In 2009, as part of its ongoing efforts to improve wind turbines technology reliability and performance, DOE expanded existing wind technology test centers and began work on additional facilities around the country. Construction began on a new blade test facility and plans are underway for a large drivetrain testing facility. DOE also began funding several university-led research consortia that will focus on critical wind energy challenges.
Finally, DOE is supporting an effort to establish regional test centers for small wind turbines technologies, and in 2010 DOE will launch a midsize (100-kW to 1,000-kW) wind turbines. Investments from 2009 Recovery Act funds in wind farm projects and transmission infrastructure will aid future growth in wind energy development.
To analyze transmission system needs, the DOE Wind Energy Program this year completed several studies on high penetrations of wind power generation (between 20% and 30%) on the synchronous electricity grids covering the contiguous 48 states. The U.S. Department of the Interior developed an approval process for DOE expanded its offshore wind energy research efforts.
Also in 2009, DOE announced the funding of 8 million USD to 53 new wind energy research projects to address market and deployment challenges, as well as 14 million USD to 28 new projects including wind turbines research and testing and transmission research and
Wind energy will make a critical contribution toward doubling the nation’s electricity generation capacity from renewable sources by 2012. DOE’s 2008 report 20% Wind Energy by 2030 examined the feasibility, costs, and benefits of supplying 20% of the nation’s electricity from wind by the year 2030.
The report estimated that during the decade preceding 2030, the U.S. wind power industry could support more than 150,000 jobs directly related to the wind power industry, 100,000 jobs in associated industries (e.g., accountants, lawyers, steelworkers, and electrical manufacturing), and 200,000 jobs resulting from local economic expansion (2).
Property tax revenues would increase to more than 1.5 billion USD by 2030 and payments to rural landowners would increase to more than 600 million USD in 2030. The United States faces several major challenges along the path to 20% wind energy by 2030. There is a need for investment in the electric transmission system to deliver wind-generated electricity to urban centers, as well as for larger electric load balancing areas and improved regional planning to increase the regional diversity of generation sources. The manufacturing supply chain must grow to provide the wind turbines components, and a skilled workforce must develop to staff these facilities.
Advancements in wind turbine technology and manufacturing should decrease capital costs and improve turbine performance. Finally, concerns about wind farm siting, including environmental impacts and social acceptance, must be addressed. DOE is targeting its investments of Recovery Act and congressionally appropriated funds to address these barriers to achieving 20% wind energy.
In 2009, the U.S. wind power industry installed 10,010 MW of generating capacity, increasing the country’s installed wind farm capacity by 39%; wind power represented 40% of all new U.S. electric generation capacity for the year. According to the American Wind Energy Association (AWEA), the wind turbines added in 2009 generate enough electricity to power the equivalent of 2.4 million homes—the generation capacity of three large nuclear power plants.
The entire wind turbine fleet’s generation capacity—more than 35,000 MW—is enough to power nearly 10 million homes. Each year, this wind power capacity will avoid an estimated 62 million metric tons of carbon dioxide, equivalent to taking 10.5 million cars off the road, and will conserve about 20 billion gallons of water that would otherwise be withdrawn for steam or cooling in conventional power plants.
Wind power now contributes nearly 2% of the total U.S. electricity supply, and wind contributes up to 14% of some individual states’ electrical generation. Renewable energy standards are credited with the rapid growth of wind power in Texas, including the world’s largest landbased wind farm, which was constructed in just over two years. The Roscoe Wind Farm’s 627 wind turbines, totaling 781.5 MW, can generate electricity for more than 230,000 U.S. homes.
The small wind market increased by 20 MW in 2009, a 15% increase over 2008, bringing the total capacity for this sector to more than 100 MW. AWEA estimates that 10,000 wind turbines with rated capacities of 100 kW or less were installed in 2009. More than 2,700 MW of utility-scale wind farm projects were under construction at the close of 2009. Nearly 270,000 MW of wind farm projects were in line for interconnection agreements, an early stage of project development.
