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New Approaches Explored for Creating Solar Panels
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New Approaches Explored for Creating Solar Panels

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

We're talking this hour about energy and the environment, and some of the key technologies which are key to an alternative energy future. We just heard Mark Jacobson, associate professor in the Department of Civil and Environmental Engineering at Stanford, telling us that he didn't like ethanol as our future way of changing our society; and he preferred to go with electricity, sort of a plug-in society from using wind power to produce enough electricity. He said there's enough electricity out there for wind power.

There's certainly enough sun out there if we wanted to go to solar power, say the experts. And joining me now is Chris Eberspacher. He is the chief scientist for a Silicon Valley company called Nanosolar. Chris Eberspacher is working on developing a product that would make solar cells a lot less expensive to manufacture and install, and he joins us from his office in Palo Alto. Welcome to SCIENCE FRIDAY.

Mr. CHRIS EBERSPACHER (Chief Scientist, Nanosolar): Thank you very much. Pleased to be with you.

FLATOW: Thank you. Do you think - you just heard Dr. Jacobson say we could have enough wind power to provide all the electricity we need. Do we have enough sun power to provide all the electricity we might need?

Mr. EBERSPACHER: Certainly if you look at the solar resource here in the U.S. and you look at the amount of ground space we have, it only took a small fraction of it to pretty much provide all the power we might need.

FLATOW: And how cheaply can we make it? How cheaply can you make it? Can you make it competitively enough?

Mr. EBERSPACHER: If you look today at the price of solar-generated electricity, it's a bit more than the average cost of electricity here in the U.S. However, there's been tremendous strides forward both in the underlying technology but also in the economies of scale and manufacturing so that the price has fallen considerably, and you don't have to look too much in the future where solar-generated electricity can be completely competitive with grid capacity today.

FLATOW: We keep hearing it's in the future, it's in the future. Where is that future?

Mr. EBERSPACHER: The future is now in a number of places, particular applications that are away from the electrical grid. But in addition to that, just right here where I live in Northern California, on my bike ride to work I pass by a number of houses that have solar on the roof of the house now where that solar-generated electricity exceeds the requirements of the house during the daytime. And they sell that electricity back to the utility. And then at nighttime, when the sun's not out, they buy electricity back from the utility.

FLATOW: You have developed a product that makes solar cells in a much different way than people are normally used to hearing about solar cells. You almost print them out like a printing press. Tell us about what you do.

Mr. EBERSPACHER: That's correct. To lay the groundwork, the largest portion of the photovoltaics market today is based on wafers of silicon, not too dissimilar from the silicon wafers that are used in the integrated circuit industry to make all of the chips in our phones, and computers and such. That technology is very efficient at converting the sunlight to electricity, but it's rather expensive in no small part due to the cost of that silicon wafer itself.

For a number of years, people have worked on replacing that silicon wafer with something inexpensive, and the most promising of those different strategies have been to go to thin films of material, where you put think coatings of photoactive materials on inexpensive substrates like glass or metal foil, or even plastics. Unfortunately, in order to get very high-quality thin films, people traditionally have had to use expensive vacuum deposition techniques. Again, akin to what's used in the integrated circuit industry.

What Nanosolar's worked on and been quite successful developing are simple particle-based techniques where in effect you just print out thin coatings of material, and then heat them to transform them into high-quality thin films that in turn can yield very efficient solar converters.

FLATOW: So you just coat objects with this stuff?

Mr. EBERSPACHER: That's correct.

FLATOW: And you can coat anything?

Mr. EBERSPACHER: You can coat most anything, but then the heating step that follows that transforms that porous layer of particles into a solid high-quality semiconductor film usually encourages you to use something that will tolerate those higher temperatures. And a classic example is just metal foils of one type or another.

FLATOW: And then you take the foils and you spread them out on buildings?

Mr. EBERSPACHER: That's correct.

FLATOW: It could be the side of the building. It could be the roof. Could be - could you make siding out of it?

Mr. EBERSPACHER: Yes. You can make all kinds of things out of it. Today what you find is increasingly they will be residential houses that have solar on the roof perhaps - on the roof of an existing house, or actually it is the roof of the house. And in addition to that, you'll see large commercial buildings. So when you drive up to your local grocery store - you know, it's a big huge building with a big flat roof - and what you might not be able to tell is there might be solar up on the flat roof of that building.

And then if you have some kind of skyscraper, then perhaps there's all of that sidewall as well. And increasingly, people can incorporate solar panels directly into the walls of these buildings.

FLATOW: And can you do it cheaply enough to compete with hooking up to the electric meter?

