|The Altamont Pass Wind Farm located in the Altamont Pass of the Diablo Range in Central California. It is a one of the earliest wind farms in the United States. The wind farm is composed of over 4900 relatively small wind turbines of various types, making it at one time the largest farm in the world in terms of capacity. Altamont Pass is still the largest concentration of wind turbines in the world, with a capacity of 576 megawatts (MW), producing about 125 MW on average and 1.1 terawatt-hours (TWh) yearly. They were installed after the 1970s energy crisis in response to favorable tax policies for investors.