State lawmakers have told investor-owned utilities that they must procure 20% of their electricity from renewable sources by 2010; Gov. Arnold Schwarzenegger is pushing for a minimum of 33% by 2020. A landmark 2006 state law forcing California to reduce its greenhouse gas emissions to 1990 levels within 12 years also is boosting green generation.
Most of the proposed utility-scale solar plants are slated for San Bernardino and Riverside counties, where vast deserts offer abundant sunshine and plenty of open space for the behemoths. The U.S. Bureau of Land Management is juggling so many requests from companies looking to build on federal land -- 79 at last count, covering more than 690,000 acres -- that it had to stop accepting applications for a few weeks last summer.
Many of these facilities may never get built. Environmentalists are mobilizing. U.S. credit markets are in a deep freeze. Oil and natural gas prices are falling, reducing some of the urgency to go green.
Still, the obstacles haven't clouded the ambitions of solar start-ups such as Ausra.
"Our investors perceive there is a huge opportunity here," said Bob Fishman, Ausra's president and chief executive.
A group of dignitaries that included Schwarzenegger gathered near Bakersfield in October to get a close-up look at the 5-megawatt operation Ausra opened.
The company uses a technology known as a compact linear Fresnel reflector. Acres of mirrors are anchored to metal frames and held roughly 6 feet off the ground in parallel rows. Controlled by computers, these panels make hundreds of barely perceptible movements throughout the day, tracking the sun's path across the sky.
The mirrors catch the sun's rays and reflect them onto a cluster of water pipes overhead. The intense heat -- it can reach 750 degrees -- generates pressurized steam inside the pipes. That steam is then fed into a turbine whose spinning generates electricity.
"It's like when you were a kid and you used a magnifying glass to fry a bug," said Dave DeGraaf, vice president of product development. "We're focusing all that energy."
Despite its mammoth size, this pilot plant generates a modest amount of electricity, enough to power just 3,500 homes when the sun is shining. Ausra is thinking much bigger.
