Salton Sea Geothermal
Located 80 miles east of San Diego, Salton Sea geothermal field is the largest of three major geothermal energy production sites in the Salton Sea Known Geothermal Resource Area, or SSKGRA, in Southern California's Imperial Valley. It consists of a network of deep wells drilled in the geothermal field which allow water heated by the earth's mantle to come to the surface and to power electrical generators. Geothermal power, which grew by 6% in the U.S. during 2009, makes use of naturally occurring subsurface magma formations to generate electric power. First steam is created by injecting water into the hot subsurface layers. The steam is then fed back trough turbine generators to create electricity.
Owned by the CalEnergy Company, The Salton Sea geothermal project consists of 10 generating plants which produce electricity solely from naturally occurring geothermal steam. According to information on CalEnergy’s website, four of the Imperial Valley facilities - Vulcan, Hoch, Elmore and Leathers - are under contract to sell power to Southern California Edison Company under 30-year power purchase agreements. Four other power plants - Salton Sea 1, 2, 3 and 4 - also sell energy to Edison under 30-year power purchase agreements. Salton Sea 5 and the CE Turbo plant sell virtually all of their power to third parties. The combined capacity at Imperial Valley is 327 net megawatts (nominal). The plants produce enough electricity to power over 100,000 homes.
Besides investing in energy generation, CalEnergy has also spent $400 million on a facility to extract 300,000 metric tonnes of zinc per year from spent geothermal brines at Salton Sea geothermal power plants.