January 23, 2012
National Public Radio
Innovative Projects Tap Renewable Energy Sources
Two projects aim to harness renewable energy using cutting-edge technology and engineering. AltaRock's Susan Petty discusses plans to turn hot rocks at a dormant volcano into a source of power. University of Maine's Habib Dagher talks about the potential of deepwater floating wind turbines.
IRA FLATOW, HOST:
You're listening to Science Friday. I'm Ira Flatow.
We here at Science Friday are constantly on the lookout for cool, innovative, renewable energy ideas. And when we came across these next two, we knew - I just knew I had to share them with you.
Our first one, we go to a dormant volcano in Oregon. It's the site of a renewable energy project that involves hot rocks, millions of gallons of cold water and cutting edge geothermal technology. Susan Petty is the president and chief technology officer for AltaRock Energy, one of the collaborators on this project. She joins us from Seattle.
Welcome to Science Friday.
SUSAN PETTY: Hi, Ira. Good to get to talk to you.
FLATOW: Hope you're weathering the storm out there.
PETTY: Well, I had to stay home today, because we have 10 inches of snow out here and the road hasn't been plowed yet. But...
FLATOW: Well, what better way than to share your phone call with us then today?
PETTY: Absolutely. And we can talk about heat, which is a good thing.
FLATOW: Well, let's talk - so how do - how are you going to use this volcano? Tell us about this. Dormant volcano in Oregon. You're going to use it to generate power.
PETTY: OK. Well, we were very fortunate. AltaRock Energy is a company that's been focused on advance technology for using geothermal energy since 2007. And we found that the - some folks, Davenport Energy, our partners, had drilled two wells at Newberry Volcano, looking for conventional geothermal resources. And they didn't find it.
What they found, though, was a lot of heat really close to the surface. And so we came to them and said, Look, we've developed this advanced technology that should let us get this heat out, even though you don't have the normal cracks and hot water that would be in place for a conventional geothermal resource.
FLATOW: So instead of - so you made lemonade out of lemons when you got there and decided to try something new.
PETTY: Something new. And it really is new. I mean, there have been other projects where people have drilled down, gotten into hot rock and made fractures and then circulated cold water down one well and produced it hot out of another well. There're two projects like that - one in Germany and one in France. And they're generating electricity now.
The problem is that it's only economic to do this in some very special places or if you have the kinds of price incentives that they have in Europe to get people to do that.
FLATOW: So what you're aiming to do is to do what? You have the rocks – have the hot rocks there. You will send cold water down, heat it up, bring it back up to the surface?
PETTY: That's right. And what we are going to do at this particular experiment is we already have a well. That's great. And it's very hot. So what we'll do is we'll put this cold water down. And the combination of the cold and a little bit of extra pressure allows the rock to start to fracture. And then we can extend those fractures out from that first place.
And as they extend out, they will bifurcate and new little fractures will open up. That makes little snapping and popping sounds, which we can use to map where the fractures are going. And we do that from the surface using sensitive seismic instruments.
Then when we finish making one set of fractures, the new thing is that we then pump a suspension of little plastic bits into the crack we've made. That stops that crack going, allows us to let the pressure come up a little bit more in the well. And then the cold water can move out and down, and extend out another set of fractures in the well.
And we can then put the plastic bits in that set of fractures. We can do that again and again until we're happy with what we got. And then when we stop pumping in cold water - this plastic is a biodegradable type of plastic that will then as it heats up break apart into little tiny components of the polymer. That will be completely soluble in water. And we can then produce them out.
FLATOW: So you're making sort of a pool or a reservoir of hot water underground?
PETTY: That's right. A reservoir in little cracks. I don't want you to think of it as an underground lake. It's a reservoir in that it's a bunch of tiny little cracks. And the more tiny cracks we can make, the better we can get at that heat that's in that volcano.
FLATOW: This is not like fracking for natural gas is it?
PETTY: No. Because in fracking for natural they want a great, big, huge crack, which they then hold open with proppant, with sand. And we don't want that, because that wouldn't get us access to that rock that we want to contact with our cold water to get it to heat up.
FLATOW: How hot does the water get?
PETTY: Well, we're very lucky. Because this is a volcano, it gets quite hot. So the temperatures in this well are higher than 600 degrees F. They're above 320 C.
FLATOW: Wow. So does the water - that's superheated water then?
PETTY: Well, yeah. So the water will get that hot, and it will then come out of the production wells at that temperature. And we'll be able to - we have two options then as it comes out of the well. We can either take the steam part - it'll boil - and we then can separate the steam and the water and put the steam through a steam turbine, which is probably what we'll do.
But we have another option. And that is that we can take the full stream of hot water and put it into heat exchangers and boil another fluid. And that will vaporize and that can go through a turbine.
Either way, it's a closed loop. We take all of this water that comes out, pick the heat out of it to make the electricity, and then we put it right back in the ground.
FLATOW: So it's sort of like a boiling water nuclear reactor, but without the nuclear reactor.
