Wind resistance: Analysis suggests generating electricity from large-scale wind farms could influence climate

March 12, 2010 by Morgan Bettex, Massachusetts Institute of Technology

Wind power has emerged as a viable renewable energy source in recent years -- one that proponents say could lessen the threat of global warming. Although the American Wind Energy Association estimates that only about 2 percent of U.S. electricity is currently generated from wind turbines, the U.S. Department of Energy has said that wind power could account for a fifth of the nation's electricity supply by 2030.

But a new MIT analysis may serve to temper enthusiasm about wind power, at least at very large scales. Ron Prinn, TEPCO Professor of Atmospheric Science, and principal research scientist Chien Wang of the Department of Earth, Atmospheric and Planetary Sciences, used a climate model to analyze the effects of millions of that would need to be installed across vast stretches of land and ocean to generate wind power on a global scale. Such a massive deployment could indeed impact the climate, they found, though not necessarily with the desired outcome.

In a paper published online Feb. 22 in Atmospheric Chemistry and Physics, Wang and Prinn suggest that using wind turbines to meet 10 percent of in 2100 could cause temperatures to rise by one degree Celsius in the regions on land where the are installed, including a smaller increase in areas beyond those regions. Their analysis indicates the opposite result for wind turbines installed in water: a drop in temperatures by one degree Celsius over those regions. The researchers also suggest that the intermittency of wind power could require significant and costly backup options, such as natural gas-fired .

Prinn cautioned against interpreting the study as an argument against wind power, urging that it be used to guide future research that explores the downsides of large-scale wind power before significant resources are invested to build vast wind farms. “We’re not pessimistic about wind,” he said. “We haven’t absolutely proven this effect, and we’d rather see that people do further research.”

Daniel Kirk-Davidoff, a chief scientist for MDA Federal Inc., which develops remote sensing technologies, and adjunct professor of meteorology at the University of Maryland, has examined the climate impacts of large-scale wind farms in previous studies. To him, the most promising result of the MIT analysis is that it indicates that the large-scale installation of wind turbines doesn’t appear to slow wind flow so much that it would be impossible to generate a desirable amount of energy. “When you put the wind turbines in, they are generating the kind of power you’d hope for,” he said.

Tapping the wind resource

Previous studies have predicted that annual world energy demand will increase from 14 terawatts (trillion watts) in 2002 to 44 terawatts by 2100. In their analysis, Prinn and Wang focus on the impact of using wind turbines to generate five terawatts of electric power.

Using a climate model developed by the U.S. National Center for Atmospheric Research, the researchers simulated the aerodynamic effects of large-scale wind farms — located both on land and on the ocean — to analyze how the atmosphere, ocean and land would respond over a 60-year span.

For the land analysis, they simulated the effects of wind farms by using data about how objects similar to turbines, such as undulating hills and clumps of trees, affect surface “roughness,” or friction that can disturb wind flow. After adding this data to the model, the researchers observed that the surface air temperature over the wind farm regions increased by about one degree Celsius, which averages out to an increase of .15 degrees Celsius over the entire global surface.

According to Prinn and Wang, this temperature increase occurs because the wind turbines affect two processes that play critical roles in determining surface temperature and atmospheric circulation: vertical turbulent motion and horizontal heat transport. Turbulent motion refers to the process by which heat and moisture are transferred from the land or ocean surface to the lower atmosphere. Horizontal heat transport is the process by which steady large-scale winds transport excessive heat away from warm regions, generally in a horizontal direction, and redistribute it to cooler regions. This process is critical for large-scale heat redistribution, whereas the effects of turbulent motion are generally more localized.

In the analysis, the wind turbines on land reduced wind speed, particularly on the downwind side of the wind farms, which reduced the strength of the turbulent motion and horizontal heat transport processes that move heat away from the Earth’s surface. This resulted in less heat being transported to the upper parts of the atmosphere, as well as to other regions farther away from the wind farms. The effect is similar to being at the beach on a windy summer day: If the wind weakened or disappeared, it would get warmer.

In contrast, when examining ocean-based wind farms, Prinn and Wang found that wind turbines cooled the surface by more than one degree Celsius. They said that these results are unreliable, however, because in their analysis, they modeled the effects of wind turbines by introducing surface friction in the form of large artificial waves. But they acknowledge that this is not an accurate comparison, meaning that a better way of simulating marine-based wind turbines must be developed before reliable conclusions can be made.

