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Wind Power Plentiful, Study Says


This is SCIENCE FRIDAY, I'm Ira Flatow. How much of the world's energy needs could be met by wind power alone? Energy analysts are always quick to point out that the wind doesn't blow all the time, but it turns out that if you look worldwide, and you look up at the sky and not just at ground level, there's a lot of wind available, and that wind carries a lot of energy.

A new study estimates that just four million wind turbines would be able to fuel half of the planet's energy needs. And if that number seems like a lot, think about how many cars are sold every year worldwide. Could wind power also be a key issue in this election season in some states like Iowa that are investing heavily in wind energy and looking for politicians who believe in helping out with energy tax credits?

What do you think? Our number: 1-800-989-8255. 1-800-989-TALK. You can also tweet us @scifri and go to our website at sciencefriday.com. Mark Jacobson is a professor of civil and environmental engineering and the director of the Atmosphere/Energy Program at Stanford University. He's one of the author of that paper published this week in the Proceedings of the National Academy of Sciences. Welcome back to the program.

MARK JACOBSON: Thank you, Ira.

FLATOW: You're welcome.

Elizabeth Salerno is the editor - is the director of industry data and analysis at the American Wind Energy Association, that's an industry trade group in Washington. Welcome to SCIENCE FRIDAY.


FLATOW: Mark, what was the exact question you were trying to answer with this study?

JACOBSON: Well, there have been some recent studies that had claimed that because wind turbines extract energy from the wind when they're generating power that there wouldn't be enough wind available for other turbines. And in fact one study claimed that there would be only about one terawatt of wind power that could be extracted from the Earth's atmosphere, near the surface over land, and for comparison, in order to power half the world with wind if we convert everything to clean energy, we would need about six terawatts for half the world.

So we wanted to see: Was this true? I mean, could it really be there's just not enough wind in the world to power our future energy needs? And so really that was the question we were trying to answer.

FLATOW: And the answer, please.

JACOBSON: Well, we found over land, in fact when we calculate this from a physical approach and actually extract the energy out of the wind when the turbines are present; over land and near shore, there are actually about 80 terawatts. And worldwide - and this is at 100 meters height above the ground, which is the height of modern wind turbines. And worldwide, if you include all the land and the ocean, there are more than 250 terawatts.

And then in fact if you go up to 10 kilometers in what are called the jet streams, there are another - there are about 380 terawatts there.

FLATOW: So that's enough to power what?

JACOBSON: So if we want to power half the world's energy on wind, and I'll explain later why we'd want to do half, then we need about six terawatts, and there are about 80. So there's more than 10 times what we need to power half the world's energy for all - this is for all purposes. This is not just electric power I'm talking about. This is for transportation, heating and cooling, industrial processes plus electric power.

FLATOW: Wow, but could you spread the turbine - would you have to cover all this area? Is there enough area to put wind turbines down to get that much?

JACOBSON: Well, so in order to get that six terawatts, which is half the world's electric all-purpose power, and this is in 2030, accounting for growth, by the way, then we'd need about four million five-megawatt turbines. And we estimate that half would go over land and half over the ocean.

And those half over land would take the spacing - the area you need is about 0.6 percent of the world's land. And to compare, if we want to do the other half, we do it with solar and geothermal and hydroelectric and some other small things, that would be another 0.4 percent of the land. So a total of one percent of the land to re-power the entire world for all purposes.

But I should point out that 0.6 percent of the land for onshore wind, that can be used for multiple purposes. So it's not only wind, including agriculture, farmland, ranchland or rangeland or open space. So really it's not taking up hardly any additional land for all the wind.

FLATOW: Elizabeth, I would imagine that the American Wind Energy Association is very happy to hear about this.

SALERNO: Well, it's always interesting to hear about the huge and vast technical potential there is for wind energy, whether it's in the U.S. or globally. You know, over here at the trade group, we are always focused on actually developing out that resource, and building wind projects and building the manufacturing facilities that actually make those wind turbines that we're talking about.

And so we're really focused on getting steel in the ground with turbines and getting folks employed at the manufacturing facilities to actually make all the different components that will use this great wind resource.

FLATOW: Here's a tweet from Robert Bunn(ph), who wants to know: Has any study been done on whether extracting so much wind energy could have effects on weather patterns?

JACOBSON: Yes, I can answer that. In fact, that's what our study did, and another study that was also published about the same time as ours, from Livermore and Stanford by Ken Caldeira and his group. We both found small impacts on climate of lots of wind turbines.

And so there - if you think about it, when you're adding wind turbines, you're really displacing coal, gas and oil and other fossil fuel technologies primarily, which are not only adding heat to the air by direct combustion, but they're also adding carbon dioxide gas and other greenhouse gases and particles that affect our climate in a much more severe way.

So without even looking at the kind of modeling component, if you just look at the emissions component of heat and pollutants, there's a big - a huge reduction in both when you add wind turbines.

But we found, in both studies, that there was minimal impact on the climate, in some cases beneficial, in fact. In other cases, it was just trivial changes in temperature in different locations.

FLATOW: Let's go to Dave(ph) in Grand Rapids on the phone. Hi, Dave.

