SAN FRANCISCO -- The latest hot spot for the Chinese solar industry is San Francisco, according to Mayor Gavin Newsom.

Speaking at Intersolar, Newsom pointed out that Suntech Power Holdings, the solar module giant, opened its U.S. headquarters here last year with four employees. It now has 50 and in about a year it will have 100.

Trina Solar also planted its U.S. headquarters here and just recently so did Yingli Solar.

"Hundreds of companies have come to San Francisco because of our tax incentives," he said.

San Francisco has also become a big market for demand because of city-wide solar incentives that come in addition to federal and state incentives. Some installers have told me that a San Francisco resident last year could put solar on his or her roof for around $2,500. Because of the incentives, San Francisco is the third largest solar city in California and the largest per capita city in the state.