In the spring of 2008, Harvey jumped on one of his Harleys and rode through the Mojave National Preserve to check out the Ivanpah Valley, where the Oakland, Calif.-based BrightSource Energy company wants to clear close to 7,000 acres of public land to generate 400 megawatts of solar power. Harvey had heard BrightSource spokespeople describe the land as disturbed by cattle grazing and off-highway vehicle use, but what he found instead was a "lush creosote forest -- some of the most beautiful desert land in the world." Within a week, he announced the startup of the National Alliance for Sensible Energy Policy, "a nonpartisan group adamantly opposed to BLM giving our lands to energy corporations."

One year later, the group has become the Alliance for Responsible Energy Policy, and Harvey has become an authority among people with long histories of desert activism, people who have spent their lives fighting garbage dumps, development and expanding military bases. "I gave them a voice," he says. "I let them know that it was all right to pound on the table and say, 'No!' to the national leaders of their organizations." He now travels around the region to Sierra Club meetings and high schools, armed with statistics about how photovoltaic technology can displace coal-fired electricity and save us from catastrophic climate change. He explains the arcane details of a new California law that promises low-interest loans for solar installations. He discusses how "thin-film" technology will drop in price as it penetrates the market. He describes how the city of Gainesville, Fla., jumpstarted rooftop solar by purchasing renewable energy from small suppliers, an effort modeled after Germany's Stromeinspeisungsgesetz, a term that translates awkwardly into English as "feed-in tariff."

"If you put a system on your roof you can sell every electron of that at a premium rate," he says. "Cities that have done it find out that it only raises electric rates a little every month."

People who continue to insist, in spite of all Harvey's carefully marshaled evidence, that we cannot quickly reduce the planet-warming carbon in the atmosphere without the help of industrial-scale solar plants -- people like Carl Zichella, the Sierra Club's director of Western Renewable Programs -- make Harvey furious. "Carl Zichella says that rooftop solar is 'no solution at all,' " Harvey hisses, referring to a quote Zichella gave the New York Times.

Harvey has one word for him: Germany.

BrightSource's proposed $3 billion Ivanpah Solar Electric Generating Station consists of three concentrating solar thermal power plants, each of which uses thousands of seven-by-10-foot sun-tracking mirrors, called "heliostats," to focus the sun's energy on a tower, where, just like any conventional fossil-fuel plant, heat turns water into steam that spins turbines. (Other kinds of concentrating solar plants use "parabolic troughs," heating liquid by focusing curved mirrors on pipes lower to the ground.) An ingenious but relatively primitive technology, concentrating solar power, or CSP, costs an average of 15 cents per kilowatt hour over a plant's 30-year lifetime, roughly half the current cost of photovoltaics, which turn the sun's radiation directly into electricity. It has been heralded as "the technology that will save humanity" by physicist Joseph Romm, a veteran of the Clinton Energy Department and author of a book about global warming called Hell and High Water. "I don't believe any set of technologies will be more important to the climate fight" he wrote on his blog at ClimateProgress.org.

Compared to other forms of energy, CSP needs a lot of land -- approximately 8.5 acres per megawatt, 17 times as much land as a nuclear plant needs to generate the same amount of electricity. Constructing the Ivanpah solar plant would require grading more than six square miles clean of vegetation, leveling 100-year-old cactuses and creosote along with 202 specimens of a rare desert plant known as Mojave milkweed -- 80 percent of the known population, as well as 11 other rare plants unique to the Mojave. It would require rerouting ephemeral creeks and washes that carry runoff from the Clark Mountains into Ivanpah Dry Lake during the desert's sometimes ferocious winter storms. It is being designed by engineers who appear to be learning about the desert ecosystem as they go: The original plan for the Ivanpah plant had no proposal for managing stormwater, as if no one had considered that rain falls in the desert.

Tom Hurshman, the project manager at the BLM, says he's "gone back and forth with hydrologists and civil engineers working on the project" to get them to address the stormwater issue; he's also "questioning some of the assumptions they put into their design.

"We're looking at pretty much an exclusive use of public lands here," Hurshman says. "The scope of these projects is far larger than anything the BLM and the Energy commission have ever seen before. It's taking us a while just to figure out what questions we need to ask."

There may be worse places to locate a solar plant than the Ivanpah Valley, including another tract BrightSource picked out in the Sleeping Beauty Mountains, a wilderness that serves as a corridor for wildlife traveling between Joshua Tree and the Mojave National Preserve. That project is among more than a dozen proposed on a 600,000-acre parcel purchased by The Wildlands Conservancy in 1999 and donated to the federal government. In early March, Sen. Dianne Feinstein, D-Calif., announced that she plans to introduce legislation putting those acres –– called the Catellus lands after the railroad-turned-real-estate company that once owned them –– off-limits to wind, transmission and solar projects.