PETTY: Well, you know what? At this place, it's without the nuclear reactor. But everywhere you go on Earth, the deeper you go, the hotter it gets. And that actually is kind of a nuclear reactor, because that heat comes largely from radioactive decay or radioactive isotopes that are in the crust of the Earth. So it's kind of a very diffused and controlled nuclear reactor there under us.
FLATOW: Yeah. So when does this all happen?
PETTY: Well, OK. So the schedule is that we're just now - we've just completed our environmental permitting work. The Bureau of Land Management has released our environmental study for public comment. We have got that public comment period almost done. The BLM will then say go ahead.
And we also have a grant from the Department of Energy to help us do this experiment. So they'll say go ahead. And we have to put in some more sensitive seismic instruments. And that will be happening in the spring. We will then rig up and start the stimulation experiment probably at the end of July, beginning of August.
FLATOW: Is this - so you're saying it's technologically feasible, but you have to discover whether it makes economic sense, right?
PETTY: This is the big part of this, Ira. Right now, we could do this pretty much anywhere. We have the technical capability to generate power from this type of method, anyplace that you would want to try and do it. The problem is it's just not economic. The wells are deep and expensive. And we don't get that much power out of each one, so it wouldn't be justified.
We're hoping that this new method, where we can get a lot more of the hot rock contacted and therefore produce more hot water out of each production well, will make this much more economic. And so then we can move off the flanks of dormant volcanoes, where it's really hot close to the surface and go to places where we would find more normal levels of heat at depth and use this technology to make power a lot of places. That's the goal.
FLATOW: Well, we wish luck. And we'll be watching to see how this turns out.
PETTY: Well, that's great. And we'll let you know what happens.
FLATOW: All right. We'll be watching. Thank you for taking time to be with us today.
PETTY: Thank you.
FLATOW: Susan Petty is president and chief technology officer for AltaRock Energy, one of the collaborators on this project.
We're going to move on now to offshore. The other project I talked about that was really different that we'd kind of like to look into. This is going offshore to deep waters in the Gulf of Maine. And that's where a group called Deep Sea Wind Consortium hopes to one day see 100 floating wind turbines, each as tall as the Washington Monument, harvesting wind energy.
And while we know all about wind turbines, but the difference here - these turbines are going to be in deep water, way out to sea. You won't even be able to see them.
Habib Dagher is director of the Advanced Structures and Composite Center at the University of Maine, which leads the consortium. He joins us from Orono.
Welcome to Science Friday.
HABIB DAGHER: Thank you. Pleasure to be with you.
FLATOW: Did I describe that correctly?
DAGHER: That's very well done.
FLATOW: You're going to have - well, you're not going to start out with 100 of them are you? You're going to just try one or two?
DAGHER: Yes. We we're going to walk before we run on this. And we started, actually, with scale models. These turbines, when they're completed, they'll be about 300 feet to the hub, but five to ten megawatt turbines. The blades would be close to 180 feet long per blade.
So what we've done is we started with smaller specimens, a 150 scale unit, that we put in a wave wind basin. And these were about six feet to the hub, the blades were four feet long. And we put them through, essentially, a variety of designed storms to understand how they perform in hundred year storms. If you've seen the movie, "The Perfect Storm," we actually created many perfect storms in a wave wind facility. And that's where we start and that's where we started them.
FLATOW: And you found that they can resist some of these great storms and not be in danger of capsizing or getting wrecked?
DAGHER: That's correct. That's the purpose of the experiments. One reason we ran the experiments is to see how these actually perform, but also to try to understand how to predict how they will perform in a variety of environment.
FLATOW: Now, what makes Maine or the offshore part of Maine a good place to do this?
DAGHER: Within 50 miles of the Gulf of Maine, of the state of Maine, there's about 150 gigawatts of offshore wind capacity. That's about 150 nuclear power plants worth of wind. And the state of Maine only uses 2.4 gigawatts of electricity at the peak summer period. So we've got quite a bit of resource out there. And the state of Maine also has a maritime history with Bath Iron Works and others who've built ships and so forth, so it made sense for us to harness this resource and then build on an existing industry base.
FLATOW: Mm-hmm. And this is the first time this idea will be tried in the U.S.?
DAGHER: That's correct. That's the first time it will be tried in the U.S.
FLATOW: Has it been tried elsewhere?
DAGHER: Yes. There's been - there's currently an international race to go after what we call deepwater offshore wind. And the reason is there's so much resources out there and it's close to major cities across the globe. To put things in perspective, there's enough offshore wind capacity around the U.S. coasts, within 50 miles of the U.S. coast, to power the U.S. four times over. And about 75 percent of that is in 100 feet of water or more. So it's a huge resource in the U.S. It's also a huge resource globally. The first operating floating wind turbine in the world was put out in Norway by a company called Statoil about a couple of years ago.
FLATOW: Mm-hmm. Now Cape Wind in - off, I'm sure as you know, off of Nantucket has been having trouble with the local people, saying this is an eyesore. You won't have that trouble because they're so far offshore?
