Most pumped storage electricity generators in the U.S. were built in the 1970s ›

Pumped storage plants for hydroelectric power in the Unites States were built primarily between 1960 and 1990; nearly half of the pumped storage capacity still in operation was built in the 1970s. Pumped storage power plants are the largest source of electricity storage technology used in the United States, both in terms of capacity and number of plants. (Virtually all remaining commercial-sized electrical storage use thermal energy or batteries.) More ›

Source: EIA, Annual Electric Generator Report