In addition to changes in temperatures and surface heat fluxes, they also observed changes in large-scale precipitation, particularly at the mid-latitudes in the Northern Hemisphere. Although these changes exceeded 10 percent in some areas, the global total changes were not very large, according to Prinn and Wang.

To investigate the effect of wind variability on the intermittency in wind power generation, the researchers used the climate model to estimate the monthly-mean consumption and electrical generation for each continent, concluding that there are very large and geographically extensive seasonal variations, particularly over North and South America, Africa and the Middle East. They explain that this unreliability means that an electrical generation system with greatly increased use of wind turbines would still require backup generation even if continental-scale power lines enabled electrical transmission from windy to non-windy areas.

Although Prinn and Wang believe their results for the land-based wind farms are robust, Wang called their analysis a “proof-of-concept” study that requires additional theoretical and modeling work, as well as field experiments for complete verification.

Their next step is to address how to simulate ocean-based wind farms more accurately. They plan to collaborate with aeronautical engineers to develop parameters for the climate model that will allow them to simulate turbines in coastal waters.

Explore further: Recycling wind turbines

Related Stories

Recycling wind turbines

September 21, 2007

The development of wind power promises much in terms of providing us with renewable energy for the future and wind turbines could be the most effective way to harness that power. Danish researchers now suggest that in order ...

Smart wind turbines can predict the wind

January 5, 2010

Risø DTU researchers have recently completed the world’s first successful test on a wind turbine with a laser-based anemometer built into the spinner in order to increase electricity generation.

Ocean Wind Power Maps Reveal Possible Wind Energy Sources

July 9, 2008

Efforts to harness the energy potential of Earth's ocean winds could soon gain an important new tool: global satellite maps from NASA. Scientists have been creating maps using nearly a decade of data from NASA's QuikSCAT ...

Global wind map identifies wind power potential

May 16, 2005

A new global wind power map has quantified global wind power and may help planners place turbines in locations that can maximize power from the winds and provide widely available low-cost energy. After analyzing more than ...

Winter shutdown approved for wind farms

September 24, 2005

To reduce bird deaths, some 4,000 aging wind turbines in California will be idled temporarily, and some will be scrapped and replaced with newer models.

Argonne gets wind of new energy models

January 11, 2010

( -- Sailors and golfers aren't the only people interested in knowing how much the wind blows; people who run wind farms need to know too.

Recommended for you

How the Elwha dam removals changed the river's mouth

January 19, 2018

For decades, resource managers agreed that removing the two dams on the Elwha River would be a big win for the watershed as a whole and, in particular, for its anadromous trout and salmon. The dams sat on the river for more ...


Adjust slider to filter visible comments by rank

Display comments: newest first

3.4 / 5 (5) Mar 12, 2010
One aspect that hasn't been discussed is the less energy available in the atmosphere after wind turbines harvest that moving force of the wind and generate electricity with it. I see a hidden benefit in this because it will decrease the amount of hurricanes that develop and also decrease their strength.

Strategically positioning wind turbines to generate electricity in places where they can cool the earth will be a triple benefit; namely a clean energy source, a cooler planet, and less hurricanes.
4.1 / 5 (7) Mar 12, 2010
If you remove translational energy from the atmosphere, it seems you would get stronger heat and pressure gradients from the lack of mixing. That might actually make hurricanes worse.
4.6 / 5 (5) Mar 12, 2010
The other way to read this is that Canada and Russia should consider land based wind farms, while southern temperate and tropical areas should only consider wind farms over oceans.

But before doing that, this research needs to be duplicated (without using the same software) and refined. It would be nice to have a model which can predict the local and global affects of particular wind farm projects.

As for hurricanes, don't expect much effect. Wind farms may change the latitude at which hurricanes become extra-tropical. To affect the creation of hurricanes from tropical depressions would require wind farms far from land at latitudes where they won't produce much power. Much easier to dump a few shiploads of ping-pong balls in the right locations.
2.1 / 5 (13) Mar 12, 2010
So nice when you are spending somebody else's money!

To guarantee the base load you need back-up facilities. So you need 200% installed capacity!

