The Potential of Solar Power Megawatt-generating solar power plants are springing up in the southwestern United States. Could now barren desert lands turn into a major source of energy? As more individuals add solar panels to their homes and businesses, how much energy will solar technology be able to provide?
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The Potential of Solar Power

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The Potential of Solar Power

The Potential of Solar Power

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You've seen the solar panels, maybe even thought about getting some for your own home. But according to my next guest, those panels are a drop in the bucket, small potatoes, compared to the energy we could be harvesting from the sun.

Their idea is to centralize the production of electricity in one location, just like your power company does, and then feed it into your home, just like the power company. It would be done using arrays of solar collectors grouped where the sun shines brightest and longest - the desert and in large open spaces.

One solar thermal company estimates that a square patch of land less than 100 miles on a side, located in, let's say, a desert in Nevada, could supply enough electricity to power the entire country. Just a pipe dream? Company hype?

California's Pacific Gas and Electric Company has already signed up for such a solar utility, looking to purchase 177 megawatts of solar thermal power from a plant located in Central California.

And Congress is holding hearings next week on the feasibility of utility-scale solar, and more solar thermal plants are in the works for Arizona, Nevada and other places and other countries like Spain. But as of now, there are going to be - solar power plants only account for a fraction, a fraction of what we might be harvesting - we could be harvesting from the sun.

What's the hold up? How big a player could solar thermal power be in our energy future? What are the technologies? What are the roadblocks? That's what we'll be talking about this hour. If you want to get in on the conversation, I invite you to give us a call. Our number 1-800-989-8255, 1-800-989-TALK. Always, you can surf over to our Web site at or in "Second Life." Join the avatars over there at SCIENCE FRIDAY and submit your questions that way.

We are - our first guest this hour is going to be - I mentioned before, the Congress will be holding field hearings on utility solar power this coming Monday. My next guest is going to be presiding over these hearings. She is Gabrielle Giffords. She's a Democrat representing Arizona's 8th Congressional District. She is vice chairman of the Subcommittee on Energy and Environment under the House Committee on Science and Technology.

Welcome to the program.

Representative GABRIELLE GIFFORDS (Democrat, Arizona; Vice Chairman, Subcommittee on Energy and Environment): I'm so glad to be on. Thank you so much.

FLATOW: How much potential do you see here?

Rep. GIFFORDS: The potential is really boundless, particularly in areas of the southwest. You mentioned Arizona, Southern California, Texas, Nevada, parts of New Mexico, Colorado. We have such an incredible, intense amount of sunshine. In fact, when you look at the areas of the country that are actually doing a better job harvesting the power of the sun - areas like New Jersey or even Northern California, they don't even have the intensity that we have in the southwest.

FLATOW: Mm-hmm.

Rep. GIFFORDS: The leader, internationally, is Germany. Germany has about as much sunshine as Anchorage, Alaska. So the potential is incredible. Now, what we see that we lack is the commitment to invest in the resources and the technology needed.

So I'm excited. We do have an actual field hearing going on in my district, in Southern Arizona. Chairman Bart Gordon will be there. We'll have six members of the science committee to be in the field to talk about some of these utility-scale projects that we've got slated for the future.

FLATOW: What can Congress do to stimulate this technology?

Rep. GIFFORDS: The most important thing that Congress can do is extend the critical tax credits. They're due to expire this year, in 2008, for both residential and commercial renewable energy sources. But, you know, I particularly focus on solar energy.

FLATOW: Mm-hmm.

Rep. GIFFORDS: The cost of soldier - solar is decreasing, but the financial incentives are imperative. We have a company that is interested in developing a project in part of Arizona. Seventy thousand homes will be fueled from the power of the sun. It's a joint project with a Spanish company named Abengoa with APS, a utility company in Arizona. One of the largest utility-scale solar projects in the world is proposed, but it won't go forward without the extension of the tax credits.

FLATOW: Mm-hmm. What about the infrastructure for transporting electricity? We're actually going to have somebody from that company on our program a little bit later. But we hear that other companies are talking about the possibility of taking a hundred mile on a side cubed, or square, I guess, and generating enough electricity to feed the whole country.

Rep. GIFFORDS: Yeah.

FLATOW: Yet - we don't have an infrastructure to actually be able to do that yet. Is there any incentive to actually create these power lines or an infrastructure that might be able to speed off of a giant concentration of solar energy?

Rep. GIFFORDS: Well, I was able to pass legislation last year called the Solar Energy Research and Development Act of 2007 which increases the federal support for critical solar research and work for development. So one of the things we have to be doing is pushing the Department of Energy and some of our research institutions to invest in the transition lines - the transmission lines to extend this power because certainly, that's one issue that we have. We can generate…

FLATOW: Mm-hmm.

