Harvesting Geothermal Energy As part of our ongoing series on alternative energy sources, we'll take a look at methods to harvest energy from the heat beneath the surface of the Earth.

Harvesting Geothermal Energy

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This is Talk of the Nation Science Friday. I'm Ira Flatow. When you think about renewable energy, there are two renewable energies I think that probably pop up into your head. First, of course, is solar and second, wind. Whichever order that you like. But there is energy technology that has been growing dramatically around the country, and that is called geothermal. It's harvesting heat from the earth - below the earth, right below the surface or way down there on a very small scale. You can work it with heat pump to heat your house or even cool your house. On a larger scale, there's a lot of hot water beneath the earth that can be used to heat buildings directly. It can even be used to generate electricity.

In California, over 4 percent of the state's electric power comes from geothermal sources. There are 13,000 gigawatt hours of electricity generated there last year and my next guest says that right now, there are a 103 significant geothermal projects under way in 13 states throughout the country, where a few years ago, there would just have been a handful. Joining me now is Karl Gawell. He's the executive director of the Geothermal Energy Association in Washington joining us on the phone. Welcome to the program.

KARL GAWELL: Hi, Ira. Thanks for having me on.

FLATOW: Simply speaking, how would this work? How does it work? You pump water into the ground or you pump hot water out or both?

GAWELL: Well basically, with the power system, what you're doing is you're finding the spot in the ground that has hot rocks and water and then you're drilling down into it and just bringing up steam which you use to run a power plant.

FLATOW: And in your home system?

GAWELL: A home system, you're using the temperature under the ground. So if you - you know, most anywhere in the country, if you go down about four or five feet, the temperature is going to be between 50 and 60 degrees. So, you can run a loop out through the ground. It comes in and comes through a sort of a little heat exchanger. While in the winter, that heat exchanger is going to be bringing in 60 degree temperatures. So you're preheating your heating all the way up to 60 degrees. In the summertime, you're going to be using that to provide your cooling and it will provide most of your cooling. In a way, it's like if you think of some of these passive solar designed homes, if you build a home underground, it has pretty steady temperature all year round.

FLATOW: Yeah. You go in the basement, it stays pretty cool.

GAWELL: Right. But what you're doing instead of building your home under the ground, you're running this pipe loop under the ground and using it to bring that energy into your house.

FLATOW: So it's just as simple as that. If you just dig five or six feet down, you lay the pipe in the ground and loop it back into a heat exchanger?

GAWELL: Well, in very simplistic terms, it's that simple. The installation really needs to be done by a qualified contractor because most of this has to be designed for the site so you're using the maximum amount of efficiency and you also have products which are usually fused piping so that most of the piping I've seen is warrantied for 50 years so you don't have leaks because it's pretty expensive to put that ground loop in.

FLATOW: Right. And they're doing this in California?

GAWELL: They're doing it all around the country. Doing some in California but frankly it's been huge in the southeast and the northeast. I think there's something around 50,000 heat pumps a year installed. And we're seeing fairly strong growth about two-thirds of that in homes and about a third in commercial building. So in the east and the southeast, you're seeing a big renaissance and growth in geothermal heat pumps. And on the west, you're seeing a dramatic growth in geothermal power.

FLATOW: And I guess then there's a struggle to keep up with the equipment and the installers.

GAWELL: Exactly. That, in fact, we get so many calls from people saying, how do I find a designer, where do I find a installer? It literally drives us a little bit crazy but it's great. I mean it's great to be busy like that. And then for the power side, the same issue. We're building so many new power plants. People are waiting for people to bring in drilling rigs or bring in turbine equipment. And right now, it's actually building the infrastructure that's holding things up a bit and raising costs a little bit.

FLATOW: Yeah. So for the industrial side, do you have to find hot rocks or if you drill just deep enough, you'll hit them anywhere?