National incentive programs
Federal tax and grant incentives and state renewable portfolio standards (RPS) played important roles in the record wind capacity growth of the past three years. In February 2009, federal tax credits were expanded and extended to 2012, providing a predictable, transparent incentive framework to attract investment.
Federal incentive programs
Because of its national importance, the energy sector receives research and development funding and tax incentives from the U.S. government. Since its inception in 1992, the production tax credit has become one of the most important federal incentives for wind power. The production tax credit provides an income tax credit of 0.021USD/kWh, adjusted for inflation, for the first 10 years of the wind power project’s operation. The Emergency Economic Stabilization Act of 2008 (P.L. 110-343) and the Recovery Act of 2009 extended and expanded the federal incentives offered for wind energy, most notably by allowing wind project owners to elect to receive an investment tax credit instead of a production tax credit.
Top ten states for wind generation
State Existing generating capacity (MW)
New York 1,274
North Dakota 1,203
The investment tax credit allows 30% of the investment in a wind power project to be refunded in the form of reduced income taxes. Both the production and investment tax credits were extended to December 31, 2012. The Recovery Act also allows project owners to elect to receive the investment tax credit in the form of an upfront cash grant equivalent to 30% of total project value. So far, more than 3 billion USD has been awarded to 99 wind power ventures in 32 states under this program.
Tax credits are also available to businesses and homeowners who purchase and install qualified small wind systems. Businesses and homeowners can claim the full 30% investment tax credit with no cap for qualified small wind systems (under 100 KW) through 2017. This tax credit was formerly capped at USD4,000. Finally, the Recovery Act also includes a 30% credit for investment in new or reequipped facilities manufacturing wind energy equipment, and extends the eligibility of DOE–issued loan guarantees to include commercial wind power technologies.
State and local incentive programs
State-mandated RPS programs require utilities to provide a percentage of their overall electrical generation or electrical generation from renewable resources. In 2008, state RPS policies collectively called for utilities to procure about 23 billion kWh of their generating capacity from new renewable energy generation (3).
By 2010, this requirement will rise to 60 billion kWh of generating capacity and to just under 100 billion kWh by 2012. By the end of 2009, RPS programs had been adopted in 45 states at the state, local, or utility level. Other market stimulus programs offered by states include grant programs, loan programs, production incentives, and utility resource planning.
Green pricing is an optional utility service that supports a greater level of investment in renewable energy technologies. Participating utility customers pay a premium on their electric bills to cover the additional incremental cost of renewable energy. To date, more than 750 utilities, including investor-owned utilities, municipal utilities, and cooperatives, offer a green pricing option. Premiums vary from 0.002 to 0.116 USD/kWh.
Issues affecting growth
Government policies addressed several issues affecting the growth of wind power in 2009. Recovery Act investments, including grants and loans from the U.S. Departments of Energy, Agriculture, Commerce, Defense and Interior, began flowing to wind power projects, thus responding to the shortage of capital and sluggish economic activity that had slowed investment in projects. The Recovery Act also supported the construction of new transmission capacity, the lack of which has posed a major obstacle to accelerated deployment of wind power projects.
For example, Recovery Act funds supported the construction of new transmission lines capable of shipping more than 6,000 MW of wind-generated electricity from Montana and Wyoming to power markets in Arizona, California, and Nevada. About 32,000 MW of new transmission capacity for wind-generated electricity has been proposed for the next four years. However, more than 270,000 MW of wind projects have applied for interconnection to the electric grid.
As a result, even the proposed 32,000 MW of transmission capacity will not be enough to transmit the output of the proposed queue of projects. In addition, transmission inadequacies may cause many grid-connected wind projects to face curtailment of their output or negative electric prices.
To address jurisdictional conflicts that have stalled U.S. offshore wind development, the Energy Policy Act of 2005 granted the U.S. Department of the Interior (DOI) the authority to regulate renewable energy development in federal waters on the Outer Continental Shelf.
In 2009, DOI established a framework to grant leases, easements, and rights-of-way for offshore wind farms. The framework established methods for sharing revenues generated from offshore wind projects with federal, state, and local agencies and with tribal governments.
