Calpine plans 98 MW expansion at the Geysers

Geothermal Plant by Calpine in The Geysers, California (source: flickr/ thinkgeoenergy, creative commons)

Alexander Richter 11 Oct 2011

Calpine Corp. announces it plans to build two new power plants at the Geysers geothermal field in northern California, adding 98 MW to its existing capaicty.

There will be an approval process that is set for later this month for two land use permits and further permits are needed including an air permit, building and grading permits.

Construction for the first proposed plant could begin in 2012 and be operational as early as 2014. The construction for the second planned plant could then begin two or more years later.

The site is based on a piece of land north of Calpine’s currently operating 15 plants in the Geysers geothermal field. The company acquired the steam field leases in 2004 from the Wild Horse Ranch and the proposed drilling sites are located there.

“The Geothermal Operator Corporation (GOC) and the Central California Power Association (CCPA) previously developed this site. These firms built their first plant in 1989 with a capacity of 135 megawatts. Due to a sharp decline in natural steam conditions, the plant was decommissioned and steam wells were plugged and abandoned in 1990.

Over the past 10 years, Calpine has been injecting up to 20 million gallons of reclaimed wastewater per day from Santa Rosa and Lake County into the underground steam reservoir to produce additional steam and manage the entire field as a whole. This injection process is what makes it possible to revisit abandoned well sites and bring them back online.

At Wild Horse Ranch, Calpine has invested approximately $80 million to date on drilling and pipelines for 16 wells — 14 of which involve the reopening of existing wells while others are new, grassroots wells.

Six wells are steam producers that have been connected to Calpine’s existing plants, and five are injectors that will be connected to the company’s injection pipeline system. Since heat is lost over the distance it must travel to the power plant, the two proposed plants are located close to steam sources to achieve maximum output.

The Geysers is the single largest geothermal operation in the world, producing up to 725 megawatts of green energy around the clock — enough electricity to power the entire city of San Francisco.

Today this 45-square mile steam field, with its 330 steam wells and 75 injection wells, represents 41 percent of overall geothermal generation in the U.S.

The new project represents an investment by Calpine of approximately $700 million and will employ an estimated 191 local, union construction jobs and 900,000 hours of labor over a 30-month buildout period.

“We originally planned to take advantage of an Investment Tax Credit offered by the federal government that would have covered approximately 30 percent of the cost,” said Gevan Reeves, Strategic Origination Director with Calpine.”

Source: North Bay Business Journal