Southern California Edison Co. said Thursday it plans to build the nation's largest solar energy installation — an array of collector cells covering two square miles of rooftops that could power about 162,000 homes.
The project, which was submitted to state regulators for approval, is an effort to meet the state's mandate that 20 percent of California's electricity be generated from renewable sources by 2010.
Gov. Arnold Schwarzenegger attended the announcement, praising the $875 million project. "If commercial buildings statewide partnered with utilities to put this solar technology on their rooftops, it would set off a huge wave of renewable energy growth," Schwarzenegger said.
Edison hopes to mount the first cells immediately on buildings in Riverside and San Bernardino counties, with some sites operational as soon as August.
"These new solar stations, which we will be installing at a rate of one megawatt a week, will provide a new source of clean energy, directly in the fast-growing regions where we need it most," said John Bryson, chairman and chief executive of Edison International, the utility's parent company.
Helping out with peak load
"The sunlight power will be available to meet our largest challenge -peak load demands on the hottest days," he added.
A one-megawatt power plant running continuously at full capacity can power 778 households a year, according to the U.S. Department of Energy.
The cells convert sunlight into electricity by using solar rays to trigger an electric current through a chemical reaction.
The array of solar cells placed atop commercial building rooftops across Southern California would generate 250 megawatts of electricity — about half as much power as a new coal or natural gas-fired power plant would generate.
So far, companies behind the largest solar projects have favored solar thermal technology, in which parabolic mirrors are used to concentrate sunlight to heat a liquid that drives a power-generating turbine.
Photovoltaic technology converts sunlight directly into electricity inside the solar cells.
SCE, which provides power to 13 million people, said its new photovoltaic project was possible because recent advances had cut in half the traditional cost of installed solar generation in California.
Solar thermal plan in desert
On Wednesday, Florida-based FPL Group Inc, the nation's largest generator of wind and solar power, announced it planned to build a 250-megawatt solar thermal plant in California's Mojave Desert.
The company's proposed Beacon Solar Energy Project would involve more than 500,000 parabolic mirrors assembled in rows on 2,000 acres in the Mojave Desert north of Los Angeles.
The project, which would generate 250 megawatts of power, was expected to take about two years to complete.
Solar power from the project will be used to make steam for a turbine generator connected to an electricity grid.
The combined 500 megawatts produced by the FPL and Edison projects would increase the state's solar power flowing to the state electricity grid by just more than 50 percent.
Utilities and power companies are increasing their portfolios of renewable energy to meet ever-increasing state demands to help reduce their output of carbon, the greenhouse gas blamed for contributing to rising global temperatures.
SCE in early March broke ground on a desert wind farm that could provide power for upwards of 3 million homes by 2013.
Officials estimate that the Tehachapi Renewable Transmission Project will eventually provide 4,500 megawatts of electricity. The project will harness the wind that blows through the Tehachapi Mountains about 100 miles north of Los Angeles.
Michael Peevey, president of the California Public Utilities Commission, said the project will create the single largest power block of wind energy in the country.
"Our action today represents a critical step in alleviating the transmission constraints that have limited our ability to access substantial wind resources in the Tehachapi region," he said in a statement.
Currently the country's largest wind farm is the Horse Hollow Wind Project in Texas that provides 730 megawatts, according to Edison spokesman Steve Conroy.
