[caption id="attachment_19861" align="alignnone" width="554" caption="Calpine operates 15 geothermal plants like this one at The Geysers complex. (photo courtesy of Calpine)"][/caption]

THE GEYSERS -- Calpine Energy Services, which operates a large geothermal power complex in northeastern Sonoma County, signed an agreement with San Diego Gas & Electric to generate 25 megawatts of electricity over a four-year period, it was announced today.

The agreement will provide green power for 15,000 households and contribute more than 200 gigawatt-hours a year toward SDG&E's Renewable Portfolio Standard procurement goal, or about 14 percent of its output. The state has mandated that utilities produce 20 percent renewable power by 2010.

Calpine has about 15 geothermal power plants at The Geysers in the Mayacamas Mountains with a capacity of 725 megawatts. No additional staff or equipment will be necessary to fulfill the agreement, said a Calpine spokesperson.

Calpine Energy Services, a subsidiary of Calpine Corp., employs 350 at the Geysers.