Nice to live in a very rich country that can put-up windmills just for fun! Always looks good on postcards!
2.7 / 5 (9) Mar 12, 2010
Another study to determine the obvious. And a massive proliferation of solar cells and solar farms sucking up sunlight will also affect the environment. Ditto for wave harnessing. The only source of power that won't affect the environment negatively is geothermal and only because we would use such a small percentage of it.
1.8 / 5 (5) Mar 12, 2010
What about the principal Precautionary Principle? Who do we sue when it might screw everything up?
2.6 / 5 (10) Mar 12, 2010
Just what we need! We can make it hotter on land by setting up more 'green' technology. Best not have any temperature stations near one of these wind farms or the results could get skewed even more than the results many of them already have had skewed by construction, bad location and siting and changes to the standard for temperature control such as a change from whitwash to titanium paint.

The researchers also suggest that the intermittency of wind power could require significant and costly backup options, such as natural gas-fired power plants.... They explain that this unreliability means that an electrical generation system with greatly increased use of wind turbines would still require backup generation even if continental-scale power lines enabled electrical transmission from windy to non-windy areas.

Meaning, that use of fossil and other hydrocarbon fuels still would be necessary in many cases, which means that there would be an increase in emissions... Nice. :)
5 / 5 (4) Mar 12, 2010
The amount of air required to power the world's supply of windmills compared to the amount of air available is so insignificantly small that there's no way this would affect the weather. It's like saying a teaspoon of sugar would make the Great Salt Lake noticably sweeter
3 / 5 (5) Mar 12, 2010
Hey! Ah kin do that kind'a science. It's like sayin' that mankind's greenhouse gas emissions would make the Earth noticeably warmer. Hey hey, AlGore science syllogism.
2.3 / 5 (3) Mar 12, 2010
Just what we need! We can make it hotter on land by setting up more 'green' technology.

I don't think that's what the study was saying. The study does not say that wind turbines heat the air; it said they slow down the transfer of natural heat away from the wind farms, which will heat the farm while cooling nearby areas that used to receive that heat (such as the atmosphere above the farm), just like a beach warming up on a still day. Likewise, wind turbines over the ocean do not cool the atmosphere overall. The atmosphere would not be warmed or cooled overall by any turbines anywhere; heat would merely be distributed differently. The article could be read to imply otherwise (especially the part where they "average out" the effect of the land-based turbines by themselves to a 0.15 deg C heating globally), but these articles are often fuzzier than the source material.
4.2 / 5 (5) Mar 12, 2010
The atmosphere would not be warmed or cooled overall by any turbines anywhere; heat would merely be distributed differently.

That would be one of the affects of CO2 production that we want to eliminate. Wind power appears to be contrary to our goals.

Yet another reason to support nuclear.

The only source of power that won't affect the environment negatively is geothermal and only because we would use such a small percentage of it.
Most geothermal plants actually increase the incidence of volcanic and tectonic activity.

Nuclear is the only option that can be used cleanly and effectively with little environmental effect.
2.5 / 5 (8) Mar 12, 2010
No, Damon Hastings, I did not say that the turbines will heat the landscape. The heat would be redistributed and these turbines will interfere with vertical and horizontal heat distribution.

In other words, there would be areas that rose in temperature in and around the wind farms that would go as high as 1 degree Celsius. The temperature rise on land at the other side of the wind farms of the sizes mentioned is predicted to rise by a smaller amount but it still will rise. Globally, it would contribute 0.15 degree Celsius. Well, at least that is what is predicted by the model. :)

It still does not change the fact that fossil fuels still will be needed, all those emissions included--unless we go nuclear as Skeptic_Heretic suggested. Otherwise, large scale wind farms are not in our best interest at present level of technology.
3.2 / 5 (5) Mar 12, 2010
Wind power derives directly from Solar(heating). I've seen calculations elsewhere on physorg showing that the amount of power which irradiates the earth every 24 hours is many orders of magnitude greater than the entirety of human power consumption in the same time period.
To some extent, wind power will merely replace the production of plant-derived solar power(fossil- an bio- fuels). Also, solar arrays themselves-especially if so engineered, will cause shade, and therefore cooling. I would expect that between the two, some balance will be struck.
The replacement of fossil fuels(and the solar energy they represent) with wind and direct solar will likely result in more overall cooling than heating. And it is inevitable that there will be some local variability in heating/cooling wherever these technologies are deployed.
4.3 / 5 (4) Mar 12, 2010
So nice when you are spending somebody else's money!

