State solar power plans are as big as all outdoors

Costing about 18 cents a kilowatt-hour at present, solar thermal power is roughly 40% cheaper than that generated by the silicon-based panels that sit on the roofs of homes and businesses, according to a June report by Clean Edge Inc. and the Co-op American Foundation. Analysts say improved technology and economies of scale should help lower the cost of solar thermal to about 5 cents a kilowatt-hour by 2025. That would put it on par with coal, the cheap but carbon-spewing fuel that generates about half the nation's electricity.

Size matters, said Sun Microsystems Inc. co-founder-turned-venture capitalist Vinod Khosla, whose Khosla Ventures has invested more than $30 million in Ausra. A square patch of desert about 92 miles long on each side blanketed with Ausra's technology could generate enough electricity to meet the entire nation's demand, company executives say.

"Utility-scale solar is probably the only way to achieve real scale . . . and reduce our carbon emissions" significantly, Khosla said.

Critics fear that massive solar farms would create as many environmental problems as they purport to solve. This new-age electricity still requires old-fashioned power towers and high-voltage lines to get it to people's homes. A proposed 150-mile transmission line known as the Sunrise Powerlink that would carry renewable power from Imperial County to San Diego has run into stiff resistance from grass-roots groups and environmentalists.

Solar plants require staggering amounts of land, which could threaten fragile ecosystems and mar the stark beauty of America's deserts. And in contrast to rooftop panels, which enable homeowners to pursue energy independence, these centralized facilities keep consumers tethered to utility companies.

"They are trying to perpetuate the old Big Energy paradigm into the renewable-energy era," said Sheila Bowers, a Santa Monica attorney and environmental activist. "They have a monopoly agenda."

California already has the largest operating collection of solar thermal facilities in the world: nine plants totaling just over 350 megawatts in San Bernardino County. Built in the 1980s, they were part of a drive toward energy self-sufficiency stemming from the '70s oil shocks. The boom ended when California dropped requirements forcing utilities to buy renewable power.

The push is back. The 2000-01 energy crisis exposed California's dependence on outsiders -- more than 30% of its electricity still comes from out of state. Renewable forms of energy are once again central to efforts to shore up supply and fight global warming.