GAWELL: Well, the center of the earth is you know 9,000 degrees Fahrenheit or so and at different points, particularly in the west, that heat comes pretty close to the surface. And in many cases, you'll see fumaroles or hot springs, but not all. And in those areas, we've had people who just accidentally run into hot water. I remember one farmer in Idaho talking about he was drilling an irrigation well for his potato farm. He drilled the well. The well started coming up with water that was 200 degrees Fahrenheit. He decided he couldn't put that on his potato crop.

FLATOW: Well, he can cook them if he wants.

GAWELL: Well, he'd have to precook the potatoes. But he's a smart man and he turned around and he uses that hot water instead of raising potatoes to raise alligators, to raise tilapia and to raise catfish, and he claims he makes something close to 100 times more money per acre foot of water than he would if he was just farming potatoes.

FLATOW: It's the nouveau Jed Clampett story.


FLATOW: Instead of oil, he's got hot water.

GAWELL: Exactly.

FLATOW: Wow. 1-800-989-8255. How - I guess this is the model when I think about geothermal, I think of Iceland. Isn't that probably where they use this the most?

GAWELL: Well, I think proportionately, Iceland maybe you know one of the largest users, although it's not alone. I mean in the Philippines, 23 percent or 25 percent of the electricity in the Philippines is geothermal-powered today. Iceland is very dominant for heating. They heat many of their buildings because all the district heating system is using geothermal energy. I think it's about a third of their power supply. The rest of which I think is hydropower, but they're one of the first renewable hundred percent renewable countries, and I think New Zealand wants to be right behind them as well. They're building a lot of additional geothermal in New Zealand.

FLATOW: Jason in Nashville, Tennessee. Hi, Jason.

JASON: Hey, guys. Big fan. Thanks for having me on the air.

FLATOW: You're welcome.

JASON: So I guess a question and a comment. The first question is we use geothermal system in our home and have been surprised with how inefficient it turned out to be, at least, you know in terms of an energy bill. I was wondering if there's been a lot of developments in the last 15 years and how efficient it is or maybe it's just a commentary on my father's building of the house and installation?

FLATOW: Did he do this himself? Installed it himself?

JASON: He didn't install it himself. He built the home himself, but he had a contractor come out and put you know these coiled loops deep in the earth, and it was supposed to be a more efficient thing and pay for itself and I guess Tennessee Valley Authority who's our local electric provider provides some incentives for people to use these more efficient heating and cooling systems. And I think, I don't know if it comes back in the form of a check or a rebate of sort, but that's about it.

FLATOW: Did something come back?

JASON: Well, I'm saying like there were financial incentives to use this system as opposed to a traditional heating and cooling system.

FLATOW: And I believe you said this is 15 years ago.

JASON: About 15, yeah.

FLATOW: About 15. Interesting question.

GAWELL: Well, you know Ira, I got to be upfront. I'm not an expert on heat pump technology but it's obviously changed in 15 years I would hope, and it would be fully my expectation that that has happened. But I think it's also important for people to make sure they have well-designed system. As I mentioned earlier, we refer people to two groups which actually have directories on their website. One is the Geothermal Heat Pump Consortium and the other is the International Ground Source Heat Pump Association. That's quite a mouthful but particularly at the Ground Source Heat Pump Association's website, actually you can go in there by state and look up designers and installers and look at different systems. And they have a well-designed system. I think it's a really huge part of making it effective.

JASON: All right. Thanks, guys. I'll pass it along.

FLATOW: Thank you, Jason.

JASON: Bye-bye.

FLATOW: Good luck. You work a lot on the industrial side, correct?

GAWELL: I work a lot with the companies that produce geothermal power and also both large and small. In fact, I was just working on my way here today to someone who was about to put two power plants for the first two in New Mexico. One of which will be a small power plant at a greenhouse which is essentially like distributed generation because it will be powering the greenhouse. And they will also be supplying a power plant that will provide 10 megawatts of power to the grid. At the same time, I think they will be groundbreaking both of those on Tuesday.

FLATOW: At what point do you say I'll go for geothermal in terms of drilling you know for industrial? When does it make sense?

