Geothermal power plants in the United States are highly concentrated in six western states including Hawaii. The western states, especially those along the Pacific coast,
have significant tectonic activity that creates geothermal activity such as hot springs, geysers, and volcanoes, indicators of geothermal activity. Naturally occurring geothermal reservoirs with hot water and steam support cost-effective electricity generation.
In 2022, 72% of installed electric generation capacity was located in California. About 0.4% of the nation’s electricity was generated in geothermal power plants. However, geothermal power accounted for 6% of electricity generation in California in 2022.1
The world’s largest complex of geothermal power plants is The Geysers project, which covers 45 square miles along the Sonoma and Lake County border in northern California. Commercial geothermal power The Geysers commenced in 1960.2 The area reached peak electrical of about 1.6 gigawatts (GW) in 1987; current production levels for the entire area are around 750–800 MW, which is enough electricity to power a city the size of San Francisco.3
1 California Energy Commission, 2022 Total System Electric Generation, accessed October 30, 2023, Link
2 U.S. Geological Survey, The Geysers Geothermal Field, September 20, 2023, Link
3 Dobson, Patrick, Dipankar Dwivedi, Dev Millstein, Nandini Krishnaswamy, Julio Garcia, and Mariam Kiran. “Analysis of Curtailment at The Geysers Geothermal Field, California.” Geothermics 87 (September 1, 2020): 101871. https://doi.org/10.1016/j.geothermics.2020.101871.