In 2009, the U.S. wind industry employed about 85,000 workers throughout all 50 states. DOE’s Wind Powering America team has calculated the economic benefits of wind power to rural areas and found that lease payments to landowners can total 2% to 3% of gross project revenue, or 2,500 USD to 4,000 USD/MW/year.
Local property tax revenues range between 3,000 USD and 17,000 USD/MW/year. A 100-MW project supports between 100 and 200 jobs during construction and 6 to 10 permanent operations and maintenance jobs for the duration of the project’s lifetime.
Sales in the small wind turbine sector were valued at 82 million USD in 2009. One-third of the small wind turbines made in the United States are exported.
To address the need for a skilled wind industry workforce—a major challenge facing the U.S. wind industry—DOE’s Wind for Schools project supports educational programs at the K-12 and university levels. These programs enable students to learn about wind energy through handson experiences with wind technology. In 2009, the Wind for Schools project started Wind Application Centers at universities in six states, installed 20 wind turbines at K-12 schools, and held training workshops at schools in five states. Early in 2010, DOE selected five additional states to receive approximately 60,000 USD each per year for three years for windrelated educational activities.
According to AWEA, 205 educational programs now offer certificates, degrees, or coursework related to wind energy. Of these programs, 45% are offered by fouryear universities and colleges and 43% are offered by community colleges and technical schools.
According to statistics gathered by AWEA, NextEra Energy Resources owns the most U.S. wind plant capacity (7,458 MW), followed by Iberdrola Renewables (3,225 MW), Horizon-EDPR (2,642 MW), and MidAmerican Energy (2,205 MW). Sixteen other companies each own 400 MW or more, indicating a diversified wind energy market.
Independent power producers, many of which are unregulated utility subsidiaries, developed and owned 84% of new capacity added in 2009. Ownership by utilities stayed at about 15% for a fourth year. Among utility owners of wind capacity, MidAmerican Energy (including PacifiCorp) owns the most with 2,205 MW installed. The utility Xcel Energy is the largest wind energy user; it owns 127 MW of generating capacity and delivers 3,049 MW of additional wind-generated electricity supplied through Power Purchase Agreement contracts with other wind plant owners.
Community wind farm projects tend to be less than 20 MW in capacity and locally owned, providing a variety of benefits to the local communities. These types of projects provide a large number of interconnection locations and often face fewer permitting barriers than larger projects, providing an opportunity to optimize the nation’s electric transmission grid. According to AWEA, community wind projects represented less than 1% of new wind generation capacity installed in 2009.
Wind energy manufacturing continued to grow in 2009. The largest expansion was in the manufacture of utility-scale wind turbine subcomponents, such as bearings, electrical components, and hydraulic systems. According to AWEA, 39 new manufacturing facilities were opened, announced or expanded in 2009 (4).
The United States now has more than 200 facilities manufacturing wind energy equipment, including facilities from nine different wind turbine manufacturers, 20 operating tower manufacturing facilities, and 13 blade manufacturing facilities. U.S. manufacturers provided more than half of the new turbines installed in 2009 and approximately 46% of the new wind generation capacity installed.
Companies selling utility-scale wind turbines in the United States, in order of market share, include: GE Energy, Vestas, Siemens, Mitsubishi, Suzlon, Clipper Windpower, Gamesa, Repower, Acciona Windpower, Nordex, AAER Inc., DeWind, Goldwind, Northern Power Systems, and Fuhrländer.
The number of U.S. manufacturers offering small wind turbines rose from 66 in 2008 to 90 in 2009; however, only 14 reported commercial sales in 2009. As in previous years, 95% of all small wind systems sold in the United States were made by U.S. manufacturers. These same manufacturers also export one-third of their production.
The United States could potentially generate an estimated 900,000 MW of electricity from its offshore wind resources. Although no offshore wind plants had been built in the United States by the close of 2009, more than a dozen offshore wind farm projects between 10-MW and 500-MW are planned in the states of Delaware, Maryland, Massachusetts, New Jersey, New York, North Carolina, Ohio, Rhode Island, Texas, and Virginia.