DAGHER: That's correct. Our turbines - our plan in Maine is to place these turbines between 20 and 50 miles offshore, so you won't see them because of the curvature of the Earth. And we've run some - the University of Maine, through a National Science Foundation-funded program, ran surveys across the Gulf of Maine, across the state of Maine, with two - over 6,000 people, and the support was over 98 percent for the concept.
FLATOW: And you would run a cable back to the shoreline?
DAGHER: That's correct. And that technology is thoroughly well known right now. In Europe, they've been building offshore wind farms since 1991, and even in the U.S., we've built another of these undersea cables, if you wish. Yeah, there would be one cable that will come from a farm to a location on that.
FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR, talking with Dr. Habib Dagher, a director of the Advanced Structures and Composites Center at the University of Maine. And you eventually - you there, you eventually - you could be an exporter of electricity, could you not?
DAGHER: Yes, absolutely. The state of Maine has a put a plan together that - to produce close to 5 gigawatts of offshore wind by 2030. That's the equivalent of five nuclear power plants worth of wind, when the wind is blowing, of course, and with an average output of 40 percent of that over the year. That's about two gigawatts. We can't use all two gigawatts in Maine, at least just for electricity. We plan to use it to heat homes, and we plan to use it to also fill up cars, essentially the electrical cars and the hybrid vehicles in the future. And then the rest of it, of course, we could sell on the New England grid.
FLATOW: Tell us your time schedule on it.
DAGHER: We are - we have just finished doing this last year the 150 scale models that we just discussed. At this stage of the game, we're designing a one to six scale unit that's going to be deployed in the spring of 2013, spring of next year, in the water off the Gulf of Maine. Following that, our goal is to put a small farm off the Gulf of Maine and just start constructing that in 2016 and have it operational in 2017. The state of Maine has put out a bid for the farm right now, for this demonstration farm, and the Maine PUC is in the process of selecting a winning bidder for that project. And then following that, between 2017 and 2020, the goal is to expand that to a larger farm in the order of a 500 megawatt farm. So that farm would have, say, 105 megawatt turbines.
FLATOW: And there's no reason why other places up and down the East Coast could not do the same thing.
DAGHER: Absolutely. So there's a lot of opportunities all across the United States and beyond to do this kind of thing. And actually, Japan, as we speak, the Japanese Parliament just two months ago has allocated $250 million to build six floating turbines off Fukushima because of the nuclear disaster in the area. They're looking for alternatives to nuclear energy and they have deep waters off their coast, so they're looking at floating wind turbines as well. The U.K. right now is also looking at doing that. So there's an international race to go to deep water offshore wind technology.
FLATOW: And, you know, what do you say to people who say, well, you know, the wind doesn't blow all the time?
DAGHER: That's correct. We all know that very well. And typically in most places in the U.S., you could integrate wind and you could deal with that. When you - about less than 10 percent penetration of wind on the grid. If you go over 10 percent, you start to have to do some things to back up the wind, so forth. So you can accommodate up to 10 percent penetration in most locations without a lot of trouble. Because what's happening is we already deal with an uncertain grid because the load changes throughout the day and throughout the week and so forth. So we know how to deal with an uncertain load, if you wish. So up to 10 percent in most places, we're OK. And 10 percent of, let's say, in the New England area, the grid is about a 30 gigawatt grid. So getting up to 3 gigawatts in the New England grid would be very doable without a lot of effort.
FLATOW: Mm-hmm. But you're taking - you're saying there is potential to go a lot further?
DAGHER: There is. There is potential to go significantly higher than that, of course, with backing up the wind properly. And also, how do you use the wind? If you use the wind, say, to fill up cars, one of the best ways to store renewables is in the electric vehicles. As - if we look down the road 10 or 20 years in the U.S., if we start, say, having a 20 or 30 or 40 or 50 percent penetration of these vehicles, they're like a bunch of batteries. They're not all in one place, but they're a large distributed battery.
And most of us use our cars less than an hour a day. So the other 23 hours they're sitting there, they can be taking that energy and storing it. And, essentially, what we'll be doing is we'll be displacing using fossil fues for the gasoline and using - and replacing that with renewable power. So that could be stored, if you wish, in these vehicles.
FLATOW: All right.
DAGHER: You can also use it to heat homes with it, and you can store that energy as well.
FLATOW: Sort of distributed storage, instead of (unintelligible). Yeah.
DAGHER: Yeah, yeah. And certainly that's one of the many ways you could use to address some of the - if you wish, the intermittency of the wind.
FLATOW: Well, Dr. Dagher, I wish you good luck. We'll...
DAGHER: Thank you.
FLATOW: ...we'll be following you. We love to look at really creative alternative energies, renewable sources. And we'll be following Dr. Habib Dagher, who is director of Advanced Structures and Composites Center at the University of Maine, where we see a whole bunch - a fleet of floating turbines off the coast. We'll watch it and wait and see.
We're going to take a break. When we come back, we're going to talk about that cruise ship and why its navigational equipment didn't work, or did it? Stay with us. I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.