GAWELL: Well, it really makes sense when you have enough - you have to have enough hot water and you have to have enough temperature. But that's what those numbers are - they interact. So now you need more flow at lower rates. But also, technology has changed that dramatically. And one of the things you see in this new growth is that 20 years ago people would say you need to have at least 300 degrees Fahrenheit water or higher to do geothermal power.

Today, with these small binary powers systems, their organic rank in cycle power systems, one they installed the Tsina Hot Springs in Alaska and the one they're going to be installing in New Mexico, they said it can generate power with water down to a 160 degrees Fahrenheit which is hot. But you know as I point out to people that's hotter than a cup of coffee - excuse me, cooler than a cup of coffee at a fast-food restaurant. And so you're going to find water at that temperature in many more places and they're also producing them in, you know, much smaller units so you could put it in a smaller agricultural unit, or like this, in a greenhouse or like the Tsina hot springs and be providing the electricity for the whole system as well as the heat that it needs to run the operation.

FLATOW: Let's go to Mark in Boston. Hi, Mark.

MARK: Hi there. I'm actually from Lawrence, where we have a very large mill that we're hoping to heat with geothermal development. It's a little bit stalled right now but they're planning to build five geothermal wells next to the Merrimack River. My question actually is when I was reading on the web about geothermal, I came across articles about a situation in Basel where there has been some seismic activity. Some people were asserting that there was seismic activity caused by geothermal drilling. I wonder if you could discuss that. I'll take the answer off the line.

FLATOW: Yeah, can you set off earthquakes - I guess that's what he's asking?

GAWELL: Well, Basel was bit of a unique example because in Boswell, they weren't drilling for geothermal. They were actually trying to do one of these enhanced geothermal systems where what they were going into a rock structure, and they were injecting a large amount of very cold water to try to fracture the rock. And when you do that, when you inject a large amount of water like that into a hot - cold water into hot rock structure, you're going to have seismic activity. But that's the rare item.

In most cases, we're just drilling into the system, we're not injecting large amounts of cold water, and there is pretty strong tracking of what happens at the, you know, geothermal power plants around the country - most of them - I think all of them run seismic monitors constantly. And while there is, you know - sometimes they - a small amount of micro-earthquakes that occur near drill bits, the geologic survey and others pretty much monitors these and have done right, it shouldn't be a problem. We haven't, I haven't seen any major problems in the U.S. but the Boswell, I've talked a lot to people about Boswell where I think they basically did it wrong.

FLATOW: There's a question from Second Life from PRMantis saying, if we take all the heat out of the center of the earth, will that lead to trouble?

GAWELL: You know, actually, I have somebody ask me whether if we did that, could we offset global warming? And I said the problem is, it's too big, you know, there's something like a hundred million megawatts of thermal energy radiatingon a continuous basis from the center of the earth. And right now, we could use as much as we can figure out how to utilize, and it would be such a small fraction of radiation, the radiating heat coming out that it wouldn't make much of a difference. But it might be - in a way if we could do, if we could use that much geothermal power, there might be some interesting trade-offs, but I don't think we'll get there in my lifetime.

FLATOW: How does that compare - I know California is installing solar power. How does that compare to, let's say, solar thermal power?

GAWELL: Ah-huh. Well I have, you know, some of the companies in the geothermal business are in the solar thermal business too, and there's a lot of both being installed in California where they are very strong, you know, state standards promoting it. The biggest difference is how the supply comes out in the sense that solar has the advantage in California of being just about on peak. So when the demand is at its peak, the solar production is just matching that really nicely. And on geothermal side, we're base-load production 24 hours a day, 365 days a year. I know many people at the Energy Commission feel that actually in California, solar and geothermal together are just about the perfect match for their demand needs for their electric system.

FLATOW: Talking about the geothermal this hour on Talk of the Nation Science Friday from NPR News, talking with Karl Gawell. How did you get involved in this?

