Environmentalists want a proposed solar-energy complex in the California desert relocated because they say it will destroy prime habitat for the desert tortoise and rare plants.
The Sierra Club and other groups say the project being pushed by BrightSource Energy should be moved closer to a freeway near the Nevada line.
The company is asking government regulators to approve the complex that would generate enough power each year for 142,000 homes.
It could be months before a decision is made. The case highlights tensions between wilderness conservation and the nation's quest for cleaner power.