Solar plantSolar farms could be sprouting in the Nevada desert.Photo: FotowatioSouthern California Edison on Wednesday announced another big photovoltaic power plant deal, this time to buy electricity from a 250-megawatt solar farm to be built by First Solar.

Add that contract to 831 megawatts’ worth of photovoltaic power purchase agreements the Los Angeles utility signed with SunPower and Fotowatio in January, and you’re talking some serious solar — more than a gigawatt. At peak output, that’s the equivalent capacity of a big nuclear power plant. I wouldn’t be surprised to see SoCal Edison execs tooling around town with “I ♥ PV” bumper stickers on their Chevrolet Volts and Nissan Leafs.

(And before you all hit the comment key, we know that a nuclear power plant generates electricity 24/7 while a solar farm only produces power when the sun shines.)

“First Solar’s industry-leading technology makes solar PV an excellent option for clean, emission-free power we can deliver to our customers,” Marc Ulrich, the utility’s vice president for renewable and alternative power, said in a statement. “When we get projects of this magnitude, we make great progress toward our renewable energy goals.”

First Solar’s Silver State South project won’t be built in California, but in neighboring Nevada, as its name implies. Like another First Solar power plant project in Nevada, the 50-megawatt Silver State North solar farm, Silver State South is planned for federal land in the Mojave Desert.

The United States Interior Department last October signed off on a lease for the Silver State North power plant, but the 250-megawatt project for Southern California Edison is still undergoing environmental review.

First Solar spokesman Alan Bernheimer told me Tuesday that the company hopes to secure a lease for 2,500 acres of desert land near the casino border town of Primm by the end of 2011. (The U.S. Bureau of Land Management on its website said it expects to issue a decision on Silver State South in 2012.)

According to Southern California Edison, Silver State South is set to begin producing electricity in early 2014 and will be fully built out by May 2017.

There are some obstacles to overcome, however. The project depends on the construction of a major transmission line proposed by Southern California Edison.

And it would be built adjacent to an area that some environmentalists consider key habitat for the imperiled desert tortoise and other fauna and flora. Last month, a 370-megawatt solar thermal power plant under construction by BrightSource Energy a few miles away became the subject of a lawsuit filed by Western Watersheds Projects. The suit contends the Interior Department and BLM officials failed to properly consider the environmental impact of the BrightSource project on the desert tortoise and other wildlife.

Regardless of the outcome of the Silver State South power plant, First Solar has plenty of other photovoltaic farms in the pipeline. According to Bernheimer, the company has signed contracts for 2,000 megawatts’ worth of big solar projects.