California set a mandate that electricy produced in the state would come from a minimum of 20 percent renewable sources by 2010. The Southern California Edison Co. announced plans in late March to accomplish that goal.

The plan needs to be approved by the state regulators. However, Gov. Arnold Schwarzenegger attended the announcement and offered praise for the utility's objective, which is expected to cost $875 million.

Edison will be placing solar collectors on the roofs of businesses and expect they can generate enough power for 162,000 homes. The total area of solar collection is estimated to cover 2 square miles in surface area. The first cells will be mounted on buildings in Riverside and San Bernardino counties, and should be operational by 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.

The utility also proposed to construct 500,000 parabolic mirrors at a location in the Mojave Desert to focus the power of the sun and ultimately produce another 250 MW of power via steam generation. A wind farm in the Tehachapi Mountains is under construction and is expected to add another 4,500 MW to the electrical grid.