Geothermal Power Plants

Located north of San Francisco in the Mayacamas Mountains, The Geysers is the single largest geothermal electrical operation in the world. Because geothermal power plants do not burn fossil fuel, they have an inherent environmental advantage.

A geothermal resource occurs when water deep below the earth’s surface is heated by exposure to hot, permeable rock, resulting in dry steam or hot water. At The Geysers, dry or superheated steam is produced.

Steam production wells, some deeper than two miles, are drilled to tap this naturally occurring steam. (Click here to view a video about geothermal steam wells.) Once the steam reaches the surface, it is piped overland to a network of interconnected power plants, where it spins conventional steam turbines that drive generators to produce clean, reliable electricity. The spent steam leaving the turbines is condensed and cycled through the cooling towers. Also, treated wastewater from local municipalities is injected underground to help replenish the geothermal reservoir.

To learn more about how Calpine is working to sustain this valuable natural resource for generations to come, visit The Geysers website.