1 million, will come from the DOE wind energy program. Compared to other solar technologies, wind energy is the hardest hit. Photovoltaic and Solar Thermal programs, for example, account for cuts of $21 million and $26 mil- lion respectively. But these two tech- nologies add up to $296 million or 52% of the entire federal solar budget. For fiscal year 1982, beginning October 1, the Reagan Administration is cutting more than three-quarters of the Carter 1982 proposed wind energy budget. DOE is ask- ing for the expenditure of $19.4 million, a Inside W.E.R. BPA-OSU wind studies Canada developing MW VAWT Reagan proposing wind cutbacks PURPA ruled ‘‘unconstitional”’ Design Notes: Boeing MOD-5 PASNY studies wind sites Conferences/Meetings New Publications ISSN: 0162-8623 $54.2 million cut from $73.6 requested. If approved by the Congress, and senti- ment in both the House and Senate indicate that much of the cuts will be sustained, the FY82 wind budget will be the lowest since 1976 and end a number of existing pro- grams and stop immediately programs al- ready underway, notably hardware pro- grams such as the MOD-5 and MOD-6. The Administration has yet to release specific details of the $26.1 million rescis- sion for this year. But Wind Energy Report has learned that the Reagan administration that $7.8 million earmarked for ‘‘market development and implementation’’ will be eliminated completely and $18.3 million for engineering development of small and in- termediate machines will be cut from the $36,453 already allocated. The Department of Energy will have to sharpen its pencil to cut $26.1 million from the wind energy budget. According to Louis V. Divone, longtime DOE wind energy pro- gram manager, federal funds not already obligated for FY81 will not be committed and pending contracts will not be signed. DOE doesn’t know yet what specific pro- grams will be affected until the figures for monies already spent have been tallied. “*To reach the $54 million level,”’ says Divone, ‘‘we’ll have to make cuts across the board.”’ One immediate casualty will be Rockwell International’s Energy Systems Group. Last September, it was awarded the MOD-6H contract to develop a large kilowatt-size, two-bladed wind turbine for NASA. That contract will not be signed. Sandia Laboratories is currently negotiat- ing with ALCOA for the MOD-6V, the Darrieus equivalent of the MOD-6H. There will be no funding available for any con- tract with ALCOA. (Continued on page 5) Canada to build multi-MW Darrieus “To help preserve Canada’s present world leadership in the technology of ver- tical-axis wind turbines,’’ the Ministry of State for Science and Technology has given the go-ahead to build the first megawatt scale Darrieus wind turbine. The ministry and theNational Research Council announced plans last month to spend $17.6 million (Canadian) during the next four years to design a multi-megawatt Darrieus jointly with one of Canada’s largest utilities, Hydro-Quebec. Hydro-Quebec will contribute an addi- tional $17.6 million towards the construc- tion of the prototype. The $35 million total project cost represents the upper limit of authorized funding for the project. When completed and erected by 1983, the unit will become the world’s largest vertical axis machine and rank among the world’s largest wind turbines. Although NRC and Hydro-Quebec’s re- search division, IREQ, will be jointly responsible for technical and design con- siderations, the utility will supervise actual construction of the machine in the role of prime contractor. At this stage, it has not been decided whether Hydro-Quebec will build the turbine itself or contract its fabrication to a Canadian manufacturer. But Canadian energy officials emphasize that the entire project will be an all Cana- dian effort with contracts let its own in- dustry for key components. Dubbed Aeolus, the two-bladed VAWT prototype will be 110 meters high (from ground level), 64.15 meters wide and be capable of generating 3.8 megawatt in a 14.3 meter/second wind regime. The 3.8 megawatt rating, NRC officials caution, is a ‘‘figure of merit’’ rather than a hard and fast size. According to NRC project man- ager Mark Chappell, generator size is one issue subject to change as NRC and IREQ continue studies to determine the proto- type’s optimum figuration. The tentative 3.8 MW rated power of the (Continued on page 3) of Wind Energy Report BPA awards Oregon State wind contract The Bonneville Power Administration has awarded a contract for $279,353 to the Atmospheric Sciences Department of Oregon State University to continue studies of the wind resource within its service area in the Pacific Northwest. “Under this contract, OSU will explore every corner of the Nor- thwest to identify areas which could support wind energy farms and to complete our assessment of the wind’s potential as an energy resource in the northwest,’’ according to Earl Gjelde, acting BPA Administrator. The award is believed to be the single largest contract award ever awarded by a utility to study its wind energy resource. The Oregon State meteorologists will use BPA helicopters to survey selected areas of southwest and northwest Montana and southern Idaho. As soon as evidence of high wind speeds, such as windblown vegetation or scoured cliffs is observed, BPA will seek permission from the landowner to install an anemometer. The anemometer will be left in place for at least one year to estimate the average annual wind speed at the site. According to BPA, if the site appears to have good potential, more complex instrumentation may be installed. Oregon State has been a leader in improving the technique of us- ing deformed vegetation to identify promising wind sites. The Griggs-Putnam Index is a subjective scale based on the degree of tree’s response to the wind and is appropriate for conifer trees or any tree with a cone-shaped crown. (The technique was first pioneered by Palmer C. Putnam and botanist R. F. Griggs while surveying the wind power potential of New England prior to the in- stallation of the Smith-Putnam wind turbine on Grandpa’s Knob in Vermont in 1941.) Central and Northeast Washington and Southern Idaho will also be examined on site to determine suitability for instrumentation. Presently, BPA is monitoring 60 sites comprising its wind power data network. Hourly data is now collected from 19 sites on strip charts and mean monthly wind speed or wind spectrum data are available from the rest of the stations. With this contract, BRA will be adding six more hourly data stations and six to 12 wind-run sta- tions. The contract also calls for OSU to develop and validate a model—incorporating the effects of thermal statification and topography—which extrapolates anemometer height winds to hub height. These models will be calibrated against tower data from the MOD-2 cluster site at Goodnoe Hills and at Seven Mile Hill, Augsburger Mountain and Carty. Oregon State University has held wind research contracts from BPA since 1976 and has already identified major wind power areas on the Columbia River Gorge, the Oregon and Washington Coasts and the high plains of the Cascade Mountains. It conducted the measurements at Goodnoe Hills, the successful candidate for the world’s first large wind machine array. Gjelde says that OSU will focus on finding new wind resource areas appropriate for large utility-scale wind farms. “Seven sites for possible wind farms already documented by Oregon State could, together, produce as much power as a large thermal plant—about 1000 megawatts,’’ according to Gijelde. These sites are: Columbia Gorge (Augsburger Mountain, Goodnoe Hills, Kennewick, Columbia Hills, Seven Mile Ridge), Cape Blan- co, Oregon, and Wells in northern Nevada. Each of these sites, according to BPA, were used in network simulation studies performed by OSU during the last four years. With the exception of Seven Mile Ridge, these sites could provide 3,022 MW of wind power, or approximately 1000 MW at one-third capacity. February 1981 In addition to looking at the overall wind resource, the contract calls for OSU to investigate wind patterns. This will permit, says BPA, identification of how much wind power could be integrated with the existing, primarily hydroelectric, northwest power system. Seeking predictable wind patterns which utility planners can count on when planning to meet forecasted loads will be another task. BPA Wind Energy Integration Study Site Data Unit No. of Capacity Size Velocity Site MOD-2s (mw) (mw) (mph) Augsburger Mtn. 15 45 67.5 16.7 Columbia Hills 60 25 150.0 13.5 Goodnoe Hills 90 45 405.0 17.2 Kennewick 400 25 1000.0 16.7 Cape Blanco 200 45 900.0 18.1 Wells 200 25 500.0 15.8 Network Total 965 3022.5 *Mean annual wind speed from December 1976-November 1977 BPA Anemometer Loan Program to Homeowners BPA has also embarked on a program to lend wind measuring devices to homeowners and to instruct 20 local utilities in the basics of wind measurement and interpretation. BPA has bought 140, low-cost ‘‘Wind Prospectors’’ from Aeolian Kinetics (P.O. Box 100, Providence, RI 02901). The anemometers will be calibrated and distributed to local utilities thought to have promising wind power potential. The participating utilities will each receive five of the devices which they, in turn, will lend to homeowners in their service areas. Measurements will be taken at one site continuously for one year and then moved to new locations each year for five years. Earlier this month, OSU conducted a workshop with represen- tatives of the 20 utilities to teach the fundamentals of wind mea- surement and a practical demonstration of how to install an ane- mometer. One result of the workshop is A Guide to Siting Anemo- meters for the BPA Anemometer Loan Program by Rich Wittrup and Robert Baker (Department of Atmospheric Sciences, Oregon - State University, January 1981.) The Guide provides some useful tips on how to site and install anemometers. Among its recommendations are: © Avoid siting an anemometer at the edge of a high cliff (greater than 100-foot drop) or directly behind a tree or buildings. © Utilize topography (ridges or hills) to site the anemometer to take advantage of accelerated wind flow. © Look for wind deformed vegetation or other wind stress features such as sand scours or dunes. © The siting of an anemometer should be approximately 1.5 times the height of the anemometer from any building, property boundary or power line. Near buildings or trees: © Site an anemometer upwind a distance of at least two times the height of the obstruction. © Site an anemometer downwind a distance of 10-20 obstruction heights. © Site an anemometer at least twice the obstruction heights above the ground if the anemometer is placed immediately down- wind of the obstruction. Thus, with a 40-foot anemometer, the obstruction must be no higher than 20 feet and preferably 10-15 feet. The Guide is a recommended supplement to the Battelle Pacific Northwest Laboratories’ Siting Handbook for Small Wind Energy Conversion Systems ($7.95 prepaid from WindBooks, P.O. Box 14, Rockville Centre, NY 11571). , Wind Energy Report Canada to build multi-megawatt Darrieus vertical axis wind machine (Continued from front page) Aeolus prototype is a function of the wind characteristics at an arbitrary site in New- foundland. Final generator sizing will be based on wind characteristics of a demon- stration site yet to be chosen. The actual site will not be selected for another six months. But site accessibility and proximity to existing power lines will be important considerations in the choice. A wind measurement program is currently be- ing underway by the Atmospheric Environ- ment Service at several locations in eastern Quebec, a half-dozen sites along both southern and northern shores of the St. Lawrence Valley River and at the Magdalen Islands. The Magdalen Islands, incident- ally, is the site of a 224 kW NRC Darrieus demonstration. NRC considers that it has an excellent wind regime. Isodyn maps in- dicate that wind speeds in eastern Quebec range from 300 to 400 watts/meter?. Some northernmost regions have energy densities as high as 700 watts/meter’. Wind resource data from the candidate demonstration site will also help determine whether Aeolus will be fixed or variable speed, the type of alternator and gear system, rated maximum power production and energy output. The design is still very “*fluid,’’ according to Chappell. Whatever its final configuration, Aeolus is an expensive research, development and prototyping effort. Research, development and erection of three MOD-2s, for exam- ple, will cost slightly more than $30 million (U.S.). Each MOD-2 is capable, theoretically at least, of generating 9.8 million kWh annually in an 18 mph wind site, nearly two-thirds more electricity than Aeolus’ 6.1 million kWh. The Aeolus, however, will continue the two-bladed tradition of Canadian Darrieus research. Explains Chappell: ‘‘Our studies show that a two-bladed machine is more cost-effective in terms of the final cost of energy . . . the cost of the additional blade is greater than the additional amount of energy it will produce.’’ A further advan- tage of a two-bladed machine, says Chap- pell, is that it can be built flat on the ground a convenience not available to the three- bladed ALCOA machines. The Aeolus will also feature the largest blade chord—7.87 feet—of any Darrieus vertical axis machine now under serious consideration. A decision on the material to be used for the blades has not yet been made, according to Chappell. ‘‘Among the attractive op- tions,’’ he says, ‘‘appear to be steel and aluminum.”’ If aluminum, it could be fab- ricated in multiple extrusions with some flat plate sections. For steel, a construction technique similar to that used to build an aircraft wing may be used. NRC and IREQ, the research arm of Hydro-Quebec, have not yet determined the construction mater- ial of the ‘‘tower’’ which will contain the transmission and generator. Steel and con- crete are leading candidates. The megawatt Darrieus will have a slower rotational speed, 15 rpm, than the Mag- dalen Island 224 kW Darrieus which is 38 rpm. The design will also have two struts connecting the torque tube or central col- umn to the blades approximately 25% down the length of each blade from both the top and both of the rotor. Sandia Na- tional Laboratories and ALCOA which is fabricating large kilowatt-size Darrieus machines contend that the struts should be much closer to the top and bottom of the rotor. ‘‘We still believe the strut location about 25% from either end seems to offer National Research Council/IREQ Multi-Megawatt Darrieus VAWT February 1981 advantages in being able to control some of the dynamic motions of the rotor blade,’’ according to Chappell. Canadian VAWT Technology Canada’s involvement with Darrieus tur- bine development dates to the late 1960s when NRC researchers Raj Rangi and Peter South ‘‘rediscovered’’ the concept original- ly invented patented by Georges Darrieus in the 1920s in France. (Monsieur Darrieus, by the way, is still alive and living near Paris, c/o CERCEM, 49 Rue du Commandant Rolland, 93350 Le Bourget, France.) NRC continued theoretical work on the concept for a number of years and funded the construction of several kilowatt-scale prototypes by Bristol Aerospace Ltd. of Winnipeg and Dominion Aluminum Fabri- cating, Ltd. (DAF-Indal) of Mississauga, Ontario. The decision to build a multi-megawatt prototype comes in the wake of the Can- ~ adian federal government’s recognition that its own dependence on oil (14% imported last year) must be reduced. In 1978, a preliminary design study of megawatt-scale Darrieus VAWTs was car- ried out by Shawinigan Engineering, Can- (Continued on next page) Central column <«— ~<—Elevation: 12m Peace Tower, Ottawa Source: National Research Council of Canada ? Wind Energy Report Canadian Darrieus VAWT (Continued from preceding page) adair Ltd., and IREQ under contract to NRC. According to Jack Templin, NRC project manager at the time, the study con- cluded that ‘‘there appear to be no insur- mountable technical problems in the design or erection of turbines over the range of sizes studied (up to swept areas of 8,000 meters? or 86,000 square feet), with rated power levels up to as high as 10 MW.”’ The study also concluded that the ratio of installed capital cost to annual energy pro- duced continued to decrease to the largest size, says Templin. ‘‘The unit cost curve,’’ he notes, ‘‘was relatively flat at the largest scales and the study recommended a proto- type turbine of 4,000 meters? or 43,000 feet?.”” According to the wind program submis- sion as part of the nation’s Task Force on Alternative Energy and Oil Substitution, “substantive contributions to Canadian Energy supplies require megawatt-scale wind turbines . . . parametric studies have shown megawatt-scale VAWTs will have competitive energy costs with traditional generation technology under today’s condi- tions.”’ Moreover, ‘‘it is essential that the wind energy program proceed at once to the logi- cal step of designing, constructing and test- ing a megawatt-scale VAWT. Failure to take this initiative now will thwart Cana- dian industrial capability in wind energy systems and will consign Canadian and world markets to foreign suppliers.’’ Future of Canadian VAWT Industry For Canada, wind power appears to be an attractive energy option, exploiting an indigenous resource and a creating new domestic manufacturing industry in the bargain. Canada is a very large country with a relatively small population, explains Temp- lin. The theoretical potential for wind power development in Canada is large in relation to total electricity demand. But most of the nation’s interconnected elec- trical network is concentrated in a narrow corridor along its border with the United States. “When the distribution of average wind energy density is taken into account,’’ says Templin, ‘‘the regions suitable for eco- nomic wind energy conversion are further narrowed to the eastern coastal regions in- cluding the Gulf of St. Lawrence and in the southern prairie provinces.” In 1979, the National Research Council estimated the average wind power that could be produced with moderate penetra- tion into the local power systems by the year 2000 range up to 5 gigawatts. That’s only 1% of Canada’s total estimated energy needs by the year 2000. Wind power has great potential in non- grid connected, isolated communities in the northern part of Canada, says Chappell, particularly in the Northwest Territories where diesel generators are the sole source of power. Not suprisingly, these commun- ities pay much more for diesel fuel. A study of one coastal province, Prince Edward Island, revealed that as many as 10 MW of wind power or 7% of its oil-fueled system capacity could be economic in its first year of service. “We see windmills being able to contri- bute energy to the system when the wind blows and relieve the diesel of its require- ment to produce as much energy,’’ says Chappell. A diesel system integrating intermittent wind energy could provide one- third to one-half of the community’s total energy demand. Canadian officials indicate that the successful design and operation of a megawatt-scale Darrieus ‘‘could open the way to a large market in both Canada and abroad.”’ NRC studies indicate that 200 megawatt- scale vertical axis machines could be manufactured by Canadian industry an- nually. Cost-of-energy calculations show that these machines could produce electrici- February 1981 approximately 30% of total installed cost. According to NRC, independent esti- , mates it has made with the Science Council of Canada forecast a cumulative one billion dollar market for the megawatt Darrieus wind turbine alone in Canada by the year | 2000. That’s in addition to a substantial ex- | port market overseas, thought to be ten times the domestic Canadian market. Large kilowatt-scale machines being developed by DAF-Indal could raise the potential value of a Canadian vertical axis wind turbine in- dustry much higher. Currently, only these Canadian compan- ies are actually building hardware. DAF- Indal built the 224 kW Magdalen Island Darrieus which has been operating since it was rebuilt and reinstalled last August after collapsing in July 1978. DAF-Indal has built about a dozen 50 kW units and is par- | ticipating in the NRC demonstration pro- |. gram with systems in utlity demonstration |, projects in Newfoundland, British Colum-— bia and Saskatchewan. DAF-Indal has a unit in Australia and another scheduled for Ireland. Next month, it expects to complete erection of a 50 kW unit for the California Department of Water Resources. Another of its units has been operating at the U.S. Department of Agriculture’s Test Center in Bushland, Texas. Bristol Aerospace has been concentrating on small, kilowatt-size Darrieus machines ty between 3-5 cents/kWh including erec- for remote telecommunications, naviga tion and site preparation costs averaging (Continued on page 10) National Research Council/IREQ Multi-Megawatt Darrieus Vertical Axis Wind Turbine Specifications Rotor Number of blades ... 2... 6... ccc enc cece eee cence eens 2 Height Diameter . Speed ......6..55.. Rotation direction . Guy wires Lee WN oi os ee Ste oe ees Centerline (from groundlevel)- Blade LONG NOE) oie ee ce nbs ceca cessed Airfoil ...... Chord ... Material . Tip speed Solidity. . Swept area Tower/Platform Height Performance FitOd POWES 6. wai dics soos sess cans sies Rated wind speed (at 30 ft.) ............ Annual Power Output (Estimated) ..... Source: National Research Council of Canada 4 ce vsaimensoctotaes 15 rpm counterclockwise 3 zinc coated 7.87 ft. 150-200 feet/second 15% +o Gisu Gos Sem ate man mers ae 3.8 megawatts Sia! 516 p's) oad PSs BI as 14.3 m/s. . . .32.0 mph rau a) wits oon fo) ats a=) sin) avo ve erate 6,100,000 kWh “ Wind Energy Report Reagan cutting back on wind energy effort (Continued from front page) Another California Company, Structural Composites, Inc. of Azusa, was awarded a federal contract to develop a4 kW SWECS. Now with a design nearly completed, actual construction of a prototype will not be funded by DOE. An undisclosed number of small wind systems, slated for the Rocky Flats Field Evaluation Program, have been paid for but Divone indicates that this pro- gram ‘‘will have to be tailed off.’’ Of the $8-10 million budgeted for FY81 for the MOD-5 contracts, monies which have not already been spent will be halted. Both General Electric and Boeing have nearly finished the ‘‘Conceptual Design Review’’ phase of the contract. There is the possibility that both contracts will be cancelled, providing Congress goes along with the $26.1 million cutback. Thé Solar Energy Research Institute has just completed a lengthy market study, Near-Term High Potential Counties for SWECS. Additional and much larger mar- ket studies contracted by SERI won’t be done. Although DOE Secretary Edwards earlier this month stated that commer- cialization studies should be done by the in- stitute, SERI is virtually out of the picture for further wind energy market and com- mercialization studies because of curtailed funding. Nearly all of the money allocated for the Innovative Wind Systems program, manag- ed by SERI, has been obligated and, thus, can’t be retrieved. Congressional Approval Needed These cuts in the FY81 budget, of course, must be approved by Congress. The pro- solar and Democratic-controlled House Science and Technology Committee’s Sub- committee on Energy Development and Applications plans hearings on the propos- ed FY81 cuts next month with a stated pur- pose of resisting these cuts and adding fun- ding for certain projects cut from the FY82 budget. One reliable source at the commit- tee indicates that an attempt will be made to salvage the MOD-S5 in a highly modified and, no doubt, less expensive form. Federal Wind Energy Funding Fiscal Year $ Millions 1981 80.0 1980 63.4 1979 59.6 1978 35.5 1977 27.6 1976 14.4 1975 7.9 1973-4 1.8 House and Senate Appropriations Com- mittees also plan hearings on the federal solar budget. The cuts in the federal wind energy pro- gram are a very small element of a massive federal budget reduction, part of the Rea- gan administration’s plans to fulfill cam- paign promises to trim federal initiatives in areas of American life best left to in- dividuals and the free enterprise system. _ Emerging Reagan Wind Policy That philosophy began to emerge at DOE during a wide-ranging two-day press con- ference held early this month by Secretary Edwards, a South Carolina dentist. Repeat- edly, Edwards touted nuclear and fossil energy as the best approaches to providing the nation with adequate supplies of energy. The administration has already de- controlled the price of oil and natural gas As expected, this policy has resulted in higher energy prices, reduced consumption and, more importantly, made the econo- mics of wind power more attractive . “There will be some support for some of the windmills,’’ said Edwards. ‘‘But this is a technology, you know, we approved it. It works. Now the commercialization of it is something else. February 1981 will be on research in high risk, potentialiy high payoff areas and on collection of wind resource and wind machine performance and reliability data for use by the emerging wind machine manufacturing and user communities.’” According to its FY82 budget proposal, the Reagan administration believes that “expansion of wind energy generating capacity can be achieved with a strong com- mitment in the private sector to develop cost effective wind systems and to invest in factory facilities and marketing networks.”’ The FY82 budget submission more ac- curately reflects the new administration’s tight budget energy policy. It calls for a $66.4 million, or 75% reduction,in the funding of the federal wind energy program from 1981. (Five days before it left office the Carter administratrion submitted a largely symbolic $73.6 million FY82 wind budget request.) The sharp reduction in funding, says the proposal, is made ‘‘in recognition of an emerging wind systems manufacturing in- dustry, an increased awareness and interest on the part of potential machine purchasers and an anticipated rapid growth of the wind industry prompted, in part, by rising conventional energy prices and tax incen- I think government’s role is to develop the technology and prove that it works and then the commercialization should be in the pri- vate sector.—DOE Secretary Edwards Edwards comments were an oblique reference to a dramatic shift in U.S. wind energy policy away from government- funded capital projects towards greater pri- vate sector involvement in commercializing a technology thought to be close to being ready for the marketplace. “Expansion of wind energy generating capacity,’ explains DOE in justifying a $19.4 million FY82 wind budget, ‘‘can be achieved with a strong commitment in the private sector to develop cost effective wind systems and to invest in factory facilities and marketing networks.”’ In its FY82 budget submission, DOE re- cognized that difficulties involved in ‘‘the cost-effectiveness of terminating techno- logy development activities which are characterized by large sunk costs and are close to being technically and economically viable.’” According to the proposed DOE wind budget, ‘‘the principal emphasis in FY 1982 5 tives provided for sources.’” In FY82, the MOD-0 test bed at Sandus- ky, Ohio, will still be used ‘‘for experi- mental evaluation of new components and verification of theories predicted by analytical research. Operational experi- ments on the MOD-0A’s and MOD-1! will continue in cooperation with the host utilities.’’ Accelerated fatigue testing to determine blade lifetimes will be perform- ed. Noise and television interference studies will be continued. DOE will continue to evaluate the three MOD-2 machine cluster at Goodnoe Hills. “The purpose of these activities will be to provide the data and modifications, as re- quired, that will permit the local utility to assume ownership and operational control of the machines when technical reliability is achieved.”” “Research on promising wind machine (Continued on next page) renewable energy Wind Energy Report FERC to appeal adverse PURPA decision The Federal Energy Regulatory Commission says that it plans to appeal the decision of a Mississippi federal judge who declared un- constitutional key provisions of the Public Utility Regulatory Policies Act of 1978. On February 26, Judge Harold H. Cox of Mississippi’s Southern District handed down a decision calling Title I, Section 210 of Title Il, and Title III of PURPA ‘“‘void in that they constitute a direct in- trusion on integral and traditional functions of the state of Mississippi.’” Judge Cox argues that the federal government has no authority to regulate the intrastate functions of the state’s utility regulatory body. FERC Acting General Counsel Jerome Nelson announced within hours of the decision that the commission will appeal the decision. “*Any further review lies exclusively in the Supreme Court of the United States. The Commission has authorized us to request the Solicitor General to take a direct appeal to the Supreme Court.”’ It is not known whether the Justice Department will agree and appeal the decision. Most of Judge Cox’s decision reads like a state’s right tract, singling out the federal role in the regulation and control of public utilities as particularly irksome to ‘‘the sovereign state’? of Mississippi. Argues Judge Cox: ‘‘The United States does not have the power or the authority to impose its three standards under PURPA upon the state of Mississippi under the guise of providing the solution to the nation’s energy problems.”’ Although the decision is poorly written and rests on challenging the supremacy of the federal government to regulate interstate commerce—a principle long established in constitutional law—it has caused deep concern among cogenerators and wind farm developers. They see the entire decision casting a cloud on the regulatory status of small power producers. Sections 201 and 210 of PURPA have been instrumental in the creation of third party en- tities allowing them to enter into negotiations with utilities to sell them electricity. Section 210 requires state utility regulatory commissions to set “‘just and reasonable”’ rates for the sale of power from the qualify- ing facilities of small power producers and exempts them from several provisions of the Federal Power Act and other utility regulations. It is these key regulatory exemptions which have made wind farm development by third party entrepreneurs possible. Investor-owned utilities have never been happy with these provi- sions of PURPA which challenge their monopoly position by crea- ting competition in the generation and sale of electricity. PURPA requires utilities to deal directly with these entrepreneurs. PURPA provides third party wind farm developer the option to appeal to the state public utility regulatory body if purchase power contracts with utilities do not contain ‘‘just and reasonable’’ buy-back rates. Southern Mississippi is hardly a hotbed of wind energy activity but it does have impact on local co-generators seeking rate redress from the Mississippi PUC. Cogeneration, mainly because they have power for sale now—have been the leaders in in setting precedents for small power producers who have power to sell to a utility. What worries some wind farmers is that the decision will provide a precedent for other jurisdictions to apply in similar cases. The Supreme Court, of course, hears only a small fraction of the cases appealed to it. There is the possibility that it will not hear the case at all. In that event, says FERC, the Mississippi ruling stands, but only in the Southern District. Ironically, appealing the decision provides an opportunity for February 1981 utilities to contest the validity and legality of PURPA by filing amicus curiae briefs before the Supreme Court. By the same token, it will also allow cogenerators and small power producers an opportunity to present their own case. Tactically speaking, the decision provides utilities with a conven- ient excuse to delay binding purchase power agreements—and wind farm projects—until the Supreme Court decides one way or the other. In either event, it could take several months or even years for the case to be heard and decided upon. This delay may make it more difficult for wind farm developers to hold out for more rewarding purchase power agreements. * * * Reagan cutting back federal wind effort (Continued from preceding page) concepts will be continued,’’ says the administration budget pro- posal, but it doesn’t specify which concepts are promising and how much funding they will receive. The administration does, however, want to examine the potential of innovative systems for urban use. The Rocky Flats small wind systems test center, considered by many SWECS manufacturers to be the most poorly organized and managed element within the entire federal wind energy program, “‘will develop performance, reliability, maintenance, and other operational data. Testing on a customer cost basis will also be pro- vided for privately developed experimental prototypes.’’ The test facility is being kept alive, according to the administration, ““because it is the only practical source of such information for dev- elopers and manufacturers and enables them to undertake necessary improvements using private funds.’’ If Rocky Flats is to continue in its controversial role as a national SWECS testing facili- ty, it will have to find a way to pay for its activities without federal subsidy. Studies of wind machine performance and economics will be undertaken for ‘‘major application areas.’’ Those areas are not specified. Wind resource siting methodologies will be developed to allow rapid identification of high potential wind sites. ‘‘This infor- mation helps potential wind systems users make their own decisions about machine purchases.’’ The Battelle Pacific Northwest Laboratories’ wind characteristics program is being put in a holding pattern with no new initiatives. The $19.4 request for FY82 virtually eliminates the hardware development of either the Boeing or General Electric MOD-5s, the Rockwell International MOD-6H or the ALCOA MOD-6H. Con- sequently, there simply won’t be any federally funded machines for utility demonstration projects. Many of the meteorological towers for 20-odd new sites have already been installed. It is not clear whether data collected from thise installations will be analyzed. In its own wind energy budget, the Reagan administration is giv- ing a clear signal that the salad days of federal involvement in wind power development are over. It will act as a supporter, cheering the private sector from the sidelines. WIND ENERGY REPORT® Copyright © 1981. Wind Publishing Corporation. All rights reserved by the copyright owners. Wind Energy Report® is published monthly. No portion of this publication may be reprinted, reproduced, stored in a computer-based re- trieval system or otherwise transmitted whole or in part without the express, written permission of the publisher. Printed in U.S.A. ISSN: 0162-8623. Subscriptions: $115. annually (USA); $125. annually (Canada & Mexico); $145. annually (foreign airmail). Two-year subscriptions: $215. (USA); $230. (Canada- Mexico); $290. (foreign airmail). Editorial offices are located at: 189 Sunrise Highway, Rockville Centre, NY 11570. Mailing address for all correspondence: P.O. Box 14, Rockville Centre, NY 11571. (516) 678-1230. Wind Energy Report Design Notes: Boeing MOD-5B Reducing the cost-of-electricity generated by large wind turbines to levels competitive with conventional fuels has been the under- lying premise of the federal involvement in large wind systems research and develop- ment. As the price of imported oil escalated in recent years, federal wind energy policy continued to emphasize reducing cost of wind-electricity by funding large machine development. Incorporating the lessons learned from the MOD-0, MOD-0A, MOD-1 and MOD-2 projects, a ‘‘third generation’’ of large WECS could reduce capital cost, operating expenses, and cost t of energy. Federal wind energy policy seeks to make wind power attractive to utilities while simultaneously laying the groundwork for a wind turbine manufacturing industry capable of mass-producing the thousands of wind machines necessary to meet the Carter administration’s goal of 1.7 quads from wind power by the end of the century. While many attractive sites in high wind regimes (18 mph+) in oil-based regions such as Hawaii, California, New England, wind power is already considered competit- ive with imported oil. Attracted by avoided cost of 6 cents/kWh or more in these regions, wind farm developers are actively tying up potentially profitable sites for wind systems arrays. Current NASA calculations indicate that the three-machine cluster of MOD-2s at Goodnoe Hills will produce electricity at 8 cents/kWh. Quantity manufacturing of the MOD.-2s could provide deliver electricity at 6 cents/kWh. Nevertheless, federal wind policy con- tinues to pursue the holy grail of 3 cents/kWh wind power. This pursuit is partly motivated by the desire of federal program managers with big budgets and large staffs to continue to manage federal programs with big budgets and large staffs and partly by companies looking for federal monies for whatever design project is readi- ly available to help pay for engineering overhead. The Advanced Multi-Megawatt Wind Turbine competition is the latest—and last—major federal effort to develop wind technology hardware. In early 1979, it set a goal of 3 cent/kWh electricity in a 14 mile- per-hour wind regime for 1985. Two com- panies, Boeing Engineering & Construction and General Electric, were selected late last year to provide the agency with design, costs, manufacturing and marketing plans for large WECS. NASA-Lewis Research Center, program manager for large WECS technology devel- opment, has finally released a truncated ‘version of the Boeing proposal submitted for the AMMWT competition. (The Gener- al Electric AMMWT proposal is contained in the November, 1980, issue of Wind Energy Report). During the past several years, Boeing has been the largest recipient of federal wind energy research and development largesse. The nation’s leading aerospace company, it has received more than $30 million to de- sign and build the three MOD-2s now being erected at Goodnoe Hills, Washington. It built the steel MOD-1 rotor for twice the original estimated cost. For the AMMWT competition, Boeing submitted a 4.4 MW design—based mainly on its experience with the 2.5 MW MOD- 2—which the company says can deliver electricity to the grid at 2.8 cents/kWh. In Boeing’s proposed design, dubbed the MOD-S5B, there is some indication that this figure could finally be as low as 2.5 cents/kWh by means of further economies in operation and maintenance areas, greater weight reduction and certain design refine- ments. February 1981 According to Boeing, the capital costs of its AMMWT ‘“‘are about the same”’ as the MOD.-2 when produced in quantity. And it claims that the design ‘‘represents over 30% reduction in the cost of energy from the MOD.-2.”” To meet these energy cost goals, Boeing has eliminated MOD-2 tip controls, the local structure supporting the moveable tip, and the slip ring system required to connect the tip controls to the computer and power supply systems from the proposed MOD- SB. MOD-5B Design Briefly, the Boeing MOD-S5B proposal is a two-bladed, fixed pitch, teetering rotor which is connected to a two-speed induction generator through a three-stage planetary gearbox. Like the MOD-2, the rotor is oriented upwind of the tower. The tower is a circular steel shell 191.5 feet tall. Here is how Boeing describes its opera- tion: “The fixed pitch rotor generates power up to 5.6 megawatts at 44 mph. At this wind velocity, aerodynamic stall begins to reduce power with the upper limit of ap- preciable power being at about 61.5 mph. “‘The generator operates at 1800 rpm above about one megawatt, which occurs at 20 mph. Below about one megawatt, a pole (Continued on next page) MOD-2/MOD-5B (AMMWT) Comparison Subsystem Component MOD-2 MOD-5B (AMMWT) Rotor Tip controlled Welded steel tip construction Teetered Upwind (300-foot dia.) Upwind (304 foot dia.) Fixed pitch Welded steel hub & mid- blade—laminated wood tip Teetered Generator Single speed synchronous (2.5 MW) Dual speed (4.4 induction) Nacelle 2.5 degrees of tilt Truss/cover construct. 4.0 degrees of tilt Truss/cover construct. Shafting Gearbox connected to rotor via a quill shaft Gearbox connected directly to low speed shaft Gearbox 3-stage epicyclic Rigid mounts 3 stage epicyclic Torsionally soft mounts Electrical elements for each function Separate electrical Integrated bus tie/gener- ator circuit breaker Power output controlled by blade pitch Active yaw drive for upwind nacelle orientation Tower Foundation Steel shell (soft) forced concrete Buried reinforced No pitch control required. Active yaw drive for upwind nacelle orientation. Steel shell (soft) Partially buried rein- concrete Wind Energy Report Boeing MOD-5B (con:.) amplitude modulated (PAM) induction generator can automatically switch to 1200 tpm with rotor rpm change aided by the generator. This lower rpm allows genera- tion of power to start as low as 10 mph with rapid achievement of synchronous speed accomplished both by aerodynamic forces and the generator acting as a motor. “The induction generator also has the very important benefit of eliminating premature shutdown under short period low wind speed conditions which would otherwise require restart. The PAM generator is, in effect, the control system and operates efficiently by being on the high speed end of the gearbox.’’ To change from (rotor) 12.67 rpm to 19.0 tpm, the generator is taken offline for about 10 seconds and a motor operated switch changes the generator pole con- figuration from 6 poles to 4 poles. the generator is then reconnected to the utility grid and pulls the rotor up to 19.0 rpm. Less than two seconds are required to change the pole configuration. To go from the high rpm to the low rpm, a similar pro- cedure is used. The generator is taken off- line. The pole configuration is switched from 4 to 6. The generator is reconnected to the utility grid and pulls the rotor down to 12.67 rpm. The generator, which has a nameplate rating of 4400 kW, ‘“‘has been sized to oper- ate above its nameplate rating less than one hour per day for the site wind speed frequency distribution’’ of 14 mph. The system will automatically shut down when the wind speed is less than 10 mph or greater than 61.5 mph. Because of its wide operating region (10-61.5 mph), the AMM- WT will run approximately 85% of the time compared to 70% on MOD-2, according to Boeing. For intermediate wind speeds, the system can be stopped by the aerodynamic drag brakes (outer 30 feet of each blade) or the mechanical shaft brake, depending on the magnitude of the wind speed. The rotor brake consists of a disc located at the high speed shaft/generator interface and a disc caliper mounted on the generator frame. The brake is disengaged by bleeding hy- draulic pressure from the yaw drive system. The brake is engaged by spring force when the hydraulic pressure from the yaw drive system. The 304-foot diameter is welded steel ex- cept for the outer 30 feet which are lamin- Baseline AMMWT Power Output AMMWT (MOD-5B) POWER-kW 0 10 20 30 40 50 60 70 Wind Speed at Hub (204.5 feet) - mph February 1981 ated wood. On the MOD-2, the moveable outer 45 feet of the steel blade is used for power regulation and start-up rpm. The outer 30 feet of each MOD-SB blade func- tion as ‘‘a mechanically activated aerodynamic brake on the entire rotor to prevent overspeed in an emergency.”’ According to Boeing, the wood provides a smooth aerodynamic surface to reduce drag and the lower weight reduces rota- tional inertia about 15% with consequent reduction in startup torque requirements. The tip has special aerodynamic shaping which can reduce tip losses, according to Boeing Vertol. Boeing contends that a NACA 430XX airfoil for the blade tip results in a 2% increase in maximum rotor power coefficient. The three-stage planetary gearbox, accor- ding to Boeing, ‘‘is similar to the MOD-2, but scaled up in size for torques consistent with peak power of 5.6 megawatts. The gearbox has flexible mountings to isolate the drive train from torque harmonics. This, along with deletion of tip controls, allows elimination of the quill shaft.’” The nacelle is 36 feet long, five feet shorter than the MOD-2 due to the elimina- tion of the quill shaft and hydraulics systems formerly needed for rotor tip con- trols. The nacelle is also tilted 4° ‘‘to allow moving the center of gravity of the rotor and nacelle nearer the tower without rotor/tower interference. This reduces the overhang loads on the yaw bearing.” By eliminating tip controls and ‘‘related equipment,’’ says Boeing, operations and maintenance costs can be reduced by 20% from MOD-2 costs. Manufacturing plans Boeing plans to build the initial units of the MOD-5 ‘‘on a continuation of the MOD-2 production environment. The same general approach is planned for the high rate production run of 1,000 AMMWTs.”’ Stal-Laval of Finspong, Sweden, will provide the gearbox.(The MOD-2 uses a Stal-Laval gearbox.) Gougeon Brothers, Bay City, Michigan, will fabricate the 30-foot outer blade sections and Westing- house will manufacture the PAM gener- ator. According to Boeing, ‘‘the anticipated high rate production plan is to fabricate and assemble 100% of the MOD-5B wind turbines with the exception of purchased equipment, forgings and raw material in a totally integrated, automated manufactur- ing facility . . . The objective of this facili- ty is to apply a single path flow for each ma- jor assembly, employing computer controll- Wind Energy Report Design Notes: Boeing MOD-5B (con:.) ed automation where feasible.’’ Boeing says this automation becomes feasible by the 100th unit. Boeing provides no indication of just how many orders it will take to make a commitment to this type of facility or even if plans to build one do exist. By contrast, Hamilton Standard has committed more than $18 million of its own money during the last several years and dedicated a blade winding facility last October. It has already obligated itself to building 22 four megawatt machines. Cost of Energy For a cluster of 25 MOD-5Bs, Boeing says that the 100th unit could produce elec- tricity at 2.8 cents/kWh based on a .92 availability, .96 cluster efficiency, and .29 capacity factor. Under these conditions, each MOD-5B would be capable of producing 11,242,753 kilowatt-hours annually in a 14 mph wind regime. That’s 1,364,000 kWh, or 13.8% more electricity than Boeing says the MOD-2 can produce in an 18 mph wind regime. And that’s with a generator nearly three-quarters again as powerful. Cluster operation and maintenance costs would be $12,000 annually per machine. Boeing contends in its proposal that it can increase energy output to 11,800,000 kWh annually by using a .97 availability factor. That reduces cost-of-electricity to 2.5 February 1981 cents/kWh. These machines, Boeing indi- cates, can be purchased for $1.5 million each ($1977) which includes a 10% profit on each one and site construction costs ap- proximating 20% of the cost of the entire unit. For single units, Boeing says it can manu- facture the MOD-S5B for a total initial cost of $2.92 million and the 100th unit for $1.95. For clusters, the first unit is $2.586 million and the 100th is $1.617 million. These figures include the machine, site preparation, transportation, erection, maintenance equipment, spares, transmis- sion system and land (valued at $3,000.) It is arguable that the Boeing AMMWT is (Continued on next page) Airfoil (outer 30 feet) . . Pian 2.2.2 5..... Twist . . Tower Diameter: at the base . atthehub .. Material Wo teecace gs eee ee BOEING ENGINEERING & CONSTRUCTION MOD-5B 4.4 MEGAWATT BASELINE DESIGN - NACA 430XX Type...........--.--. cylindrical steel shell, conical base Rated power..... Wind speed at 30 feet Rotor (above tower) Rotor Generator MOEION IN CODD cs oo cc ce ccs os Ge ewan ot os Sin ake 2 Type ........ 2-speed pole amplitude modulated induction TIN 5 050k oo sci cre 5 gin 20k on 8'e20 v0 gio ss a 304 feet Rating 1355 kW & 4470 kW Speed ... 12.67 rpm & 19 rpm Power Factor ... 2.0.0.0... 000.0 c cece cece cece Rotation direction.............. clockwise (looking upwind) Voltage ....... Location, relative to tower . upwind Speed..... Tepe... 2 se . teetered Efficiency. . . Method of power regulation .fixed pitch WNC Y re eos es rss ee Cone angle ...none Tilt angle . ae Orientation Drive CO eS Se er cere ret 2.5% Wipe iar soso iv os ore eo os ee es we active yaw Swept area : -not available Activation . electric motor/hydraulic pump Tip speed ratio. ... 2.2... cece ee eee ee eee eee 9.375 Me a eran hydraulic brake Ms a ho nc 8 Soe coin 30s a Sale Sg 0g o oka ood eseiay er eeee 0.443 petit ING 5 x2 cies Sites oes Sesto % °lsecond ‘pmax Blade Control System Gerth otal)... eee eee eet SRPOTVIOOFY . 2. ect cc ee see microprocessor Ground clearance . Overspeed control ............... mechanical shaft brake Material drag flaps Weight/total ..... Airfoil (inboard section) ........... - NACA 230XX Performance eee ae es ee ee os 4.4 megawatts WN 9 accent a oie aie ae ew a cle setae are 10.0 mph vaste ste Rated . 34.2mph Cut-out............... 61.5 mph Maximum design (survival) ..................-.--- NIA amas ser 191.5 feet Annual Power Output (Estimated) 14 mph (at 30 feet) ...................0.. 11,242,753 kWh Weight Sore i oe 183,399 Ibs. Ground clearance . : Drive train ...... .113,700 Ibs. Hub height ...... neste eee ees 204.5 feet Gearbox __ "67.100 Ibs. Access .... : internal elevator, ladder Generator . 26,400 Ibs. Foundation.......... reinforced concrete with overburden Shaft ... : 20,200 Ibs. . Nacelle .. . -77,100 Ibs. Transmission Tower ......... 225,597 Ibs. TYP... - 00ers eee eee eee es 3 stage, planetary Total (on foundation) ....................005 599,302 Ibs. eos 95:1 Input speed ....... 12.67 and 19.0 rpm System Design Life Output speed .......-------- 2220-0 1200 & 1800 rpm Allcomponents ..............00.-0eeeee eee 30 years Source: Boeing Engineering & Construction/NASA SystemC, .-. eee eee ec eee eee e eens 0.402 pmax . Wind Energy Report Design Notes: Boeing MOD-5B (con:.) little more than an uprated MOD-2, cleverly optimized to meet NASA/DOE requirements for a ‘‘third generation’? large wind machine. Cluster Installation Cost of Electricity (mid $1977) Levelized Unit An. Energy Total Initial O&M Costs C.O.E. Number Available (10° kWhiyr.) Cost (10°$) (10°$) Cents/kWh 1 92 11.24 2,586 24 4.35 2 92 11.24 2,393 24 4.04 3 92 11.24 2,297 24 3.80 100 92 11.24 1,617 24 2.80 Source: Boeing/NASA Trade Studies In its proposal, Boeing recommends a number of ‘‘trade’’ studies to be accomplished during the ‘‘complete design review’’ phase of the contract: free yaw downwind vs. the controlled yaw upwind configuration; variable pitch control vs. the baseline fixed pitch rotor; and a retrofit MOD-2 with minimum modifications to incor- porate fixed pitch rotor and two-speed induction generators. Unlike the General Electric MOD-S5A and the Hamilton Stan- dard WTS-4, Boeing is not convinced of the effectiveness of a downwind configuration. ‘There is a static stability problem in the downwind configuration which forces the rotor out of alignment with the free stream. This condition is further amplified by teeter.”’ Boeing has already indicated it wants to use the MOD-2s at Goodnoe Hills as a test bed for a number of its design choices. The MOD-2 retrofit option may be the most realistic in light of the Reagan administration’s deep cuts in the federal wind program. A retrofit ‘‘with minimum modifications,’’ says Boeing, ‘‘may be an attractive alternative.’’ Even Boeing concedes that ‘‘the MOD-2 machine meets all of the AMMWT proposal requirements except for the cost of energy goal of less than 3 cents/k Wh.” The retrofit option will be studied by Boeing with its AMMWT funding. For FY81, the administration wants to end further MOD-5S development. The original FY82 submission by the outgoing Carter administration allowed for only one MOD-S construction award. A MOD.