In his recent State of the Union address, President Obama pledged to support efforts to generate 80% of the nation’s electricity from clean sources by 2035. Days before his speech, the U.S. Energy Dept. offered two conditional loan guarantees—one for a solar farm in Arizona, the other for a renewable diesel facility in Louisiana—that will help achieve Obama’s goal and diversify the nation’s fuel mix.

Photo: Courtesy Of First Solar

Sarnia, Ontario’s 80-MW plant is currently the world’s largest operating PV solar plant.

Photo: Courtesy of First Solar

First Solar’s 21-MW project in Blythe, Calif.

On Jan. 21, DOE awarded NRG Solar, a subsidiary of Princeton, N.J.-based NRG Energy, a $967-million loan guarantee to support construction of the 290-MW Agua Caliente solar facility currently being built in Yuma, Ariz.

NRG acquired the project in December from Tempe, Ariz.-based First Solar, which is providing engineering, procurement and construction services. NRG declined to provide a project cost.

Switchyard site preparation and access-road construction began in the third quarter of 2010. Construction of the solar plant, which NRG says will be the largest of its kind in the world, will start in the second quarter of this year and continue through the first quarter of 2014.

The Agua Caliente project will use technologies that are new to U.S. solar powerplants. Fault ride-through and dynamic voltage regulation are deployed to improve the reliability and predictability of energy that solar powerplants supply to electricity grids, according to First Solar. The solar photovoltaic panels, to be mounted six feet off the ground, will be able to withstand the region’s high winds, according to First Solar.

The plant is slated to sell power to Pacific Gas & Electric in late 2011 or early next year, says Alan Bernheimer, a First Solar spokesman.

Also on Jan. 21, DOE awarded a conditional $241-million loan guarantee to Diamond Green Diesel LLC—a joint venture between Valero Energy Corp., San Antonio, Texas, and Darling International Inc., Irving, Texas—for construction of a 137-million-gallon-per-year renewable diesel facility in Norco, La.

The plant will create diesel fuel from animal fats, used cooking oil and other waste grease. It will be the first U.S. facility of its kind to use a hydrotreating/isomerization process to convert feedstock into diesel.

“Strong biofuels projects [such as] Diamond Green Diesel can help to diversify our transportation fuel supply while creating jobs and strengthening our economy,” said U.S. Energy Secretary Steven Chu.

Although construction is expected to begin in September, Diamond Green Diesel has yet to procure bids for the new facility. The plant will be built near an existing traditional Valero refinery and will share some of its facilities, says Bill Day, a spokesman for Valero.

He did not provide a project cost, but says the $241-million loan guarantee will cover a big portion of the project.