LOS ANGELES, Nov 5 (Reuters) - Pacific Gas & Electric Co announced Monday it signed solar thermal developer Ausra Inc to build a 177-megawatt solar farm in central California.
The solar farm in San Luis Obispo County is to open in 2010 and is the second large solar thermal project contracted by PG&E this year. The utility is negotiating for a third major solar thermal project, of about 500 megawatts rated capacity.
PG&E three months ago singed with Israel's Solel Solar Systems to build a 553-megawatt solar farm in the Mojave Desert that is to open in 2011. PG&E Co is a unit of PG&E Corp (PCG.N) based in San Francisco.
Ausra's farm in to come on line first, and Ausra CEO Bob Fishman said it will be able to deliver no-emissions electricity to the power grid at a price comparable to that of natural gas.
Fishman said that he sees solar thermal technology as a viable answer to coal-fired and natural gas-fired power plants because it has the promise to deliver power at a competitive cost and plants that are truly utility-scale.
"We are very bullish on solar thermal technology," said PG&E spokesman Keely Wachs. "It is one of, if not the most, promising renewable energy sources currently on the market."
Solar thermal power uses more conventional mirrored glass than does solar photovoltaic panels and does not need silicon as do photovoltaic panels.
The 177-MW solar farm will have an array of mirrors spread over one square mile -- 640 acres.
Ausra's solar thermal method is to concentrate the sun's light light on a tube filled with water. Water goes in at one end of the tube and comes out the other end as steam which powers a turbine like those used in natural gas-fired plants. Steam can also be stored, which allows Ausra's solar plants to produce power when the sun is not shining.
"We can deploy clean, dispatchable renewable energy on a scale that really impacts the grid," said Fishman.
He said the power is "dispatchable" which means its delivery will be reliable enough for power grid operators to count on it.
"Up to now, renewables have been on the fringe with a few megawatts here and a few megawatts there," Fishman said. "When we put hundreds and thousands of megawatts on the grid, people will pay attention."
Fishman said Ausra may be be able to get a second solar thermal plant on line in 2010 and expects to be opening "several plants a year starting in 2011."
In addition to signing up Ausra and Solel for solar thermal power projects, PG&E is negotiating with BrightSource Energy, based in Israel with a U.S. base in Oakland, California, for a 500-megawatt solar farm.
Ausra is a company that started in Australia and is now based in Palo Alto, California.