-2 retrofit may be the least costly option for a Congress faced with a diminishing budget andhard choices on cuts in social programs. Moreover, Boeing contends that ‘‘preliminary analyses show a potential improvement in performance of the MOD-2 of about 20% if the proposed AMMWT fixed pitch rotor/two-speed induc- tion generator are incorporated by retrofit.’” Canada to build multi-megawatt Darrieus (Continued from page 4) tional aids and other applications requiring high reliability and on- site energy storage. These units are mainly for test and experi- mentation for applications in remote, hostile environments. Both companies have received substantial funding from NRC to develop and build their machines. But two companies do not an industry make, certainly not a billion dollar industry by the year 2000. And Canadian optimism about their role in the vertical axis industry knows few limits. “‘Canadian know-how,”’ according to Dr. Larkin Kerwin, presi- dent of the National Research Council of Canada, ‘‘leads the world . . . and has profound commercial connotations.”” “If we maintain our present advantage in specialized areas of 10 February 1981 wind energy technology,”’ predicts Kerwin, ‘‘much of tomorrow’s { sales in wind generators might be ours. Canada might within two | decades be to wind power what Japan is now to cars.’” | For further information about the Canadian wind energy pro- gram, contact: Mark Chappell, National Research Council of |./ Canada, M-2 Montreal Road, Ottawa, Ontario KIA OR6. (613) 993-3405. For information about Darrieus machines manufactured in Canada, contact: H. Sevier, Rocket and Space Division, Bristol Aerospace Ltd., P.O. Box 874, Winnipeg, Manitoba, R3C 2S4, Canada. Chuck Wood, DAF-Indal Ltd., 3570 Hawkestone Road, Mississauga, Ontario, LSC 2U8, Canada. (416) 275-5300. William Nicholson, DAF Indal, Inc. 332 Salem St., Andover, MA 01810. (617) 470-0016. PASNY studying sites for WECS project The Power Authority of the State of New York has selected seven sites for detailed wind resource monitoring during the next three months to determine the best location for the authority’s first wind turbine. The sites were selected from 40 surveyed by the Atmospheric Sciences Research Center at the State University at Albany. Sites on both private and Power Authority property were chosen. Topo- graphy varies from shoreline to mountaintop areas. Two of the authority-owned sites—Blenheim-Gilboa pumped storage hydro- electric project in Schoharie County and the Fitzpatrick nuclear plant in Oswego—were unsuccessful contenders for the U.S. Department of Energy’s candidate site selection for large wind sys- tem demonstration projects completed last year. These two sites have an average annual wind speed of 14 mph. The five other sites are: PASNY’s ice boom storage area in Buf- falo; Hunter Mountain, a private ski facility in Greene County; LaSalle Academy, a private high school in Oakdale, Suffolk Coun- ty; Pillar Point, inactive farmland in Jefferson County; and the U.S. Department of Agriculture’s research center on Plum Island, located off the eastern coast of Suffolk County. Average wind speeds at these sites range from 11 to 20 mph. Data from 50-foot elevations will be correlated with that from the nearest National Weather Service stations to estimate long-term wind averages. The Authority is still studying operational and performance data on a number of commercially available wind machines but hasn’t decided on a large or a small machine for its first demonstration project, according to Dr. Harvey Brudner of PASNY’s Research and Development Group. For further information about potential wind sites in New York State, contact: Dr. Bruce Bailey, Atmospheric Sciences Research Center, SUNY at Albany, E.S. 324, Albany, NY 12222. (518) 457-4930. For information about PASNY’s wind energy research program, contact: Dr. Harvey Brudner or Concepcion Tan, R%D Group, “ Power Authority of the State of New York, 10 Columbus Circle, New York, NY 10019. (212) 397-8723. * * * MOD-2 dedication set for late May The formal dedication of the Boeing MOD-2 wind turbine generators currently under final construction at Goodnoe Hills will be held on Friday, May 29, at 10 A.M. at the site. For further information about the dedication, contact: Public Information Office A-1, Bonneville Power Administration, P.O. Box 3621, Portland, OR 97208. Wind Energy Report Meetings/Conferences Wind Energy—General Course on Producing Electrical Power from the Wind, will be held on May 2, 1981, in Pittsfield, MA. For further information, contact: Alan Silverstein, Center for Ecological Technology, 74 North Street, Pittsfield, MA 01201 . (413) 445-4556. * * * The U.S. Department of Agriculture and U.S. Department of Energy’s Small Wind Systems Program, Rocky Flats, will hold a workshop, Small Wind Turbine Systems 1981, in Boulder, Col- orado, May 12, 13, 14. The workshop will cover small wind energy conversion systems hardware development, R&D requirements, utility interface, and institutional issues relevant to SWECS commercialization. Approx- imately 55 papers will be presented during the three-day workshop on the following topics: Systems Development: 4 kW, 15 kW, 1-2 kW high reliability, 8 kW, 40 kW and Productivity Analysis. Test Programs: ATS Capability, CVT Capability, Vibration, Electrical, Feeder Saturation, and USDA Overview. Special Research Programs: Wake Measurements, Tower Dynamics, Rotor/Load Matching, Dynamic Stall, Yaw Control, and Airfoil Data. RSEC/ Utilities: Regional Solar Centers, Technical Issues, and Policy Issues. Utility Interface: PURPA Implementation, RCS Im- pact, Standards Development, FEP/NEWP Overview, and SCI Utility Study. Safety/Reliability: Fatigue Analysis, Electrical Testing, Cer- tification Issues, Field Installation/Certification. Non-Electrical Applications: Irrigation Pumping, Building Heating, Water Heating, Refrigeration, and Heat Churn Analysis. Commercialization: WESA ’80/Federal Incentives, State Incen- tive Programs, Market Study, and Product Liability. Jnfrastructure Issues: Dealer Presentation, Training/Certification, Marketing Strategies, and User Issues. State of the Industry. For more information about the conference, contact: Don Mar- tin, Workshop Coordinator, Rockwell International, Energy \/ Systems Group, P.O. Box 464, Golden, CO 80401. (303) 441-1349. * * * Solar Rising, the annual meeting of the American Section, Inter- national Solar Energy Society, will be held at the Philadelphia Civic Center, Philadelphia, PA, May 26-30, 1981. The meeting will have only one session on wind power, Wind Commercialization, which will be held on Saturday, May 30, at 10:40 A.M. * * * A three-day DOE/NASA Workshop on Large Horizontal Axis Wind Turbines will be held on July 28-30, 1981 in Cleveland, Ohio. Co-sponsored with Cleveland State University and Oregon State University, the workshop will be held on the Campus of Cleveland State University with lodging in the adjacent Downtown Holiday Inn. Planned reports on design, operation and data will will focus on the following topical areas: tests data from the MOD-0 experimen- tal wind turbine; operating data from DOE/NASA wind turbines located at utility sites; design of advanced systems; electric utility experience and future plans; and rotor blade design data. For further information, contact: Dr. David A. Spera, Workshop Chairman, NASA-Lewis Research Center, Mail Stop 500-202, Cleveland, OH. 44135. (216) 433-4000, ext. 6629. ll February 1981 The Von Karman Institute Lecture Series on Wind Energy Devices, will be held June 1-5, 1981, in Belgium. For further information, contact: Von Karman Institute for Fluid Dynamics, Chaussee de Waterloo 72, B-1640 Rhode-St. Genese, Belgium. * * * The British Wind Energy Association will hold a one day Inter- national Colloquium on Wind Energy on Thursday, August 27, 1981 at the Solar World Forum Congress and Exhibition in Brighton, England. The Colloquium will present a forum for discussing the current status and future plans of national programs as well as a wide range of topics in wind energy utilization. Papers will include the follow- ing topics: large and small wind turbines, wind data and meteorology, power system integration and economics, control systems, offshore potential, wakes and clusters, materials and structural problems, measurement techniques and environmental aspects. Invited speakers include: Dr. Freddy Clarke, UK Department of Energy; Dr. Louis Divone, US Department of Energy; Dr. Peter Musgrove; Chairman, British Wind Energy Association; and Dr. Horst Selzer, ERNO, West Germany. For further information, contact: Dr. Leslie F. Jesch, Chairman, Organizing Committee, Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, England. Tel.: 021-472-1301. * * * Wind Workshop V, the Fifth Biennial Conference on wind energy conversion systems, will be held in Washington, DC, October 4-7. Further details can be obtained from: Conferences and Staff Development Branch, Solar Energy Research Institute, 1617 Cole Blvd, Golden, CO 80401. (303) 231-7361. * * * The Second AIAA Terrestrial Energy Systems Conference will be held in Colorado Springs, Colorado, December 1-3, 1981. Several papers on wind energy are planned. For further information, contact: Dr. Irwin Vas, Solar Energy Research Institute, 1617 Cole Blvd., Golden, CO 80401. (303) 231-1935. Opportunity Wind Energy Specialist The California State Office of Appropriate Technology (OAT), located in the Governor’s Office, is a nationally recognized leader in the development and implementation of alternative technologies. The office provides information and technical assistance to the Governor of California, state agencies, the legislature, and the public in areas of energy and resource-conserving technologies. OAT is seeking a special individual who understands the poten- tial of wind as a renewable energy supply source. Minimum qualifications include: substantial knowledge of small-to- intermediate sized electric generating wind energy conversion systems with specific experience in areas of technical feasibility, in- tegration of wirid electrical systems with utility grids, knowledge of structural components, and basic engineering economic analysis. All salaries are competitive, commensurate with education and experience. As members of the Governor’s staff, OAT employees are exempt from state civil service. Health and retirement benefits are available. Respond immediately by sending a statement of qualifications to: Jan Warner, 1530 Tenth Street, Sacramento, CA 95814. Mark your application in the upper right hand corner “*Wind Energy.”’ OAT is an equal opportunity employer. Wind Energy Report NEW PUBLICATIONS/STUDIES/REPORTS The following papers were presented at the Second Department of Energy/NASA Wind Turbine Dynamics Workshop held at the NASA-Lewis Research Center, Cleveland, OH, from February 24-26. Complete Proceedings will be available from the National Technical Information Center in June, 1981. * * * Whirl Flutter Analysis of a Horizontal-Axis Wind Turbine with a Two-Blade Teetering Rotor by David C. Janetzke, NASA Lewis Research Center, Cleveland, OH 44135 and Krishna R.V.. Kaza, The University of Toledo and NASA Lewis Research Center. An investigation to explore the possibility of whirl flutter and to find the effect of pitch-flap coupling (Delta 3) on teetering motion of the DOE/NASA MOD-2 wind turbine is presented. The equations of motion are derived for an idealized five-degree-of-freedom mathematical model of a horizontal-axis wind turbine with a two-bladed teetering rotor. The model accounts for the out-of-plane bending motion of each blade, the teetering motion of the rotor, and both the pitching and yawing motions of the rotor support. Results show that the MOD-2 design is free from whirl flutter. Selected results are presented indicating the effect of variations in rotor support damping, rotor support stiffness, and Delta 3 on pitching, yawing, teetering, and blade motions. A computer program was used to study the possibility of whirl flutter in the DOE/NASA MOD-2 wind turbine and the effect of parametric varia- tions in pitch-flap coupling, rotor support stiffnesses, and structural damp- ing on its response.Based on these limited studies, the following conclu- sions were obtained. The ASTERS program is capable of predicting whirl flutter for two-bladed teetering rotor systems. The baseline design of the MOD-2 HAWT is free of whirl flutter. Positive Delta 3 has an adverse ef- fect on cyclic blade out-of-plane bending motions for the MOD-2 design, whereas negative Delta 3 has little effect. Reduction in rotor support stiff- ness or structural damping increases the possibility of whirl flutter. * * * A Review of Resonance Response in Large, Horizontal-Axis Wind Turbines by Timothy L. Sullivan, NASA Lewis Research Center, Cleveland, Ohio. Field operaton of the MOD-0 and MOD-1 wind turbines has provided valuable information concerning resonance response in large, two-bladed, horizontal axis wind turbines. Operational experience has shown that 1 per rev excitation exists in the drive train, high aerodynamic damping prevents resonance response of the blade flatwise modes and teetering the hube substantially reduces the chordwise blade response to odd harmonic excita- tion. These results can be used by the designer as a guide to system frequen- cy placement. In addition it has been found that present analytical techni- ques can accurately predict wind turbine natural frequencies. Based on the operation of the MOD-0 and MOD-! wind turbines, the following conclusions concerning resonance response in large, two-bladed, horizontal axis wind turbines can be made. The important natural frequen- cies of wind turbines can be calculated with reasonable accuracy. Odd har- monic content is present in the drive train and can cause significant resonance response. Resonance associated with yaw drive flexibility causes blade load amplification. Resonance associated with tower bending flex- ibility does not cause blade load amplification. Odd harmonic excitations up to and including 5/rev can cause significant blade chordwise resonance response; teetering the rotor will reduce this response substantially. High aerodynamic damping prevents resonance response in the blade flatwise direction at all frequencies. * * * Applications of the DOE/NASA Wind Turbine Engineering Infor- mation System by Harold E. Neustadter and David A. Spera, NASA-Lewis Research Center, Cleveland, OH. The NASA-Lewis Research Center manages for the Department of Energy the technology and engineering development of large horizontal axis wind turbines. In support of this activity each wind turbine has a varie- ty of information systems used to acquire, process, and analyze data. In 12 February 1981 general four categories of data systems, each responding to a distinct infor- mation need, can be identified. The categories are: Control, Technology, Engineering, and Performance. The focus of this report is on the information that can be extracted by Statistical analysis of data obtained from the Technology and Engineering Information Systems. These systems consist of the following elements: (1) sensors which measure critical parameters (e.g., wind speed and direction, output power, blade loads and component vibrations; (2) remote multiplex- ing units (RMUs) on each wind turbine which frequency-modulate, multiplex and transmit sensor outputs; (3) on-site instrumentation to record, process and display the sensor output; and (4) statistical analysis of data at the NASA-Lewis Research Center in Cleveland, Ohio. Two examples of the capabilities of these systems are presented. The first illustrates the standardized format for application of statistical analysis to each directly measured parameter. The second shows the use of a model to estimate the variability of the rotor thrust loading, a derived parameter. . * *. The NASA-LeRC Wind Turbine Sound Prediction Code by Larry A. Viterna, NASA-Lewis Research Center, Cleveland, Ohio. Since regular operation of the DOE/NASA MOD-1 wind turbine began in October 1979, approximately 10 nearby households have complained of noise from the machine. Development of the NASA-LeRC wind turbine sound prediction code began in May 1980 as part of an effort to understand and reduce the noise generated by MOD-1. Tone sound levels predicted with this code are in generally good agreement with measured data taken in the vicinity MOD-1 wind turbine (less than 2 rotor diameters). Comparison in the far field indicates that propagation effects due to terrain and at- mospheric conditions may be amplifying the actual sound levels by about 6 db. Parametric analysis using the code has shown that the predominant contributors to MOD-1 rotor noise are: (1) the velocity deficit in the wake of the support tower, (2) the high rotor speed, and (3) off-optimum opera- tion. The WTSOUND computer code shows generally good agreement with sound spectra measured in the vicinity of a wind turbine. In the far field, however, correlation of the absolute amplitude of the sound level is com- plicated by propagation effects. For the case in this study, terrain and meterological conditions caused an increase of about 6 dB. Analysis using the SOUND code shows that the predominant contributor to the noise pro- blem of MOD-1 is the wind velocity deficit in the wake of the tower. Changes in the aerodynamic forces, as the blades pass through the deficit, produce sound pressure variations in the acoustic field. The level of the sound pressure variations are most directly affected by rotor speed and windspeed. Reducing the rotor speed from 35 to 23 rpm is predicted to reduce sound levels by about 11 dB. The increase in sound levels with wind- speed is predicted to be 12 dB between cutin and rated. * * * Comparison of Upwind and Downwind Rotor Operations of the DOE/NASA 100-kW MOD-O Wind Turbine by John C. Glasgow, Dean R. Miller, and Robert D. Corrigan, NASA-Lewis Research Center, Cleveland, Ohio. Tests have been conducted on a 38 meter diameter horizontal axis wind turbine, which had first a rotor downwind of the supporting truss tower and then upwind of the tower. Aside from the placement of the rotor and the direction of rotation of the drive train, the wind turbine was identical for both tests. Three aspects of the test results are compared: rotor blade bending loads, rotor teeter response, and nacelle yaw moments. As a result of the tests, it is shown that while mean flatwise bending moments were unaffected by the placement of the rotor, cyclic flatwise bending tended to increase with wind speed for the downwind rotor while remaining some- what uniform with wind speed for the upwind rotor, reflecting the effects of increased flow disturbance for a downwind rotor. Rotor teeter response was not significantly affected by the rotor location relative to the tower, but appears to reflect reduced teeter stability near rated wind speed for both configurations. Teeter stability appears to return above rated wind speed, however. Nacelle yaw moments are higher for the upwind rotor but do not indicate significant design problems for either configuration. Tests have been conducted on a 100 kW horizontal axis wind turbine hav- ing first a rotor downwind of the supporting truss tower and then upwind of the tower. Aside from the placement of the rotor and the direction of Wind Energy Report rotation relative to the nacelle, the wind turbines tested were identical. Three aspects of the test results were compared: rator blade bending loads, rotor teeter response, and nacelle yaw moments. Conclusions based on the comparisons are presented below: 1. Cyclic flatwise bending moments are higher for the downwind rotor and increase with wind speed, reflecting the flow disturbance created by the tower. Cyclic bending moments for the upwind rotor appear to be relatively unaffected by wind speed. Mean flatwise bending moments were the same for upwind and downwind rotors. 2. Rotor teeter response appears to indicate a tendency toward teeter in- stability near rated wind speed for both upwind and downwind rotors. Fur- ther testing is required to verify this conclusion. No significant differences were noted between upwind rotor and downwind rotor teeter response. 3. Nacelle yaw moments were smaller for the downwind rotor but the in- creased yaw loads on the upwind rotor do not indicate significant design problems. * . * Calculation of Guaranteed Mean Power From Wind. Turbine Generators by David A. Spera, NASA-Lewis Research Center, Cleveland, Ohio. Much research has been devoted to the nominal power generated by wind machines, but little work has been done on the subject of guaranteed power. Yet power guarantees will be part of the commercialization of wind energy systems. This paper describes in step-by-step fashion a proposed method for calculating the ‘“‘guaranteed mean’’ power output of a wind tur- bine generator. The term ‘‘mean power”’ as used in this study refers to the average power generated at specified wind speeds during short-term tests. Extrapolation to an annual mean power, based on wind statistics, is beyond the scope of this paper. Guaranteed energy is not addressed. The DOE/NASA MOD-OA 200 kW plant in Clayton, New Mexico, is used as a sample case. Subjects discussed and illustrated are correlation of anemometers, the method of bins for analyzing non-steady data, the PROP Code for predicting turbine power, and statistical analysis of deviations in test data from theory. A method of calculating the guaranteed mean power output of a wind turbine generator has been described. The steps in the calculation proce- dure have been illustrated with data from the DOE/NASA MOD-OA 200 kW wind power plant in Clayton, New Mexico. The PROP Code is a practical analytical tool with which the power from a wind turbine like the MOD-OA can be accurately predicted. Deviations between measured and theoretical power do not appear to depend on power density up to 200 watts per square meter. Their distribution is random. Subtracting 8 watts per square meter (9 kW) from the theoretical power output of the Mod-OA system gives a guaranteed mean power with a high degree of confidence. Standard statistical analysis techniques and the method of bins are adequate for the calculation of guaranteed mean power from theory and test data. * * * Comparison of Field and Wind Tunnel Darrieus Wind Turbine Data by Robert E. Sheldahl, Aerothermodynamics Division 5633, Sandia National Laboratories, Albuquerque, NM. January 1981, SAND80-2469. A 2-meter diameter Darrieus Vertical Axis Wind Turbine with NACA-0012 airfoil blades was extensively tested in the Vought Corpora- tion Low Speed Wind Tunnel. The data obtained from these tests were used as the data base for the development of other turbines. Concern about the applicability of wind-tunnel data obtained under ideal conditions to tur- bines operating in the field precipitated the installation of the wind tunnel model in the field at the Sandia National Laboratories Wind Turbine Site. The 2-meter diameter Darrieus Vertical Axis Wind Turbine was tested in the field at the Sandia National Laboratories Wind Turbine Site for a limited number of conditions to make a direct comparison with the data ob- tained previously with the same identically configured turbine in a wind tunnel. One comparison with the wind tunnel data was made with field data of equivalent Re,. A second comparison was made at an equivalent rota- tional speed. The maximum values of the power coefficients compared very favorably. The C,,,,,, for the wind tunnel was 0.32, and the Cemax Of the field data at equivalent Rec (1.5 x 10°) was 0.34. The slight difference is within the experimental accuracy of the measurements. The second set of field data at equivalent rotational speed (400 rpm) shows identical values 13 February 1981 for Coax: It is believed that comparisons should be made on the basis of equivalent Re,. However, the equivalent rotational speed was included for com- pleteness. The field data show improved (higher) values of C,, over the wind-tunnel data for tip-speed ratios in excess of 5.0. This may be due to the blockage correction factor used to correct the wind tunnel velocity or it may be a real difference (although slight) between wind tunnel and field turbine performance. An examination of performance coefficients which do not have the cub- ed dependence on wind speed shows again the excellent agreement between the wind tunnel and field data. The value of Kp,,,, from the wind-tunnel test was 3.8 x 10° whereas K,,,,,, for the equivalent Re, in the field was 4.0 x 10°. K,,,q, for the equivalent rotational speed was 3.4 x 10°. This lower value of performance coefficient was expected because it was obtained with the turbine operating at a lower Re,. Field testing of the 2-meter turbine for direct data comparison was terminated due to the excellent agreement of the first two field-data sets with the wind-tunnel data. It is believed that the accuracy of the wind-tunnel test data was verified and the credibility of that data base was further established. * * * The Effect of Geographical Separation of Clusters of Wind Tur- bines, by R.J. Lowe and G. Alexander, Energy Research Group, Open University, United Kingdom. Presented at the Third Interna- tional Conference on Future Energy Concepts at the Institution of Elec- trical Engineers, London, United Kingdom. January 27-30, 1981. IEE Con- ference Publication Number 192. The effect of spatial separation of wind power sites on the reliability of a system of wind generators has not been investigated in depth for the UK. This paper reports work which shows that geographical dispersion of wind sites can reduce the effect of these short term fluctuations. Conclusions are: At the high frequency end of the spectrum all the groups of sites shown here show no correlation. The Fourier transform of the power output in all cases is reduced by the number of sites. For the pair of sites closest together the correlation starts to increase almost immediately and is close to 100 per- cent at a period of 100 hours. The suggestion is that the 100 km spacing is sufficient to smooth fluctuations from a large number of wind sites for periods of the order of 5-10 hours. A policy of dispersed siting of wind generator clusters around the UK coast with say 25 sites at separation of about 100 km could therefore be expected to reduce the standard deviation of fluctuations of power over a period of 5-10 hours by a factor of about 5. More work is needed to establish how close clusters can be before the smoothing effect is lost. As the spacing between wind sites increases, the smoothing effect extends to lower frequencies. There is little significance in data beyond a period of about 300 hours, but the results for Fraserburgh and Gorleston show prac- tically no significant increase in correlation even at this period. The results for Valley and St. Mawgan show some increase in correlation. All the spectra show a large 24 hour peak. We would not expect this peak to be smoothed as much as adjacent frequencies, but the effect, if any, needs higher resolution to substantiate. The reduction in the total variance of wind power from dispersed sites will reduce the number of conventional power station starts associated with wind power. Because the peak in the spectrum of wind power is at a period of about 2 days, smoothing on this time scale (which will not reduce spinn- ing reserve requirements) will improve the economics of wind power. Geographical smoothing will also increase the capacity credit of wind plant at non-zero penetrations due to the reduction in the total variance of power output. We have not explored this effect in detail, and analysis of the effect will need to account explicitly for the seasonal variation of wind power output. * * * Developing the Variable Geometry Vertical Axis Wind Turbine for Production by I1.D. Mays and B.A. Holmes, P.I. Specialist Engineers Ltd., UK. Presented at the Third International Conference on Future Energy Concepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. The supply of electrical power for the protection of pipelines from corro- sion can pose numerous problems, particularly in remote areas. With