Mr. EBERSPACHER: Certainly we believe that with this new generation of techniques that we'll be able to make solar modules, as they're called, cheaply enough that we'll be able to compete head-to-head with grid electricity. And at that point you'll see an enormous further acceleration of the application of solar.

FLATOW: Tell us about the factories that you're building, because, you know, if you can't get the product, what's the sense of building?

Mr. EBERSPACHER: True. We're currently in the final stages of development of our technology. It's made it's way through the, if you will, the laboratory stage and is in the pilot production stage. We have a large factory building here in northern California, truthfully enough, idled by the largely offshore integrated circuit industry now. And we're populating that building with manufacturing equipment as we speak.

FLATOW: So it's like building printing presses, so to speak?

Mr. EBERSPACHER: Exactly. So if you imagine what's necessary, you need to make fine powders of material; you need machines that will then take that fine powder and mix it together with liquids to make something that's akin to the writing ink in your pen. And then there are coating machines, if you will, printing machines not unlike what you might have seen as a kid when you toured the newspaper printing buildings. And then there's big furnaces where layers are dried and heated to solidify into high-quality semiconductor films.

And then there's various dicing machines to dice things up and reassemble them into final product.

FLATOW: Now what technology makes this possible? There's the word nano in your company. Are you using nanoparticles here?

Mr. EBERSPACHER: We are using nanoparticles. Unlike some other people who use nanotechnology to achieve particular material characteristics that bulk forms of material don't have, Nanosolar applies nanotechnology as a means to an end, namely to allow us to have a very low-cost manufacturing technique for making high-quality thin films. So we start off with nanoparticulate material. Again, we mix it with liquids to make an ink, and we make a layer of that. And then what you're left with is a porous layer of particles - very small particles.

And those can be solidified and transformed into these high-quality semiconductor films so that when the product leaves the factory door, if you will, there's no nanotech to it, if you will. The nanotechnology is a means to an end to drive down the manufacturing costs.

FLATOW: The last time I visited a nanosolar - not yours, and I shouldn't say nanosolar - a solar laboratory in Golden - the government's solo laboratory - they said that all - 75 percent of the solar panels made in the U.S. are being shipped abroad…

Mr. EBERSPACHER: That's correct.

FLATOW: …and that you can't buy one here.

Mr. EBERSPACHER: Well, certainly the power of the marketplace has drawn photovoltaic products to the markets where one can achieve the best cost - excuse me, the best prices. So if you turn the clock back maybe ten years, that location was Japan. Japan had a very big national push to try to build their solar industry. They encouraged people to put it on the roofs of houses and commercial buildings. About the time that Japanese program was successfully winding down, a very similar large program was created in Germany.

And now what you've seen is you've seen Germany in particular, and pretty much Western Europe in general, explode into the world's largest photovoltaics market. And a lot of products manufactured in Asia, in the U.S. and in Europe and elsewhere, are all drawn to that marketplace today.

FLATOW: And you're going to be opening a factory in Germany, too, correct?

Mr. EBERSPACHER: We're going to open a factory here in California that builds the basic building block of our product, which is the photovoltaic cell. And we're opening a factory in Germany where cells are assembled into a multi-cell module. And the difference between a cell and a module is that a cell is maybe something about the size of your open hand and it generates a certain amount of power. In order to get useful amounts of power, and in particular in order to package those cells so they can have a very long life outdoor in the elements, you package it into a so-called module. And modules typically have plastic, glass, metal frames, things of this sort that are heavy. So you want to do that near to wherever the end market's going to be. And so a merging combination of the sort that Nanosolar's pursuing is to build the cells close to where the technology experts are and where are the leverage is for building low-cost cells, and then to assemble modules near where the current customer base is. And for right now, that's in Europe.

FLATOW: Do you think the solar industry, such as yours, needs some help from the federal government in forms of tax credits or subsidies or, you know, kilowatt-hour subsidies like that to be competitive, or are you doing well enough on your own?

Mr. EBERSPACHER: If you look today, today the cost structure of photovoltaics is higher than grid electricity in many places, and so various source of assistance with tax credits and other incentives can help draw the current generation of products further into our environment and further improve the economies of scale as factories ramp up to meet that demand.

If you look in the not-too-distant future, perhaps only a few years away, 2010, 2015 at the outside, what people realistically project is that the cost of solar will drop so far that it will be fully grid competitive with no subsidies whatsoever.

FLATOW: Do you think there's enough time to bring solar in competition with this headlong rush in ethanol production so that you can have - make a real dent in the industry?

Mr. EBERSPACHER: Certainly, if you look at ethanol production, ethanol is designed to be a transportation fuel, whereas most of the solar applications are designed to be electricity supply. A combination could be quite effective for the nation, for this nation and others, in order to provide a further diversification of energy sources, over time perhaps the lion's share if not all of the energy needs. But in the near term, they don't compete one with the other. They actually address very different market opportunities.

