Rising rebelliously from the desert floor on the northern end of Ivanpah Valley, the town of Primm, Nevada, calls to mind man's triumph over nature. Its gaudy fashion outlet and three hotel-casinos crowd the freeway just east of the California border near the Mojave National Preserve, contrasting severely with the flat expanse surrounding on all sides. Nearby, the world-class 36-hole Primm Valley Golf Club sports glowing green lawns and luxuriant water features. And, across the highway, a cement factory and natural gas power plant spew greenhouse gases.

To the typical traveler passing by on the way to Las Vegas, the town and its neighbors amount to a surreal desert outpost. Little do most know that not far away, another drama between man and the environment is playing out. And its implications could be far greater.

Five miles from Primm, on the valley's western slope, Oakland company BrightSource Energy aims to build what will be, at least for a while, the world's largest solar-thermal power plant. Drawn by the valley's 330 days of sun per year and heat-intensifying 3,300-foot elevation, the project will encompass 5.6 square miles and generate 370 megawatts — enough to power 140,000 homes at peak hours — when it's complete in 2013. It will nearly double the amount of commercial solar thermal power produced in the United States today.

The project is the first in a wave of utility-scale solar energy plants being constructed on public lands that will soon dwarf BrightSource's groundbreaking venture. And a surprisingly large number of them will be built by companies based right here in the East Bay. The entire California desert is under siege by solar power developers, thanks to federal incentives promoting renewable energy that expire at the end of the year, along with California's call for public utilities to draw 33 percent of their power from renewable sources by 2020 (versus today's 14 percent) and a critical mass of interest in the state's untapped solar resources. Under the guidance of the US Department of the Interior, both the California Energy Commission and Bureau of Land Management have approved seven huge solar plants on federal land in the desert since late August, and more are on the way. At least one hundred applications are waiting to be reviewed. "We're open for business with respect to renewable energy on public lands," US Interior Secretary Ken Salazar announced in October.

Combined, the seven approved plants will contribute a total of 3,492 megawatts to California's energy grid — at peak output, the equivalent to several nuclear power plants. More striking, however, is the amount of public land they'll eat up: according to current site designs, more than 27,000 acres. Two more plants may be approved by the end of the year, adding another 650 megawatts and 6,600 acres. In all, that's 53 square miles — roughly the size of the City of Oakland. The energy they produce should help power between one and two million homes.

Not only does this boom cycle represent the beginning of one of the largest transfers of land from public to private use in US history, but the amount of new power being added to the grid in such a short time, especially renewable, is likewise unparalleled, said Tom Pogacnik, deputy state director of natural resources for the Bureau of Land Management. Adam Eventov, spokesman for BrightSource's Ivanpah project, likened the atmosphere to "the wild, wild West."

Yet the mad rush to develop poses serious consequences for desert ecosystems, which are easily damaged and slow to regenerate. In the Ivanpah Valley, for example, what may look like a barren field of tumbleweed is in fact a thriving desert scrub ecosystem featuring Mojave yucca, multiple species of cholla cactus, and creosote scrub, one of the oldest living plants on Earth. While nothing in the valley grows much taller than a few feet, it's enough to provide habitat for a variety of animal species including kangaroo rats, burrowing owls, desert horned lizards, migratory bighorn sheep, and the endangered — and highly vulnerable — desert tortoise. The floor and eastern end of the valley also serves as a natural floodplain called Ivanpah Dry Lake, collecting rainwater from the mountains that ring the valley.

Solar development in the desert has thus pitted environmentalists against environmentalists, renewable-energy advocates against conservationists, and global-warming activists against ecologists. In some cases, projects have been stalled by the infighting; in most, their designs have been modified. Environmental groups have sought to walk the narrow path between encouraging green energy and protecting desert habitat, while developers have struggled to meet federally imposed deadlines with minimal collateral damage. The process has been anything but smooth: BrightSource's Ivanpah project alone took three years to permit, both by virtue of being first and because of nagging land-use issues.

Solar power's rise can be largely attributed to two key environmental benefits: it's almost infinitely renewable and emits no greenhouse gases. But in addition to its environmental costs, solar power remains expensive. The per-kilowatt-hour production cost of solar energy, while falling rapidly, remains about triple that of most other forms of renewable energy, and approximately double that of most coal and natural gas plants, according to a study released earlier this year by the California Energy Commission.

Nevertheless, three other East Bay companies — FirstSolar, Solar Millennium, and SunPower — have joined BrightSource at the forefront of utility-scale solar development in the United States. "In many ways, the East Bay is central to our nation's solar industry," said Keely Wachs, senior director of corporate communications for BrightSource. "It's ground zero for most of the meaningful solar development." It's also, according to some desert conservationists, complicit in an ill-considered attack on the desert.