A collaborative effort by government and industry partners, combined with laboratory-based research, has identified a favorable market for a U.S. offshore wind industry. Accordingly, the DOE Wind Energy Program will invest in offshore wind turbine technology research and development to promote and accelerate responsible development of U.S. commercial offshore wind projects. If approved by Congress, a budget request of $49 million for fiscal year 2011 will fund research to address common barriers to offshore projects, including financial, regulatory, technical, and environmental risks.
According to community wind advocacy group Windustry, of the 35,000 MW of wind capacity installed in the United States today, more than 1,000 MW are community wind farm projects. Rural landowners, public and customer-owned utilities, school districts, colleges, and Native American tribes are all benefiting from these projects. In 2009, DOE selected five community renewable energy deployment
projects to receive more than $20.5 million in Recovery Act funding. One of these awards will support the development of a 30-MW wind project in Northeastern Colorado.
The United States is home to 2.4 million Native Americans living on 96 million acres of tribal lands. Wind farm projects on tribal lands can help reduce energy costs and support overall economic development. DOE researchers estimate that tribal lands could provide for 14% of the nation’s annual electricity demand while supplying electricity and revenue to the reservations. Through DOE’s Wind Powering America outreach and stakeholder engagement initiative, DOE experts have worked with multiple tribal entities to move wind projects forward.
According to AWEA, the average capacity of new wind turbines installed in 2009 was 1.75 MW, compared with 1.67 MW for 2008. More than 5,600 wind turbines were installed in 2009, bringing the U.S. total to more than 33,000 wind turbines. Average wind farm project size for projects installed in 2009 is about 75 MW; however, if projects with wind turbines smaller than 1 MW are excluded, the average project size rises to 85 MW.
Operators report that the percentage of time that wind turbines are available to generate electricity is above 98%. According to AWEA, capacity factors in the best wind resource areas are about 40% annually.
Wind energy costs
Capacity-weighted average installed wind turbine cost for a sample consisting of 90% of new capacity added in 2009 was around 2,080 USD/kW (1,444 €/kW). The capacity-weighted average wind price among 30 projects built in 2009 and totaling 2,629 MW was 61.20 USD/MWh (42.47 €/MWh). This price reflects the receipt of incentives such as the production tax credit or cash grants under the 1603 program; it would be higher without these incentives.
R, D&D Activities
Beginning in FY 2009, the U.S. Department of Energy Wind Power Program substantially increased its R&D activities through competitively-awarded funding to the wind industry and 12 U.S. national laboratories. DOE-funded R&D activities work to improve wind technologies, increase wind turbine reliability, and reduce the costs of utility-scale and small wind systems. DOE also works to reduce nontechnical barriers to the increased deployment of wind energy.
DOE’s budget for the Wind Power Program was 55 million USD in 2009, up from 49 million USD the previous year. An infusion of 118 million USD in Recovery Act funds for wind R&D supplemented the congressionally-appropriated budget. Congress has appropriated 80 million USD for 2010, and DOE has requested 122 million USD for 2011 (5).
In 2009, DOE expanded the testing capabilities at existing centers and began work on additional facilities around the country:
• Invested 45 million USD in Recovery Act funds to build a new drivetrain test facility, capable of testing up to 15-MW drivetrains, in Charleston, South Carolina.
• Began construction on a new 90-m blade test facility in Boston, Massachusetts, with the help of 25 million USD in Recovery Act funds.
• Invested 10 million USD in Recovery Act funds to upgrade the 2.5-MW dynamometer at the National Wind Technology Center (NWTC) to 5.5 MW.
• Installed a 1.5-MW turbine at the NWTC to conduct aerodynamics, load, and performance research.
• Launched three university-led wind energy research consortia with 24 million USD in Recovery Act funds:
Illinois Institute of Technology – Will conduct research on a utility-scale, land-based wind turbine to develop control algorithms for increasing wind turbine reliability and to develop operation and planning tools for utility power systems University of Maine – will design, develop, and deploy prototype floating platforms for offshore wind turbines.
