Like so many of this state’s troubles, the industry’s problems are rooted in real estate.

After President George W. Bush ordered public lands to be opened to renewable energy development and California passed a law in 2006 to reduce carbon emissions, scores of developers staked lease claims on nearly a million acres of Mojave Desert land. The government-owned land offered affordable, wide-open spaces and the abundant sunshine needed by solar thermal plants, which use huge arrays of mirrors to heat liquids to create steam that drives electricity-generating turbines.

But many of the areas planned for solar development  including the five projects being challenged  are in fragile landscapes and are home to desert tortoises, bighorn sheep and other protected flora and fauna. The government sped through some of the required environmental reviews, and opponents are challenging those reviews as inadequate.

“There’s no good reason to go into these pristine wilderness areas and build huge solar farms, and less reason for the taxpayers to be subsidizing it,” said Cory J. Briggs, a lawyer representing an American Indian group that has sued the United States Interior Department and the Bureau of Land Management to stop five of the solar thermal plants. “The impacts to Native American culture and the environment are extraordinary.”

The risk that the suits will succeed in blocking construction could make it more difficult for the builders to get federal loan guarantees or attract private financing.

Officials with the Loan Programs Office of the United States Energy Department did not respond to requests for comment. However, department guidelines classify litigation risk as a significant factor to be considered when qualifying renewable energy projects for a loan guarantee.