Onshore wind turbines capture energy from the wind and produce electricity using long, rotating blades that drive a generator located at the top of the tower behind the blades. Onshore wind energy is among the fastest-growing utility-scale renewable energy technologies in the country. The best wind resources are located in areas that receive strong, sustained wind speeds 50 to 80 meters above the ground. Total annual U.S. electricity generation from wind energy increased from about 6 billion kilowatthours (kWh) in 2000 to about 380 billion kWh in 2021. In 2021, wind turbines were the source of about 9.2% of total U.S. utility-scale electricity generation.