To guarantee the base load you need back-up facilities. So you need 200% installed capacity!

Nice to live in a very rich country that can put-up windmills just for fun! Always looks good on postcards!

No investor in their right mind would invest in windmills just for fun. They cost money to install, and to maintain, and you get power to sell. At the end of the equation you get profit. Thats why people put up windmills.
3.3 / 5 (7) Mar 12, 2010
No, Caliban, you are wrong on the solar arrays contributing to cooling. They not only absorb heat but radiate it as well. Large scale solar farms will also contribute to heating the air around them. I don't know about you but I have been around solar arrays. Those babies get hot and even the air under them gets blistering hot under various conditions.

They are not talking about replacement of fossil fuel generators with wind. They are talking about adding wind to existing infrastructure. The same goes for solar.

Both large scale solar and wind farms are bad for the environment. The gases used to manufacture and clean them are respectively over 17,000 and 23,000 times more potent GHGs than CO2. And, both require backup power plants, to boot. That means fossil fuels unless the backup plants are nuclear.

They will make the situation worse than you know done large scale. Geothermal or nuclear (whether by fission or, when the technology becomes viable, fusion) are the way to go.
2.5 / 5 (4) Mar 12, 2010
It is understood, dachy, that this is a partial replacement/substitute strategy. As such, it prevents the release of that many more GHGs, especially as the manufacturing tech becomes cleaner.

Both need backup storage, not generation.

The amount of relative heating created by solar arrays depends on surface proximity and co-generation tech being deployed, and again, also depends on the way the arrays are materially engineered.

I do agree with you though, that fusion would be the way to go- barring some truly breakthrough technology like harvesting vacuum energy or something along those lines.
2.2 / 5 (6) Mar 12, 2010
It is understood, dachy, that this is a partial replacement/substitute strategy....

Where does the article above say that? I have not yet read the paper. Perhaps it says this there. It is sitting on my desktop as I type this so I will read it as I find a little spare time.

As to solar arrays, large solar arrays are not laid on rooftops or mounted on frames like those one sees in home installations. They are on stands that resemble rows of rather large bleachers and have heatsinks attached to their backs to increase efficiency. These suckers radiate quite a bit of heat all around them. Your mileage may vary, however... :)
1 / 5 (2) Mar 13, 2010
Nuclear is the only option that can be used cleanly and effectively with little environmental effect.

The waste produced is dangerously radioactive for ten thousand years. All the waste produced so far is sitting around in temporary storage in containers that are in danger of leaking radioactive material and there has been no permanant storage sites yet agreed upon.

This is very dangerous material that could contaminate water, soil or air at any time in that next ten thousand years.It could also be stolen and used in a dirty bomb.I would hardly call that clean with little environment effect.
4 / 5 (1) Mar 13, 2010
At the end of the equation you get profit. That's why people put up windmills.

Believe nothing that you read or hear without verifying it yourself unless it fits your preexisting world view. I live on a small poor Island (and like it that way). Through careful management our power costs 6¢ KWh^-1. Our infrastructure costs are very high, for maintaining the 10 miles of UW cable and the 5 MW diesel-electric capability.

Please cite a reliable audit of a windmill producing a profit today and with zero indebtedness, subsidies, grants ad nauseam.

If such existed then Wisconsin Statutes §66.0401 would not be needed.
4 / 5 (1) Mar 13, 2010
No investor in their right mind would invest in windmills just for fun. They cost money to install, and to maintain, and you get power to sell. At the end of the equation you get profit. Thats why people put up windmills

The US isn't in it's right mind. You know that.
2.3 / 5 (3) Mar 13, 2010
anyone else noticing the familiar climate change deniers going along with this report, which uses global climate models, you know those models they go on about not be worth anything.
but a win for irony
1.8 / 5 (5) Mar 14, 2010
Since I am not a climate change denier I cannot speak for those who are. I know for a fact that climate always changes. It has changed for millions of years and will change for millions more.

