PG&E Signs Contracts for 800 Megawatts of Solar Photovoltaic Power

California's Pacific Gas and Electric Company (PG&E) has signed contracts for two of the most ambitious solar photovoltaic projects in the world: a 550-megawatt (MW) solar farm and a 250-MW "solar ranch," both of which will be located in San Luis Obispo County. The Bay Area utility announced the agreements with OptiSolar Inc. and SunPower Corporation last week and expects both of the record-breaking solar power plants to be fully operational by 2013.

OptiSolar's 550-MW Topaz Solar Farm will begin producing power from its thin-film solar panels in 2011, while SunPower's 250-MW solar ranch will employ the company's crystalline solar cells to begin producing power in 2010. Both of the facilities will break all current records for solar photovoltaic systems when they are completed, and the agreement led SunPower to declare on its home page that "utility-scale solar power has officially arrived in the United States." Topaz Solar Farms LLC, a subsidiary of OptiSolar, is already charging ahead on its project, having submitted a Conditional Use Permit application to the San Luis Obispo County Planning and Building Department in July. See the PG&E press release and the SunPower and OptiSolar Web sites.

PG&E's announcement dwarfs other large-scale solar power plans that would otherwise garner headlines. For instance, San Diego Gas & Electric Company (SDG&E) announced in July that it will install 70-80 MW of advanced, solar-tracking photovoltaic systems throughout its service area. The utility will own about two-thirds of the systems, with the remainder being privately owned, and the systems will be located at SDG&E facilities as well as retail and commercial parking lots, county landfills, and other locations. The utility plans to invest up to $250 million in solar installations over the next 5 years.

Meanwhile, another subsidiary of SDG&E's parent company, Sempra Energy, plans to develop a 10-MW solar photovoltaic facility near Boulder City, Nevada, about 40 miles southeast of Las Vegas. The facility will employ thin-film solar panels from First Solar, Inc. But not all large solar plants are being built in the West, as Kovatch Enterprises and Green Energy Capital Partners (GECP) have announced plans to build a 10.6-MW solar plant in Nesquehoning, Pennsylvania. See the Sempra Energy press releases on SDG&E's solar plans and the Nevada solar facility and see the Pennsylvania announcement on the GECP Web site.

NREL Solar Cell Sets World-Record Conversion Efficiency of 40.8%

Researchers at DOE's National Renewable Energy Laboratory (NREL) have developed a solar cell that can convert a record 40.8% of the sunlight that hits it into electricity. The new NREL solar cell is a triple-junction device, which means it uses three layers of photovoltaic material stacked atop one another to catch different parts of the solar spectrum. Sunlight that isn't converting into electricity by the top layer passes into the lower layers of the solar cell, which convert more of the sunlight into electricity, boosting the cell's conversion efficiency.

The cell is unique in that it is grown in an inverted order, from the top down, and is then removed from the substrate it is grown on to produce a lightweight, flexible film. The inverted approach also allows the use of a bottom layer material with a different crystalline lattice spacing than the other materials in the cell, which makes it a "mismatched lattice" or "metamorphic" solar cell. NREL's inverted metamorphic triple-junction solar cell also won an R&D 100 Award this year. It achieved its record efficiency while exposed to sunlight concentrated by a factor of 326-in industry parlance, "326 suns." See the NREL press releases on the record efficiency and the R&D 100 Award.