Wind power has been the fastest-growing source of new electric power generation for several years. In 2010, generation from wind power increased 28.1 percent over 2009, bringing the share of total generation to 2.3 percent. This followed year-over-year generation gains of 33.4 percent in 2008, 60.7 percent in 2008, 29.6 percent in 2007, and 49.3 percent in 2006 (See the "Electric Power Annual" Table ES.1). Wind capacity in 20109 totaled 39,135 megawatts (MW), as compared to 24,651 MW in 2008.
In 2010, wind generators were eligible for Federal production and investment tax credits or a cash grant in lieu of those tax credits. Since passage of the 2005 Energy Policy Act (EPACT2005), interest-free financing via Clean Renewable Energy Bonds (CREBs) has been available to government entities investing in wind. Section 9006, under Title IX of the 2002 and 2008 Farm Bills, also contains grant and loan guarantee provisions for wind projects for farmers, ranchers, and other rural businesses.
Renewable generation is fostered by both Federal incentives and State renewable portfolio standards. As of October 2010, 29 States, the District of Columbia, and Puerto Rico have legislated renewable energy portfolio standards, and 7 more States have adopted renewable portfolio goals.
Wind power basics
Winds are created by uneven heating of the atmosphere by the sun, irregularities of the Earth's surface, and the rotation of the Earth. As a result, winds are strongly influenced and modified by local terrain, bodies of water, weather patterns, vegetative cover, and other factors. The wind flow, or motion of energy when harvested by wind turbines, can be used to generate electricity. Wind-based electricity generating capacity has increased markedly in the United States since 1970, although it remains a small faction of total electric capacity. more wind basics
of State Incentives for Renewable Energy (DSIRE)
Resources on Federal Lands
 The grant program arose out of Section 1603 of the American Economic Recovery and Reinvestment Act of 2009 (ARRA) and was intended to allow investors who could not take advantage of tax credits to fund these projects with an equivalent government grants. This program expires December 31, 2010. See the Database of State Incentives for Renewables and Efficiency (DSIRE) at http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=US53F&re=1&ee=1
Capacity plans are constantly evolving as electric power producers navigate a dynamic, rapidly changing market. Each year, EIA asks electric power producers for a snapshot of their plans as of the end of the previous year.
As of the end of 2010 electric power producers planned to add 72,273 MW of capacity between 2011 and 2015. Of this, 47.3 percent was planned to be fired by natural gas (34,151 MW) and 13.1 percent from coal (9,480 MW). Planned wind additions totaled 15,043 MW, or 20.8 percent of total reported planned additions.
Wind plants have a much shorter planning horizon and are built more quickly than fossil fuel-fired plants; only 2.3 percent of the reported new wind capacity additions were planned to occur after 2013.