Rep. GIFFORDS: …the energy but then delivering that to other areas becomes more difficult. But there's a lot going on in solar technology. There's about three different types. There's residential. There's, of course, the panels you see on your roof, commercial scale panels that you'll see on big-box stores, using the foldable type. But this utility scale, the big solar fields that use mirrors that can turn - again, sunshine, even on non-sunny days, but just light into energy has tremendous, tremendous potential particularly because the costs are going down every single day.

FLATOW: Well, Congresswoman, I want to thank you for taking time to talk with us. I know you have to run. That's what we will be talking about for the rest of the hour. So thank you for kicking it off for us.

Rep. GIFFORDS: Thank you so much.

FLATOW: Gabrielle Giffords who's a Democrat representing Arizona's 8th Congressional District and vice chairman of the Subcommittee on Energy and Environment, and that is under the House Committee on Science and Technology.

Now, let me introduce my other guests. Fred Morse is the senior advisor for the U.S. for Abengoa Solar. He joins us from our NPR studios in Washington.

Thanks for joining us, Mr. Morse.

Mr. FRED MORSE (Senior Advisor for U.S. Operations, Abengoa Solar): Thank you.

FLATOW: David Mills is the chairman, founder, and chief research officer for Ausra Incorporated in Palo Alto, and he joins us today from San Jose.


Mr. DAVID MILLS (Chairman, Founder and Chief Research Officer, Ausra Incorporated): Thanks.

FLATOW: Mark Mehos is a program manager for the Concentrating Solar Power Program at the Department of Energy's National Renewable Energy Laboratory in Golden, Colorado. He joins us from Golden.


Mr. MARK MEHOS (Program Manager, Concentrating Solar Power Program, U.S. Energy Department): Glad to be here.

FLATOW: Let me talk to you, Fred, because you were mentioned by the congresswoman. Abengoa Solar is multinational; you're around the world. Tell us about some of the places you are already producing power.

Mr. MORSE: Well, Abengoa Solar has a commercial power tower. It's a technology where very large fields of mirrors, the size of billboards, are used to focus the sun's energy on a - at the top of a tower and then that heat is used to generate steam and run a power plant. So that project is running in Spain. It started last year. There are other projects being built by the same company in Spain using this trough technology where there's a curved mirror which focuses the sun's light on a pipe. The pipe contains fluid and that fluid is heated, which generates steam. So they're building that. They're also building, in Algeria and Morocco, the world's first combined cycle plants.

You know, Ira, that there are combined cycle plants where you have a gas turbine and a steam turbine and they work off natural gas; they're very efficient. These plants in the desert of Algeria and Morocco will add solar energy to augment the steam and thereby increasing the output.

FLATOW: Mm-hmm. Mark Mehos, you're going to be at that hearing next Monday in Arizona. What will you be listening for? What will you be talking about?

Mr. MEHOS: Yeah. I'll be in Tucson on Monday. I have been asked to describe the solar technologies that Fred just mentioned and the congresswoman just mentioned probably in a little bit more detail just to give some background on those technologies that we consider to be utility-scale technologies. I'm also going to talk about the potential - the land area we heard earlier about 100-mile-by-100-mile track of land and how much potential that can provide to the U.S. I will…

FLATOW: Is that an accurate figure?

Mr. MEHOS: The figure is accurate. I don't think you would be putting a single 100 or 10,000-square-mile plant in a single location. You mentioned the transmission to do that - that's not necessary. There is a lot of land available in the southwest and we've done a lot of analysis here at NREL looking just at that.

But these plants while large - 100 megawatts, 200 megawatts, maybe even a gigawatt - would be distributed throughout the southwest. The transmission is still an issue and we're looking at that also.

FLATOW: And it seems like we have gone a lot further than we used to think about solar energy then.

Mr. MEHOS: Oh, we have. A lot of that is being driven by the plants that Fred just talked about. There are policies in place in Spain, especially in Spain, for concentrating solar power that make that technology very attractive. And that has built an industry, and that industry has been noticed here in the U.S., as well as other energy issues like high prices of natural gas, for example.

FLATOW: David Mills, you're one of the international figures here. You have a contract with the State of California to build a 177-megawatt plant. How will that compete with costs of other types of electricity in California?

r. MILLS: Well, it's getting pretty close. We're starting to look at forward costs of natural gas generation of the order of 9 cents a kilowatt-hour in California according to the California government. And we believe this technology is only slightly above that and is on a trajectory, which is going to pass through that fairly shortly.