FLATOW: 1-800-989-8255 is our number. Talking with Chris Eberspacher who is -of the Nanosolar Company. How soon could we - if I'm building a home, how soon might I be able to take or find some of your paneling to put on my home?

Mr. EBERSPACHER: One of the things that has happened in the solar industry is there's been such a large growth in demand that our industry has grown at maybe 35 percent per year for the last seven, eight, almost 10 years now. Because of that, the industry is quite large, tens of billions of dollars.

So Nanosolar looks to have products out in the reasonably near future, but you have to go to quite some scale in order to be anything more enough to blip on the screen, if you will. And so we're looking sometime in 2008 or there about, you'll be able to find these next generation of products that we believe in fairly short order will both supplant much of the existing technology based on crystal and silicon, but also open up for consumers entirely new low-cost ways to provide power.

FLATOW: Talking about solar power of this hour on TALK OF THE NATION: SCIENCE FRIDAY from NPR News. Talking with Chris Eberspacher of Nanosolar. You've got some pretty heavy bucks behind your company, including the Google guys.

Mr. EBERSPACHER: Yeah, a pair of the angel investors in Nanosolar some years back were the pair of guys that founded Google.

FLATOW: Is Silicon Valley now no longer a Silicon Valley and becoming Alternative Energy Solar Valley?

Mr. EBERSPACHER: There's been some talk of that. One of the valley's quintessential venture capitalist John Doerr of Kleiner Perkins used that very phrase to describe of what he thinks the valley might be headed.

FLATOW: Which phrase was that?

Mr. EBERSPACHER: Solar Valley.

FLATOW: Solar Valley.

Mr. EBERSPACHER: If you look at photovoltaics for many years, there was perhaps a small university program and maybe one fledgling company that constituted most of the solar activity in Silicon Valley. Now there's easily half a dozen companies, and another three or four seem to spring up every quarter.

FLATOW: And what is it about - it's not the water in the valley, what is about the valley that makes these things spring up?

Mr. EBERSPACHER: This area has a potent combination of, number one, being in California, where there is sunshine and people are interested in these sorts of products. Number two, it has a very talented labor force that's been developed by the integrated circuit industry. And the third thing that it has is the venture capital community who are adept at looking at markets, looking at technologies, looking both at the present and the future, and making smart bets. And when they make those bets, making bets with considerable amounts of money necessary to get new ventures not only up, but moving quickly.

FLATOW: And it is California, after all.

Mr. EBERSPACHER: That's correct.

FLATOW: And has the state helped you along here?

Mr. EBERSPACHER: The state, over the years, has provided variety of assistance - research moneys have gone into this area. In addition to that, California is one of the states that's been on the forefront in trying to remove regulatory barriers that have prevented people in the early days from putting solar on the roof of their house.

So, for example, California is one of the states now that has a so-called Net Metering Law. Where if you have photovoltaics on your house, it simply turns your electric meter backwards during the day, and then later in the day or later in the year, whenever that you need electricity, your meter simply runs forward. So you get paid the same amount of money for electricity by the utility as you subsequently pay them to buy it back.

FLATOW: Are we going to be seeing the ability to sell solar power, the electricity produced across states, or is it going to be a local phenomenon?

Mr. EBERSPACHER: I think that if you look at the electrical grids, the electrical grids are already regional, but one of the significant stresses on the nation's electrical grids are the large trunk lines between major metropolitan areas.

So solar does a great job of generating electricity right where people are, whether it's photovoltaics systems on the roof of the house generating electricity that might be used by you and your neighbors, or whether its photovoltaics on the roof of a commercial building or a large factory building generating electricity for use in those industrial and commercial applications. And that removes a lot of that burden off those transport lines back and forth between major areas.

FLATOW: Well, Chris, I want to thank you for taking time to talk with us, and good luck to you.

Mr. EBERSPACHER: It's been a pleasure. Thank you very much.

FLATOW: We'll be looking at Home Depot for your stuff someday.

Mr. EBERSPACHER: Good.

FLATOW: Chris Eberspacher is the chief scientist for a Silicon Valley company called Nanosolar, and they aim to become one of the biggest solar panel, solar provider technology in the world. So we're going to switch - break. We'll get switch gears and take a break, like in a car, you've got to step on the clutch first, then change the gear.

Come back and talk lots more of the energy, this time about batteries. We've got the electricity. Do we the storage means to store the electricity, put it on a battery and drive a car with it? We'll look at battery technology when we come back. So stay with us. We will be right back after the short break.

(Soundbite of music)

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

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