LOS ANGELES — The agreement by investor Warren Buffett’s MidAmerican Energy Holdings to buy a $2 billion photovoltaic farm in San Luis Obispo County could bring a ray of financial sunshine to the battered solar-energy industry.

The scale of Buffett’s foray into this sector of the renewable energy scene is considerably more modest than his $34 billion purchase of BNSF Railway, but it could provide the same kind of boost to the solar power business that the 2009 acquisition did to the railroad industry, experts said.

“In a lot of ways, this is classic Warren Buffett,” said Bruce Bullock, executive director of the Maguire Energy Institute at Southern Methodist University. “He comes into an industry that is starving for capital investment. At the same time, this is something that also tells people it’s time to take solar power seriously.”

MidAmerican is buying the 550-megawatt solar energy development called Topaz Solar Farm from First Solar Inc. of Tempe, Ariz., the two companies said Wednesday. How much the Berkshire Hathaway Inc. subsidiary is paying for the solar project, which will be able to generate electricity for about 160,000 homes, wasn’t disclosed.

First Solar will build and operate the solar plant for MidAmerican, the companies said.

The U.S. solar industry has struggled for several reasons. It has been bludgeoned by falling solar-panel prices and, some say, unfair competition from China.

Green energy supporters said the move by Buffett’s company could get other investors to focus on solar’s strengths, which have largely been ignored in the face of recent bad publicity.

The value of the nation’s solar industry has grown 67 percent, to $6 billion, since 2009, making it the fastest-growing segment of the nation’s renewable energy offerings, said Michelle Kinman, a clean energy advocate for the group Environment California. The solar industry also is producing jobs at a fast rate during a time of distressingly high unemployment in America, she said.