But as to the models, I can give anecdotal testimony that large scale windmill farms do cause a degree of interference with respect to air flow across a landscape and thereby raise temperatures, the same as solar farms do in their own way. It stands to reason that this effect would only increase on larger scale deployment of said environmentally unfriendly technology.

But, if you noticed my post above, I placed a smiley after the word "model" and qualified my remarks with the words "at least" in the same sentence.

And, even the scientists who wrote the study acknowledged problems with the models. Read the article and the actual paper. I did. :)
5 / 5 (1) Mar 14, 2010
I question the underlying premise of this study. Saying the turbines adversely effect the transport of energy may be true, but so do large stands of trees. The fact that large tracts of forests are being and have been removed would have the opposite effect of placing more windmills by increasing heat transport.

I'm not suggesting that more forests be removed, just stating the fact that there has already been large-scale deforestation, so at the very least, more turbines would restore the regime closer to it's original state.

If, at some point, deforestation stops and windmill farms continue to proliferate, then we may see the effects that this study suggests.
2.1 / 5 (7) Mar 14, 2010
Deforestation is not as large-scale as alarmists such as the WWF have maintained. Their collections of false facts are partially what have gotten the IPCC into trouble.

Valid, functional peer-review would have caught the errors before their finding their way into the final version of the report.

Nevertheless, the fact remains that the WWF and like organizations exaggerate information to draw in funding from those of like mindset.

The article and the actual study already lend support to what I already suspected only anecdotally. Well, there is that and the fact that thousands of birds of all kinds (including endangered species) are killed every year by these environmentally unfriendly monstrosities.
3.7 / 5 (7) Mar 14, 2010
dachpy your cosy capitalist view of the world being all fine and therefore open for exploitation is going to run up against reality at some point.
you quote something often said by nimby's against windfarms, the bird death rate, quite wrong, well not when their correctly placed anyways.

maybe you could consider how our energy infrastructure could be changed? instead of having centralised power distribution, change it to a more localised system, taking it out of the hands of multi-national power generation companies and into the hands of local communities. or would that be against your capitalist growth model to have local communities empowered and making decisions for themselves?
1.8 / 5 (4) Mar 14, 2010
Nice attempt at mindreading and divination but it failed. I have no view regarding the world as "open for exploitation" or otherwise. I do think we should exploit other planets but our technology is not there yet so we have to make due with what we have and manage it wisely.

Bird kills are not the only thing I have against wind farms. Those on large scale are not a viable solution to the energy problem for several reasons, not the least of which are inefficiency, unsightliness and potential to modify climate, environment and habitat in serious ways.

How many windfarms are "placed correctly" and would you be so kind as to describe how one sets one up "correctly" so as not to kill flying wildlife?

As to how to change the energy infrastructure, I have no real idea as to how we can accomplish that at this point. Local control? Government control? World control? Everyone for oneself with individual power generation for all? Who could afford it? Better or worse for society?
2.7 / 5 (3) Mar 14, 2010
Just to keep it in perspective: how much environmental degradation, wildlife kill, unsightliness, and other negatives associated with fossil fuel exploitation/exploration/development/distribution, and then the specific damage done with the industrial-scale power production and distribution would be offset by a 10% contribution by these alternate power production methods?
1.8 / 5 (4) Mar 15, 2010
That would depend upon with whom you spoke.

The facility in the Diablo Mountains/Altamont Pass area, in California, alone kills--conservatively--4,700 birds a year, including California Golden Eagles and a number of migratory birds. That facility is the No. 2 producer of wind power.

The facility over in Backbone Mountain, in the Appalachians, killed over 4,000 bats in one year alone (2004). I have not even bothered to tally up the total kills to date.

I cannot even fathom the amount of kills that could grow with a 10% increase. I can conceive of more damage done to the environment than the current done by fossil fuels as a whole, to date. (Just to keep things in perspective, mind you). But, your mileage may vary--depending upon with whom you speak. :)
3 / 5 (1) Mar 15, 2010
I'm very pro-nuclear (and pro-reprocessing to minimize waste. There are ways to partially reprocess the fuel to prevent its ready use in a bomb. Not that I think that's likely. Unlike heavy metals used for solar or fossil fuel exhaust, nuclear waste is rigorously contained. It should be used as a helium source. We currently rely on oil wells.) Back on topic; I don't think that wind power will be the savior that some think it will be. But I often wonder why it can't be matched more often with tasks that don't require steady power. Water desalination, for instance.