this in Wind Energy Report NEW PUBLICATIONS/REPORTS/STUDIES (conz.) mind, P.I. Corrosion Engineers Ltd. became interested in the work of Dr. Peter Musgrove of Reading University in 1976 on the development of a new type of windmill—the Variable Geometry Vertical Axis Wind Turbine (VGVAWT). The decision was taken to use the concept and build a machine suitable for the commercial market. After some initial work, it soon became ap- parent that there was a far wider market than purely cathodic protection for applications such as telecommunications and lighthouses. In 1978, P.1. Specialist Engineers Ltd. was set up to market the turbine. In the four years P.1. has been involved with the development of the Variable Geometry Ver- tical Axis Wind Turbine, the project has progressed to become a commer- cially available machine. Orders have been received from many parts of the world ranging from the Scottish Islands to the Caribbean. Currently P.I. Specialist Engineers Ltd are participating in the ‘Field Measurements Collaboration’ funded by the Department of Energy. For this program extensive data collection is proposed for machines constructed by both universities and industrial organizations, and which are to be in- stalled over a wide geographical area. Detailed power and wake measurements will be made on an array of three P.1. wind turbines. It is hoped to relate the data collected from array models in wind tunnels to these field measurements. In a supplementary program it is anticipated that structural information will be obtained by strain gauge monitoring of the structure. This will be very valuable information for future use relating to both small and large wind turbines of this type. P.1. anticipates producing a smaller version of their present machine to meet power demands up to the 100 watt level for numerous applications, both industrial and domestic. * * * Development of the Aldborough Wind Turbine by W.R. Nickols, Sir Henry Lawson-Tancred, Sons & Co. LTD., U.K. and D.J. Milborrow, Central Electricity Research Laboratories, U.K. Presented at the Third International Conference on Future Energy Con- cepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. In August 1979, the Aldborough wind turbine was rebuilt and commis- sioned following extensive modifications to the rotor, yaw control mechanism and drive system. In its present form which has generated at power levels up to 150 kW. In its original form, with a hydraulic drive system, the machine had operated successfully since July 1977 at power levels up to 30 kW. Tests have shown that the use of a constant-pressure hydraulic system employing gear pumps caused operating problems under certain conditions and the system was subsequently modified to use a variable displacement pump which overcame these difficulties. The hydraulic power was absorbed, in part, by a constant-speed motor so as to demonstrate the feasibility of synchronous power generation. The present system has a direct drive and generates power at variable frequency and voltage. It is, therefore, suitable only for direct connection to heating loads but the possibility of connecting the machine to the network via a rectifier- inverter set is currently being investigated. Recent operational experience with the Aldborough wind turbine has demonstrated the feasibility of operating a fixed pitch machine in the variable speed mode. The control system is simple and has proved to be reliable and is capable of adjustment in the light of operating experience. This flexibility is an important characteristic of variable speed machines and enables their energy yield to be maximized to a degree which is not possible with fixed speed machines. It is hoped to link the machine with the local network via a rectifier inverter set in the near future to derive operating experience of this type of transmission system and designs are be- ing developed for hydraulic transmission so that the aerogenerator will be suitable for power generation and system connection. Dynamics and Control of an Experimental 5m Diameter Variable Pitch Wind Powered Generator by R.G. Herapath and Francis K.C. Shi, Energy Studies Group, University College of Swansea, U.K. Presented at the Third International Conference on Future Energy Concepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. The Swansea horizontal axis test machine is to be fitted with automatic 14 February 1981 speed and pitch control circuits. These are used in conjunction with a microcomputer based ‘power hillclimber’ which seeks to optimize on power output for any particular wind velocity. This paper describes the initial simulation studies on the control circuits. Functional block diagrams are employed to show the significance of each component characteristics. Transfer functions of the variable pitch unit and rotor dynamics for small variations about the operating point have been derived. Results on speed and wind velocity perturbation are given. A dynamic model of wind turbine generator-control system arrangement is developed based on small vari- ations of the system variables about the operating point. Transfer functions for the variable pitch unit and rotor dynamics are derived. Theoretical res- ponse curves are plotted for variation of turbine output speed and torque with time for the given wind disturbance and reference speed perturbation. Analysis of Strong Nocturnal Shears for Wind Machine Design: Progress Report by L. Mahrt and R.C. Heald, Dept. of At- mospheric Sciences, Oregon State University, Corvallis. December 1979. DOE/ET/23116-79-1. Available: National Technical Infor- mation Service. At continental locations, at levels near the top of wind turbines, the wind speed accelerates at night to speeds which average 50% greater than daytime speeds at the same levels. On many individual clear nights, the winds at these levels may increase by several factors. This implies enhanced wind power potential, but also significant increases in wind shear. These nocturnal accelerations are found to be sensitive to the details of the evolution of the stress divergence field during the early evening transi- tion from mixed layer to nocturnal boundary layer flow. In particular, the potential strength of the low-level nocturnal jet depends crucially on the associated rapid increase in the ageostrophic flow during the transition period. This increase is due to the fact that the decrease in surface stress lags the decrease in downward transport of momentum from higher levels. As a result, surface flow and surface stress rotate toward low pressure while at the potential jet level both the flow and the momentum flux convergence vector rotate toward low pressure. On clear nights, this process increases the ageostrophic wind and potential acceleration at the jet level by typically a factor of three over that due to daytime frictional generation of ageostrophic flow. According to the authors, the assessment of noctural wind shear and wind power potential for regions with limited data is greatly facilitated by a physical understanding of the generation of ageostrophic flow during the transition period. (In the second year of the contract, data analysis will be carried out to help relate this generation to climatic features such as cloud cover, atmospheric water vapor content and surface properties. This development will lead to the development of a simple model of the noctural boundary layer which can be used to estimate the climatology of noctural wind structure in regions with incomplete data.) Analysis of data at Wangara, near Hay, Australia, and at two sites over the plains regions of the United States (Sangamon, IL and Cedar Hill, TX) indicates that wind speeds and shears in the noctural boundary layer are considerably greater than earlier estimates from surface observations and from use of the conventional power law. The power law—with stability cor- rected coefficients—can still not adequately represent the vertical structure of the nocturnal boundary layer. Existing alternatives to the power law re- quire values of variables not normally measured and are rather poor in the wind power turbine part of the nocturnal boundary layer. A new format for representation of statistics of the vertical structure of winds is developed and found to describe successfully mean profiles for the various stability classes. However, the statistical stability of this model as well as procedures for application to standard surface data remains to be investigated. Data is also analyzed to determine the physical causes of the strong noc- turnal accelerations and attendant low-level jet. Over the high plains region of the United States, this low-level jet is typically only 100 meters above ground level and thus near the top of many wind power turbines. The low- level jet is found to be driven primarily by generation of ageostrophic flow during the early evening transition period and not ageostrophic flow generated directly by daytime frictional effects. Future research will deter- mine parameters for this generation of ageostrophic flow to assist the assessment of enhanced nocturnal shear in regions of incomplete data. . . * , Wind Energy Report Electric Utility Value Determination for Wind Energy. Volume 1: A Methodology; Volume 2: A User’s Guide. by David Percival and James Harper, Utility Applications and Policy Branch. Solar Y Energy Research Institute, Golden, CO. SERI/TR-732-604. Available: National Technical Information Service. During the past several years, there have been a number of studies on the value of wind energy conversion systems to utilities. Because the ap- proaches taken varied from study to study and different degrees of sophistication were used, the Solar Energy Research Institute sponsored by the Wind Energy Systems Division of the U.S. Department of Energy began to develop a package of computerized tools to determine the value of WECS to electric utilities. These tools were to be capable of varying sophistication and were not to require the modification of the electric utility planning models that must be used in concert with the models developed here. The programs were not to be built around any specific versions of the utility planning models. The objective of this two volume report is to describe these methods and tools. The method is performed by a package of computer models available from SERI. The first volume describes the value determination method and gives detailed discussion on each computer program available from SERI. The second volume is a user’s guide for these computer programs. The value determination process begins with the processing of weather data by computer programs WTP or WEIBUL to produce hourly wind speed data or wind probability distributions, respectively. These data are then provided as input to the program ROSEW which estimates wind- derived electricity production. The results from ROSEW, which can give the probabilities of certain WECS power levels being produced, are next provided as input to the pro- gram ULMOD so that the utility load forecast may be modified to incor- porate the WECS generation. These results, which are for as many years as desired, are provided to the utility planning models. The expansion plann- ing model develops an optimal scenario of conventional generating unit ad- ditions. This amount of conventional units is given to a production cost model to develop a more accurate estimate of the variable operating costs needed for the conventional generating system. This cost information and the conventional capacity information from the expansion model for the base case (zero WECS) and for all the change cases (varying WECS capacity) are provided to FINAM. This final routine determines the break-even cost of each WECS penetration ($/rated kW) and the WECS marginal value ($/rated kW), where value is the utility’s present worth savings of reduced operating costs and modified capital addi- tions. These values may be combined with total WECS cost to determine the maximum amount of WECS capacity that can be economically justified for addition to the utility system. If the WECS value obtained exceeds the amount for which WECS may be purchased, the utility planner might next perform a financial analysis by the utility’s corporate model to determine the effects on cash flow, debt re- quirements, etc. While the analysis was primarily developed for utility- owned and controlled WECS, the analysis could easily be applied to non- utility-owned WECS with proper treatment of WECS availability. A planning group interested in this wind value determination method can obtain copies of the SERI-developed computer programs (WTP, WEIBUL, ROSEW, ULMOD, and FINAM) together with this two-volume report. This group of programs and associated materials are identified by the name WECS. The SERI codes are available through two sources. Qualifying organizations may use the SERI Solar Energy Information Data Bank (SEIDB) network, which houses the computer models. To determine qualification status, contact: Rafael Ubico, SEIDB Coordinator, SERI, 1617 Cole Blvd. Golden, CO 80401 . (303) 231-1032. (FTS-327-1032). These models are also available through the National Energy Software Center, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439. The utility expansion planning and production cost models are currently used by many utilities and are not available through SERI. The utility may prefer to use its own financial model instead of FINAM in the last step of the method. Only minimal effort should be required to make the programs operational on hardware other than the CDC hardware on which the pro- grams were developed and used. * * * 15 February 1981 Location of Sites for Wind Power Development in Northeastern — California: Final Report, by Richard L. Simon, Global Weather Consultants, Inc., San Jose, CA. May 15, 1980. Submitted to: California Energy Commission, Sacramento, CA. A wind energy prospecting methodology developed by the California En- ergy Commission was applied and evaluated during a one-year study in re- mote northeastern California, where only sketchy information about the wind resource potential was available. Existing wind data were analyzed, and a field survey of the region was made to determine the general char- acteristics of the wind regime and select sites for anemometer installation. Winds were measured at twenty-five locations as part of this study, with mostly totalizing and several recording anemometers. The suggested guidelines proved most useful with respect to their objec- tive: to define the wind resource in sufficient detail so that locations for fur- ther study could be identified along with an estimate of the available wind energy. Several recommendations for improving and refining the procedure were made, especially for the field survey and data analysis phase. Mean annual wind speeds apparently exceed 15 mph along the entire 60-mile crestline of the Warner Mountains, the one topographic feature of the region well-suited for wind farm development. There is an excellent wind resource (annual mean wind speed exceeding 14 mph) in northeastern California at well-exposed sites about 6500 feet and certain passes at lower elevations that channel the prevailing westerly or southwesterly flow. Specific high wind locations include the Warner Mountains of Modoc County, the Diamond Mountains of Lassen and Plumas Counties and numerous individual peaks in Lassen County. Wind farm development in northeastern California would require a more detailed monitoring program and a consideration of land use, environmen- tal impacts and economics. The harsh climate and remoteness of this part of the state would certainly add to development costs. A follow-on study should combine these costs with simulated farm output and other factors to estimate a busbar energy cost. The Warner Mountains would be the most logical place in northeastern California for any such development. It is thus recommeded that at least a minimal effort be made to collect better wind data in the Warners. Specifically, the recording anemometer at Fandango Pass should be kept there (or upgraded with a better system) for at least one more year. Access is relatively easy, minimizing technician costs. The data would give future planners a more concise picture of the wind flow over the Warner Moun- tains. Even if no development takes place there, the site would serve well as one of the benchmark stations the state should establish. Several smaller-scale development scenarios are also envisioned. There are several small utilities in northeastern California who might benefit greatly with just a few megawatts of wind-generating capacity. A single installation atop a peak or at Fandago Pass, for example, might be worthy of consideration. Also a smaller turbine atop a peak could be used to power colocated radio facilities, microwave repeaters, or even fire lookouts. Peo- ple in northeastern California live at the lower elevations where winds are very light. Wind generation on residential property thus appears imprac- tical. * * * Experiences with a Grumman Windstream 25 by L. H. Soderholm, Science and Education Administration, U.S. Dept. of Agriculture, Ames, lowa. Proceedings, Summer Conference of the American Wind Energy Association, Pittsburgh, Pennsylvania, June 8-11, 1980. The complete 167 pages of the Proceedings are available for $35.00 postpaid from: WindBooks, P.O. Box 14, Rockville Centre, NY 11571. The problems and experiences obtained from the operation of the Grum- man Windstream 25 wind system are presented. Wind system design considerations dereived from these operational experiences suggest that providing readily accessible adjustments, safety control redundancy, ease of installation, proper yaw orientation forces, accurate evaluation of stresses, adaptability to a wide range of ambient temperature and proper generator excitation are all important factors in obtaining satisfactory and reliable wind system operation. Although multiple problems have been en- countered, a solution has been found for each one. Wind Energy Report The Meteorological Aspects of Siting Large Wind Turbines by T.R. Hiester and W.T. Pennell, Battelle Pacific Northwest Laboratory. January 1981. Available: WindBooks, P.O. Box 14, Rockville Cen- tre, NY 11571. 515 pages. $59.50 postpaid. Order title: Siting Handbook for Large Wind Energy Conversion Systems. This report focuses on the meteorological aspects of siting large wind tur- bines (turbines with a rated output exceeding 100 kW), and has four main goals. The first is to outline the elements of a siting strategy that will iden- tify the most favorable wind energy sites in a region and that will provide sufficient wind data to make responsible economic evaluations of the site wind resource possible. The second is to critique and summarize siting techniques studied in the U.S. Department of Energy (DOE) Wind Energy Program. The third goal is to educate utility technical personnel, engineer- ing consultants, and meteorological consultants (who may have not yet undertaken wind energy consulting) on meteorological phenomena relevant to wind turbine siting in order to enhance dialogues between these groups. The fourth goal is to minimize the chances of failure of early sitimg pro- grams due to insufficient understanding of wind behavior. The problems of wind turbine siting are briefly outlined in Chapter |, Introduction. The main meteorological problem in siting is variability of the wind resource. The spatial variability of the wind resource makes it dif- ficult to identify potential wind turbine cluster sites. The temporal variabili- ty makes it difficult to know the economic value of the wind resource, which is dominated by the conventional fuels that wind energy intermittent- ly replaces. The magnitude and diurnal variation of the wind resource experienced by a large wind turbine cannot be accurately predicted from near-surface measurements. This requires—once a potential site is iden- tified—that measurements from a tall tower be made to assess responsibly wind energy value. Strategies for solving the meteorological problems are outlimed in Chapter 2, Strategies for Wind Turbine Siting. Depending upon the specific problem, wind prospecting begins by screening the utilities’ region of in- terest to identify potential candidate sites. The regional wind energy atlases, prepared for DOE by the Pacific Northwest Laboratory (PNL) and its sub- contractors (Appendix 1, Regional Wind Resource Assessment) are the starting point for identifying areas with an economically viable wind resource. In addition, the wind prospector can use numerical models con- tained in Chapter 3, Numerical Modeling. Consideration of airflow imterac- tion with topography is examined in Chapter 5, Topographical Indicators of Wind Power Potentialand Appendix 2, Some Background Meteorology Pertinent to Siting Large WECS. Chapters entitled Measurements and In- strumentation (Chapter 10), studies of wind effects on tree deformation (Chapter 6, Biological Indicators of Wind Power Potential), on geological features (Chapter 7, Geomorphological Indicators of Wind Power Poten- tial), and on use of land by people (Chapter 8, Social and Cultural In- dicators of Wind Power Potential) examine important methods to identify promising wind turbine sites. Once candidate sites are identified, they are instrumented near hub height (about 200 ft.) for detailed sampling of wind speed and direction (about one minute averages, Chapter 2 and Chapter 10). If the site still looks economically viable, a cluster of wind turbines is designed (Chapter 9, Wind Turbine Wakes and Cluster Design), possibly with the aid of wind tunnel models (Chapter 4, Physical Modeling). Also useful to the wind prospector are two additional appendices. Variability of the Wind Resource illustrates the degree of spatial and temporal variability that can be expected in key wind characteristics and ex- amines limitations to the use of the existing data base in determining the economic value of wind-generated electricity. Estimating Average Wind Speeds from Average Sand Transport Rates uses Bagnold’s theory of sand transport to determine very gross approximations of climatological wind speed. A comprehensive Glossary contains more than 120 meteorological definitions pertaining to wind turbine siting. Following the outline of siting strategies in Chapter 2, specific technical discussions follow in the remaining chapters. The major conclusions of these technical discussions are summarized below. Numerical models provide an objective method for interpolating wind re- source characteristics between data stations. Models may be used to iden- tify good resource areas within a larger region or used to estimate cli- matological statistics at a given site. Simple models, in which conservation of mass is the only physical constraint, are useful where topography is the major influence on airflow. A hierarchy of models based on the comserva- tion of momentum and thermodynamic energy have been developed that 16 February 1981 should be capable of indicating where topographical and thermodynamic effects enhance the resource. However, these complex models are often dif- ficult to use. Modeling is not a stand-alone siting tool but should be used in concert with other techniques. The sensitivity of model results to input data and assumptions should be tested for every region where they are applied. Physical models (wind tunnels, towing tanks) are superior to numerical models when small areas of land (cluster size) are being modeled for stabili- ty conditions that are nearly neutral. Neutral stability exists when vertical motions of air are neither enhanced nor suppressed by effects of the temperature structure of the atmosphere. As the modeled region or height of terrain features become larger and the thermal stratification departs from neutrality, physical modeling becomes less able to model all of the im- portant aspects of the real atmosphere. The best uses for physical modeling are for cluster site analysis and development of generic understanding of flow over specific terrain shapes. é Estimating topographic effects on wind flow (such as the acceleration of wind over a ridge) is the oldest technique of wind energy site assessment. It is still valuable today. Little quantitative information exists so an ex- perienced boundary layer meteorologist should be consulted. Topographical indicators of wind potential assist in understanding flow over terrain— knowing where to measure—and in interpreting measure- ment and modeling program results. Wind-deformed trees are examples of biological indicators of wind. Biological indicators are very useful in screening fairly large areas for evidence of persistent winds. They may also be useful when investigating flow around specific topographical features. It is often possible to estimate the annual mean wind speed to within +20% from trees. However, biological indicators provide only qualitative informaton. The uncertainty of quantitative information derived from geomor- phological indicators (such as wind-formed sand dunes) is large, but the techniques can be applied quickly. Therefore, this technique is recommend- ed only if the geological information can be obtained at little additional cost, €.g., as part of site-screening visits for other purposes. No specific method exists for using social and cultural indicators of wind power potential. The wind prospector should remain alert to certain clues, such as previous uses of wind power in an area, location of snow fences, and evidence of turbulence or high wind damage. Designing a cluster of wind turbines requires knowledge of how closely wind turbines can be spaced and of how the cluster’s geometric design af- fects overall performance. Cluster design is based on an understanding of how the wakes created by individual machines evolve and interact and of how these wakes affect the performance of downstream machines. Results of numerical modeling studies, wind tunnel simulations, and a limited number of experiments in which the wakes of full-scale machines were observed are used to develop wind turbine spacing guidelines. These studies indicate that at spacing greater than 10 rotor diameters, the effect of the wake of one turbine on a downstream machine will be negligible. At a spac- ing of 7 to 8 diameters, there could be some reduction in the output of downwind machines, particularly at night when the intensity of at- mospheric turbulence is low. At a spacing of less than 5 diameters, there is evidence that reductions in the output of downwind machines would be significant. Considerations of the effects of turbine wakes on cluster per- formance are most critical in the prevailing wind directions. In nonprevail- ing wind directions, wind turbines could be spaced very close together in order to reduce land requirements. Wind measurements are the only sure way to assess the resource, and on- ly then when the correct instruments are used properly to measure the ap- propriate quantities. Conventional cup and vane anemometry is adequate for all siting work, but reliability is a prime consideration. Numerous recor- ding system options are discussed. Near-surface (10-meter) measurement has some limited value in the early stages of site selection, as do short-term measurements to detect turbulence and flow separation zones using kite anemometers and tethered balloons. Ultimately, a tall tower is required for site evaluation because techniques to extrapolate 10-meter measurements to hub height for a large wind turbine do not work well, especially over nonflat terrain. . * * Unless otherwise indicated, all abstracted articles, reports, studies and other publications cited in each monthly issue of Wind Energy Report are available from: The National Technical Information Service, U.S. Department of Commerce, Port Royal Road, Spring- field, Virginia 22161. WIND ENERGY Report The International Newsletter of Wind Power January 1981 WIND SYSTEMS ENGINEERING, INC. eas Udo Gad Great Britain to Build 3 MW, 250 kW WECS The United Kingdom has become the fifth European nation to begin serious hardware development of utility wind tur- bines by announcing late this month plans to finance the construction of two wind machines. The U.K. Department Energy will spend 5.6 million pounds ($12.5 million) to finish design work and to build a 3 megawatt, horizontal-axis, two-bladed prototype and site the unit in Scotland. Simultaneously, the Department of In- dustry announced that it will provide 25% of the estimated 1 million pounds ($2.25 million) for a one-third scale, 250 kW ver- sion of the megawatt machine. The United Kingdom, thus, becomes the third European country, joining West Ger- many and Sweden, to fund megawatt-size prototypes. (The Netherlands and Denmark are concentrating their research and de- velopment efforts on large, kilowatt-size, horizontal-axis demonstration projects. Denmark has already built and is testing two 630 kW machines at on its western coast.) A group of three companies, headed by Taylor Woodrow Construction, Ltd., will Inside W.E.R. IRS issues final ETC regs UK to build 3 MW, 250 KW WECS CEGB selecting WECS sites DOE seeks comments on WESA SWECS windfarm in NH PSNHIU.S. Windpower contract . . New Publications ISSN: 0162-8623 build both machines. Both U.K. wind turbines will be erected at Burgar Hill on the Island of Orkney, lo- cated off the north coast of Scotland. Plans call for the large turbine to be installed and interconnected to the island’s 30 MW diesel network by late 1983 or early 1984. The smaller wind system is expected to be generating power as early as this winter. For the megawatt machine, the United Kingdom Department of Energy will pro- vide 4.6 million pounds and the North of Scotland Hydro Electric Board will furnish the remaining | million pounds. The Scot- tish utility will also provide the site and monitor the machine’s performance and operation. The Energy Department will pay for the performance studies expected to last two years after installation. “*It is hoped that a major step forward in the development of wind energy in this country will be taken with the building of the U.K.’s first megawatt-size wind power generator,’’ responded David Howell, Sec- retary of State for Energy, to a question in Parliament on the nation’s involvement in wind power. “This project is an important develop- ment of wind power in the UK and will en- able us to gain experience of the basic prob- lems of aerogenerators.’’ Continues How- ell, ‘‘the wind speeds on Orkney together with its relatively small capacity electricity grid and the high generating costs of its die- sel sets, make it a good site for testing wind generators.”” Main contractors for the 60-meter dia- meter turbine will be the Wind Energy Sys- tem Group, led by Taylor Woodrow Con- struciion Ltd. British Aerospace Dynamics Group and the GEC Power Engineering Limited are partners in the venture. The one other major U.K. contender for (Continued on page 3) World’s first SWECS windfarm built on mountain ridge in New Hampshire Greenfield, New Hampshire—The world’s first small wind system array began producing electricity this past New Year’s Eve on a windy, exposed mountain ridge in southern New Hampshire. Twenty 30 kW, 40-foot diameter, three- bladed, horizontal machines—designed and built by U.S. Windpower, Inc.—produced a nominal amount of power during the afternoon of December 31. And by doing so, U.S. Windpower Inc. became the first wind machine manufacturer in the world to have a functioning, revenue-producing windfarm. And no sooner had the facility generated its first few kilowatt-hours than U.S. Wind- power, Inc. formally notified the Federal Energy Regulatory Commission that it was “‘self-certifying’’ the project as a small power production facility. (As a ‘‘quali- fying facility’? under Sections 201 and 210 of the 1978 Public Utilities Regulatory Policies Act, the windfarm is not consid- ered a utility and not subject to a host of federal regulations.) The 600 kW windfarm, viewed as an ex- perimental, pilot project by U.S. Wind- power, is situated on 25 acres of land ona sloping ridge southwest of the peak of Crot- ched Mountain, New Hampshire. The land is owned by the Crotched Mountain Foun- dation, a world-renowned rehabilitation center for the handicapped. The 25 acres of land on the ridge have been leased to U.S. Windpower, Inc. for an undetermined per- iod for an undisclosed amount of money. The windfarm is not yet fully operation- al, pending final installation of micropro- cessor controllers which govern major oper- ating functions of each machine and regulate the power production of the entire (Continued on page 7) 4 ‘ Wind Energy Report IRS issues final regulations for ETC The Internal Revenue Service has issued final regulations govern- ing the eligibility and implementation of the 10% energy tax credit for wind energy and other alternative energy property. In addition to a normal 10% tax credit for investment in tangible business property, the Energy Tax Act of 1978 adds an additional 10% for energy property. (The Windfall Profits Act amends the "Energy Tax Act by adding 5% more and extending the deadline for eligibility to December 31, 1985, vice December 30, 1982.) The energy tax credits are closely patterned after the investment tax credits familiar to all businessmen. Importantly, the energy tax credit may offset 100% of the tax liability remaining after applying the regular investment tax credit. In its rules, the IRS defines energy property ‘‘as alternative energy property, solar or wind energy property.’’ According to its interpretation, ‘‘wind energy property consists of a windmill, wind- driven generator, storage devices, power conditioning equipment and parts solely related to the functioning of those items.’ Significantly, the IRS expanded this definition to include “transfer equipment,”’ such as tranformers, voltage regulators, etc. “Transfer equipment includes equipment which permits the ag- gregation of electricity generated by several windmills and equip- ment which alters voltage in order to permit transfer to a transmis- sion line.’’ The transmission line itself, however, is excluded from the credit ‘‘based upon the technical definition of the terms transfe: and transmission.” An entire windfarm, consisting of several wind machines and a substation, is thus eligible for the energy tax credits. The transmis- sion lines connecting the windfarm to the local utility are not. Utili- ty energy property is specifically excluded by the regulations. Significantly, the regulations also excludes mechanical energy from a wind turbine but allows wind energy ‘‘to heat, or cool, or provide hot water for use in a building or structure.’’ The regula- tions don’t resolve the issue of whether a heat churn, using shaft power to provide heat would be eligible. Mechanical applications for irrigation, for example, are not eligible. But if wind generated electricity were used to power an electric water pump, presumably, that wind device would be eligible. IRS officials caution that each specific example will be examined and technical questions over what is mechanical and what is elec- trical end-use power will be determined on a case-by-case basis. The 25% total tax credit is seen by many windfarm developers as an attractive financial incentive to prospective investors to shelter income. Along with state tax incentives, the tax credits are the lynchpin of many windfarm investment strategies—particularly for limited partnerships—and for businesses seeking additional writeoffs for new equipment. The revenue generated by a windfarm or the energy saved by using a wind turbine to generate electricity is, incidentally, taxable revenue. But what the IRS giveth, the IRS can taketh away. The regula- tions also provide a recapture procedure when the windfarm or wind machine ‘‘ceases to be energy property.”” There is no guarantee that a windfarm or wind turbine will pro- duce power indefinitely. And similar to the investment tax credit, the regulations stipulate a recapture procedure based on an ‘“‘the estimated useful life of the property.’”’ For both tax credit and depreciation, the IRS has determined that a wind machine has a “‘useful’’ life of seven years. According to Mary Frances Pearson who drafted the IRS regula- tions, if a windfarm or wind machine ceases to be energy property (that is, capable of generating electricity) within the first three January 1981 years, the IRS can reclaim the entire energy tax credit (and the in- vestment tax credit, too). A windfarm that fails between year three and year five of its lifetime will have give up two-thirds of the credit. If a windfarm no longer generates power between the fifth and seventh year of installation, the IRS can ask for one-third of the tax credit. After seven years of the operation, the IRS has no claim on the tax credit. When a windfarm or wind machine ceases to be energy property may well prove to be a knotty technical problem. For example, what happens tax-wise to a windfarm which produces some power in its first year, develops problems in the next, and resumes generating power in the third. Are the recapture provisions ap- plicable for the second year or all three? In a typical WECS array, some machines may produce power while others do not. Is part of the tax credit liable to recapture? Moreover, there are no definitions of how much power, if any, a wind machine must produce to remain eligible for the original tax credit. Details of the Energy Tax Act credits can be found in the Federal Register, Vol. 46, No. 15, January 23, 1981, pages 7287-7298 or by calling M. F. Pearson, (202) 566-3458. Specific answers to ques- tions of eligibility are to be handled by the IRS Technical Division, (202) 566-3755. Opportunity The California Energy Commission is seeking a qualified individual to direct the state’s wind energy program by per- forming the following tasks: © Develop and implement the Commission’s program to promote and accelerate the development of wind energy in California. © Plan, organize, and direct the activities of a professional staff involved in wind resource assessment, technology as- sessment and demonstrations, barrier identification and re- solution, and the development of a market for wind energy. © Present program results and policy recommendations to the commission, administration, legislature, and utility and public groups. Desirable experience/qualifications include: experience in formulating and managing controversial and politically sen- sitive programs; promoting development and market crea- tion for new technologies; developing energy policy; commu- nicating and negotiating with top level executives in govern- ment and/or business; communicating effectively with policy makers. To qualify for this position, the applicants must have four years progressive responsible energy research, modeling, or demonstration project experience. (Research performed in the completion of a dissertation for a doctoral degree in a field of specialization appropriate to the research may be substituted for one year of the required general experience.) Must also have education equivalent to graduation from col- lege supplemented by one year of postgraduate work. Salary Range: $3,284—$3,973 (monthly). This position is located in Sacramento. Resume should be sent to: Carol Johnson, California Energy Commission, Dept. 1975. 1111 Howe Avenue, M/S 51, Sacramento, CA 95825, no later than March 30, 1981. The California Energy Commission is an equal opportunity employer. Wind Energy Specialist Wind Energy Report UK to build 3 MW, 250 kW WECS (Continued from front page) the contract, Cleveland Bridge, has effec- tively withdrawn from serious further wind turbine development. Sources close to the U.K. wind program intimate that Cleveland Bridge was never seriously interested in wind power and was indifferent to promo- ting its lattice tower design aggressively with the Energy Department. As project manager, Taylor Woodrow will continue concept design, systems engin- eering, dynamic analyses, and marketing. It will also be responsible for constructing the foundation and the reinforced concrete tower, building access roads and other site preparation work. Taylor Woodrow will in- strument the site with wind measuring de- vices placed at 18- and 26-meter heights and use TALA kites to measure wind shear. It also plans to build a topographical model of the Burgar Hill site and conduct wind tun- nel tests in a simulated atmospheric boun- dary layer. GEC Engineering will design, manufac- ture, assemble and ground test the nacelle and its contents, the generator and trans- mission. British Aerospace will design, build and test the rotor system. Four-year design effort In 1976, the U.K. Department of Energy = | | Wi | Gearbox | Generator Nacelle eoecececooee Fp esceseceeeee jj I : 10-Om, ee -+-3-0m Clearance between max. deflected blade concrete tower. eo Brake Flap 8m 0/0 x 0-35m thick wall reinforced x concrete tower. funded a study to determine the design and cost of a large wind turbine generator for grid-connected operation. A group of in- dustrial companies comprising British Aerospace Dynamics Group, Cleveland Bridge & Engineering, the Electrical Re- search Association and Taylor Woodrow collaborated on the project and eventually decided on a 3.7 MW, two-bladed, induc- tion generator design for very high wind sites. (See Wind Energy Report, April 1980.) Due mainly to aesthetic considerations, the Energy Department stipulated options for both a lattice steel tower (Cleveland Bridge) and a reinforced concrete tower (Taylor Woodrow) configuration. The original design was predicated, how- ever, on using the wind data and topo- graphical features of a hilltop site south of Ayr in Scotland with the wind turbine inter- tied to the strong grid of the South of Scot- land Electricity Board. Late last year, after much discussion with two scottish utilities, the Energy Depart- ment selected the Island of Orkney within the jurisdiction of the North of Scotland Hydro Electric Board, as the site for the first U.K. megawatt wind turbine. In 1980, the NSHEB lost $11 million pro- \ Rotation January 1981 viding power to Orkney residents and anti- cipates that its losses will reach $18 million in 1981. The diesel fuel cost alone is 8 cents/kWh but the utility is required to charge customers the uniform national rate, considerably lower than the true cost of providing electricity to the islanders. The north scotland utility is no stranger to wind power. In 1950, it commissioned the John Brown Company to build an ex- perimental wind turbine on Cape Costa in the Orkney Islands. Its lattice steel tower, three-bladed, 100 kW unit operated inter- mittently until 1955 when it was shut down due to operational problems. For a brief period during the early 1950s, two British pioneers of wind power, E. Golding and A. Stoddard, took wind mea- surements at nearly 100 sites in Great Brit- ain, including the Orkney Islands. Three sets of wind speed data exist from Costa Hill, Vestra Fiold, and Big Nold Park on Orkney. These data were then compared and integrated with longterm data from the island’s airport. The results showed that the annual average mean wind speed at hub height of 45-meters exceeds 12 m/s (26.88 mph). Moreover, the Burgar Hill site is smooth with round hills and has few trees or obstructions. Thus, the combination of high energy costs and an excellent high wind regime made Burgar Hill a more attractive site. Design changes for Orkney Nevertheless, the choice of the Orkney site—with a weak, 30 megawatt diesel- based grid—has caused a number of signifi- cant design changes. Rather than an induction generator, amenable to a strong grid, the 3 MW will have a synchronous generator, suitable to a weak system like Ornkey’s. A synchronous generator, though, requires some degree of rotor torque control, according to Taylor Woodrow’s Dr. David Lindley, the Wind Energy System Group’s project manager. “‘With a synchronous generator,’’ he says, “we decided the WECS needed a soft trans- mission with rotor torque control using movable blade tips, similar to the MOD-2, on the outer 20% of the blade length.’’ A stall controlled, fixed pitch design with an induction generator would not be compati- ble for such an island application. The two steel blades will still be fixed pitch, except for the tips which will be variable to provide speed control and brak- ing. The main structural spar will be made of steel. According to the U.K. DOE, ‘‘the mach- ine is planned to operate at a nominal 34.1 Wind Energy Report January 1981 UK to build 3 MW, 250 kW WECS rpm at windspeeds between 7 and 27 m/s (15.7-60.5 mph). The machine reaches rated 3 MW electrical output at 17 m/s (38 mph) and continues to generate electricity until it shuts down at 27 m/s. Taylor Woodrow estimates that the 60-meter wind turbine could generate 11 million kilowatt-hours annually at Orkney. The 60-meter blade-diameter of the 3 MW machine is 7.5 feet shorter than the 200-foot MOD-1, rated at 2 MW. Accor- ding to the U.K. DOE, ‘“‘the turbine axis will be located 45 meters above the ground and the turbine will drive a synchronous generator through a gear transmission. The turbine transmission and generator will be mounted on the top of a 46-meter high con- crete tower on a detachable steel platform within a rotatable steel nacelle.’’ The machine will actively yaw into the wind using a ‘‘novel system consisting of vertical support bogies and a walking mech- anism which operates on the vertical surface of the tower, driven by hydraulic rams.” Unlike the trend among two-bladed megawatt designs toward a teetered hub and a soft tower, the 3 MW U.K. design has a rigid hub and stiff tower. ‘‘Potential hur- ricane loading in the Orkneys is 70 m/s (156 mph),”’ explains Lindley, “‘so it’s a fairly high risk situation for a soft, compliant design for the first large machine ever made in the U.K.” But there is some indication that the Wind Energy System Group may incorpor- ate some important changes, based on the operating experience with the 250 kW machine and on closer examination of test results from U.S. and West German experi- mental machines. Taylor Woodrow has al- ready reduced the rotor rotational speed from the original 34.1 to 31 rpm. Lindley contends that ‘‘it is a bit early to determine the precise configuration”’ for the 3 MW design. But the final 60-meter design, according to Lindley, will be strong- ly influenced by its 20-meter, one-third scale prototype. ‘‘As we are procuring and building the 20-meter unit,”’ says Lindley, “‘we will be designing the 60-meter machine in parallel.”” Taylor Woodrow sees the 3 MW machine as a standard piece of utility electrical generating equipment with the prime, per- haps singular, application for shallow off- shore installations along Great Britain’s coastline. Taylor Woodrow recently com- pleted a study of offshore siting prospects for WECS in the U.K. ‘‘We are almost cer- tainly going to get an additional contract from the Energy Department to conduct the second phase of the offshore study,”’ says Lindley. Moreover, Taylor Woodrow will be working with the Central Electricity Generating Board to uprate the machine to al00-meter diameter atop an 80-meter tower. ‘‘We’ll be looking at cost scenarios for production runs of 2,000 of ‘the 100-meter, 5-6 MW wind machines,’’ predicts Lindley. 250 kW prototype The 250 kW prototype will be nearly identical to the proposed 3 MW machine, says Lindley. But there are some intriguing changes. The 20-meter machine will have a steel blade spar with fiberglass ribs filled with plastic foam. The outer shell will be made of fiberglass. The 250 kW unit will also have a soft transmission which, accor- ding to Lindley, ‘‘can take up to 28° of tor- sion movement to reduce power spikes.”’ It will use a stiff, tubular steel tower. Significantly, the 250 kW machine will operate in the rotor torque control mode at constant speed. ‘‘We are building a special- ly designed power conditioning unit so that it can be operated at variable speeds.’’ says Lindley. At Orkney, Lindsay says the 250 kW could produce 750,000 kilowatt-hours annually. With a 20-meter rotor diameter, it is about half the rotor size of the MOD-OA. Lindley explains that with a 10.5 m/s speed at hub height at Orkney, the 250 kW unit will have three times the power available to it than the 125-foot rotor diameters of the Westinghouse 200 kW MOD-OA or the 350 kW Rockwell International machines. According to some observers, the final cost of the larger Taylor Woodrow wind machine could be as high as 7-8 million pounds, once critical design changes have been included. The company says it has al- ready contributed $1 million of its own funds so far toward development of the 250 kW machine. Markets for the 250 kW: remote non-grid connected applications The 20-meter machine is expected to cost 1 million pounds with the Wind Energy Sys- tem Group providing 50% and the North of Scotland Hydro Electric Board paying 25% of development costs. Although the 20-meter unit is viewed as a test bed for the larger 60-meter machine, the Wind Energy System Group and its gov- ernment sponsors see the machine princip- ally as a commercial, exportable product. According to the Department of Indus- try, ‘‘it is hoped that this project will lead to a U.K. capability for machines of the 250 4 kW size, which are expected to find overseas markets in some areas of the world with plentiful wind and high energy costs, particularly island communities.”” And Taylor Woodrow sees the 250 kW unit as more than a mere test bed prototype for the 3 MW machine. ‘‘We want a sellable machine,”’ says Lindley. ‘‘We are designing the 20-meter machine as a product that can be marketed in its own right. That’s why we’re designing it for two speed modes: constant and variable. We’ll have a range of options, separate data for both modes, to show to clients.’’ The choice of Orkney may prove to be an excellent test site providing useful operating experience—applicable to hundreds of sim- ilarly remote and isolated communities. “Orkney is an island very typical of other small power systems in the world with 20-30 MW diesel sets,’’ notes Lindley. ‘In a very small grid, where you have a very tight con- trol on power deviations from the mean, where the power spikes will not be greater than 10% of any mean value, you are im- posing some tough design and operating conditions.”” Lindley contends that if the 20-meter machine works well on Orkney in 10.5 m/s winds, with hurricane force wind loading of 70 m/s, Taylor Woodrow will have a ‘“‘sell- able’’ machine for this market. The Orkney site is seen by U.K. Energy Department officials as having application primarily for diesel-based utility networks. “This type of grid is a characteristic of other isolated communities which often rely on diesel generation and these too could benefit from the use of wind power.’’ “Eventually, we’re looking at penetra- tion rates of 25-30% on the islands.’’ says Lindley. For Orkney, that’s 30 to 40 of the 20-meter machines. With the exception of the Orkneys, the Shetlands and a very few other island chains in the United Kingdom, the domestic market is too small to justify large production runs of the 20-meter unit. Taylor Woodrow wind machines will, no doubt, will be for export only—not for ad- ding new generating capacity to the CEGB network. After twelve months of successful opera- tion in the Orkneys, says Lindley, Taylor Woodrow could be producing large num- bers of the 20-meter units. For more information on the wind tur- bines of the Wind Energy System Group, contact: Dr. David Lindley, Project Man- ager, Taylor Woodrow Construction Limit- ed, Taywood House, 345 Ruislip Road, Southall, Middlesex UB1 2QX, United Kingdom. Tel.: 011-44-01-575-4316. Wind Energy Report DOE seeking comments on 1980 Wind Act The Department of Energy’s Wind Energy Systems Division is soliciting advice on how the agency should implement the Wind En- ergy Systems Act of 1980, the most significant piece of federal wind power legislation ever passed by Congress. With speculation widespread about massive federal budget cuts—particularly in the conservation, solar and wind programs for the 1981 and 1982 fiscal years—from the Reagan Administration, DOE’s Conservation and Solar Applications Branch hastily au- thorized meetings in Denver and Boston hours before the Reagan administration took office. DOE wants specific recommendations on how the act should be funded and administered. Among its major goals, the Act calls for the following: (1) to reduce the average cost of electricity produced by installed wind en- ergy systems by the end of fiscal year 1988 to a level competitive with conventional energy sources. (2) to reach a total megawatt capacity in the U.S. from wind energy systems by the end of FY88 of at least 800 MW of which at least one hundred megawatts are provided by small wind energy systems. (3) to accelerate the growth of a commercially viable and competitive industry to make wind en- ergy systems available to the general public as an option in order to reduce national consumption of fossil fuel. In order to meet these goals, the Act requires that DOE submit a Comprehensive Program Management Plan to Congress by June 8, 1981. The management plan will include: (1) a five-year plan for small wind energy systems (less than 100 kW); (2) an eight-year program for large wind energy systems (greate than 100 kW); and (3) a three-year program for wind resource assessment. Written comments should be addressed to: Carol A. Snipes, U.S. Department of Energy, Hearings Procedures, Office of Conserva- tion and Solar Energy, Mail Stop 6B-025, Docket Number CAS- RM-81-404, Washington, DC 20585. Deadline for receipt of com- ments is March 15, 1981. United Kingdom utility selecting WECS sites The Central Electricity Generating Board has selected a site at its Carmarthen Bay power station in Wales to erect a medium sized wind energy system. By 1982, the CEGB—Europe’s largest electrical utility—hopes to have a large kilowatt wind machine operating at Carmarthen Bay. Such a demonstration is seen as a forerunner for megawatt class wind turbines. A demonstration wind machine, says the CEGB, ‘“‘will then provide operating experience and research information to help in the choice of the first large wind-powered generator.”’ In the early 1950s, according to the CEGB, its predecessor agency sought to erect a small prototype in the Lleyn Peninsula in Wales, considered one of the windiest sites in Great Britain. The project was eventually dropped because of local opposition. The utility has also selected three other possible installation sites for megawatt-size wind turbines: an unused airfield at Wigsley, near Lin- coln, the Bradwell nuclear power station, Essex, and the Richborough power station in Kent. At these three sites, the CEGB will record windspeed and other pertinent meteorological data. According to the CEGB, “‘each site will be assessed for its suitability for the first large machine and the surrounding areas will also be assessed for extending the installation off the site to form a cluster of as many as ten large machines spaced approximately one-half mile apart. Just how far ‘‘off the site’ a cluster could be is left unanswered by the CEGB. As part its participation in the wind energy program of the Interna- January 1981 tional Energy Agency, the CEGB has been collecting wind data ona number of possible offshore locations. One of these locations is at Carmarthen Bay. At the Third BHRA Conference on Wind Energy last August, the utility announced that it planned to select an inland site and then ac- quire a wind machine of at least one megawatt capacity from equip- ment available on the world market. The CEGB indicated that it in- tended to buy a ‘‘proven commercial design when such machines are available and show promise of low cost in series production’’ speculating that such equipment would be available by 1985. The utility, apparently, is revising its plans to include a smaller demonstra- tion unit in a shorter period. Whether the utility will buy a ‘‘made in the U.K.’’ wind machine is the source of some bewilderment, particularly to the Wind Energy System Group charged with producing both an intermediate and a megawatt size machine for testing at Orkney. (See related article on next page) The CEGB says that it will make application to the U.K. Depart- ment of Energy for permission to erect a machine, so far unselected, at Carmarthen Bay. The CEGB announcement came two weeks before the Energy Department selection of the Orkney site. Some British wind energy observers saw the timing of the CEGB an- nouncement as a last minute ploy to influence the siting decision in favor of Carmarthen Bay. The U.K. DOE is providing 82% of the funds for the 3 MW Orkney prototype to be built by a consortium headed by Taylor Woodrow Construction. The consortium will also build a 250 kW prototype. Whether or not the Energy Department will require the CEGB to buy a U.K. designed and built wind machine remains to be seen. * * * Meetings/Conferences A two-day conference/workshop, Wind Power—Energy Alter- natives for the Upper Midwest, will be held in Rochester, Min- nesota, April 3-4, 1981. Devoted almost exclusively to small wind energy systems, topics include: The Wisconsin Anemometer Loan Program by Ed Hirshberg, Wisconsin State Solar Office; The Wisconsin Power & Light Research Programby Dr. Carel DeWinkel, WP&L; Overview: The Rocky Flats Field Evaluation Pro- gram by Jim Sherman, Rockwell International; and The Public Utility Regulatory Policies Act by John O’Sullivan, Chief Advisory ‘Counsel, Federal Energy Regulatory Commission. Also: Ethics of Marketing the Wind, Jack Bolger, Aerowind/Bolger Publications; Approaching the Insurance Marketplace, Richard Kroeger, Alexander & Alexander; Land Use Implications of WECS, Robert Noun, SERI; New Mexico: An Overview of Ongoing Wind Energy Research, Ken Barnett, N.M. Solar Energy Institute; Overview: Current and Future Pro- spects of Wind Energy, Irwin Vas, SERI. There will be two workshop sessions for the general public: Wind Equipment Primer: Introduction to Wind Systems, John Cuddy, Min- nesota Energy Agency; Towers, Phil Metcalf, UNARCO Rohn; Batteries, Harold Cragg, H.M. Cragg Co.; Stand-by Systems, Terry Paul, BEST Energy Systems; Inverters, Terry Paul, BEST Energy Systems and Tom Werking, Windworks. Wind Power: Institutional Issues: Financing a Wind System, Jim Laukes, Nat. Center for Appropriate Technology and Len Laulainen, Mid American Solar Energy Complex; The Residential Conservation Service Program, John Lupoli, Mid American Solar Energy Complex; Zoning Issues, John Cuddy, Minnesota Energy Agency; Working with Your Utili- ty, Stan Selander, United Power Assn., Dan Nordell, Northern States Power Co. and Dr. Carel De Winkel, WP&L. Manufacturers of small wind energy conversion systems will be * Wind Energy Report Meetings/Conferences available to discuss their equipment. A 55-minute videotape will look at the development of large and medium sized machines for industrial and agricultural use. Combined registration for the two-day event is $55.00. For registration and further information, contact: Wind Energy Con- ference, Rochester Area Vocational Technical Institute, 1926 2nd St., SE, Rochester, MN 55901. (507) 285-8498 or Abby Marier, Alternate Sources of Energy, Inc., Milaca, MN 56353. (612) 983-6892. * * * The California Energy Commission will hold a two-day con- ference: Wind Energy: Investing in Our Energy Future at the Palm Springs (California) Riviera Hilton, April 5-7. Governor Edmund G. Brown, Jr. will deliver the keynote ad- dress and Tom Hannigan, Chairman of the California Assembly’s Energy and Natural Resources Committee will speak at lunch. The conference is divided into the following sessions: Making Dollars and Sense Out of Wind Energy: John Bryson, Chairman, California Public Utilities Commission, ‘‘PURPA: The New Market for Wind Energy;’’ Michael Lotker, Synectic Group, Inc., ‘Making the Most of Federal Tax Incentives,’’ and Lynn Schenk, Secretary of Business, Transportation & Housing, ‘‘State Financial Incentives.” Developing a Wind Farm: James A. Walker, Commissioner, California Energy Commission, ‘‘Wind Resource Assessment;”’ Robert J. Noun, Solar Energy Research Institute, ‘‘Siting and Land Use Issues in Wind Development;’’ and Maurice J. Katz, Director, DOE Office of Solar Power Applications, ‘‘Wind Tur- bines for the 80s and Beyond.”’ Financing a Wind Farm: Philip M. Huyck, The First Boston Corporation; John Moynier, Bank of America; and Dr. Larry T. Papay, Southern California. Emerging Success Stories: Wayne K. Van Dyck, Windfarms, Ltd.; Peter B.S. Lissaman, Ph.D, Aerovironment; and B. Gale Wilson, City Manager, City of Fairfield Five two-hour workshops will be held throughout April 7 and wind turbine manufacturers will provide displays and exhibits. Workshop include: Financing a Wind Project; Siting and En- vironmental Issues; Utilities, Third Parties and PURPA; Wind Resource Assessment; and Wind Opportunities Abroad (Tentative). A tour of the San Gorgonia Pass, site of Southern California Edison’s two wind turbine demonstrations, will during the afternoon of April 7. Registration fee is $75.00 for the two-day conference/workshop. For further information, contact: Alan Friedman, California Energy Commission, 1111 Howe Avenue, Sacramento, CA 95825. (916) 924-2404. The British Wind Energy Association will hold its Annual Con- ference at the Cranfield Institute of Technology in Cranfield, Bed- fordshire, England, from April 8-10. The following papers will be presented: Large Machines—Design, Construction and Performance: The Horizon- tal Axis Wind Turbine Project on Orkney, D. Lindley and W. Stevenson, Taylor-Woodrow and N.S.H.B.; Development of the Musgrove Vertical Axis Wind Turbine, R. Clare, and J. Allan, McAlpine and Aircraft Designs Bembridge; Wind Turbine Transmission Systems, A. Garrad, Taylor- Woodrow; and The Hamilton Standard/Karlskronavarvet WTS 3&4 Large Wind-Turbine Programme. Offshore Wind Energy Systems: The Offshore Wind Energy Resource, January 1981 A. Rockingham, R. Taylor, and J. Walker, Central Electricity Generating Board; Estimation of the Availability of an Offshore Wind Power Installa- tion, J. Walker, Central Electricity Generating Board; and Offshore Wind Turbines: Design and Economics; J. Dixon, Open University. Economics and System Integration: Effects of Wind Power and Pumped Storage in an Electricity Generating System, G. Whittle, Reading Universi- ty; The Frequency of Wind Turbine Shut Downs, E. Bossanyi, Reading University; A Comparative Study of Wind Power Conversion Systems, R. Wilson, James Howden and Co. Energy Investment in Wind Turbines, J. Dixon and R. Lowe, Open University. Small Machines - Design, Construction and Performance: An Apprecia- tion of the IDM Windmatic Aerogenerator Operating on Orkney, R. Cattle and W. Somerville, NEI Clarke Chapman Engineering; The Relative Economics of Wind Pumps Compared with Engine Driven Pumps, P. Fraenkel, 1.T.D.G.; Wind Turbine Research at Napier College, W. Ban- nister, Napier College; Practical Aspects of Small Turbine Installations, G. Watson, Northumbrian Energy Workshop. Aerodynamics: Measurement and Interpretation of Wind Turbine Wake Data, D. Milborrow, CERL; The Effect of Fixed Pitch Offset on a High Solidity Vertical Axis Windmill, G. Stacey and P. Musgrove, Reading University; Wind Turbine Wake Studies, B. Clayton and P. Filby, Univer- sity College London; Wake Measurements in Clusters of Model Wind Tur- bines Using Laser Doppler Anemometry, J. Ross and J. Ainslie, CERL; The Effect of Terrain and Construction Method on the Flow over Complex Terrain Models in a Simulated Atmospheric Boundary Layer, J. Pearce and D. Neal, University of Canterbury, N.Z. and D. Lindley and D. Stevenson, Taylor-Woodrow. For further information, contact: Dr. Peter Musgrove, Chair- man, British Wind Energy Association, Department of Engineer- ing, University of Reading, Whiteknights, Reading RG6 2AY, England. * * * The American Wind Energy Association will hold its Spring Conference from April 19-22 at the Marriott Hotel in Portland, Oregon. The conference will include technical sessions for the wind in- dustry, workshops on product liability, siting and manufacturers design tools. A field trip to the MOD-2 site at Goodnoe Hills, Washington, will be available. For further information, contact: AWEA Conference Commit- tee, American Wind Energy Association, 1609 Connecticut Avenue, NW, Washington, DC 20009. (202) 667-9137. * * * The British Wind Energy Association will hold a one day Inter- national Colloquium on Wind Energy on Thursday, August 27, 1981 at the Solar World Forum Congress and Exhibition in Brighton, England. Invited speakers include: Dr. Freddy Clarke, UK Department of Energy; Dr. Louis Divone, US Department of Energy; Dr. Peter Musgrove; Chairman, British Wind Energy Association; and Dr. Horst Selzer, ERNO, West Germany. For further information, contact: Dr. Leslie F. Jesch, Chairman, Organizing Committee, Department of Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, England. WIND ENERGY REPORT® Copyright © 1981 Wind Publishing Corporation. All rights reserv- ed by the copyright owners. Wind Energy Report® is published monthly. No portion of this publication may be reprinted, reproduc- ed, stored in a computer-based retrieval system or otherwise transmitted in whole or in part without the express, written permis- sion of the publisher. Printed in U.S.A. Subscriptions: $115.00 annually (USA); $125.00 annually (Canada & Mexico); $155.00 annually (foreign airmail). Two-year subscriptions: $195.00 (USA); $230.00 (Canada-Mexico); $290.00 (foreign airmail). Editorial offices are located at: 189 Sunrise Highway, Rockville Centre, NY 11570. Mailing address for all correspondence: P.O. Box 14, Rockville Centre, NY 11571. (516) 678-1230. Wind Energy Report SWECS array built in New Hampshire (Continued from front page) array. Nevertheless, the array did produce some electricity—less than a dollar’s worth—on December 31 and approximately 200 kilo- watt-hours during January, according to Public Service of New Hampshire. U.S. Windpower, located in Burlington, Mass- achusetts, a two-hour drive from the site, in- dicates that the entire array should be com- pletely operational later in the spring. 40-foot diameter, 30 kW SWECS The 20 small wind systems at Crotched Mountain are identical. According to U.S. Windpower, ‘‘each wind turbine is compos- ed of three slender fiberlass blades turning at approximately one and a half revolu- tions/second and driving a 30 revolu- tions/second generator through a speed-up transmission. “This mechanical power train is automa- tically controlled by blade pitch to provide start-up, shutdown, efficient constant speed operation and redundant safety pro- tection. “The operation of the machines is dir- ected by a microprocessor ‘brain’ in each turbine and by a centralized remote control system that enables the windmills to be run in concert as a single electric generating unit.”” Each wind machine is positioned down- wind, yaws freely and rotates counterclock- wise. The blades are tapered from root to tip. The root section is about twice the chord of the tip. The cut-in speed is 10 mph and each machine reaches rated power at 27 mph. According to Moore, U.S. Windpower hasn’t established a cut-out speed yet. As a pilot array, the company will experiment with various machines within the array to determine the most efficient shut down speed. Each cluster of three or four machines are tied to a common transformer which feeds power to a 12.47 kV substation at the foot of the hill. At the base of the array, a trailer houses the electronic and metering equipment. According to a 20-year purchase power agreement with Public Service of New Hampshire, the state’s largest utility, the electricity generated by the 20 wind machines will be transmitted to the utility’s lines via the 12.47 kV transmission inter- connect. U.S. Windpower will be responsible for installing and maintaining ‘‘at its own ex- pense such protective devices and equip- ment as are necessary for the protection of the Public Service electric system and per- sonnel,”’ and to install capacitors and other equipment necessary to maintain the wind- farm’s power factor ‘‘as close to 100% as reasonably possible.”” The agreement stipulates that U.S. Wind- power Inc. ‘‘will have sole responsibility for operation and maintenance of its genera- ting units, including any relays, locks, seals, breakers and other control and protection January 1981 apparatus that are necessary’’ for the facili- ty to operate in parallel with Public Service. Moreover, U.S. Windpower will be re- quired to install, own and maintain a meter and related facilities so that the electricity generated by the windfarm can be measured hourly and Public Service be notified every 24 hours of just how much energy has been produced. The contract itself is a precedent insofar as it is the first purchase power agreement governing the operation of a small wind ar- ray. No doubt, it will used as a model for (Continued on next page) 30 EE EUR OT I CR ' ‘Wind Energy Report SWECS windfarm built in New Hampshire (Continued from preceding page) other arrangements between small power producers and local utilities.(For complete text of agreement, see page 11). The actual location of the facility is on the grounds of the Crotched Mountain Foundation but not on the mountain peak itself which is located in nearby Francestown. The facility—20 wind machines, substa- tion and control trailer—was erected in 79 calendar days from the time the Greenfield Town Board gave its official approval on October 13. ‘“‘The Town of Greenfield stuck its neck out,’’ says Norman Moore, president of U.S. Windpower,‘‘when nobody else would.” Construction crews from New England Power Company, a subsidiary of New Eng- land Electric Systems, built the facility after a local New Hampshire firm, McMillan Company, constructed the roads and poured the concrete for the foundations. NEPCO, under contract to U.S. Wind- power, erected the towers and installed the wind machines on the towers using conven- tional ‘‘cherrypickers.’”” NEPCO also inter- connected each machine and wired them to the power poles. “It was a very tough installation to go in- to in terms of being cold and very windy. When we’re through, we will have learned a lot more than we would have at a benign site and learned it a lot sooner,’’ argues Moore. Meteorological data is scarce at the site. U.S. Windpower has installed two meteoro- logical towers at 35-foot and 75-foot January 1981 heights, respectively. What little windspeed and direction data is known comes from measurements taken at Crotched Moun- tain. According to a study last year of New Hampshire’s wind potential by Arthur D. Little, Inc., windflagged Balsam Fir on the peak of Crotched Mountain reveal an 18.1 mph wind speed from the westnorthwester- ly direction. The windfarm site itself is at a slightly lower elevation than Crotched Mountain (2,011 feet above sea level) and so far has yielded instrument measured windspeeds in the neighborhood of 16 mph, according to Moore. Moore says that the site have a very narrow windrose and nearly all of the en- ergy producing winds will come from the prevailing direction. SWECS array spacing The majority of the wind machines are Rotor Gere GF Dlades 26.423. dope oes. se Diameter ....... Location, relative to tower Re ee Cone angle . Tilt angle ... Nacelle Blade ET CONE {5 foie > win Sc dink: oa ine~ eh Material ........ Weight, Ib/blade . Tower BUM poo 5. ee tc se ee ee 60 feet FMD BIOIM os... 5s os Senko 552 cccwtesengeeccwe 62 feet TN iis soos 270 . three-legged, steel tripod INO 5. ci tivtinnticljgnsnsineaesxe galvanized steel 12 mph* WIQN . 2.2... s cc ceee ccc ee cc cecccscseccces 4,500 Ibs. 14mph* RS soe co ee ee three concrete footings 16 mph* 18 mph* Transmission Weight Above tower .... Tower .... Total ... U.S. Windpower, Inc. 30 kW Wind Turbine Specifications Generator Soe in cameo 3 ek. -- 5 pee 40 feet Rating . -constant 100 rpm Power Factor .... Ss eas 103 rpm Saaeas's downwind Control System Supervisory ..... Overspeed control . Blade pitch...... Performance Source: U.S. Windpower, Inc. . 18° Orientation Drive eeeee pe tn ase Rated power ..... Peak power ... Wind speed at centerline of hub: ain, oe Cee cals ee ene microprocessor blade pitch/electronically activated i aerodynamic/microprocessor Annual Power Output (Estimated) Wind Energy Report strung along a vague northwest-southeast axis with a minimum of 150 feet or approximately 3% rotor diameters between them. Some are spaced further apart along this axis. Several machines, set parallel to the prevailing wind, are approx- imately 300 feet from one another or 7% rotor diameters apart. “If people are going to look at this array for some subtle or calculated spacing,’’ observes Moore, ‘“‘the answer is no.” Topography and prevailing wind direction had an important, perhaps dominant, influence the specific siting of each turbine within the array, he says. “*We have consciously placed a couple closer than good engineer- ing might otherwise dictate for maximum power output,”’ says Moore, ‘‘just so it will be easier for us to study interference.’’ U.S. Windpower doesn’t place much stock in rotor diameter rules of thumb for system spacing in a cluster. Conventional wind tunnel experiments or speculations in a number of theoretical studies are no substitute for a real world experiment, he says. “*After we have run those machines for a while, feathered one and seen the effect on the next one over a statistically significant period,’’ predicts Moore, ‘‘we’ll know a lot more than anyone else about machine spacing within an array.’’ The 30 kW machine at the Crotched Mountain facility won’t be manufactured by U.S. Windpower. It represents an earlier concept, partly inspired by the University of Massachusetts Wind Furnace, itself a three-bladed, fiberglass, downwind configuration. Rather, the company is developing a 56-foot rotor diameter, 50 kW machine for the additional windfarms it is planning. Most of the major components, such as the transmission and generator, will be mass-produced off-the-shelf items from existing manufacturers and suppliers. The rotor, however, will still be fiberglass. A Rhode Island firm, Tillotson-Pearson of Barrington, has been contracted to fabricate the blades for the 50 kW machines according to U.S. Windpower specifications. Prototype for other windfarms For U.S. Windpower, the Crotched Mountain array is the first in a series of such installations at windy sites in high energy cost regions throughout the nation. In early 1979, U.S. Windpower announced plans for a 100 MW windfarm in the San Pacheco Pass on property of the California Department of Water Resources. Subsequently, the company began a wind monitoring program in the Pass and is also paying for environmental studies. Representatives of the company have been actively seeking out suitable sites, particularly in the Pacific Northwest. U.S. Wind- power has an option to construct windfarms on 4500 acres of land adjacent to Goodnoe Hills, Washington, the site of the installation of the first three MOD-2s. (When completely built this spring, they will be the first large machine windfarm.) To date, however, U.S. Windpower has not secured a purchase power agreement with the Bonneville Power Administration, the federal power marketing agency in the region. According to Moore, the company already has cleared land on the Knapp Ranch near Cape Blanco, Oregon, and has clearances to put its wind machines there. The company is also looking into a project on Nantucket Island off the coast of Massachusetts. Both Cape Blanco and Nantucket were among 20+ sites chosen by the Department of Energy last year for wind measurement programs. The Crotched Mountain project came on the heels of a failure to convince authorities in Gloucester and Cape Cod, (Continued on next page) Jamuary 1981 = Wind Energy Report SWECS windfarm built in New Hampshire (Continued from preceding page) Massachusetts, of the benefit of building two arrays. One project would have called for the erection of 100 50 kW machines at Otis Air Force Base which could have sup- plied a reported 30% of the facility’s electricity. Both projects were stymied, ap- parently, for environmental reasons. (Says Moore, ‘*One Harvard professor worried aloud about the effect of low level radiation generated by the blades!’’) 800 megawatt windfarm goal Russell Wolfe, vice president of the firm, indicates that U.S. Windpower alone could meet the 800 MW goal of the Wind Energy Systems Act of 1980. In itself, that trans- lates into 16,000 SO kW machines and a cap- ital investment of $800 million if the cost of the Crotched Mountain facility is used as a yardstick. That’s an ambitious goal for a company which just a little more than a year ago raised $5.4 million in capital through a private equity offering. How does a small company with a high- risk product attract investment? The twenty machine windfarm generated little electricity on the last day of 1980, but it did provide a wealthy San Francisco in- surance executive, Karl Bach, and his two sons a $250,000 federal tax credit. Bach has been a close personal friend of Moore for thirty years and this partly ex- plains how U.S. Windpower went about raising seed capital for the company and how it plans to finance future windfarm projects. Alvin Duskin, executive vice president of the company in charge of marketing, says Annual Revenue Production $165,000 188,100 214,434 244,455 278,678 Annual Expenses $45,000 48,150 51,520 55,127 58,986 317,693 362,770 412,874 470,676 1 536,571 63,114 67,532 72,260 77,318 82,730 that the initial financing came from wealthy friends and acquaintances. Duskin con- tends that raising seed money through personal or business connections is more productive because they are more willing than institutional investors to stand by the business during its early years of struggle and uncertainty. U.S. Windpower says it approached a number of venture capital firms for capital but were turned down by each. According to Duskin, ‘‘everyone turned us down because the structure of the deal was not compatible with them or us. They wanted to give us a small amount of money, see how it went, then keep adding money to it. We wanted to raise all the money we needed to proceed, to get out of the fundraising business and into the windmill business. So we looked for people who had developed companies from nothing to something large and successful.” U.S. Windpower’s marketing approach is relatively simple: find big electricity con- sumers, secure a purchase power contract with them, attract good people to the firm, and attract the financing on the basis of a signed contract and key personnel. U.S. Windpower won’t give the details of the project’s financing, but Moore allows that the entire project cost “around $1 million.” U.S. Windpower Inc. has structured the financing of the Crotched Mountain pro- ject and, presumably, others to come as a limited partnership. A subsidiary of the Burlington firm acts as the general partner and the investor, a limited partner. Accord- $1,000,000 500 kW WECS Installation Interest Tax Payment Credit $82,500 $250,000 77,566 0 72,090 0 66,011 0 59,264 0 Adjusted Balance $705,149 655,364 600,103 538,764 470,676 395,099 311,209 218,091 34,233 114,730 23,990 0 12,620 51,774 43,460 Total $1,545,402 January 1981 ing to U.S. Windpower officials, the com- pany builds the wind machines and erects the windfarm for the investor. The firm then enters into an agreement with the lim- ited partner whereby the general partner, U.S. Windpower, operates and maintains the facility for an annual fee. The limited partner continues to write off depreciation, maintenance, and the inci- dental costs of running the facility for an in- definite period of time, or at least for the seven-year period necessary to take full ad- vantage of the investment tax credit, the en- ergy tax credits and maximum depreciation. PSNH must buy all of the power gener- ated by a windfarm at 7.7 cents/kilowatt- hour. That price has been set by the New Hampshire Public Service Commission by virtue of a 1978 state law, the Limited Elec- trical Energy Producers Act, designed to encourage development of renewable ener- gy resources in the state. “‘Crotched Mountain is definitely going to be an economic site,’’ predicts Moore. He may well be right. If the pilot windfarm produces only 35%, or 1,839,000 kWh, of its potential electrical output annually, that yields $141,649 in revenue—or 14% of the initial cost before the limited partner takes the tax credits and depreciation. For those states with less generous buy- back rates, the following abbreviated cash flow analysis by Michael Lotker of The Synectic Group, a Washington, DC con- sulting firm, shows that windfarms are a very appealing financial investment indeed. For more information about the Crotch- ed Mountain array, contact: Norman Moore, President, U.S. Windpower, Inc., 160 Wheeler Road, Burlington, MA 01803. Cash Flow $242,649 12,598 35,562 61,977 92,341 $445,129 127,227 167,286 213,263 266,006 326,489 Taxable Income ($105,357) (80,473) (52,033) (19,541) 17,571 ($239,834) 59,947 108,319 306,381 369,368 441,220 $1,045,402 Return (After Tax) $295,327 52,835 61,579 71,747 83,555 $565,045 97,253 113,126 60,072 81,323 105,879 $1,022,701 Assumptions: $142,857 (annual depreciation-7 years); $127,351 (annual debt service-10 years); 2% of cap. cost (annual O&M); 2% of cap. cost (annual Property tax); 0.5% of cap. cost (annual insurance cost); 2,750,000 kWh (annual energy production); 50% (investors’ tax bracket); 6.0 cents/kWh (initial energy value); 14% (annual energy escalation rate); 10 year length of loan; 11% loan interest rate; $250,000 (equity); $750,000 (debt); 7% (expense ex- calation rate). 