Southern California Edison's Nicole Neeman Brady said the MidAmerican development will help the utility meet California's renewable energy goals.
SunPower CEO Tom Werner said this deal is a big positive for his 25-year-old company, because it will bring in nearly as much revenue as SunPower expected to generate in 2012.
Werner said this project is also important for the industry because its size and cost will show that solar power is competitive with traditional fossil fuels. And SunPower will benefit from being able to say that a unit of Buffett's company invested in its work.
"Because of the size of this project, we think it's a stamp of credibility for our company," he said.
Werner expects to see similar projects built all across the southwestern U.S. in the next few years.
SunPower operates more than 1,000 megawatts of solar power plants globally. Its shares rose 51 cents, or 9.1 percent, to close at $6.13.
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MidAmerican Renewables: www.midamericanrenewablesllc.com
Berkshire Hathaway Inc.: www.berkshirehathaway.com