Two companies in California have announced plans to construct new photovoltaic (PV) power plants in that sunny state, each vastly larger than any photovoltain power facilities anywhere in the world. The plants together will cover 12.5 square miles of central California and will generate, at peak, 800 megawatts of power. While the actual capacity will be somewhat lower than that (because they won't always produce at their peak and at night won't produce power at all), they will be peaking during the part of the day when demand is the highest and energy the most expensive.
Both plants will supply power to Pacific Gas & Electric, which is under a California state mandate to deliver 20 percent of its electricity from renewable sources by 2010. PG&E says that the two plants will help it reach a total of 24 percent of its energy from renewable sources, but not until they care completed, which should be around 2013.
Both plants will be in San Luis Obispo County. One, built by OptiSolar, will generate 550 MW of peak energy. The other, built by SunPower, will generate 250 MW of peak energy. The largest existing PV installation in the U.S. is a 14 MW facility at Nellis Air Force Base in Nevada. The largest in the world currently in use in Spain is a 23 MW facility. There are larger facilities under construction in several areas, but none that come close to matching these two new facilities.
The plants will not come close to the efficiency and pricing of fossil fuel-based power plants, but should be competitive with wind and solar thermal plants and far more cost-effective than existing PV installations, due to economies of scale.