Thursday, May 15, 2008

The desert will bloom.

The Google blog today announced a $10 million equity investment in BrightSource Energy, a solar-thermal power plant developer that's agreed to provide 900 megawatts of renewable electricity to Pacific Gas and Electric. That's about as much electricity as could be provided by a small nuclear power plant.

This investment is part of Google's effort to develop renewable energy technology that's cheaper than coal: to do so, BrightSource will build huge fields of mirrors (as in the picture above) that will concentrate extreme heat on a central water tower, which will then generate steam to spin huge turbines. Unlike wind turbines, which only deliver juice when the wind blows, these power plants can be relied on to deliver their full capability of electricity in the middle of hot summer days, when SoCal's air conditioning units are working their hardest.

Let's wait to see if any of it really comes to pass. The Mojave is a recalcitrant frontier and the graveyard of so many destinies that once seemed manifest. There are abandoned farms, ghost towns, and failed real estate schemes. Check out this ambitious subdivision near California City:

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If you zoom in on the map above, you'll notice that someone, at some point, actually went to the trouble of naming all of those abandoned cul-de-sacs in the middle of nowhere. Incredible.

But with Google's faith and another $115 million in venture capital in its pocket, it looks likely that these solar plants will be built in the next few years. And, since California generates most of its electricity with expensive natural gas, utilizing free sunlight for energy seems like a safe investment.

What if California decides to decommission its natural gas plants entirely and replace them with thousands of acres of mirrors covering the dry lakebeds of the Mojave? That could be a significant step towards saving the global climate.

But it's possible that these huge fields of mirrors would also begin to cool the local climate. If these mirrors begin reflecting the Mojave's sunlight back up into the sky, instead of letting it bake the hot desert soil, it seems likely that these arrays will also be oases of cool air. Maybe they'll begin attracting an understory of desert scrub plants to cool the local microclimate further.

As time goes on, the growing island of shaded ground and cooler air squeezes out any moisture that incoming desert breezes might contain, like a stationary cold front. The ground beneath the mirrors will grow increasingly verdant. The power plants won't work as well as they used to before the clouds arrived, but a new generation of frontiersmen will till the fertile soil in the shade of California's solar farms. The century-old promise will be fulfilled: the desert will bloom.

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