The Agua Caliente Solar Project in Arizona is fast on its way to becoming the largest solar photovoltaic power plant in the world.

Plant owners NRG and MidAmerican Solar, along with developer First Solar, said today that the Yuma County, Ariz., plant is more than two-thirds complete and is delivering more than 200 megawatts to the grid.

agua caliente solar project
image via First Solar

Agua Caliente, which is supported by a $967 million federal loan guarantee, is expected to ultimately have a generating capacity of 290 MW. That it is at 200 MW already is a bit surprising given that just last December, when Warren Buffett’s MidAmerican Energy Holdings acquired a 49 percent stake in the project, the companies involved said it was expected to be completed in 2014.

First Solar, which has been struggling in the past year, was obviously happy to tout the quick progress on the plant, notable especially as Republican attacks on the loan guarantee program that are making it possible continue unabated.

“First Solar is very proud of the rapid progress we are making at Agua Caliente,” Jim Lamon, First Solar senior vice president for engineering, procurement and construction and operations and maintenance, said in a statement. “We have achieved record-setting installation velocities, while maintaining our excellent safety record and achieving the highest quality in the industry. It is pleasure to be a part of moving utility scale solar to its rightful place as a dependable and cost-effective power generation source for U.S. and international utilities.”

The companies said that on average between 400 to 450 workers are on the job at Agua Caliente every day.

At 200 MW, Agua Caliente appears to be close to the generating capacity of the Gujarat Solar Park in India, which claims 214 MW of PV, although it’s not entirely clear if it is actually operating at that capacity.

In any case, the title of largest PV plant is a moving target; Gujarat plans to get bigger, and work is under way in San Luis Obispo County, Calif., on the 550-MW Topaz Solar Farm, which is owned exclusively by MidAmerican Solar and is also being developed by First Solar using the company’s thin-film PV modules.

Pacific Gas and Electric Company, in Northern California, has a long-term power purchase agreement for the power generated at Agua Caliente. In the press release put out today, the companies said the plant’s output “is projected to offset approximately 5.5 million metric tons of carbon dioxide over 25 years, the equivalent of taking more than 40,000 cars off the road annually.”

Agua Caliente Solar Project
image via First Solar

Announcement of the progress on Agua Caliente gave First Solar’s downtrodden stock a little lift Monday morning, but the company will probably need more such good news to return it to the lofty heights it enjoyed it until early 2011, when its stock was trading at more than 10 times its current value.

In May, First Solar said it lost $449 million in the first quarter of 2012, most of it attributable to a big restructuring charge that trimmed its workforce by 30 percent and closed a plant in Germany.