A wind turbine system transforms the kinetic energy of the wind into electrical energy that can be harnessed for practical use.
Large, high-tech turbines, grouped into "wind farms" with generating capacities that range from a few megawatts to hundreds of megawatts, produce power that flows into the electricity grid.
While wind contributes less than 1% of the electricity generated in the U.S. today, installed capacity has been expanding at an average annual rate that exceeds 20%. In the early 1980s, when the first utility-scale turbines were installed, wind-generated electricity cost as much as 30 cents per kilowatt-hour. Now, some state-of-the-art wind power plants can generate electricity for less than 5 cents per kilowatt-hour, a price that is competitive with new coal and gas-fired power plants.