FLATOW: And when will this be complete and be delivering electricity?

Mr. MILLS: Probably between 2010 and 2011. The main stumbling block is getting an early turbine delivery. There's a huge demand for turbines at the moment. These are the giant steam turbines that are used in not only solar but fossil and nuclear plants.

FLATOW: And it is your - it's on your Web page that we found that figure for that 100-mile-square figure to be able…

Mr. MILLS: Yeah. That's right.

FLATOW: …the whole - electricity for the whole country.

Mr. MILLS: That's right. And - but we said equivalent to.


MR. MILLS: We didn't mean it would all be in one spot, and Mark is quite right in that. In fact, it's probably one of the more distributed forms of electricity that you could get because, you know, it isn't like - where we have lot of the coal coming from Wyoming. It's really that there are about half the land area of the United States which is eligible for putting down these sort of plants, all the way to Texas in the south and all the way up to Colorado.

FLATOW: All right. We're going to come back and talk lots more for the rest of the hour about solar energy. Our number 1-800-989-8255. The new technologies in solar thermal power, maybe it could come to a neighborhood near you. Talking with Fred Morse, David Mills, and Mark Mehos. And your questions, 1-800-989-8255. Go to our Web site, click on "Second Life" and you can talk to the - leave questions through your avatars. Stay with us. We'll be right back after this short message.

I'm Ira Flatow. This is TALK OF THE NATION: SCIENCE FRIDAY from NPR News.

(Soundbite of music)

FLATOW: You're listening to TALK OF THE NATION: SCIENCE FRIDAY. I'm Ira Flatow.

We're talking about the growth of solar thermal energy with my guests Mark Mehos, who's program manager for Concentrating Solar Power Program at the Department of Energy's Renewable Energy Lab in Golden, Colorado; David Mills, chairman, founder and chief research officer at Ausra in Palo Alto; Fred Morse, senior advisor for the U.S. for Abengoa Solar.

And our number 1-800-989-8255.

Let's get into some of the nitty-gritty of the technologies we're talking about, because I'm sure my listeners are very interested in this. Let's talk about Ausra's Fresnel lenses first. Tell us what a Fresnel lens is and how are you able to concentrate the solar power so well so that you can make it so efficiently.

Mr. MILLS: Well, in the first place, it's not a lens; it's a Fresnel mirror. Fresnel was an interesting Frenchman that lived a couple of hundred years ago and found that you could - instead of having one large mirror, you could break up a mirror into lots of smaller bits and make it do the same thing.

So, this is what we are doing. Instead of a large parabolic trough - and I'm sure Fred will talk about those later - we break that up into many smaller bits which track individually and train their light on what we call a receiver or an absorber of solar radiation.

In our case, that allows us to make the essential minimum structure very large. Our absorber lines, if you will, are about 1,300 feet long and about 100 feet wide. It's not something you put on your roof, but it is very efficient at collecting energy for very little expenditure on structural materials.

FLATOW: And how do you collect that? Where are you collecting it in?

Mr. MILLS: Well, we're collecting it in steam pipes. You talked previously, or Mark talked previously, about fluids in the pipes. In our case, the fluid is water. We actually just boil the water in the tubes and that steam goes either directly to a turbine or into some sort of storage system.

FLATOW: And what happens at night?

Mr. MILLS: Well, at night, we would normally wind down to a very low level of operation if we don't have much storage in the system. But as storage comes on stronger and stronger and we put more of it in, we'll be running 24 hours a day in trying to capture the majority of the grid load.

FLATOW: So, you can store the hot water in sort of a giant tank like we do in our basements with a hot water tank overnight?

Mr. MILLS: That's right. So that's called sensible heat storage, but you can do it in a variety of ways and there are many projects around the world using different materials.

Fred's company uses giant tanks of molten salt. There are some companies using concrete to store heat. We use another system which we can't really talk about because it's on the leading edge.

FLATOW: So, you have - you don't want to give away any trade secrets in other words?

Mr. MILLS: Well, some of the other technologies have been around a while everybody knows what's going on. But in our case, a little bit of advantage is gained by having a new technology.

FLATOW: Fred Morse, let's talk about your system. What does it do? Was it described accurately here?

Mr. MORSE: Yes, it was. We use large parabolic troughs. What that is, is it's a curved mirror in a shape of a parabola. If you want to visualize it, you try to imagine a curved surface that's about 15 feet open at the aperture that stands about 15 feet high, and that's one-and-a-half football fields in length. So, it's a very long mirrored surface.