DAVE: Hi, Ira. Thanks, as always, for a great show.

FLATOW: Thank you.

DAVE: I am calling from Michigan, where hopefully we will pass the renewable energy standard on the election. But there's been a lot of controversy, including the aesthetics of offshore turbines, and a lot of misinformation about bat and bird kills. My understanding is that a lot of that bird kill data comes from the original wind turbine farms, like Altamont Pass, which were poorly sited, and that birds and cats are actually responsible for a lot more bird kills than wind turbines. Is that true?

JACOBSON: The - so we've looked at this in detail. There was a recent study that found that wind turbines, when you compare them to coal and gas in particular, kill one-tenth the number of birds that coal and gas kill. And that's because when you look at coal and gas, there's not only land degradation, in the case of coal it's mountaintop removal, in the case of gas it's land degradation through, in one case, hydrofracking, the other case drilling.

And it's also air pollution and also the buildings themselves. And so in the - so there is a one-tenth of - you do reduce your bird kills when you add wind turbines. Now according to the American Bird Conservancy, over - between 200 million and a billion birds are killed every year by buildings.

Eighty million are killed by cats. Ten to 50 million are killed by communication towers, and wind turbines kill only 40,000 birds per year every year - sorry, 400,000 birds per year every year. So this is according to the Bird Conservancy itself. So I don't think that - I think it's a myth that wind turbines enhance bird kills compared to other energy sources.

FLATOW: Elizabeth Salerno, I was reading recently about when the presidential candidates were visiting Iowa, that the Iowans were trying to raise tax credits as an issue. Do you think this will be an issue in the election year this year?

SALERNO: Well, the production tax credit is the business tax credit that has encouraged the development of wind over the past few years and been very successful, and it has come up in the state of Iowa where, you know, the state of Iowa right now is the number one state with wind jobs. And so they are very familiar with what wind means to their community and to their businesses.

And so it has come up as an issue, and it's something that has generated a lot of bipartisan support, at least the congressional level, where they're going to need to make a decision about whether or not they want to extend that tax credit past 2012 and allow this great resource that we've been talking about continue to be developed and bring all of the benefits to the U.S.

And so it's an issue in Iowa, it's an issue in Colorado, in Michigan - where our caller's from - and across the country. And I think we're looking - you know, we're looking at a lot of bipartisan support already. It's a question of how is Congress going to get this to the finish line.

FLATOW: What's your bet on this, whether it's going to get to the finish line?

SALERNO: Well, it's been amazing. You know, we have - obviously we look to members of Congress to see where they're at, but we're also constantly seeing polls from the public of their view of do they want more wind power. And one of the most recent ones in Iowa found that most Iowans will not support a candidate that does not support more wind power in this country.

And so that's been repeated, poll after poll, with over 80 percent of Americans, across the Republican, independent and Democratic spectrum, wanting to see more wind. So I think there's a very strong support base out there for wind and for this production tax credit to get done. And, you know, I should add that this is not we're just talking about and thinking about the impacts of not extending this tax credit today, are already actually hitting this industry.

We've started to see layoffs, unfortunately, at the manufacturing facilities in places like Michigan, Iowa, Colorado that we've built up. And so, you know, we're worried about losing more manufacturing jobs that we spent so much time trying to attract to this country. So it's a real issue that's right now, and decisions do make all the difference.

FLATOW: 1-800-989-8255 is our number. It should be issues, I guess, in other windy states, too, possibly South Dakota, Texas, places like that perhaps.

SALERNO: Well, you know, every state across the U.S. actually has some sort of business impact from wind, whether or not they have a wind project in their state, in windy places like the Dakotas or Kansas or Oklahoma, or the Southeast, which you know, has a lot of manufacturing right now. Every state has some form of business involved with the wind industry right now.

So everyone, sort of, has a stake in the game of whether or not Congress decides to move forward with this production tax credit and continue to encourage, you know, energy independence and affordable, clean and really domestic energy.

You know, it's all about building out the domestic energy resources we have here in the country.

FLATOW: All right, we're going to take a break, come back and talk more with Mark Jacobson and Elizabeth Salerno. Our number, 1-800-989-8255. And you're welcome to tweet us @scifri. Stay with us. We'll be right back after this break.


FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.


FLATOW: This is SCIENCE FRIDAY; I'm Ira Flatow. We're talking this hour about wind energy with my guest Mark Jacobson of Stanford University; Elizabeth Salerno from the American Wind Energy Association. Our number, 1-800-989-8255. A lot of interesting tweets coming in wondering about do we have the resources to build all those wind turbines, Mark? I mean...

JACOBSON: In fact we looked at the materials needed, and so for example for wind turbines, you need a rare earth element called neodymium, and there's actually about seven times more neodymium resources available that we know of worldwide than you would need to produce four million large wind turbines. And there's plenty of steel and concrete, as well. So the resources are not limits.

SALERNO: Let me add that there was actually a study that was done. I mean, this is a great question, something we've asked, as well. There was a study done back in 2008, actually under the Bush administration, looking at what would it take for us to do 20 percent of our generation from wind in the United States. And it looked at the technical needs, the steel, concrete, all of the different component parts, the transmission, the human resources, all the skilled labor.