And if it could be used for that, why not for farming desert areas using rechargable machines. If it were in a place like Arizona, you could use the supports for shade cloth to lessen the sun. Plants reflect IR pretty darn well.

This whole article is just discussing a model, not an actual study. Though it would be interesting if you could generate a very mild hurricane in the tropics and then harvest the wind...
1 / 5 (1) Mar 15, 2010
I am not sure how credit I would give this article. The author has used TW to describe world energy demand. I will accept watt hours, joules, ergs, BTUs or even horsepower fortnights to describe world energy demand. He could have said world power demand is x TW. If Morgan Bettex is confused about the difference between power and energy, perhaps he/she should not be writing about energy for something called physorg. What else in the source publication did he not understand?
I am amazed that no one else noticed.
2 / 5 (4) Mar 15, 2010
The original paper gives both EJ and TW. The summarizer left out the EJ measurements. The Ej measurements are not pertinent to general readership and were likely left out on purpose.

In addition, generative capacity/availability/demand very often is measured by Watts (W), Kilowatts (KW), Megawatts (MW), Gigawatts (GW), and Terawatts (TW), whereas a term like kwH (kilowatt Hour) is often applied to actual consumption. Something like that isn't worth mentioning in such a context.
1 / 5 (3) Mar 16, 2010
Here is a report from 2008 regarding curtailing bat kills on wind farms:


Note that the way to limit the kills is to shut the turbines down during certain times or to lower cut-in time so as not to attact them. Even the report states that for some facilities such practices will impact productivity.

A search for information will show other information regarding kills of wildlife by these monstrosities.

Nonetheless, shutting them down or limiting cut-in time means use of fossil fuels during these times to make up for lower productivity.
3.7 / 5 (3) Mar 17, 2010
...and how many birds are killed by automobiles every day, thousands of times more than wind turbines in a year I'd wager...
1 / 5 (2) Mar 17, 2010
Sure more are killed by automobiles but most of those kinds of birds are along the varieties that multiply like crazy. But, if I am not mistaken, wind turbines get more of the endangered varieties.

Certainly it is alright to kill tens of thousands more birds and tens of thousands of bats because so many flying things die by automobile, right? :rolleyes:

Silly me! I thought the reasoning behind so-called green techologies was to help the environment, not make things worse.

Combined with with all the new bird and bat kills that should be expected, the fact that there is a chance that these devices potentially could make things worse globally to any degree seem to me to make them not so green an option, after all.
3 / 5 (2) Mar 18, 2010
Yet another pathetic comment by dachpyarseville that make each thread he/she/its involved with, degrade in quality and descend to farce.
May be you should reread what you have written, and hopefully you can see the funny side otherwise you just might go insane with shame..
1 / 5 (2) Mar 18, 2010
Cats beat cars!

One domesticated cat kills approx 200 birds per year! Non IPCC peer-reviewed source and therefor more reliable than next week's weather forecast!

Go Green! Ban all pets!
3.7 / 5 (3) Mar 18, 2010
It's interesting to put into context the number of wind turbine attributed deaths. From this document http://www.west-i...ions.pdf
It is plain to see that they account for a tiny fraction of mortalities, summarised here:
We have reviewed reports indicating the following estimated annual avian collision mortality in
the United States:
; Vehicles: 60 million - 80 million
; Buildings and Windows: 98 million - 980 million
; Powerlines: tens of thousands - 174 million
; Communication Towers: 4 million - 50 million
Housecats 100 million
; Wind Generation Facilities: 10,000 - 40,000

I hope no-one is suggesting there is a form of avian apartheid where only the rare and endangered birds can seek out wind turbines..that would be insane... wouldn't it?
1 / 5 (2) Mar 18, 2010
Warning: The comments regarding bird kills and their relative smallness in numbers comes from sources with vested interest in having wind power generators proliferate. Just saying...
1 / 5 (1) Mar 20, 2010
studies like this are utter and total wastes of research dollars that could have been spent on more useful and concrete research. the results of this study are the probabilistic conjecture on the indirect affects of wind farm development on potential rises in temperature 100 years from now.

seems like a nonsense thing to even think about. the answer is " i don't know" nothing more.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.