The massive Ivanpah Solar Electric Generating System in California’s Mojave Desert will eventually generate 370 megawatts, a 60 percent increase in US solar-power capacity. Scheduled for completion in 2013 by energy company BrightSource, the 5½ square miles of mirrors will reflect the sun’s heat at water towers, producing steam to spin turbines (natural gas will serve as cloudy-day backup). Ivanpah is supposed to help California generate a third of its electricity from renewables by 2020. Awesome, right?

After all, the Mojave is perfect for producing solar energy (lots of photons). But building there has costs—costs that environmental groups and others say aren’t worth it. (They’ve filed suits to stop the project.) Do cultural and ecological concerns trump fighting climate change? Here’s a look at the planned facility—and its ledger.

KERN RIVER GAS LINE

WATER LINES

POWER LINES

GAS LINE

Pluses ——

ADVANCED MIRRORS

The computer-controlled sun trackers leave space underneath so plants can grow.

The computer-controlled sun trackers leave space underneath so plants can grow. NEW JOBS

The plant will employ 650 people in the first three years, according to BrightSource.

The plant will employ 650 people in the first three years, according to BrightSource. UPGRADED POWER GRID

Southern California Edison will rebuild 36 miles of existing transmission line and infrastructure.

Southern California Edison will rebuild 36 miles of existing transmission line and infrastructure. LESS CARBON

Ivanpah’s power output is comparable to that of a small coal plant—but without the more than 640,000 tons of carbon emissions each year.

Minuses ——-

HARM TO CULTURE

Metamorphic Hill is one of several Native American sites threatened by construction.

Metamorphic Hill is one of several Native American sites threatened by construction. COST

The federal government is loaning $1.6 billion to BrightSource for the relatively risky project—the tech is untested at this scale.

The federal government is loaning $1.6 billion to BrightSource for the relatively risky project—the tech is untested at this scale. DISRUPTED WILDLIFE

Unique desert plants will be bulldozed. Bighorn sheep and desert tortoises will lose habitat.

Unique desert plants will be bulldozed. Bighorn sheep and desert tortoises will lose habitat. MORE CARBON

Every square meter of the Mojave hoovers up 106 grams of carbon each year, so strike 1,655 tons from the plant’s annual savings.

Illustration: Nook