The use of wind power to generate electricity has a long history. However, the concept of building wind farms is a newer phenomenon that developed as a cheap and sustainable alternative to the use of fossil fuels. Large wind farms consist of hundred of giant turbines located on an area of land or offshore combined to produce large amounts of electrical power.
In 2011, U.S. wind-turbine power generation was about 60000 megawatts (MW). Only China, with an output of 62 gigawatts (GW), produced more turbine power. In 2011, the electricity produced by U.S. turbines provided just over 140 terrawatt hours (TWh) of electricity. This output equaled about 3.5% of U.S. electrical use.
Ongoing construction of 10,312 MW of capacity, and the planned construction of 8,430 MW would have raised total production to 78000 MW in 2012. Given this scenario, the U.S. Department of Energy envisioned that wind power would supply 20% of U.S. energy needs by 2030. Unfortunately, fiscal uncertainties have placed these predictions in jeopardy.
In total, 39 states have some utility-scale wind power facilities. Fifteen states possess wind farms that together provide over 1,000 MW. Five states lead in over all power commitment to turbine energy: Texas (12,212 MW), California (5,549 MW), Iowa (5,137 MW), Illinois (3,568 MW) and Oregon (3, 153 MW). The top two states, according to percentage of total state power usage generated by wind farms, are Iowa (24.5%) and South Dakota (23.9%). The five largest wind farms in order are:
Alta Wind Energy Center
Alta Wind Energy Center is the largest wind farm in the United States. It is situated near the Tehachapi Pass Wind Farm in the Tehachapi Pass of the Tehachapi Mountains in California. Built in phases, beginning in the 70s, it was commissioned in 2010 and now has a capacity of 1320 MW from 490 turbines.
Shepherds Flat Wind Farm
Shepherds Flat Wind Farm is located in Morrow and Gilliam counties in Eastern Oregon. Commissioned in 2012, the farm produces 845 MW from 338 GE 2.5 MW turbines.
Roscoe Wind Farm
The Roscoe Wind Farm is owned and operated by E.ON Climate and Renewables in the area of Roscoe, Texas. Its total capacity is 781.5 MW generated by 209 Mitsubishi 1-MW, 55 Siemens 2.3 MW, 166 GE 1.5 MW and 197 Mitsubishi 1-MW turbines.
Horse Hollow Wind Energy Center
Horse Hollow Wind Energy Center is spread over 47K aches in Nolan and Taylor counties in central Texas. Commissioned in 2005, it has a capacity of 735.5 MW generated from 292 GE 1.5 MW and 130 Siemens 2.3 MW turbines.
Tehachapi Pass Wind Farm
Tehachapi Pass Wind Farm has a capacity at 705 Mw from 690 turbines. Begun in the 1980s, the wind farm has some turbines with capacities measured in kWs not MWs and with single blades. Its modern turbines generate up to 3 megawatts. The Tehachapi wind resource area exports to other parts of California.
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