University of Minnesota – will install a utility-scale, land-based wind turbine to investigate aerodynamics and acoustics, novel systems for mechanical power transmission and electric power generation, wind farm siting, and interactions between wind turbines and radar.
A wind resource assessment completed by the Wind Power Program in 2009 found more than three times the wind power potential previously calculated for the United States. According to the new numbers, land-based wind resources could generate nearly 37 TWh annually—more than nine times the total U.S. electrical generation capacity in 2009.
Previous government assessments, published in 1991, estimated the total wind power potential at approximately 10 TWh. The new estimates are based on high-resolution wind resource datasets for tower heights between 80 m to 100 m and capacity factors accepted by developers. In addition to the wind potential estimates, as part of its collaborative effort with AWS Truepower, DOE’s National Renewable Energy Laboratory produced maps of the annual average wind speed at 80-m height for the contiguous United States and for each individual state.
In 2009, DOE’s National Renewable Energy Laboratory published the Eastern Wind Integration and Transmission Study (6). This study evaluates the future operational and integration impacts of integrating up to 30% wind-generated electricity into the Eastern Interconnection power system by the study year 2024.
Results from the study show that there are no fundamental technical barriers to the integration of 20% wind energy into the electrical system; however, transmission planning, system operation policy, and market development need to continue to evolve for these integration levels to be achieved. The Western Wind and Solar Integration Study, published in May 2010, examines the operational impact of up to 30% wind and 5% solar energy integration into the WestConnect grid in Arizona, Colorado, Nevada, New Mexico, and Wyoming (7).
This study concluded that integration of these wind and solar energy levels into the WestConnect system is feasible, provided that there is sub-hourly scheduling and substantial cooperation between utility balancing areas.
DOE’s Argonne National Laboratory completed the Wind Power Forecasting: State-of-the-Art 2009 report, which includes an in-depth description of physical and statistical forecasting approaches, an overview of available forecasting models and typical application areas, and a discussion of the strengths and limitations of current tools.
DOE’s Small Wind Turbine Independent test project tested four small wind turbines to International Electrotechnical Commission standards as well as to draft AWEA standards for small wind turbine systems.
Research projects underway
The DOE Wind Power Program is working with Siemens under a cooperative research agreement to test a late stage prototype that features a novel blade design. Instrumentation of the 2.3-MW turbine installed at the NWTC in 2009 will provide data on aerodynamics, power characteristics, vibrations, system fatigue, and acoustics. Tests conducted on the Siemens turbine will provide knowledge to optimize turbine structures, mitigate loads, increase power production, test safety systems, develop and validate controls, improve system and component reliability, and better understand wind turbine aerodynamics.
The Wind Power Program partnered with RES Americas through a cooperative research agreement to help reduce costs of foundations and electrical power infrastructure for utility-scale wind turbines. For this project, foundations for the two multi-megawatt turbines installed at the NWTC in 2009 were custom-designed and heavily instrumented to provide data on loads. The Wind Power Program and RES Americas are also using the wind turbines to optimize thermal performance of underground electrical cables by installing cabling in various types of soil conditions and measuring heat dissipation.
More than 30 companies and organizations worldwide now participate in the wind turbine Gearbox Reliability Collaborative launched by the Wind Power Program in 2006. The goal of the Gearbox Reliability Collaborative is to validate the typical gearbox design process through a comprehensive dynamometer and fieldtest program. In 2009, the first 750-kW gearbox was instrumented and tested at DOE’s NWTC dynamometer to establish baseline characteristics.
The gearbox was then installed at the Xcel Energy Ponnequin wind farm in Colorado for field testing. Evaluation of the data will be shared among all participants in the collaborative and used to improve gearbox design codes. The Wind Power Program is working with several industry and academic partners to develop innovative wind turbine load-reducing control systems.