And it looked at all of those elements and said yes, it is not only technically possible, but it economically makes sense for this country. And it was a technical study, not necessarily a goal, but it was something that we looked at, and we've decided that we can get there. We can get to 20 percent, and if you look at where we're at today in the U.S., we're actually on track to get to 20 percent by 2030.

FLATOW: Aren't there some states already at 20 percent? Isn't Iowa already at 20 percent?

SALERNO: You've got - absolutely. A variety of states across the U.S. are getting upwards of that 20 percent mark and even going beyond it, and more and more states are joining that group: Iowa, South Dakota and other states are already producing around 20 percent of their generation from wind.

FLATOW: Mark Jacobson, some of the ideas you modeled on your computer model seem to be pretty hard to achieve, especially, I'm thinking about the - extracting energy from the jet stream, way high up there. Is that feasible and practical to do?

JACOBSON: It's more difficult, certainly, but there are companies that are developing high-altitude wind devices. There are several of them have been around for many years. And they're actually - are focusing more on somewhere between the surface and the jet streams at this point, because there are difficulties in terms of tethering, connecting transmission up to that high. But it's still not out of the question.

But we think almost all - in the short term, at least, all wind turbines will be either on land or near shore, and there are even some floating turbines up, kind of test turbines that are actually up. A high-wind one, for example, has been up since 2009, and it's been - it's a floating turbine that's far offshore.

FLATOW: Let's go to Marty(ph) in Chapel Hill, North Carolina. Hi, Marty.

MARTY: Hey, how are you?

FLATOW: Hi there. Go ahead.

MARTY: So my question, I guess my statement was - are your guests actually looking at, kind of flip the coin a little bit, ways to gather wind in nontraditional locations. As a struggling inventor and people who are trying to push different new designs in wind turbines, we actually looked at placing vertical access turbines on highways because you have the large off-gassing of a large byproduct wind off interstate. Highways have a low (unintelligible) ratio. Bridge structures increase wind speed, and there's actually a USBOT wind tunnel facility that tests the negative or interactions between wind and bridges.

We would get - we got seven to 12 miles per hour standing eight feet off the ground. Has that been looked into, things like that?

FLATOW: Good question.

JACOBSON: Well, if you can get seven to 12 miles per hour, that's OK. It's not quite so good as you will get as you go higher up in the atmosphere. And also you have a lot of turbulence near a highway. So I'm not trying to dissuade you, I think that's a good resource to try to keep studying, but to get your most efficient energy outputs, you want big turbines going higher up because the higher you go in the atmosphere, the faster the wind, and you get economies of scale in terms of just the amount of power you can extract.

So there are building turbines also available for city and street canyons, for example, and these are effective at producing some energy, but you're not going to get nearly the efficiency as a large turbine high in the atmosphere.

FLATOW: Elizabeth, how close are we to getting our first offshore wind turbine system?

SALERNO: Well, you know, in the U.S., which I'll speak to, which is the area we cover, you know, we're very blessed that we have a vast onshore wind resource with a lot of open land where we're developing projects right now. And then on top of that, we're blessed with this fantastic wind resource offshore that is close to cities and towns, particularly along the Eastern Seaboard.

So that's where you see projects getting proposed sort of along the Northeastern Seaboard. So those projects are moving forward with key milestones getting passed really over the past 24, 36 months. I don't think we know exactly when the first project's going to go up, but, you know, we're going to go after both wind resources, both land-based and offshore, because, you know, we need the domestic energy, we want to be energy independent. So both are worth pursuing.

But hopefully we'll see one of those offshore projects come up real soon.

FLATOW: Last question to you, Mark. You said that you only looked into getting half the power from wind. And you said there was a reason for that.

JACOBSON: Yes, because if you want to actually match the power demand, the electric power demand, you need - reliably. Wind is intermittent, but it turns out that if you combine wind with solar in particular, they're very complimentary in nature. When the wind's not blowing, the sun is usually shining during the day and vice versa.

And then if you use hydroelectricity to fill in the gaps, or what's called concentrated solar power - which you can store the heat from the sunlight in a fluid and then use it at night - you can then use both of those - both hydro and the concentrated solar to fill in the gaps.

So we found for a study of California, that we were able to match the minute by - or really the hour-by-hour power demand over two years, 99.8 percent of all the hours just using a little bit of geothermal, a lot of wind, a lot of solar and the current existing hydroelectric power.

And so you really need both wind and solar together in order to be able to match that power demand. Because that's what people complain about a lot is that the wind doesn't always blow, so what are you going to do. You'll need expensive storage. But it turns out you don't need expensive storage when - because if you just combine these resources optimally, you can actually match that power demand very well.

It's really just an optimization problem.

FLATOW: All right, thank you both for taking time to be with us today.

JACOBSON: Thank you very much.

SALERNO: Thank you.

FLATOW: Mark Jacobson, professor of civil and environmental engineering and director of the Atmosphere/Energy Program at Stanford; Elizabeth Salerno, director of industry data and analysis at the American Wind Energy Association. Transcript provided by NPR, Copyright NPR.