GAWELL: Oh, boy. I used to work with the wind industry and before that, with the National Allied Federation and some of the environmental groups, and, I guess my interest in both wind and geothermal was promoting, you know, environmentally better energy sources and trying to, you know, turn around what we're doing with fossil fuels around the world.

FLATOW: So do you agree that it's really up to the states, the state to taking the leads in all of these things? Are they - what about the energy tax credit that remains mired in the Senate, that has yet to be passed this year?

GAWELL: Well, right now, I think what's driving the market are state renewable standards which are giving you a very strong market and, you know, California is talking about even pushing it further. Also, high prices. You can't ignore the fact that prices right now are not just high but investors and people looking at the energy business are beginning to say they're going to stay high. So they're willing to invest in renewable power across the board just about, solar geothermal, it's cost much more up front, so you've got to have a longer term view to be willing to invest in it. But the third part, third, you know, part of the story that's really propping up this dramatic growth we're seeing, are federal tax incentives, which as you've mentioned.

Congress right now is one of the awkward situations where everybody, Democrat and Republican, seem to say oh yes, those are important credits, let's get them extended. And no one just seems to disagree with that, but they seem to have a major disagreement about whether and how to pay for doing that, and that seems to be hanging it up right now, although I understand they're going to come back in September and try one more time. So we'll what happens.

FLATOW: That will be seventh time, I think, something like that.

GAWELL: Yeah, it's - you know, many times that they took it to the altar here, but not quite yet married.

FLATOW: So where do we go with geothermal? I mean, are we looking for people to work in the industry? There's such a demand here?

GAWELL: We're running job ads in our newsletter every week and getting new ones constantly. There's actually a shortage of, especially trained people from the drilling business to the power plant business.

FLATOW: Is there a degree you can get in geothermal or is basically the parts - the drillers, the power, you know the electricians, things like that?

GAWELL: There's a lot of skilled labor that, it works - in fact, a lot of the labor is going to be construction of the power plants themselves. One of the biggest parts is the first couple of years for building the plant and doing the drilling rigs. But there are some programs at the university level that do specialize in geothermal. The University of Nevada-Reno has a geothermal center, Stanford University has a geothermal center, and Southern Methodist University in Texas also has a geothermal center.

FLATOW: And as far as installing it, a small system in your own home, there are ways to find out how to do that and hopefully, not a shortage of installers.

GAWELL: Well actually, the qualified installers are in short supply, and it took me those to install the ground loop, and actually Oklahoma State University is where the International Ground Source Heat Pump Association is located, at Oklahoma State, and if you go there, they can talk to you about training programs for heat pumps and installers as well.

FLATOW: Because these are all the new green jobs we keep talking about.

GAWELL: Yes, absolutely and the good news and the bad news is we employ a lot of people. The reason it's bad news is that some of the people who run these companies look at their geothermal plants and then they look at their natural gas plants and they go wow, look how many people I have to pay for. But I think that's good for the economy, particularly right now. I think what we need is new green jobs, and that's where we're starting to see and its very dramatic way.

FLATOW: Well Karl, thank you for taking time to be us.

GAWELL: OK, thanks Ira.

FLATOW: Karl Gawell is executive director of the Geothermal Energy Association In Washington. We're going to take a break. When we come back, a different energy alternative - ethanol. Yeah, we've been talking about ethanol but there may be some mythology about it that you haven't heard about. Can we have fuel and food at the same time? My next guest says we can. And we can do it by producing ethanol locally. We're talk about it, get your opinions. Our number 1-800-989-8255, stay with us, we'll be right back.

FLATOW: I'm Ira Flatow, this is Talk of the Nation Science Friday from NPR News.


FLATOW: New research suggests we're facing a mass extinction. I'm Ira Flatow, join me on Science Friday for a talk with ecologist Paul Ehrlich about how we might cut our losses. Plus the fungus in the fruit or why chili peppers are hot. And new materials that pull of something nature cannot - bending light backwards. That's next on Talk of the Nation from NPR News.

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