Industry partners include Catch the Wind, Garrad Hassan and Partners, Ltd., Risø National Laboratory in Denmark, the Colorado School of Mines, and the University of Colorado. One project aims to develop advanced feed-back and feed-forward controls that can be implemented on commercial wind turbines to mitigate loads, improve turbine performance, and reduce costs.
A 2008 renewable energy market report by ICF International Consulting identified a market potential of 220 GW for midsize wind turbines between 100 kW and 1,000 kW (8). In response, DOE will begin a project in 2010 to support the development and commercialization in the United States of midsize wind turbines for the global market.
Wind-radar interactions drew the attention of researchers and developers in 2006 when the U.S. Department of Defense discovered that wind turbine structures and rotors can reflect radar signals and thus interfere with accurate readings. Researchers at Idaho National Laboratory, Sandia National Laboratories, and Savannah River National Laboratory are working with federal radar agencies to determine the extent of wind-radar interactions and to develop measures to mitigate the possible effects of wind turbines on civilian and military radar systems.
The Wind Power Program works with groups like the National Wind Coordinating Collaborative, the Grassland Shrub Steppe Species Collaborative, Bat Conservation International, the Bats and Wind Energy Cooperative, and the U.S. Fish and Wildlife Service to better understand and mitigate the effects of wind projects on wildlife. In 2009, the Wind Power Program funded 12 new projects to study wind-wildlife interactions.
Collaborative research with international partners contributes to the Wind Power Program’s R&D efforts. Through the Wind Power Program’s work with the IEA Wind Implementing Agreement, U.S. researchers participated in all IEA Wind research tasks. U.S. researchers participated in topical expert meetings of Task 11, Base Technology Information Exchange. Active participation in Task 19, Wind Energy in Cold Climates, informs U.S. strategy for wind development in the northern states.
The Wind Power Program supported U.S. researchers who acted as managers (operating agents) for Task 23, Offshore Wind Energy Technology and Deployment; Task 24, Integration of Wind and Hydropower Systems; and Task 26, Cost of Wind Energy. U.S. experts participate in Task 25, Power Systems with Large Amounts of Wind Power, which issued key reports in 2009 addressing issues of grid connection that are relevant in all countries.
The United States is working with Task 27, Consumer Labeling of Small Wind Turbines, to develop a labeling protocol for small wind turbines. The Wind Power Program hosted a meeting of Task 28, Social Acceptance of Wind Energy Projects, in 2009 and data from wind tunnel tests at NASA contributes to the cooperation in aerodynamic research in Task 29, Analysis of Wind Tunnel Measurements and Improvement of Aerodynamic Models. The Wind Power Program also makes important contributions to the IEC and standards groups and has several productive bilateral agreements.
The Next Term
In fiscal year 2011, DOE will invest in activities that promote responsible offshore wind project development. Public investments will address common barriers to offshore projects, including financial, regulatory, technical, environmental, and social issues. DOE will also expand its efforts to analyze and facilitate technology supply chains and to improve manufacturing processes, and will continue its ongoing landbased wind R&D activities.
U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, www.eere.energy.gov/
(1) American Wind Energy Association, www.awea.org/
(2) 20% Wind Energy by 2030, www.20percentwind.org/20p.aspx?page=Overview
(3) Green Power Marketing in the United States: A Status Report (2008 Data), www.nrel.gov/docs/fy09osti/46581.pdf
(4) U.S. Wind Industry Annual Market Report Year Ending 2009 (April 2010). American Wind Energy Association, www.awea.org
(5) FY 2010 Congressional Budget, EERE/Wind Energy, pp 183-206, www.cfo.doe.gov/budget/10budget/Content/Volumes/Volume3.pdf, accessed February 18, 2010
(6) Eastern Wind Integration and Transmission Study, www.nrel.gov/docs/fy09osti/46505.pdf
(7) Western Wind and Solar Integration Study, www.nrel.gov/docs/fy09osti/46517.pdf
(8) ICF International U.S. Renewable Power Market Study, Webinar Presentation, May 2008.
Author: U.S. Department of Energy’s National Renewable Energy Laboratory, United States.