WASHINGTON, DC — The Department of Energy (DOE) has announced the selection of two companies under a cooperative agreement to develop and demonstrate an Enhanced Geothermal System (EGS) in California. DOE will provide $4.5 million over the next five years to support the $12 million effort by the University of Utah’s Energy and Geoscience Institute (UU-EGI) and Caithness Energy, LLC, New York, NY, to increase energy production in the Coso geothermal field.

“The new system is expected to add about 15 megawatts of electrical capacity — enough to power 11,250 homes — to the 270 megawatts now being generated at the site,” Secretary of Energy Spencer Abraham said.

The Coso geothermal field is located about 25 miles north of Ridgecrest, CA, on the China Lake Naval Air Weapons Station. UU-EGI and Caithness will pump water under high pressure into a portion of the Coso field to fracture subsurface rocks and create channels for hot water to move from the geothermal reservoir to existing geothermal wells. The process, called “hydrofracing,” is commonly used in oil and gas production. The Coso geothermal plant operates under agreements with the U.S. Navy and Bureau of Land Management, paying royalties to the federal government.

This EGS cooperative agreement, the first award in a three-part program, will develop technology and demonstrate the potential for expanding an existing geothermal reservoir. DOE is currently seeking applications for stage two, which is designed to improve economically unproductive geothermal fields. During stage three, DOE will develop technology for locating new geothermal fields in the U.S. where EGS technology can be applied.

EGS is expected to more than double the amount of geothermal energy economically recoverable in the U.S. and extend the productive life of existing geothermal fields.

Publication date: 04/29/2002