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Know the West

A Solar Plant a Tortoise Could Love


On the Web site of GreenBiz.com, Mark Gunther describes Bill Gross as "a serial entrepreneur" and "one of the most interesting business people I've known." Gross is the guy who gave Google its paid-search idea. He likes robots. He has Google's money invested in his electric car project (only fair, right?). He also may be the guy to best solve the land wars that continue between desert conservationists and national environmental organizations over large-scale concentrating solar thermal power (CSP) in the desert.

Last week, Gross and the solar-power company he founded, eSolar, held a grand opening for a 5-megawatt plant called the Sierra SunTower near the California desert city of Lancaster, 70 miles from Los Angeles. It's the first of many such plants:  eSolar has contracts with Southern California Edison and NRG for hundreds of megawatts in CSP. What Gunther doesn't mention is that Gross is committed to doing it all in relatively small parcels on private, already disturbed land.

Here's what he told BNET.com's Chris Morrison last spring:

Of the $130 million we raised, we spent $30 million on land. We went and bought, specifically, previously disturbed farmland near transmission. So we don’t have to worry about wildlife migration patterns. We bought private land, so we don’t need special permission. Our 46 megawatt plant takes up  a quarter square mile, much smaller than other power tower plants. And one other benefit of going smaller is that the towers are smaller; that’s important for neighbors. If you’re above 180 feet, the FAA comes into play and neighbors may complain. We stayed lower than 180, around the height transmission towers are anyway. So we can locate much closer to the city.

I wanted to include eSolar in the story I wrote about distributed energy resources, but their public-relations person argued that the plants didn't really qualify as distributed generation. That's probably right -- 46 megawatts is a little on the high side for DG. But the same principles apply. CSP uses mirrors to focus the sun's energy on a liquid, which turns to steam and spins a turbine to produce electricity just like a coal plant does. It's cheaper than the photovoltaics we put on our roofs, which turn sunlight into electrons. But a 400-megawatt plant, like the ones BrightSource want to build in the Mojave Desert, will require clearing six-square miles of land -- much of it undisturbed public land conservationists have struggled to protect. Building it small, the way eSolar does, allows for building it close to the places it will power. And it allows eSolar to dodge a lot of trouble.

There are conservationists who will object to eSolar's plans as well, just as there are people who will continue to defend large-scale solar on public land. Both sides have their increasingly well-argued cases. But it's worthwhile to watch Gross plow ahead on his middle-ground solution while the other sides duke it out.