Southern California Edison on Tuesday announced a deal to buy 550 megawatts of electricity from two massive photovoltaic solar farms to be built in the Mojave Desert by First Solar
It’s the biggest move yet by First Solar, a Tempe, Ariz.-based maker of thin-film solar cells, into the power plant business and another sign utilities see big photovoltaic solar farms as a viable alternative to solar thermal projects. Those power plants generate electricity by using mirrors to focus sunlight on liquid-filled boilers to create steam that drives turbines. Photovoltaic farms take solar panels like those found on residential rooftops and mount them on the ground in large arrays.
Falling solar module prices and First Solar’s low production costs have helped overcome the lower efficiencies of thin-film cells and make large-scale photovoltaic farms competitive with solar thermal power plants.
“This is the very largest photovoltaic project we have done, demonstrating that at a utility scale, the time has come for such projects,” said Stuart Hemphill, a senior vice president for power procurement at Southern California Edison.
Vanessa McGrady, a spokeswoman for the utility, would not disclose the price the utility will pay for the electricity to be produced by the First Solar plants, but noted the cost was below the state’s “market referent” rate for natural gas-fired facilities. “It’s a good deal for the customers and a good deal for the industry,” she said.
With few moving parts, solid-state photovoltaic power plants can be built relatively quickly and in California do not have to undergo a lengthy licensing process required of solar thermal projects.
But First Solar faces hurdles in getting the two Southern California Edison power plants online. Utility substations must be licensed and built to connect the 250-megawatt Desert Sunlight solar farm and the 300-megawatt Stateline power plant to the power grid.
First Solar has proposed building both solar farms on desert property managed by the U.S. Bureau of Land Management and the projects must undergo a detailed environmental review. First Solar inherited lease claims filed on 136,000 acres of federal land in March when it acquired now-defunct OptiSolar’s portfolio of projects in a $400 million deal.
The Desert Sunlight project is in a “solar energy study zone” established by the Department of the Interior to accelerate development of solar power plants. The Stateline project site is near a solar thermal power plant complex being built by BrightSource Energy, which in May signed the world’s biggest solar deal with Pacific Gas & Electric to supply 1,310 megawatts.
The two projects, scheduled to go online in 2015, would supply enough electricity for roughly 170,000 homes.
The world’s biggest photovoltaic power plant is also being built by First Solar. Called Topaz, the 550-megawatt solar farm was originally proposed by OptiSolar and is planned for agricultural land in California’s San Luis Obispo County and will provide electricity to PG&E.
Alan Bernheimer, a First Solar spokesman, said the company will ramp up production to supply modules for the power plant projects. “We have a pretty good methodology, called Copy Smart, which allows us to clone our manufacturing lines as needed,” he said.