And down the center of that, where the sun's rays are focused, is a large glass pipe and it's evacuated so that, like a roach motel, all the sun's rays that get in don't get out, and you can achieve very high temperatures - well over 700 degrees Fahrenheit - and that's hot enough to make steam to run a steam turbine.

We then make the solar field larger so we can put some of that energy into storage. And the storage is just a large tank where this hot fluid is collected. And when the sun goes down, we continue to run.

The plant in Arizona that Congresswoman Giffords mentioned will have three square miles of solar field and will have six hours of storage, which means when the sun goes down in Phoenix in August and the residents still have their air conditioners on at 10 or 11 at night, this solar plant will still be providing energy.

FLATOW: Mark Mehos, this all sounds so great. As a final test, I - we used to ask investors, what is your test for new inventions coming online? They say, well, if you're so smart, why ain't you rich? Why are we not, you know, seeing these springing up everywhere yet?

Mr. MEHOS: Well, I think we're just starting to see - the reason we haven't seen that, I'd say over the past decade or two decades, there are several reasons.

One is we went through a decade of very low energy prices, extremely low energy - natural gas prices here in the U.S. and it was just difficult for solar power or any renewable technology to compete in that market. In addition to that, here in the U.S., we had uncertainty in the southwest and everywhere due to deregulation of the utilities, and utilities were very averse to taking on that kind of risk. So, over the past decade, that's what happened.

Now, more recently, we have increases in cost of natural gas - significant increases. We have state policies that are now in place here in the U.S., and internationally, that promote deployment of renewable energies. We're starting to see some sensitivity to the environment with climate change. And all those combined are having people look at renewable technologies in general.

Now, four, because as I mentioned Spain, previously, is starting to come on because there are very large, very well capitalized companies that are getting into this market.

FLATOW: What has to be proven here yet? What - I mean, scaled up to sizes to show that they work in large scale?

Mr. MEHOS: Yes, essentially. And there's a couple things you need to prove. In one technology Abengoa is pushing - and there are several that they are looking at, but the parabolic trough that will be built in - by APS or with APS in Arizona are the most proven. They've already been scaled up. They've been built as large as 80 megawatts. There's two 80-megawatt plants in California, for example, that have been operating for 20 years now. So, they are proven.

Now the investor community, especially the large traditional project finance community, has to be comfortable with financing these plants. And the plant -the 250-megawatt plant in Arizona will cost over a billion dollars. You're into traditional project finance that brings more conservative investors along with it.

FLATOW: And how much would that replace - people talk about as an option of nuclear power - how would that compare in the price of outfitting a nuclear power generator that might make the same amount of energy?

Mr. MEHOS: Well, there's - well, compared to nuclear power, we're probably similar on a - or at least in the near terms, similar on a cost per kilowatt hour.

Now, nuclear power does present a different market. Nuclear power is what's considered a base-load technology. It operates around the clock, basically 24 hours a day. Solar technologies, even solar technologies that have storage, are not, at least in the near term, base-load technologies. They are what we call intermediate load generation, and they generate power maybe 50 percent of the time.

So, we're not - we don't consider ourselves as trying to compete against nuclear power, we're competing against the combined cycle plants, the near term that Fred mentioned earlier.

FLATOW: Fred and David, you agree with that?

Mr. MILLS: Well, it's David here - well, we've recently done a study of how a solar plant or large number of solar plants might integrate into the electricity grid. And it should be understood that the electricity grid is not going full power the whole time, either. So something that goes flat out all time same level is not exactly mirroring what the grid load demands. And, typically, we've gotten around this by supplementing nuclear or coal plants to do the same thing with gas plants that can adapt the load.

What we found in the study was that we could get a standard solar plant with about 16 hours storage, bigger than the six used by Abengoa, and it generally carry more than 90 percent of the load not only in the southwestern states, but over the entire U.S. grid network. And so this is a very different kind of power plant in the sense - we call it load following. It actually fulfills the function of both the base load and the peaking conventional plants.


Mr. MORSE: Well, I would add to that, it's the load following capability that has captured the excitement of the utilities.

FLATOW: Explain that.

Mr. MORSE: Well, you know, you mentioned that these are central station and it's - the utility would deliver the energy to the customer and they would.

So, this is a large plant and the fact that there is thermal storage which allows the utility to match the load - for example, in the wintertime, there may be a peak when people wake up, they turn on their heaters or whatever, and energy stored from the night before can be used to meet that load, and the utility would not have to turn on or turn up a larger, perhaps more expensive, plant.

