It’s been a huge month for solar in the western U.S., and now the approval of another utility-scale solar project in Nevada makes it even bigger.

The newest member of the mega-solar team is the Amargosa Farm Solar Project, slated for construction on public land in Nevada. Because of this public land status, builder Solar Millennium had to jump through hoops to insure that the solar farm was environmentally friendly, or in the words of the various supervisory agencies – the Bureau of Land Management (BLM), the U.S. Fish and Wildlife Service, and the National Park Service – that it has a “net neutral benefit” on the regional ecosphere.

This ecosphere is found nearby at the Ash Meadows National Wildlife Refuge and Devils Hole, in Death Valley National Park, and the benefit is insured, one supposes, by a public review process followed by both a draft environmental impact review (DEIR) and a final, more comprehensive environmental impact statement (EIR) published Oct. 15.

The BLM was the lead agency on the project, making sure that such national treasures as the Devils Hole pupfish and the 26 other species of plants and animals in Ash Meadows – including two other endangered fish species – were adequately protected.

To this end, BLM worked with Solar Millennium to reduce the project footprint from 7,630 acres to 6,320 acres. Not a huge reduction, but one aimed at preserving vital habitat for the above-named endangered fishes. This meant an ultimate impact area of about 4,350 acres, which – added to a water mitigation plan essential to desert ecospheres (and one that can serve as a model to future desert solar development) – means the Amargosa farm, its natural color palette and its night-lighting measures sit gently on the land.

Approval means that Solar Millennium is now eligible for approximately $1 billion in Investment Tax credits through the American Recovery and Reinvestment Act of 2009 (ARRA, or the stimulus), and can also apply for project financing through the U.S. Department of Energy’s Title 17 Loan Guarantee Program.

The Amargosa project itself consists of two segments of 250 megawatts each of dry-cooled parabolic troughs which focus intense sunlight on a central collector, or shaft, running midway along and outside of the trough. Located about 80 miles northwest of Las Vegas, the concentrating solar power (CSP) technology will add up to 4.5 hours of thermal storage (likely molten salt) and will begin construction at the end of 2011.

Solar Millenium hopes to sell the power to regional utility Nevada Energy under a power purchase agreement, or PPA, and negotiations are ongoing, as is construction of the One Nevada transmission project linking the northern and southern Nevada power grids.