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PRI's Environmental News Magazine

The world’s largest solar power plant

Air Date: Week of September 24, 2010

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The Blythe Solar Power Project will use parabolic trough technology to generate electricity. (Photo: California Energy Commission)

California’s Mojave Desert may soon house the world’s largest solar power plant, after The Blythe Solar project won clearance from the California Energy Commission. The plant would pump renewable energy right into southern California’s central artery, but some environmentalists are concnerned. Host Bruce Gellerman talks with Matthew Nordan, Vice President of Venrock, a venture capital firm specializing in clean energy.

Transcript

GELLERMAN: What would be the largest solar power plant on the planet has just gotten a giant boost of support. The Blythe Solar Power Project has won approval from the California Energy Commission. Now it’s up to the Federal Bureau of Land Management to decide if the project gets the environmental go-ahead. If it does, the solar thermal station in the Mohave Desert could soon be generating enough energy to power 300 thousand homes in southern California. Matthew Nordan is vice president of the venture capital firm Venrock where he specializes in energy and environmental technologies. Mr. Nordan, thanks for coming by.

NORDAN: Thank you for having me!

GELLERMAN: We’re not talking about rooftop solar here, this is not photovoltaics.

NORDAN: Very different beast. So in rooftop, you have a solar panel, and it both harnesses the sun’s energy and converts it into electricity. This is an entirely different thing.

GELLERMAN: So, how does this work? How does solar-thermal work??

NORDAN: So, you have these mirrors, they’re in the shape of a parabola. They’re curved, right. Imagine a long trough of these, kind of like a feeding trough for pigs up on its side, and it’s angled so that the sun is going to hit it.

And running down the middle of that trough, you have a tube, and that tube contains an oil. And what happens is the mirrors concentrate the sunlight on that tube, it heats the oil up. Then you move the oil from one end of the tube to the other, where you have a turbine, the same kind of thing you’d find in a coal plant, or a nuclear plant, that boils water to make steam and spins it around. In this case the heat that you’re using is in the oil from the concentrated sun rays bounced by the mirrors, rather than from burning coal or burning something else.


The Blythe Solar Power Project will use parabolic trough technology to generate electricity. (Photo: California Energy Commission)

GELLERMAN: And this is going to produce the energy equivalent of a small nuclear power plant.

NORDAN: One gigawatt of power. It’s right up the alley of a typical nuclear power plant.

GELLERMAN: Now, this plant, that they’re proposing has won clearance from the California Energy Commission.

NORDAN: Yep.

GELLERMAN: What does that do? Does that give it the green light to go ahead?

NORDAN: It gives part of the green light. It gives one of the green lights. There are some other green lights to go. This enables the plant to be constructed, and, to interface with California’s electricity grid.

GELLERMAN: So, where does the Federal Bureau of Land Management come in?

NORDAN: So, that was the next step, actually right after the approval came from the California Energy Commission. There was an approval from the Bureau of Land Management that said, ‘we’ve completed the environmental approvals, we think this is fine.’ That thing goes out for a 30-day comment period, which is happening now. And then, once those comments come back they’ll be processed by the BLM. If they were to give the final go-ahead, that’s probably some time in October.

That’s not the biggest hurdle though. Right, after all these things are done, the plant still has to get financing. People to stump out the capital to go out and build this one gigawatt, seven thousand acre monstrosity. And that won’t be done until all these approvals are completed.

GELLERMAN: And how much money are we talking here?

NORDAN: Six billion dollars, I think is the target price tag.

GELLERMAN: Are there federal subsidies to this?

NORDAN: There is a federal loan guarantee program. The Department of Energy would not speak about using that until all the Bureau of Land Management stuff is done. So, I would expect the DOE raise its voice on this project sometime in October, November, something like that.

GELLERMAN: Environmentalists, curiously enough, have raised their voices about this project, some are for it, and some are against it.

NORDAN: Yep.

GELLERMAN: Why? Why would you be against renewable energy resources?

NORDAN: Renewable energy is a wonderful thing. And, if you compare this kind of technology against the way we get most of our power now, from nuclear and coal, it’s the one way in which it’s unambiguously better, right? There’s no risk of radiation like there is in nuclear, no CO2 emissions like in coal, undeniably a good thing. The downfall of this kind of technology is that you need an enormous amount of land.

If you do the back-of-the envelope math on this, to make one gigawatt, we’re using seven thousand acres. That’s about 35 watts per square meter of surface. Take a typical coal plant. I just picked a random one out of Wisconsin, 595 megawatts, 345 acres. That’s 426 watts per square acre, more than ten times the amount of energy per unit of area that you get from solar-thermal.

So, if you’re going to build one of these, first of all, you need a place that’s a lot of land, a lot of sunlight, no competing use for the land, and it’s got to be one big contiguous tract. And, there just aren’t many places like that in the world. It’s hard to go out and build something this big on one, without getting environmentalists concerned about habitat destruction, disrupting migration routes for wildlife, things like that.

GELLERMAN: But we’re talking Mojave Desert here, there’s not a lot out there. Is there?

NORDAN: While there’s not a lot out there, you can’t get anything for free, right? You’re going to be disrupting somebody’s habitat, if you go out and take seven thousand acres of land and devote them to some different kind of use.

GELLERMAN: So, do you anticipate that environmentalists would sue to prevent this project from going ahead?

NORDAN: It’s possible. I think if that trigger was going to be pulled, it probably would have been done. There was a bill that went through Congress last year, called the California Desert Protection Act of 2009 that aimed to block off a large amount of land to the north in the Mojave, from projects exactly like this one. This is a little further away form people, it’s not attached to things that have been thought of as tourist destinations or public lands that people have wanted to preserve. So, it’s a little less controversial than the northern sites of them.

GELLERMAN: Now, I understand that a solar-thermal plant like this winds up using a lot of water. And this is going to be in the desert, where does the water come from?

NORDAN: It does. So typical solar-thermal….again, you’re concentrating the power of the sun to create heat, but on the back end, you’re using that heat to boil water and turn a turbine, just like in any other kind of power plant. The challenge on that back end is that you need that same kind of water that you do in coal and nuclear, which you typically find with big cooling towers next to lakes, right?

Because you have a way of cooling the steam down to turn it back into water. People usually do that by using more water, which means you need to be located near a river or a lake, some kind of source like this. You don’t have this in the desert. The way they’ve gotten around that in this project is by using dry-cooling technology, a fancy name for blowing air past the steam to get it to cool again. That increases the expense, that makes the power more costly, but it also fixes the environmental bomb.

GELLERMAN: So, Matthew Nordan, when do you expect that solar-thermal will become a formidable form of energy in the United States?

NORDAN: My bet would be never, in terms of being a very large part of the electricity mix. And, the reason is, that to build one plant like this one, you have about ten times the amount of land required to build a comparable coal facility, even a greater multiple against a nuclear facility.

And you’ve got to get it all in once place. It’s got to be all together; one continuous big tract, located where there’s a lot of sunlight, where people don’t live, the land is not being put to another use, and there’s not a tremendous concern about wildlife that you might disrupt. I just don’t think that there are that many sites.

This one is the low-hanging fruit. It makes perfect sense. There may be several dozen more like this in California, perhaps multiples of those in other states like Arizona and New Mexico. But as a major contributor to the electricity mix across the country? There just aren’t many places you can put these things.

GELLERMAN: Well, Matthew Nordan, thank you very much, it’s been a real pleasure.

NORDAN: Thank you.

GELLERMAN: Matthew Nordan is vice president of VenRock, it’s an early-stage venture capital firm, specializing in clean energy.

 

 

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