And I think what's happened is the utilities are seeing their options closing for new power. Nuclear is - has its risks and expenses and long permitting time. Coal seems to be not an attractive option in many states in the southwest. Natural gas is an option, but the price is uncertain; it fluctuates. No utility can tell you what the cost to power would be from a gas plant five or 10 years from now. But from a solar plant, a CSP plant, solar thermal, the price is fixed; there is no fuel component to alter it. And the utilities find that to be of great value. And I think that's the added motivation in addition to the ones that Mark mentioned.

FLATOW: Mark, I also found it interesting that Congresswoman Giffords pointed out that outside of Arizona and California, there are lots of other places around the country that could install these kinds of solar thermal units, or these utilities.

Mr. MEHOS: Yeah, yeah, that's right. And we are focused, again, in the near-term, in the midterm, let's say over the next 10 or 20 years, on the Southwest U.S. The Southwest U.S. has some of the highest solar resources in the world. And it's similar to levels that we see in the southern Mediterranean or northern Africa or the Middle East, but at least as higher or higher than those. So our initial emphasis is on the southwest - in Colorado, California, Arizona, New Mexico, Texas, Utah - all of these states have very good solar resources.

FLATOW: And you might be competing or augmenting wind power in some of those Midwestern states.

Mr. MEHOS: Yeah, there's analysis - there's a large working group that the Department of Energy, NREL, is supporting, looking at exactly that, looking at the integration of wind and solar. Can solar provide a benefit to the high levels of wind penetrations that we are seeing in this country due to the cost-effectiveness of wind right now? The issue that we find with wind, apart from solar, is that wind in fact is an intermittent technology. When the wind does die off, the output from any particular plant does die off, and that can cause some problems on the grid. Solar has the advantages, as we've already discussed, of having thermal storage. So, when the sun does go down late in the evening or if there is a cloud that comes over, our power doesn't go out - we can keep operating, you know, per the design of that particular plant.


Going now to the phones, to Arizona. Is it the Chiricahuas, Jane(ph)?

JANE (Caller): You have got it. It is the Chiricahuas. First of all, I want to say I love your show. I really enjoy it so much. You do a great job.

FLATOW: Thank you.

JANE: And I am indeed in the Chiricahuas, which is one of the Sky Islands in Arizona. It's been called the Grand Canyon of biodiversity of the whole country. We have more endangered plants, birds, et cetera, than any other place. So I'm calling because my husband - who's been in solar for, gosh, 20 years - and myself have solar energy, and we have our water catchment. We live in a building that's called bioshelter, which comes out of the New Alchemy Institute. And having been using solar for 20, 25 years or so, we love it - we love the quiet of it. And we just recently read all five of the bills that the State of Arizona has proposed about solar, and we couldn't see that any of them made much sense, quite frankly, for homeowners and residential people like ourselves who…

FLATOW: What do you think then of a solar utility, where they would make the electricity using the sun and pipe it to you?

JANE: Oh, well, first of all, we're off the grid. We have all our own juice. We don't need any piping. We have no electrical line whatsoever and haven't ever had one. I guess my comment is that, you know, about 20 years ago, there was a doc at the U of A who wanted to take the (unintelligible) range and put up solar, and it would've cost something like $33 million, and it would have been able to provide power to a whole part of the southwest, and no one went for it.

FLATOW: Well, if…

JANE: And now…

FLATOW: …if we had - yeah.

JANE: …we're not - I guess when I'm listening to you guys, and you say, well, why hasn't solar taken off? Well, A, solar hasn't taken off because it's expensive and most folks don't want to spend 20 or 25 grand on a system. And no, the price of solar has not come down; in fact, it's been bought up by large companies like Kyocera from Japan, and it's still pretty cost-prohibitive for homeowners.

FLATOW: Okay, let me get a reaction to that.

JANE: Thank you.


Mr. MORSE: Well, maybe I can comment on it. I think it's an excellent question, and I think, Ira, it points out how important it is to distinguish utility-scale generation from residential. The cost of solar from a utility-scale project is very close to competitive with other sources of energy. And while I commend the caller for having an off-grid house, most people are not going to be able to do that, and central-station solar will meet the needs of the other people quite well.

FLATOW: All right. I wanted just - she mentioned that 30 years - imagine where we would have been 30 years ago if we had gone that way. I understand, Fred, that you were in charge of designing the solar panels that Jimmy Carter installed on the White House, is that right?

Mr. MORSE: I was, that's correct. I was working at the Department of Energy at the time, and President Carter wanted a solar water-heating system on the White House, and I was involved in the - in bringing that about. In fact, President Carter had solar heating in the inauguration stand. But unfortunately, it was one of the coldest days in January. And that poor system just could not keep the president or his guests warm enough.