10 Wind Energy Report Agreement for the Purchase and Sale of Electric Energy AGREEMENT, dated December 23, 1980, by and between U.S. WINDPOWER, INC., a Massachusetts corporation with its principal of- fice in Burlington, Massachusetts (hereinafter referred to as SELLER), and PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE, a New Hamp- shire corporation with its principal office in Manchester, New Hampshire (hereinafter referred to as PUBLIC SERVICE). Article 1. Basic Agreement. Subject to the terms, provisions and conditions of this Agreement, SELLER agrees to furnish and sell and PUBLIC SERVICE agrees to pur- chase and receive all of the electric energy produced by the twenty (20) wind turbine generating units to be installed, owned and operated by SELLER at its wind turbine generating facility located in Greenfield, New Hamphire. Article 2. Availability. During the term hereof, SELLER shall endeavor to operate its wind turbine generating units to the maximum extent reasonably possible under the circumstances and shall make available to PUBLIC SERVICE the en- tire net output in kilowatthours from said units when in operation. It is agreed that SELLER shall have sole responsibility for operation and maintenance of its generating units, including any relays, locks, seals, breakers, and other control and protection apparatus that are necessary, or which PUBLIC SERVICE may designate as being necessary, for the opera- tion of SELLER‘S generating units in parallel with the system of PUBLIC SERVICE, and that SELLER will maintain said generating units and the entire wind turbine generating facility in good operating order and repair without cost to PUBLIC SERVICE. Article 3. Price. The price charged by SELLER to PUBLIC SERVICE for sales of elec- tric energy under this Agreement shall be 7.7 cents per kilowatthour. The parties understand that the price to be charged for sales of electric energy from wind turbine generating units was established by the New Hampshire Public Utilities Commission. Whenever an order by a regulatory body hav- ing jurisdiction over this contract establishes a new price to be charged by SELLER, or if SELLER and PUBLIC SERVICE should mutually agree to a new price, the parties shall enter into a written amendment to this agree- ment incorporating the new pricing provision. Article 4. Delivery and Metering. The point of interconnection (the Delivery Point) between the generating facility of SELLER and the electric system of PUBLIC SER- VICE is at the point of connection of the 12.47 kilovolt electric system own- ed by PUBLIC SERVICE to the electric facilities owned by SELLER. SELLER shall be obligated to pay all costs of interconnecting with PUBLIC SERVICE. Once those costs are known, the parties shall agree on the manner for payment of interconnection costs by SELLER. SELLER will deliver all electric energy to PUBLIC SERVICE in the form of three-phase, sixty hertz current at 12.47 kilovolts at the Delivery Point. SELLER will install, own and maintain a meter and related facilities to measure the flow of electrical energy from SELLER to PUBLIC SER- VICE. If at any time metering equipment is found to be in error by more than two percent up or down (+ or — 2%), SELLER shall cause such metering equipment to be corrected and the meter readings for the period of inaccuracy shall be adjusted to correct such inaccuracy so far as the same can be reasonably ascertained, but no adjustment prior to the beginning of the preceding month shall be made except by agreement of the parties. In additon to the regular routine tests, SELLER shall cause such equipment to be tested at any time upon request of and in the presence of a representative of PUBLIC SERVICE. If such equipment proves accurate within two per- cent up or down (+ or—2%), the expense of the test shall be borne by PUBLIC SERVICE. PUBLIC SERVICE reserves the right to require SELLER to measure electric energy sold to PUBLIC SERVICE on an hour-by-hour basis and to also notify PUBLIC SERVICE once each day of its generation in kilowatt- hours during the prior 24 hours. i January 1981 Article 5. Billing and Payment. SELLER shall read the meter installed in accordance with Article 4 at or near the end of each month. SELLER will then bill PUBLIC SERVICE for the amount due, which will be determined by multiplying the rate per kilowatthour specified in Article 3 times the number of kilowatthours delivered to PUBLIC SERVICE for the amount due, which will be deter- mined by multiplying the rate per kilowatthour specified in Article 3 times the number of kilowatthours delivered to PUBLIC SERVICE since the prior reading of the meter, and PUBLIC SERVICE will send to SELLER a payment for the amount within twenty days of receipt of SELLER‘s bill. PUBLIC SERVICE may read the meter at any time to verify the accuracy of the billings. Article 6. Facilities. SELLER shall install and maintain at its own expense such protective devices and equipment as are necessary for the protection of the PUBLIC SERVICE electric system and personnel. SELLER shall also install capacitors and other equipment necessary to maintain SELLER’s power factor as close to 100% as reasonably possible. SELLER agrees to give PUBLIC SERVICE 30 days advance written notice of any future installation by SELLER of additional wind turbine generating units at its facilility in Greenfield or of any future increase in the capacity of the units initially installed. If such additional units or increase in capacity would create stability or reliability problems, or cause PUBLIC SERVICE to incur additional expenses associated with such change, SELLER agrees no to make the change until arrangements are made with PUBLIC SERVICE which will correct the problems created or reimiburse PUBLIC SERVICE for any expenses incurred. Article 7. Liability and Insurance. a. Each party be responsible for its facilities and the operation thereof to the Delivery Point and will indemnify and save the other harmless from any and all loss by reason of property damage, bodily injuries, including death resulting therefrom (and all expenses in connection therewith, in- cluding attorney’s fees) caused by or sustained on, or alleged to be caused by or sustained on, facilities owned or controlled by such party, except that each party shall be solely responsible for and shall bear all costs of claims by its own employees or contractors growing out of any workmen’s com- pensation law. b. PUBLIC SERVICE shall not be considered to be in default hereunder and shall be excused from purchasing electricity hereunder if and to the extent that it shall be prevented from doing so by storm, flood, lightning, earthquake, explosion, equipment failure, civil disturbance, labor dispute, act of God or the public enemy, action of a court or public authority, withdrawal of facilities from operation for maintenance and repair, or any cause beyond the reasonable control of PUBLIC SERVICE. c. (i) SELLER hereby agrees to maintain in force and effect for the duration of this agreement, such general property damage and liability in- surance, including workmen’s compensation, as PUBLIC SERVICE may reasonably require; and all such insurance will be carried in amounts suffi- cient to prevent SELLER from becoming a co-insurer. (ii) SELLER agrees to provide a certificate of such insurance to PUBLIC SERVICE upon reasonable demand. Article 8. Effective Date and Contract Term. This Agreement shall become effective between the parties and the term hereof shall commence as of the date hereof and shall continue in full force and effect for twenty years so long as SELLER has the right to operate on Crotched Mountain Foundation property. SELLER will give PUBLIC SERVICE notification of any notice to remove equipment that is received from Crotched Mountain Foundation within 10 days of receiving such notice. This Agreement shall remain in effect after the expiration of such period unless one party gives the other party twelve months’ written notice of its intention to terminate this Agreement; if such written notice is given, this Agreement shall terminate twelve months thereafter. After termination, both parties shall be discharged from all further obligation under the terms of this Agreement, excepting any liability which may have been incurred before the date of such termination. (Continued on next page) Wind Energy Report AGREEMENT FOR THE PURCHASE AND SALE OF ELECTRIC ENERGY (Contirmed from preceding page) Article 9. Prior Agreement Superseded. This Agreement represents the entire agreement between the parties hereto relating to the subject matter hereof, and all previous agreements, discussion, communications and correspondence with respect to the said subject matier are superseded by the execution of this Agreement. Article 10. | Waiver of Terms of Conditions. The faiure of either party to enforce or insist upon compliance with any of the terms or conditions of this Agreement shall not constitute a general waiver or relinquishment of any such terms or conditions, but the same shall be and remain at all times in full force and effect. Article 11. General. This Agreement shall be binding upon, and inure to the benefit of, the respective successors and assigns of the parties herto, provided that SELLER shall not assign this Agreement except to an affiliated company, without the prior written consent of Crotched Mountain Foundation. The term “‘affiieted company” shall include any partnership in which SELLER or SELLER’s subsidiaries or affiliates is a general partner or any corpora- tion in which SELLER or one of its subsidiaries or affiliates owns or con- trols more that 50% of the voting stock or otherwise has operating control. Article 12. Applicable Law. This Agreement is made under the laws of The State of New Hamp- shire and the interpretation and performance hereof shall be in accordance with and controlled by the laws of that State. Article 13. Mailing Addresses. The mziling addresses of the parties are as follows: U.S. Windpower, Inc. 160 Wheeler Road Burlington, Massachusetts 01803 PUBLIC SERVICE: Public Service Company of New Hamphire Post Office Box 330 1000 Elm Street Manchester, New Hampshire 03105 Henry J. Ellis, Vice President IN WITNESS WHEREOF, the parties have hereunto caused their names to be subscribed, as of the day and year first above written. U. S. WINDPOWER, INC. By Name: Norman H. Moore Title: President PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE By. Henry J. Ellis Vice President Editor’s Note: This contract is made possible by virtue of The New Hampshire Limited Limited Electrical Energy Producers Act of 1978 and regulations issued pursuant to it by the state public utility commission. Copies of the Act, the Eighth Supplemental Order No. 14,628, December 22, 1980, (DE 79-208), governing wind- power and the text of the U.S. Windpower/Public Service of New Hampshire contract are available from: New Hampshire Public Utilties Commission, 8 Old Suncook Road, Concord, New Hamp- shire 03301. 12 January 1981 NEW PUBLICATIONS/STUDIES/REPORTS Small Wind Systems Technology Assessment: State of the Art and Near Term Goals by W.S. Bollmeier, C.P. Butterfield, R.P. Cingo, D.M. Dodge, A.C. Hansen, D.C. Shepherd, and J.L. Tangler. Prepared by U.S. Department of Energy’s Small Wind Systems Program, Rocky Flats, Golden, CO 80401. February 1980. RFP-3136/3533/80/18. The objective of this study was to find the current state-of-the-art for small wind energy conversion systems (SWECS) and project future SWECS characteristics and energy costs. For purposes of assessing the current status of SWECS, six commercially available systems (purchased through the Field Evaluation Program) and seven DOE-funded first generation pro- totype systems were used. No empirical performance data for these systems are available, since the commercially available units are recently developed systems (and have not been sufficiently tested at Rocky Flats) and the DOE prototypes have only been recently fabricated. In the absence of data, manufacturer estimates were used. These estimates were subjected to detail- ed analysis and conservatively adjusted when the analysis indicated this necessary to produce the most accurate figures-of-merit possible. Near term improvements have been projected by improving DOE proto- types to create second generation units. The modifications used were pro- posed by the systems subcontractors for indicated by Rocky Flats analysis. Improvements which could be realized later in the 1980s are presented in a series of Advanced Concepts for three size ranges (3-6 meters, 6-12 meters , and 12-25 meters) with significant potential in remote direct current utility interconnection and direct heating applications. Several system configura- tions are excluded from various stages of the anlysis. All Advanced Con- cepts are horizontal axis systems. Several ‘‘cyclogiro‘‘ concepts were ex- plored, but their figures-of-merit were poor, according to the study. Dar- rieus systems were omitted from all phases of this assessment due to Rocky Flats’s current inexperience with these systems. The energy costs achievable from commercially available, DOE pro- totype, and advanced concept SWECS by 1990 are plotted. These costs assume 1980 dollars and high volume production with a doubling of pro- duction (from an original run of more than 1,000) every three years for 3-6 meter and 6-12 meter systems and every five years for 12-25 meter systems. A 95 percent learning curve has been used. The production volume achiev- ed by 1990 is conservative ( i.e., 7,000 units for an 8 kw prototype system). but if a consistent increase was maintained to the year 2000, total SWECS installed capacity in the year (from only three manufacturers) would be more than 5,000 megawatts. This analysis shows that major advances in energy cost reduction can be made with advanced concepts in the 3-6 meter and 6-12 meter size ranges. In each figure, it can be seen that improved DOE prototypes and/or ad- vanced concepts achieve significant energy cost improvements over com- mercially available systems. The major conclusions of this analysis are: significant cost-of-energy im- provements can be made in SWECS of all size ranges. Reliability and system life are key factors in SWECS utilization but the reliability and life of commercially available and DOE prototype systems are not known. Additionally, claims the report, use of off-the-shelf components in com- mercially available small wind systems has inhibited innovative systems ap- proaches to design and achievement of the full low-cost potential of SWECS. Contractor prototype tradeoff analyses to achieve higher reliability have been limited by the requirements of lowest contract cost and accelerated schedules and by lack of test data. This has required the use of off-the-shelf components on DOE prototypes and has prevented them from achieving widely competitive cost, although reliability and service life should be significantly improved over commercially available units. Futhermore, a need for component and subsystem development is in- dicated by the inability of improved first generation SWECS to achieve their lowest cost potential. This study indicates that such development will be beneficial. Cost-of-energy is more sensitive to SWECS performance (through increased system efficiency, reliability, and lifetime) than to hard- ware cost. Future development efforts must consider cost-of-energy reduc- tion through performance improvement. Components specifically designed for SWECS may offer improvements in reliability as well as lower hardware cost. Through component im- provements, SWECS can produce energy at cost competitive with non- renewable energy sources. This is based on the following energy costs Wind Energy Report estimated as achievable in 1990 for second generation SWECS (1980 dollars): 5.8°/kwh (3-6 meter), 2.2 /kWh (6-12 meter), 1.8° /kWh (12-25 meter). * . * Wind, Pumps and Desalination by Frederik H. Theyse, Theyse Energieberatung, Bergisch Gladbach, West Germany. Presented at the Third Miami International Conference on Alternative Energy Sources, December 15-17, 1980, Miami, FL, sponsored by the Clean Energy Research Institute, University of Miami, Coral Gables, Florida. Worldwide there exists an increasing need for waterpuming. Functions to be served include control of water level, irrigation, reclamation of soil, con- trol of a watertable in general. Specifically, in the developing countries with their still underdeveloped infrastructure this need increases rapidly. For this pumping energy is needed—energy of high energy to drive the pumps. With the increasing costs of fossil fuels and electricity, there is ample reason to investigate the potential of wind anew. A two-bladed fixed-rotor WECS, driving screwpumps by an automotive geartrain proves to offer a very reliable, fail-safe and self-optimizing solution for up to about 200 kW power, providing water at a cost of 4-6 cents/kWh of water pumped. Using the same concept to drive an adapted water-brake, it proves that desalination via the multiple-flash evaporisation route also becomes a self- optimizing, fail-safe, cheap and reliable operation, providing fresh water at less than 3 dollars per meter’, under the worst conditios. This is not only of importance to the developing countries with their sparse watersupply, but even more for the industrialised countries, where lack of adequate water is an increasing problem. Costs can get substantially below the level in- dicated. It proves, according to the author, that for this type of operations at ac- ceptable costs, vertical axis windmills are basically unsuited. Although the horizontal axis machines need provisions to follow the wind, such provi- sions prove far cheaper in their effect on energy costs, then the controls and/or loss in power coefficient of vertical axis machines. The author contends that, using a two-bladed fixed-rotor WECS with horizontal shaft, using automotive brakes and transmissions to drive centri- fugal-or screwpumps, a concept for waterpumping is achieved, leading to reliable, low-cost, self-optimizing plant. Prerequisite is the use of the right blade-profile, where is x constant over a wide range of conditions. Such a plant produces waterpumping in a very reliable and cheap way. Moreover, as so many cheap standard parts are used, the building of such plant is also possible to advantage in developing countries, while not over- stretching their resources and still yielding a product of high reliability and low maintenance. Using the same WECS to drive a heat-generating water- brake, a good means is achieved to produce cost-effective desalination. * * * Evaluation of Production Costs and Capacity Credits of a Wind Energy Conversion System Supplying An Electric Utility by K. F. Schenk, S. Chan, P. Uko, Dept. of Electrical Engineering, Univ. of Ottawa, and N. S. Rau, Electric Power Branch, National Energy Board, Ottawa, Ontario, Canada. Presented at the Third Miami Inter- national Conference on Alternative Energy Sources, December 15-17, 1980, Miami, Florida. Sponsored by the Clean Energy Research Institute, Univ. of Miami, Coral Gables, FL. The use of wind energy poses a variety of problems for electric utilities primarily caused by the variability of the wind. This paper models a wind energy conversion system, or WECS, operating on a non-demand basis, in two ways. Firstly, a WECS is modelled as a multistate unit whose derated capacities are caused by wind variability. Secondly, a WECS hourly output is taken as a negative demand which is subtracted directly from the utility’s chronological load curve. The first model simulates a WECS integrated in- to an electric utility system for one year of operation to obtain the impact on system reliability and energy displacements or fuel credits. The second model is used in WASP-II (an electric utility optimal generation expansion planning computer model) to obtain optimal mixes of generation for a 30 year period with and without a WECS. This allows the evaluation of the ac- tual capacity displacement or credit resulting from different penetrations of a WECS and the impact on system reliability, production costs and energy displacement. The study is limited to WECS without storage capacity. Probabilistic 13 January 1981 simulation is used to determine the value of WECS and to accurately assess its impact on system reliability, capacity reserve margin, increase. in load carrying capability and production costing. Because of the variability of the wind, the WECS power output consists of many capacity states. The pro- cedure that is followed is to convolve the hourly probability distribution of unavailable capacity of the WECS into the hourly load distribution. Addi- tionally, because of mechanical equipment failure of the WECS, the pro- bability of the different wind capacity states are modified to reflect the ef- fect of wind and forced outage due to mechanical failure. The convolution procedure over the 24 daily distributions is accomplish- ed very efficiently by the method of moments. This method is based on ob- taining the statistical moments and cumulants of the different probability distributions. Convolution or deconvolution is simulated by the addition or subtraction of the appropriate cumulants. From the cumulants the Gram- Charlier expansion may be used to evaluate LOLP, reserve margins, capacity credits and expected energy generation. The models are applied to the IEEE Reliability Test System. * * * Optimum Design Assessment of Wind Power For Household Elec- tricity by R. K. Tsui, Northeastern University, Boston, MA. Presented at the Third Miami International Conference on Alternative Energy Sources, December 15-17, 1980, Miami, Florida. Sponsored by the Clean Energy Research Institute, Univ. of Miami, Coral Gables, Fl. This paper presents a theoretical and cost-effective design of a residential energy system. The system combines the use of a wind turbine with a therm- al system forming resistance heating power; with a generator system Producing alternate current electrical power and with a battery storage system retrieving direct current electrical power. This study developed a ra- tional design assessment for a small range of (10 to 200 kw) wind power generation. The primary objective is the development of a suitable methodology to be used by individual household electric utilities to assess Prospects for wind power generation at their sites. A complete mathematical algorithm for evaluating and designing such system is Presented. Simulated results can be demonstrated by a hand-held program- mable calculator (TI-59 & PC-100C). The optimum total blade design of the wind turbine is one that max- imizes the product of the volumetric flow rate (small total blade area main- tains a high volumetric flow rate of airstream) and the pressure drop across the turbine. Experimental evidence indicates that a two-bladed vertical-axis Darrieus rotor can be expected to reach a maximum power coefficient of about 0.35 at a blade-tip of 6. Authoritative studies suggest that Darrieus wind turbines are the most suitable choice for residential aplications of small rated power output. Qualitatively, the elimination of yaw controls, ground level placement of mechanical equipment and low-cost blade fabrication techniques contribute directly into its low capital investment. Assessment of wind power for household electricity (10-200 kW) can be optimally achieved by designing a vertical-axis Darrieus-type wind turbine interconnecting with a variable-speed constant-frequency generating system in addition to a synchronous inverter and an advanced battery system for electrical energy storage. * * * Effect of Site Wind Characteristics on Energy Production by W. T. Pennell and H. L. Wegley, Pacific Northwest Laboratory Richland, WA. Presented at the Third Miami International Conference on Alternative Energy Sources, December 15-17, 1980, Miami, Florida. Sponsored by the Clean Energy Research Institute, Univ. of Miami, Coral Gables, FL. The decision to purchase a wind machine, large or small is usually based on the economic value of the machine user. Obviously, economic value is a strong function of machine performance evaluated at a particular site. When there is no direct experience with wind machines at or near a propos- ed installation, machine performance can be simulated using machine per- formance information (power output as a function of wind speed) and wind data representative of the site. This paper examines the sensitivity of per- formance computations to uncertainties in the wind characteristics. Two potential applications are examined—one in which the load to be serviced is constant in time and one in which the load has large diurnal fluctuations. When the energy produced by a wind machine has constant value, in- dependent of what time of the day or season it is produced, determination of economic value is fairly simple. It can be deduced from the average “wind Energy Report NEW PUBLICATIONS/REPORTS/STUDIES (con:.) energy production and a levelized cost of energy model. Average energy production can be calculated from machine performance information and the probability density function (PDF) of the wind speed. A wide range of machine performance characteristics and PDFs were examined. It is shown that within an annual average wind speed range of four to eight m/s, estimates of average power output using the average wind speed at the site