May 3, 2002 — The U.S. Department of Energy will provide $4.5 million to the University of Utah’s Energy & Geoscience Institute (EGI) to aid a five-year, $12 million effort to boost electric power production at California’s Coso geothermal field.
“We are attempting to tap into the less permeable and less productive margins of existing geothermal systems,” said Peter E. Rose, coordinator of EGI’s geothermal program and a research associate professor of chemical and fuels engineering. “Although barriers exist, the potential for clean, domestic energy production is quite large.”
EGI Director Raymond A. Levey said the $4.5 million award – announced in Washington on April 29 by U.S. Secretary of Energy Spencer Abraham – was “great news for the university, which has a 20-year track record in geothermal research.”
The award calls for the University of Utah institute and Caithness Energy, LLC, of New York, to cooperatively develop and demonstrate an “enhanced geothermal system” at the Coso Geothermal Project, located in eastern California’s Coso volcanic field, about 150 miles north of Los Angeles.
Caithness has owned and operated the Coso Geothermal Project since 2000, when the company purchased it from CalEnergy Co., the original co-owner and co-developer. Located in the Mojave Desert on the China Lake Naval Weapons Center, the project’s three geothermal power plants generate 270 megawatts of geothermal energy, or enough electricity for 202,500 homes.
Rose said the new effort is expected to add about 20 megawatts, enough for another 15,000 homes.
During their $12 million effort, the university’s EGI and Caithness will pump water under high pressure into a portion of the Coso field to reopen sealed fractures in subsurface rocks. Water pumped into the ground from injection wells then will circulate through the fractured rocks, flow to the surface through existing geothermal wells and drive steam turbines. The process – called “hydrofracturing” or “reservoir stimulation” – commonly is used in oil and gas production.
“Developing and demonstrating this enhanced geothermal system technology advances the President’s National Energy Plan goals of deploying next-generation technology and increasing renewable energy production on federal lands,” Abraham said.
Rose said the “enhanced geothermal system” is part of the Department of Energy’s first major attempt to expand geothermal energy resources since the demise of its “hot dry rock” program, in which cold water was pumped through subsurface hot rocks to produce steam for geothermal power. A 1994 General Accounting Office report concluded the method was technically feasible but not economically viable.
Caithness will provide $7.5 million of the total for drilling and completing water- injection and geothermal production wells. The $4.5 million from the Department of Energy will be sent to the University of Utah, where the Energy & Geoscience Institute will retain $1.5 million for research related to the project and subcontract $3 million to other institutes and companies involved in the technical research, Rose said.
The Department of Energy said the “enhanced geothermal system” effort by the University of Utah and Caithness “will develop technology and demonstrate the potential for expanding an existing geothermal reservoir.”
The agency now is seeking proposals for two later stages that are, respectively “designed to improve economically unproductive geothermal fields” and “develop technology for locating new geothermal fields in the United States where enhanced geothermal system technology can be applied.”
Overall, the enhanced geothermal system “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,” the agency said.
The Coso Geothermal Project operates under agreements with the U.S. Navy and the Bureau of Land Management, paying production royalties to the federal government. The 270 megawatts of electricity are sold to Southern California Edison.
The Energy & Geoscience Institute is part of the University of Utah’s Department of Civil and Environmental Engineering within the College of Engineering.
The University of Utah Energy & Geoscience Institute:
http://www.egi.utah.edu
The Energy & Geoscience Institute’s geothermal research group:
http://egi-geothermal.org
The U.S. Department of Energy’s geothermal program:
http://www.eren.doe.gov/geothermal