FLATOW: But if - but it's ironic that one of the first, if not the first act, that Ronald Reagan did, following President Carter, was to rip out the solar panels…

Mr. MORSE: Correct.

FLATOW: …off the White House.

Mr. MORSE: Correct.

FLATOW: Which sent us down this road, and you know, we're - imagine where we could've been 30 years ago when that happened, if we had continued along that -his ideas of energy independence.

We have to take a short break. We'll come right back. Talk more about solar energy, solar-thermal power.

Our number, 1-800-989-8255 is our number here. Also, you can go to "Second Life," where we have our avatars taking questions for you. And stay with us. We'll be right back after this short break.


(Soundbite of music)

FLATOW: You're listening to TALK OF THE NATION: SCIENCE FRIDAY. I'm Ira Flatow.

We're talking about solar energy this hour - solar thermal energy - with Fred Morse of Abengoa, with David Mills of the Ausra Incorporation, and Mark Mehos who is in the National Renewable Energy Laboratory in Golden - a wonderful place to visit if you're out there - I've been there a few times. It's terrific.

Our number is 1-800-989-8255. Let's go to some meaty questions, one from Kurt(ph) in Osceola, Wisconsin.

Hi, Kurt.

KURT (Caller): Hello.

FLATOW: Hi there.

KURT: Hi, I'm very interested in finding employment in this industry. And I was wondering where you would start. Do you have to work for the power company to find something in that industry? Or…

FLATOW: Well, that's a very good question because that brings up the whole topic of if you want to stimulate an economy and plow some money into it, this would create lots of jobs, would it not, Fred?

Mr. MORSE: It absolutely would. The plant that Abengoa will build in Arizona, the 280-megawatt plant, will create - will need one and a half to 2,000 construction jobs and will have 85 permanent people onsite running that plant. And so, if you multiply that by the amount of power that we see coming in from solar power, it's a huge job opportunity.

FLATOW: So, if Kurt wanted to work on that, how would he go about?

Mr. MORSE: He would give me his phone number and I'll make an offer.

KURT: Is there mostly construction work done or is more technical?

Mr. MORSE: No. No, it's everything. It's construction, for sure. We need people who are engineers, who understand thermal power systems. There's a whole range of jobs, optics, these things are big optical devices. Mark could probably comment on all the R&D jobs.

KURT: So, would it be a - what type of engineering background? Would you need something like that or is there some other type of education needed to get into that? Or…

Mr. MORSE: No, I think you could be a pipe-fitter. You can be in construction. You can be an electrical engineer. You can be an electrician. You can drive a scraper that's going to level those three square miles.

KURT: Mm-hmm.

FLATOW: Well, that sounds like interesting stuff of…

KURT: Were you serious about wanting my phone number?

FLATOW: Well, go to his Web site, and give him a call. Go to the Web site - for both of them, and I imagine, also for - Ausra's going to need all kinds of people to work on their stuff, too, right?

Mr. MILLS: That's true. Well, if you look - check in our Web site, there are jobs occasionally advertised there as well. I just want to say that the job description does go very broad - from very, very technical people down to people that might normally work in agricultural jobs. We're tending to work in the areas of depleted farmland. And the local communities just love us because we're offering jobs such as O&M and cleaning mirrors and those sorts of things which do not require a very high training but offer jobs to the local community. So we're not getting that pushback that wind plants sometimes get.

FLATOW: Thanks for calling, Kurt.

KURT: Is there any informative books that I could maybe look up just at a basic level about your type of work(ph)…

FLATOW: Mark, you got a book?

Mr. MEHOS: Well, I have a Web site.

FLATOW: Web site - better.

Mr. MEHOS: If you want to know quite a bit about concentrating solar power, you can go to Take a look at our site - there's a publication there, yeah, and it gets into a lot of detail or fairly broad categories of description.

FLATOW: Thanks for calling.

You talked a bit about getting the site preparation ready. There'll be jobs of people doing that. And when we talk about building in deserts - you sort of assume that no one would object to using that land. You mentioned that not-in-my-backyard may not be as prevalent, but are there environmental concerns -environmental impact statements, things like that, endangered animals - that need to be talked about here?

Mr. MILLS: Well, there certainly are. This is a big part of our project team's activity - to make sure that, you know, we do the best for the land and the animals and plants around it. And there's no doubt though that a very large plant does change the environment somewhat, underneath the reflectors and in and about there. We've just got to minimize that. Our approach up to now has been to use land which is already degraded in a sense that it is farmland going out of production, so it's flat, it's been ploughed many times, and the animal life isn't nearly as prevalent there.