and a Rayleigh model for the PDF differ by no more than 20% from estimates made using the actual PDF. This uncertainty is about the same as the uncertainty that can be expected in estimating the performance of small wind machines from hourly averaged wind speeds. The economic value of wind power in many applications may depend on the match between temporal variations in the load and temporal variations in machine output. The importance of load matching is examined by com- puting the fraction of the total energy consumption of a typical residence that could be satisfied by a small wind machine under a variety of wind con- ditions. A small residence has very large diurnal fluctuations in energy con- sumption. Thus this aspect of the study concentrates on the match between the load and diurnal wind speed fluctuations. Time series of hourly average power output spanning a three-month season were produced for two small machines. These machines have significantly different performance characteristics. Wind data were used from four actual sites having typical, but widely differing diurnal characteristics. To isolate the importance of load matching, the average wind speeds at the four sites were adjusted so that the seasonal average power production at each of the sites was the same. The results show the fraction of total energy consumption displaced by a wind machine to be very dependent on the degree of load matching. In some applications, the economic value of a wind machine may be more dependent on the diurnal characteristics of the wind at the site than on the average wind speed. . . . New Elements in Wind Energy Conversion Siting by Lambros Lois, Department of Chemical Engineering, University of Maryland, College Park, MD.Presented at the Third Miami International Con- ference on Alternative Energy Sources, December 15-17, 1980, Miami, Florida. Sponsored by the Clean Energy Research Institute, Univ. of Miami, Coral Gables, FL. This paper examines the parameters and their effect on the selection of a second and subsequent sites for the installation of wind turbines to be in- tegrated into conventional electrical generating systems. Assuming no system storage (nor wind energy conversion dedicated storage) most of the benefits associated with wind power were thought to result from fuel sav- ings. More recently, however, based on wind energy generation reliability, conventional energy generation reliability and power grid load demand, analysis has shown that wind power electric generators can also replace conventional installed capacity. It is reasonable that the first unit (or group of units) will be located at the site with the highest energy production potential. However, after some penetration has been achieved with installations at one site, subsequent in- stallation sites should not necessarily be chosen for their maximum energy production potential alone. Indeed it is possible that the installed capacity displacement value to outweigh the fuel displacement worth. This is possi- ble due to the fact that increased installed wind power has a low saturation limit for installed capacity displacement when it is subject to the same wind characteristics. Several investigations have shown the importance and the impact of the reliability of the conventional generating capacity, the grid load features and the wind charcteristics for a given site. Here the diversity of the sites available to a power grid is examined as a new element in wind energy conversion siting optimization. The meteorological data of two dif- ferent sites have been examined and analized and a correlation coefficient has been derived which quantifies the site diversity. This correlation con- stitutes an additional element for an integrated examination of the totality of the available sites. Some topological features are examined which can contribute to site diversity. Coastal and mountain features as they affect the wind patterns and the seasonal and diurnal variations, enter as elements of the correlation coefficient. . . . Coastal Zone Wind Energy. Part 1. Synoptic and Mesoscale Con- trols and Distributions of Coastal Wind Energy: Final Report. by 14 January 1981 M. Garstang, S. Nnaji, R.A. Pielke, J. Gusdorf, C. Lindsey and J.W. Snow, University of Virginia, Charlottesville, VA. March, 1980. DOE/ET/20274-7. This report describes a method of determining coastal wind energy resources. Climatological data and a mesoscale numerical model are used to delineate the available wind energy along the Atlantic and Gulf coasts of the United States. It is found that the spatial distribution of this energy is dependent on the locations of the observing sites in relation to the major synoptic weather features as well as the particular orientation of the coastline with respect to the large-scale wind. The synoptic weather situation at a site is categorized according to its location relative to the wave cyclones on the polar front and to the sub- tropical ridge. Fundamental physical concepts are used to define these classifications. Six categories describe almost all weather situations: (1) in the warm sector, (2) ahead of the warm front, (3) behind the cold front, (4) under the polar ridge, (5) west of the subtropical ridge, and (6) under the subtropical ridge. The four seasons—winter, spring, summer and fall—are defined quantitatively in terms of the variation of these categories within the year. Seven regions along the Atlantic and Gulf coasts of comparatively homogeneous conditions (similar distribution of categories during the year) are defined along with the beginning and ending of the four seasons. The variation of wind with height is calculated from detailed vertical measurements of the horizontal wind for each category from National Aeronautic & Space Administration data collected at Wallops Island, Virginia. This information is used to normalize the winds at each climatological site to a specific height to permit regional comparisons. From these analyses it is found that classification by synoptic category provides better estimates of the vertical variation of wind energy than a simple 1/7 power law, as conventionnally used. The greatest chance of wind with height is in the warm sector within and west of the subtropical ridge and ahead of the cold front. This result is to be expected because the atmosphere is more stably stratified for these conditions. The dominant synoptic category varied considerably from Brunswick, Maine, to Brownsville, Texas. In the extreme north, for example, in the an- nual mean over 65% of the available power at 50-meter is provided when the site is behind the cold front or under a polar high. Such conditions oc- cur often because of the frequent occlusion and stagnation of extratropical lows off the New England coast. Along the Texas coast, on the other hand, the largest mean annual contribution of the wind energy at 50-meter (41%) occurs when the site is west of the subtropical ridge. These differences are significant in estimating the available wind energy as a function of height and of time (season) of year. The variation of synoptic categories within the year is also significant, particulary in the south. At Brownsville, for example, during the winter over 45% of the available wind power at 50 meters comes when the site is under a polar high with only about 12% being contibuted by the subtropi- cal ridge. During the summer, with the dominance of the Bermuda high, more than 75% of the wind energy comes when the site is west of this warm ridge. The climatological analysis of the large- and synoptic-scale time and space distributions of the velocity and thermal fields is used as a framework to determine the effects of the coastline of the final wind power potential. The physical processes of interaction between the large-scale fields and the coastline are described by the University of Virginia three-demensional mesoscale numerical model. The model provides a 10-kilometer horizontal resolution at 17 levels in the lower atmosphere over a 300 x 300 km domain. The model is appled in three areas of the Atlantic and Gulf coasts: the Chesapeake Bay, the Apalachee Bay and the south Texas coast. Simulation experiments are performed for the dominant regimes of winter and summer as defined by the climatic analysis. In each case the model shows detail and complexity which cannot be depicted by existing observations. This is particulary true over the near and offshore waters. Further, 24-hour in- tegrations over a 100-meter depth of the atmosphere above the surface show important horizontal gradients in the wind field. When converted to potential wind power, these integrated fields show that certain locations contain up to three times more power than other locations. Local areas on the order of a few tens-of-kilmoters on a side can be identified in the model- predicted fields as containing optimum wind energy potential. The combin- ed climatic and modeling interpretation of the coastal wind fields represents a powerful tool to assess wind energy potential. Further work is required to test and validate this method of wind energy assessment. Wind Energy Report Estimation of Wind System Performance and Economics Using Unit Availability Criteria by A. J. Unione, E. Y. Lim and A. Mc- Clymont, Science Applications, Inc., Palo Alto, CA. Presented at the Third Miami International Conference on Alternative Energy Sources, December 15-17, 1980, Miami, Florida. Sponsored by the Clean Energy Research Institute, Univ. of Miami, Coral Gables, Fl. This paper describes a methodology for evaluating the impact of unit availability on the overall performance and costs of wind energy conversion systems (WECS). The WECS is modeled as a collection of wind turbines, possibly with backup energy sources (e.g. diesel generators or batteries), tied to a time-varying demand and a (randomly) variable wind resource. Each wind turbine is modeled as a series of subsystems. The reliability of a subsystem is given as a probability distribution of the time to failure for the subsystem. The parameters of this distribution are obtained either from the literature or by using fault tree techniques to combine estimates of compo- nent reliabilities. System performance is calculated using Monte Carlo simulation of system operation under various scenarios. The results of the simulation then can be used as input to an economic model which calculates the system life-cycle cost. The sensitivity of system performance and cost to different subsystem reliabilities operating and maintenance policies, system configurations, and economic assumptions is illustrated in parametric studies. Specifically, these studies clearly demonstrate that unit availability exerts a large impact on WECS performance. The WESP-WESC package was used to investigate the impact of sub- system reliability on overall WECS performance and cost. Each wind tur- bine was assumed to consist of four subsystems, each with exponentially distributed failure times. The system operation was simulated under four different levels of subsystem reliability, and the effect of additional wind turbines was examined. Figure 1 shows the results of this study over a 10,000 hour period when energy demand shortfalls due to wind resource or WECS hardware unavailability can be met by purchase from a utility grid. As the number of wind turbines included in the system is increased, the grid purchases required to make up for unmet demand decrease in all reliability cases. When a large number of wind turbines being used (i.e., WECS capacity is much greater than demand), the energy purchased represents energy required during periods when the wind was unavailable. In this case, unit unavailability is unimportant because of system redundancy. The plateau (observed in Figure 1 around 10,000 -13,000 MWh) where grid pur- chase reductions due to additional turbine are small, occur at lower wind turbine populations for those systems with better subsystem reliabilities. For example, the plateau is approached with eight turbines under the high reliability case, with twelve turbines under base case reliability, and with more than sixteen under the poor reliability case. The results suggest that subsystem reliability impacts WECS perfor- mance and cost greatly. The failure of a utility or other operator of a WECS to solve reliability and maintainability problems risks a significant negative effect on system effectiveness. In addition, evaluative studies of WECS which ignore unit unavailability or assume overly optimistic levels of reliability may yield unrealistic results. Availability of Wind Energy in Saudi Arabia and Its Applica- tions by M. Barkat Ullah, University of Petroleum and Minerals, Dhahran, Saudi Arabia. Presented at the Third Miami International Conference on Alternative Energy Sources, December 15-17, 1980, Miami, Florida. Sponsored by the Clean Energy Research Institute, Univ. of Miami, Coral Gables, Fl. Wind energy application in the production of electricity in Saudi Arabia has got great potential. However, as is the case in any other places, the wind energy is intermittent. One important advantage for the Eastern Province of Saudi Arabia is that the wind is from one direction for most of the time of the year. At the present cost of fossil fuel in Saudi Arabia, the economics of aerogenerator is not likely to be attractive. But keeping in mind the the future, it is worthwhile to examine the potential of this natural source of energy. In this paper, long term meteorological data for several weather stations in Saudi Arabia have been analysed to obtain wind pattern and characteristics. Availability of energy is estimated on the basis of fun- damental fluid flow analysis and a procedure is presented for that purpose. Normalized cumulative distribution for fourteen observing sites in Saudi Arabia has been made. The normalization is done with respect to V_ where Veg is the speed exceeded 50 per cent of the time. Normalized wirid speed 15 January 1981 contour map for Saudi Arabia has been drawn and a contour map for the annual wind energy is developed. The application of the wind energy is the environmental control of houses is discussed. * * * The Modelling and Analysis of a Vertical-Axis Wind-Turbine Driven Self-Excited Induction Generator by M. Ermis and C. Arikan, Middle East Technical University, Turkey. Presented at the Third International Conference on Future Energy Concepts at the Institu- tion of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. In this work a vertical-axis wind-turbine driven self-excited induction generator which operates as an isolated power source at constant voltage and frequency has been analysed. For transient analysis a state-space model of the system including the nonlinearity of the magnetisation branch has been obtained. The results showed that a multivariable control mechanism has to be used to regulate the output variables. The performance characteristics of the proposed feed-forward mechanism are presented and discussed. The transient performance characteristics of a VAWT driven SEIG has shown that such a system can not be operated without any control. The transient behaviour of the system is then studied for a feed-forward control strategy and the results showed that the response of the system is not as good as it should be. Therefore it is suggested that either this control strategy has to be modified or a new control strategy has to be used. . . . The Value of Wind Turbines to Large Electricity Utilities by A. P. Rockingham and R. H. Taylor, Central Electricity Generating Board. Presented at the Third International Conference on Future Energy Concepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. If wind energy is eventually to be used on a large scale for the operation of electricity, it will be required to operate alongside conventional fossil, nuclear and hydro plant. The economics of wind power will be influenced by the future costs of fuel, the plant type existing in the system and the alternative investment choices. In addition, the economics will be influenc- ed by the characteristics of the wind resource and the wind turbine itself. Predictions must be made about each of these factors before the economics of wind energy conversion systems (WECS) can be evaluated. This paper describes a preliminary analysis of how each of these factors affects the economics of WECS and analyses the sensitivity of these economics for UK conditions. A computer simulation model has been developed to carry out a preliminary analysis of the value of WECS on the CEGB system. Initial results for an assumed base case show that although quite high capacity credits can be ascribed to WECS, most of the value of WECS arises from their ability to save fuel. The operating penalty— on the pessimistic assumption that part-loaded conventional plant would be required to meet variations in WECS output equal to the total installed capacity—is estimated to be about 15% of the gross fuel saving value. Some attempt has also been made to analyse the sensitivity of these results to variation of a number of parameters. The values of WECS will be a function of penetration, the part-loading limit assumed for conventional plant, the geographical dispersion of the WECS, machine type and rating, and will vary considerably from year to year. Estimates of the value are particularly sensitive to the assumed mix of conventional plant and fuel price but appear to be less sensitive to the level of part-loading assumed. * * * Wind Turbine Response and System Integration by E.A. Bossanyi, G. E. Whittle, N.H. Lipman and P.J. Musgrove, University of Reading, UK. Presented at the Third International Conference on Future Energy Concepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. The integration of wind power into an electricity generating system has been investigated using an hour-by-hour simulation model. As an example, an illustration is presented of how a 24-hour demand profile is met by the various types of generating plants. When considering fuel costs it is shown that depending on the fuel cost ratios considered the optimum saving is so Wind Energy Report achieved by attempting to carry between 25% and 80% of the hourly wind power as spinning reserve. In these cases the optimum fuel cost saving associated with the utilisation of wind energy will be between 85% and 91% of the potential saving. A simple dynamic model of a wind turbine has been developed, and from this a time constant appropriate to a large horizontal axis fixed speed fixed pitch machine was found to be 0.5 second. The frequency response was such that the wind turbine would respond fully to wind speed fluctuations slower than 0.1 Hz., but would not respond at all to frequencies higher that 10Hz. The frequency response is related to a wind turbulence spectrum, and it is found for the circumstances considered that about 91% of the tur- bulence energy in the wind is available to the wind turbine. Considering the coherence of wind speed fluctuations across a rotor disc, it is shown for the large wind turbine considered earlier that the effect of coherence is to reduce to only about 46% the turbulence energy that is available to the rotor. Results are presented of the effect of turbulence on the power output from a wind turbine, both for a single machine and for a cluster. It is shown that turbulence can be responsible for either increasing or decreasing the power output. Finally, a consideration of the coherence of wind speed fluctuations across a cluster of wind turbines suggests that the statistical smoothing of power output results in a standard deviation of power output of less that 1% of the installed wind plant capacity. It is stated that this compares well with the uncertainty in electricity demand predictions in the CEGB grid. A Unified Site Evaluation System for Wind Energy Conversion By George G. Biro, Gibbs & Hill, Inc. New York, NY Presented at the Third Miami International Conference on Alternative Energy Sources, December 15-17, 1980, Miami, Florida. Sponsored by the Clean Energy Research Institute, Univ. of Miami, Coral Gables, Fl. The described evaluation system includes all field and office engineering work needed for proper site selections and for writing the environmental impact statements. Meteorological measurements with collapsible towers trucked to the site, the needed instrumentation, and data transmission with satellite telemetry for storing the meteorological data on a magnetic tape for direct input into the computer are described. A computer program WESES was developed to calculate the energy output of WECS using the meteorological data on the magnetic tapes. A test site analysis using 7 years of wind velocity measurements is performed, and two 500-kW power wind energy conversion systems have been evaluated. The calculational results give the hourly fluctuations of energy output for any day of the measurements, which also can be used for comparing with load demands. It also calculates and shows in graphs the daily and monthly cumulative energy outputs and compares the energy conversion systems for any desired time period. *. * . Power Transmission from Offshore Wind Generation Systems by P.J. Franklin and G.E. Gardner, Central Electricity Generating Board, Planning Department. Presented at the Third International Conference on Future Energy Concepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Con- ference Publication Number 192. Since wind power appears to be one of the more cost effective alternative energy sources, the problems of integrating it into the supply system are be- ing examined in some detail. To obtain a significant proportion of the U.K.’s energy demand from the wind requires a very large number of machines and it is unlikely that sufficient sites could be found for all of these on land. The alternative of locating groups of machines in the shallow coastal waters has advantage both in the increased energy recovery and reduced visual impact. The disadvantages are higher capital costs and more difficult access for maintaenance. A typical offshore array will occupy many square kilometres and be subject to a range of wind conditions. An examination of the electrical connection of a cluster of large aerogenerators into the supply network has shown that effective control can be achieved. Induction generators have the merit of simpler and more robust construction which is desirable for an offshore location and they are eminently suitable for starting fixed pitch aerogenerators. The high current requirement during starting makes the use of a controlled sequential star- ting system desirable but with microprocessors this can be made fully 16 January 1981 automatic. Examination of the stability to faults within the cluster shows that fast fault clearance would only be required for faults on the transmis- sion link to the shore, though this high speed would only be required for 3-phase faults. Synchronous machines appear to offer some limited advan- tage in respect of stability following clearance of network faults but it is doubtful whether this outweights the disadvantages of increased cost and complexity in an offshore environment. An Assessment of Offshore Siting of Wind Turbine Generators in the United Kingdom by P.B. Simpson and D. Lindley, Taywood Engineering Ltd., and W.E. Hardy, ERA Technology Ltd., UK. Presented at the Third International Conference on Future Energy Con- cepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. In a study completed in December 1979 for the United Kingdom Depart- ment of Energy, a technical and economic assessment was made of the generation of electricity using wind turbine generators located in shallow coastal waters. The following conclusions are drawn from the investigation of the sensitivity of generation cost to various parameters. The parameters having the most significant influence are mean and rated wind speeds, turbine diameter and cluster efficiency. An increase in annual mean wind speed from 9.5 to 11 m/s, for example, reduces generation cost by roughly 22%. An increase in turbine diameter from 80 meters to 100 meters reduces generation cost by roughly 20%. Wide spacing of machines improves generation performance. With equal cross wind and downwind spacing, for example, increasing the spacing from 7 to 10 turbine diameters reduces generation cost by roughly 20%. Over the ranges covered in the study, mean water depth (10 to 25 meters) and height of turbine hub above mean water depth (1.0 to 1.5 x turbine diameter) have only secondary effect. The main uncertainty in the produc- tion of generation cost lies in the lack of confidence with which wind speeds offshore can be estimated. There is potential for lowering generation cost in increased rotor diameter, improved rotor performance, lighter support structure, innovative construction methods, increased operational life and quantity production. Rotational Dynamics of Wind Turbine Generators by R.H. Swansborough and L.J. Ballard, ERA Technology, Ltd., UK. Presented at the Third International Conference on Future Energy Con- cepts at the Institution of Electrical Engineers, London, United Kingdom. January 27-30, 1981. IEE Conference Publication Number 192. The fuel saving benefits of large wind turbine generators whose output is connected to the utility supply network make this one of the most attractive applications of wind power, provided that adequate reliability can be pro- ven, and that network voltage and frequency disturbance can be maintain- ed within acceptable limits. The variable and uncertain nature of the wind and the remoteness of the most economic windy sites from the main load centers may, however, give rise to operational problems, especially if wind turbines represent a large contribution to total system generation. This paper examines the use of a generalised simulation model capable of predicting the dynamic response of wind turbines for a range of operating conditions. The model is also useful for studying the sensitivities to changes in the major design parameters such as network impedance, and rated slip of the induction machine, thus providing a useful design optimisation tool. It is also readily adaptable, say the authors, to accommodate the addition of shunt capacitors for reactive power compensation. The mechanical power train has been modelled on the assumption that shaft flexure and damping effects can be neglected. The validity of. this assumption, however, needs to be further considered and requires a more precise understanding of turbulent wind conditions and turbine aeroelastic response. * * * Unless otherwise indicated, all abstracted articles, reports, studies and other publications cited in each monthly issue of Wind Energy Report are available from: The National Technical Information Service, U.S. Department of Commerce, Port Royal Road, Spring- field, Virginia 22161.