Coso Operating Company

Coso Operating Company, LLC, has operated the Coso Geothermal Projects at the U.S. Naval Weapons Center in Inyo County since 1987.  Consisting of four separate but interlinked geothermal power plants, the Coso site is one of the top three producers of geothermal electrical power in the United States.  The company leases the geothermal site from the U.S. Navy.  The project has produced as much as 270 megawatts of electricity, enough power to supply 250,000 homes, but currently generates approximately 145 net megawatts.

Coso provides power from its site to southern California power grid, and plays an important role in supporting the State’s mandated Renewable Portfolio Standard (RPS).  This premier resource supplies approximately 8% of the entire geothermal power in the United States.

Coso Operating Company is committed to not only sustaining the quality of energy, but also the quality of life in both Inyo and Kern county.

How the Coso Geothermal Power Plants Work

Under pressure from the natural geothermal resource, or reservoir, thousands of feet below the surface, hot geothermal fluid (brine), travels up wells, some as deep as 11,000 feet, and flashes into steam that drives turbines which in turn drive electrical power generators.  Brine that does not flash into steam, along with condensed steam from the turbines, are collected and injected back into the geothermal reservoir through injection wells.

Like all geothermal resources, the Coso projects are a clean, renewable source of energy that can provide power generation 24 hours a day, seven days a week with near perfect reliability.  As time goes by, because of the loss of brine through cooling tower evaporation, it becomes necessary to augment brine reinjection back into the geothermal resource to maintain reservoir pressure for optimizing the extraction of the hot geothermal fluid.  Indeed, the Coso project’s original 1980 Environmental Impact Study (EIS) anticipated this possibility.