FLATOW: Let's go to - let's go Mike(ph) in Ann Arbor. Hi, Mike.

MIKE (Caller): Hi.

FLATOW: Hi there.

MIKE: First of all, thanks for having me on your phone - show. I enjoy the heck out of it.

FLATOW: Thank you.

MIKE: My question is is how much land per kilowatt would a solar panel take up as compared to wind generation? And why don't the two get together and do, like, a combination of, say, wind in Kansas, where they have a lot of that, and the sun in Arizona, where they have that, and you know, put the two together and get a good power - national power grid going?


Mr. MEHOS: That's a great question. The answer, not on a per-kilowatt scale, I guess, but we usually use five acres per megawatt or, as somebody described earlier, a 100-megawatt plant would take roughly a square mile, give or take, you know, some percentage of that.

As far as integrating that with wind, definitely that is being considered. Like I mentioned earlier, not that you would necessarily co-locate the two technologies - where the sun shines isn't generally where the wind blows - but on the grid, on the southwest grid, they're still interconnected and so we're still looking at how we can balance or integrate those two technologies.

As far as land area per wind - a big advantage of wind is that it does have multi-use capability there. You can site these plants on existing farm land and still farm the territory and generate power. The density of wind compared to solar is quite a bit less. I think it's maybe a factor of five or 10 times less energy dense than a solar plant.

FLATOW: What about siting these offshore? Could you put solar offshore in very bright area?

Mr. MORSE: I don't think you would want to do that. We have such good areas on land that I think it would be a lot easier and certainly a lot cheaper to use that.

FLATOW: Let's talk about the integration you mentioned between solar and wind and any other technologies. There is no national policy, it appears - you talked about Arizona, we're talking about California - that, like wind, a similar sort of situation is happening and it's everybody for themselves, for solar.

Mr. MILLS: Yeah. That's true. But already there are people looking, and ourselves included, looking at certain lines where you might have wind and solar on the same line and sharing that line.

FLATOW: Well, I'm talking about just developing solar in itself. There's no national besides, you know, there's no national energy policy to sort of direct it on.

Mr. MILLS: No. And that's very important for the transmission part of that. We have to recognize that solar preferentially comes from some parts of the nation - the southwest where it's cheapest. Wind comes from perhaps other parts. Hydroelectricity from other parts. And the integration of these is very, very important if we're to get a coherent system.

Mr. MORSE: But I think the question of a national solar policy - it doesn't exist. Right now, we have the states taking the lead with their policies driven by environmental concerns. We have the federal government supporting R&D and this very crucial investment tax credit, which - without which this technology we're talking about would not go anywhere.

But the country has not produced an energy plan that seems to - that would support the development of this country's vast and very available renewable resources. And it's, you know, it's in many ways, it's - you know, we have a carbon-based energy economy and it takes time to deal with that.

FLATOW: But from what I hear, you're saying that the price of oil, the price of energy - well, actually the price of solar is coming down fast enough that it will soon compete.

Mr. MORSE: Correct. And it will compete very soon. The Western Governors' Association had a taskforce and they predicted that with another 4,000 megawatts of CSP that the price would be competitive with natural gas, and if there's any carbon policy, that will close even sooner. And there are 3,000 megawatts already signed and waiting to be built if the investment tax credit were extended.

FLATOW: And that's so far on a year-to-year basis - these credits are going?

Mr. MORSE: This credit expires the end of this year and it should be extended for eight years. If it's extended year to year, absolutely nothing will…


Mr. MORSE: …help with these plants because they take so long to permit and build and get operating.

FLATOW: We have some questions from "Second Life." Let me see if I can get to a few of them. Chloe(ph) wants to know, would there be other effects such as meteorological if we direct that much solar energy up into the air? What happens to the atmosphere?

Mr. MILLS: Well, the actual technology used is basically solar energy that's already coming in and we use it on its way through. Normally, it would just heat up the Earth and that would be radiated into space. But we take some of it away for a while, convert some to electricity, eventually that all converts to heat and radiates out again. So, we don't really affect the balance of the atmosphere at all.

FLATOW: Are there more efficiencies yet to be discovered technologically in making this even more efficient - this solar collectors? And what are the - some of those things that you would like - I'd give you the blank check question. If you had a blank check to do research and development on the parts themselves, what would you like to make more efficient? I'll ask all of you to answer that.

Mr. MEHOS: This is Mark. From the NREL perspective or DOE perspective, there are a lot of efficiencies to be gained here. And I should say that other people are looking at lower efficiencies, and David's technology isn't as interested in high efficiency as they are in lower cost, and these all combine to give us a low cost output of power.

