The Department of the Interior (DOI) on Monday approved the Blythe Solar Power Project—the largest solar energy project ever proposed to be built on public lands in the U.S.

The project, proposed by Solar Millennium subsidiary Palo Verde Solar I, is expected to produce up to 1,000 MW of solar power using parabolic trough technology. The German firm is looking to build the project over 7,025 acres of public lands eight miles west of Blythe in Riverside County, Calif. If built, the project could include a new 230 kV transmission line to connect the Blythe Solar Project to the Devers-Palo Verde #2 500 kV line at the Colorado River substation.

The Record of Decision signed on Monday by Interior Secretary Ken Salazar offers Solar Millennium a right-of-way grant to use these public lands for 30 years if all rents and other conditions are met.

The DOI added that the solar project joins a host of landmark announcements in recent weeks. Earlier this month, Salazar approved the first five renewable energy projects ever on public lands: Imperial Valley Solar Project, Chevron Lucerne Valley Solar Project, Ivanpah Solar Electric Generating System, and the Calico Solar Project, all in California; and the Silver State North Solar Project in Nevada.

The Blythe project was earlier licensed by the California Energy Commission, which regulates solar thermal projects in California that generate at least 50 MW. According to the DOI, it has undergone extensive environmental review, starting with public scoping in November 2009, followed by a draft environment impact statement (EIS) in March 2010, and a final EIS on August 20, 2010.

Through the American Recovery and Reinvestment Act, Solar Millennium is also eligible to secure $1.9 billion in conditional loan guarantees from the U.S. Department of Energy for the project. The first 242-MW block of the project is now expected to be connected to the grid as early as 2013.

Solar Millenium had earlier amended the project design so that it would use “dry cooling” technology (fans and heat exchangers), as opposed to the traditional “wet cooling.” The change would reduce the plant’s efficiency, but it could reduce water use by 90%, the company claims.

On Monday, meanwhile, the DOI’s Bureau of Land Management (BLM) said it is required that Solar Millennium provide funding for more than 8,000 acres of desert tortoise, western burrowing owl, bighorn sheep, and Mojave fringe-toed lizard habitat to mitigate the project’s impacts.

Sources: POWERnews, DOI, Solar Millenium