Editor’s note: The following story by David Baker appeared Aug. 21 in the San Francisco Chronicle.

California energy regulators on Thursday (Aug. 20) gave Pacific Gas and Electric Co. permission to buy electricity from two large solar power plants that an Oakland firm plans to build in the Mojave Desert.

The California Public Utilities Commission also decided Thursday to explore the effects that electric cars will have on the state’s power grid and devise policies to encourage their use.

PG&E won the commission’s approval for two contracts with BrightSource Energy, one of several companies planning large-scale solar plants in the Southern California desert.

The plants will use BrightSource’s version of “solar thermal” technology. Fields of mirrors will focus sunlight on centralized towers, boiling water within the towers, creating steam and turning turbines. The first plant is scheduled to open in July 2012 at the Ivanpah dry lake bed in San Bernardino County.

The two companies did not disclose financial details of the contracts, which will help PG&E meet a state mandate to increase its use of renewable power. California law requires utility companies to get 20 percent of their electricity from renewable sources by the end of 2010, and Gov. Arnold Schwarzenegger wants to raise the target to 33 percent by 2020.

The commission also set in motion a process to study the impact that electric cars – as well as those that burn natural gas – could have on the state’s energy infrastructure.

With plug-in cars planned by such automakers as Ford, GM and Nissan – not to mention the Bay Area’s Tesla Motors, which already sells them – the commission wants a consistent set of policies to make sure the state has the right infrastructure to accommodate those vehicles.