But the types of research that we are looking at or we hope to be funded for include advanced materials, high-reflective mirrors, better absorbing receivers, and very importantly, cost-effective, high-performance thermal storage.

A lot of interest, as we've heard, is on how we can make these plants not only operate as intermittent-low technology like I mentioned earlier, but in fact go to these base-load technologies. And David mentioned his proprietary technology, can we develop those sorts of high-capacity storage technology.

FLATOW: Could we use new - after the generation - new line, new kinds of possibly super-cooled, underground cables to carry the electricities from one place to another? Those kinds of technology, so we don't have those high losses.

Mr. MILLS: I don't think the losses are that bad. If you took just the conventional high-voltage DC technology, which is already working in parts of the United States and between Canada and the United States, you could find a 10 percent loss between coast - from coast to coast, approximately that. So…

FLATOW: It's not much?

Mr. MILLS: It's not much. And so, when you consider that you can generate a lot more energy in the good solar spots, then 10 percent - compared to the northeast, for example, it's worth it to transmit that energy.

Mr. MEHOS: Yeah. And that brings up a very good point, and we've focused on the technology. The transmission system itself in trying to get the power generated from the southwest out to the load centers, which aren't necessarily in the southwest, we can significantly expand our capacity just by sending it east somewhere.

FLATOW: Talking about solar hour - solar power this hour on TALK OF THE NATION: SCIENCE FRIDAY from NPR News.

Of course, that is one of the problems - how do you get the electricity from one place to another once it is generated? Might you also consider turning it into hydrogen, you know, think of different power, kind of, carrier and pipe it out that way?

Mr. MILLS: Well I have bit - sorry, you want to go, Mark?

Mr. MEHOS: No. Dave, go ahead.

Mr. MILLS: Okay. I'm not a great fan of hydrogen at this stage. I'm not saying there won't be applications for it, but we've got an electrical grid infrastructure already in place which can transmit the energy at high efficiency. And we've got technologies that are essentially electric in terms of large central technologies or wind technologies or solar technologies. And so it's important to understand that we can actually develop a system which is totally independent of hydrogen, which is very close to our present system, and also can operate a, say, a vehicle system, which is based around electricity if we transition to that.

FLATOW: So - we're running out of time, so I'd like to ask this question sort of as a summary question. Do I hear you all saying that we have the technology available now - we don't need any great breakthroughs, maybe just tune it and tweak it a little bit - to actually make solar thermal power over the next few years if we would really put the effort into it a large part of our electrical generating system?

Mr. MILLS: Well, I consider the technology juvenile at the moment. It's adolescent. It has a long way to go from point of development, but it's already ready to install.

So, for example, as Fred's company is showing, you can put large storage plants into the United States now. But if you want to get to the price of fossil fuel, then we're going to have to continue to develop new technologies, and this is where companies like our own come in. We're quite confident that we can lower that price to fossil fuel in a very short time.


Mr. MORSE: I would agree. I think the key is to get back into the market. We had a 15-year pause from the last plants that were built in the Mojave that Mark mentioned. We have to get the plants that have been signed up for - like ours, like Ausra's, like other's - built. And when we build them, we will learn how to build them faster, more efficiently. We will find ways to improve the technology. The research that NREL is doing will be brought into the market by these various companies. As we compete, the cost will come down and at the same time any carbon policy will raise the price of the competition, and I think you will see thousands of megawatts in the southwest being built annually in a few years.

FLATOW: Mark, you have the last word.

Mr. MEHOS: I would agree with what David and Fred both said. We need a combination of deployment - that means policies. We need the research and development that takes place here at NREL or down at Sandia or other places to reduce the cost of the technologies so that we're not dependent on those policies. But then I don't believe there are any fundamental stumbling blocks in our way.

FLATOW: For years we kept hearing about the price of oil being, you know - remember when it was down to $20 a barrel, and we kept saying, well, if it just went above $40 a barrel, it would be the right time. Well, it's 110 bucks or something like that, so maybe it is the right time. You know, timing is so important.

Thank you, gentlemen, for taking time to be with us.

Mr. MEHOS: Thank you.

Mr. MILLS: Thank you.

Mr. MORSE: Thanks.

FLATOW: Fred Morse, senior advisor for the U.S. for the Abengoa Solar Company. David Mills is chairman, founder, and chief researcher - research officer for Ausra Incorporated. Mark Mehos is program manager for the Concentrating Solar Power Program at the National Renewable Energy Laboratory in Golden, Colorado.

I'm Ira Flatow in New York.

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