Speculators have filed applications to develop more than 1 million acres of desert in Southern California with solar, wind and geothermal power plants, setting up a classic clash over land use with environmentalists and off-road enthusiasts.

They have submitted at least 130 proposals with the Bureau of Land Management, which oversees all of the territory, in recent years and especially since 2007. The interest is so hot that even if many of the projects fall through, the remaining ones would change the look of the arid landscape.

California, particularly the southern half, is the epicenter of the nation's push for renewable energy. While some of the bureau's parcels in the state already contain wind and geothermal facilities, the agency hasn't approved any solar project here or elsewhere.

Last week, leaders for the bureau called a timeout in accepting new applications for solar developments, the most active category of renewable-energy proposals. They want to assess the environmental, social and economic impacts of such activity in the Southwest, starting with public meetings this month.

Despite state and local demands to increase production of renewable power and growing concern about fossil fuels' influence on global warming, the agency "did not anticipate the level of interest that was shown in 2007 and in the first part of 2008. The applications started coming in fast and furious," said Linda Resseguie, manager of the solar review process in Washington, D.C.

Although many of the bureau's properties may look barren, they generate interest from environmental and recreation groups. Off-roaders are fighting to keep their open space in spots such as Imperial County's Truckhaven, while conservationists are vying to preserve relatively pristine stretches of desert by encouraging renewable-energy projects for existing homes and businesses.

"We have worked for decades to protect the desert. . . . Let's not trash what we've saved," said Elden Hughes, who has worked with the Sierra Club and other environmental groups for decades.

David Hubbard, a Carlsbad lawyer for off-road vehicle organizations, expressed concern that "there is almost a feeding frenzy for the desert."
Officials for the Bureau of Land Management said they are trying to balance the mounting demand to tap renewable sources of energy with the traditional value of desert land as habitat for numerous plants and animals. They said the agency has rejected about a dozen energy applications in recent months because the companies that filed them didn't provide enough information or wanted to use ecologically sensitive lands.

"We try to discourage applicants from applying for projects within the most important habitat areas," said Alan Stein, a top bureau official in Southern California.

In the past few years, land speculation has been stimulated by tax incentives and state and national policies promoting renewable sources of energy. California aims to get 20 percent of its power from solar, wind and other renewable sources by 2010.

Numerous firms are proposing facilities on bureau-managed lands that, when combined, could provide electricity for more than 20 million homes.

The bureau controls 260 million acres, mainly desert, grassland and high-mountain terrain in the West. That includes about 11 million acres in Southern California, with 183,000 acres in San Diego County.

Unlike some other federal land agencies, the bureau accepts "multiple uses" such as mining, timber harvesting, recreational activities and projects for alternative energy.

Its officials welcome companies' plans for producing alternative power. They have completed an overarching environmental review for wind energy and started one for geothermal development.

"The nation is demanding that renewables help supply our energy needs and the BLM aims to be part of that solution," said Matt Spangler, a spokesman for the agency in Washington, D.C. "Our vast lands and waters provide boundless opportunities."

A few applications rolled into the bureau's offices in Southern California before 2005. Then interest spiked last year, when companies filed more than 70 requests for solar projects on bureau land in the region. More proposals are flowing in this year, along with applications for areas in Nevada and Arizona.

Companies can spend $200,000 or more to go through the bureau's energy application process - with no guarantee of final approval.

The agency's leaders said it's not clear how much they will charge for solar leases because they haven't approved a project yet. The price will be based on appraisals of targeted properties.

Fees to rent land for wind projects commonly have been based on how much power each facility produces.

Energy developers use precise measurements of sunlight and wind to gauge the value of specific parcels, and they look for areas with easy access to power lines. Proposed solar projects are clustered near Ridgecrest, Ludlow and Blythe. Applications to harvest wind energy are concentrated near Palm Springs, Barstow and Tehachapi.

The bureau also might allow more geothermal plants, which tap heat stored underground.

One contentious concept is to build geothermal facilities in the Truckhaven area, a popular off-road playground in western Imperial County. The bureau has finished an environmental impact statement for the spot, anticipating efforts to develop it.

"Off-roaders are sensitive to the fact that we do need renewable energy projects, but . . . our off-road parks could have test wells and ugly pipes running (through them) and that ruins the users' recreation experience," said Meg Grossglass, spokeswoman for the Bakersfield-based Off-Road Business Association.

Statewide, few projects are attracting as much attention as a solar power complex that would be erected near the Mojave National Preserve.

BrightSource Energy of Oakland looks to build a solar power system that would produce 400 megawatts, enough to power about 300,000 homes. The Ivanpah project would cover 3,400 acres of San Bernardino County.

Company officials hope to start construction next year and begin operating the plant by 2011. Of all solar projects being considered by the Bureau of Land Management, Ivanpah is the furthest along. It likely will set the precedent for other facilities.

"It's the best place in the world to build a solar plant," said Charlie Ricker, senior vice president of development for BrightSource.

Ricker sees clean-energy projects in the California desert as a necessary step as the United States tries to break away from dirty power sources such as petroleum and coal, which are linked to global warming.

"The good outweighs the fact that some small portion of the desert may not be available for all the kinds of things that desert is used for," Ricker said.

For some conservationists, power projects such as Ivanpah fall into the same category as nuclear fuel dumps, sewage sludge treatment plants, military bases and landfills that various entities have proposed for desert lands.

"Our take has been from day one, 'Here we go again. Here is where we can do everything out in the desert that we don't want to do in our own backyards in the city,' " said Terry Weiner, Imperial County conservation coordinator for the San Diego-based Desert Protective Council.

Weiner and others worry that utilities will use alternative-energy projects to justify major new transmission lines such as San Diego Gas & Electric's controversial Sunrise Powerlink project.

They said a better solution is to retrofit homes and businesses with solar panels or put large solar arrays in places where farmers and others already have used the land.