Imperial Valley

TransAlta’s Imperial Valley operations in Southern California use a renewable fuel source: naturally occurring geothermal steam. Imperial Valley is comprised of 10 geothermal power plants: Vulcan, Del Ranch, Elmore, Leathers, CE Turbo, Salton Sea I, Salton Sea II, Salton Sea III, Salton Sea IV and Salton Sea V. The combined capacity of the Imperial Valley facilities is 326 megawatts.

Geothermal production wells tap into super-heated water reservoirs thousands of feet beneath the earth's surface to release tremendous pressure caused by the hot water, which rushes to the surface. Geothermal technology captures this heat energy and transforms it into electricity. Instead of burning a fuel to heat water into steam, as is the case with conventional forms of generation, heat from the earth is used to create the steam to power the turbines.

Power from eight of the 10 units is sold under long-term contracts to Southern California Edison Co. The balance is sold as merchant power.

TransAlta holds a 50 per cent interest in the project. MidAmerican Energy Holdings Company owns the other 50 per cent. MidAmerican is the manager and operator of the assets.

Last updated: January 28, 2013