Big solar power planned for California coast

Silicon ValleyÂ’s solar boom continues with Ausra, a Palo Alto startup backed by venture capitalist heavyweights Vinod Khosla and Kleiner Perkins Caufield & Byers, filing an application to build a 177-megawatt solar power plant on CaliforniaÂ’s Central Coast.

Ausra’s lodging of its more than 1,000 page “application for certification” with the California Energy Commission is another sign the company, which relocated to Silicon Valley from Sydney last year, is about to sign a major deal with a California utility.

Khosla has previously said Ausra is negotiating with PG&E (PCG). In its application, the company stated that the San Luis Obispo County project, called the Carrizo Energy Solar Farm, would begin providing greenhouse gas-free electricity to “a major California utility” by June 2010 under a 20-year power purchase agreement.

If the Commission licenses the project - at least a year-long process - construction would begin in 2009. In September, Florida utility FPL (FPL) announced it would use AusraÂ’s technology for a planned 300-megawatt solar power plant.

While thereÂ’s no shortage of solar startups with big plans for Big Solar, only three companies have actually taken the expensive and time-consuming step of filing a construction application with the California Energy Commission. (Oakland, Calif.-based solar company BrightSource Energy recently cleared a major regulatory hurdle when the Commission signed off on its application for a 400-megawatt Mojave Desert power plant and began the licensing process.)

The Carrizo solar thermal power plant will deploy 195 long rows of flat mirrors to focus the sunÂ’s rays on tubes of water suspended over the arrays. The superheated water creates saturated steam that will drive two electricity-generating turbines, to be supplied by either GE (GE) or Siemens (SI).

While the efficiency of AusraÂ’s compact linear fresnel reflector system is lower than competing technologies, company executives claim they will able to drive down the costing of producing solar electricity to make it competitive with natural gas.

Unlike most solar power plants in the works for California, Ausra has chosen not to locate its facility in the Mojave Desert, where solar sites are sun-drenched but are often on government land and far from transmission lines. Instead, the Carrizo project will be built on 640 acres of old ranch land on the Carrizo Plain, where Ausra will just need to construct a 850-foot transmission line to connect to the power grid.