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    Rethinking Wind Power As The Latest, Greatest Thing
    By News Staff | February 25th 2013 03:13 PM | 23 comments | Print | E-mail | Track Comments

    Activists love wind power the way they once loved ethanol and natural gas - it is good until scientists show them it is not. 

    Claims that there is no upper bound for wind power, that it is scalable because gusts and breezes don't seem likely to "run out" on a global scale, are not based on reality.  And neither are claims that the generating capacity of large-scale wind farms is unlimited. 

    A paper on mesoscale atmospheric modeling in Environmental Research Letters instead found that each wind turbine creates behind it a "wind shadow" in which the air has been slowed down by drag on the turbine's blades. The ideal wind farm strikes a balance, packing as many turbines onto the land as possible, while also spacing them enough to reduce the impact of these wind shadows. But as wind farms grow larger, they start to interact, and the regional-scale wind patterns matter more.

    The generating capacity of very large wind power installations (larger than 100 square kilometers) may peak at between 0.5 and 1 watts per square meter. Previous estimates, which ignored the turbines' slowing effect on the wind, had put that figure at between 2 and 7 watts per square meter.

    In short, we may not have access to as much wind power as thought.

    "One of the inherent challenges of wind energy is that as soon as you start to develop wind farms and harvest the resource, you change the resource, making it difficult to assess what's really available," says co-author Amanda S. Adams, assistant professor of Geography and Earth Sciences at the University of North Carolina at Charlotte.

    Having a truly accurate estimate matters when taxpayer subsidies are being funneled into carbon-neutral energy companies. 

    "If wind power's going to make a contribution to global energy requirements that's serious, 10 or 20 percent or more, then it really has to contribute on the scale of terawatts in the next half-century or less," says co-author David Keith, Professor of Applied Physics at the Harvard School of Engineering and Applied Sciences..

    If we were to cover the entire Earth with wind farms, he notes, "the system could potentially generate enormous amounts of power, well in excess of 100 terawatts, but at that point my guess, based on our climate modeling, is that the effect of that on global winds, and therefore on climate, would be severe—perhaps bigger than the impact of doubling CO2."

    "Our findings don't mean that we shouldn't pursue wind power—wind is much better for the environment than conventional coal—but these geophysical limits may be meaningful if we really want to scale wind power up to supply a third, let's say, of our primary energy," says Keith.

    And the climatic effect of turbine drag is not the only constraint; geography and economics matter too.

    "It's clear the theoretical upper limit to wind power is huge, if you don't care about the impacts of covering the whole world with wind turbines," Keith said. "What's not clear—and this is a topic for future research—is what the practical limit to wind power would be if you consider all of the real-world constraints. You'd have to assume that wind turbines need to be located relatively close to where people actually live and where there's a fairly constant wind supply, and that they have to deal with environmental constraints. You can't just put them everywhere.

    "The real punch line is that if you can't get much more than half a watt out, and you accept that you can't put them everywhere, then you may start to reach a limit that matters."

    In order to stabilize the Earth's climate, Keith estimates, the world will need to identify sources for several tens of terawatts of carbon-free power within a human lifetime. In the meantime, policymakers must also decide how to allocate resources to develop new technologies to harness that energy.

    In doing so, Keith says, "It's worth asking about the scalability of each potential energy source—whether it can supply, say, 3 terawatts, which would be 10 percent of our global energy need, or whether it's more like 0.3 terawatts and 1 percent."

    "Wind power is in a middle ground," he says. "It is still one of the most scalable renewables, but our research suggests that we will need to pay attention to its limits and climatic impacts if we try to scale it beyond a few terawatts."




     New research by David Keith suggests that we may not have access to as much wind power as scientists thought. Credit: Rose Lincoln, Harvard News Office



    Comments

    Ironic you don't consider--even in one sentence--the impact on human life next to those civilized towns where you'd like them to be placed.  I keep praying (yes, I know that's taboo with science nerds) that they keep them from my backyard where my brilliant commissioners deemed over 45db day or night at my house to be fair (they are allowed to be 85db with their loud thumping, so long as it doesn't break an average...and then who do we call at that time, the pinwheel police?!).

    Of course, I'm not one of those fools who believe plant food, aka carbon dioxide, is destroying our planet. 

    Hank
    Impact is subjective - but it isn't science insisting this is a great idea, science prefers nuclear power, it is environmental activists claiming wind power is perfect. You're right, they have never been near one of these.  And in ideal locations, off the coast of Massachusetts, for example, the ideal dies rather fast because it will hurt the quality of life of rich people. 

    Science doesn't recommend you live next to giant electrical towers or a geothermal plant either.
    Thor Russell
    "science prefers nuclear power" - references to modern up to date science please?
    Thor Russell
    Hank
    There's more consensus on nuclear power than there is on global warming. I don't know what you mean by "modern up to date science" - it sounds like 'it is against my world view and therefore I do not accept it'.  If so, you are a perfect candidate for believing wind power will help us all.
    Thor Russell
    What?? Referring to your own book is not impartial science.
    I am a bit surprised that I need to explain what I mean by up to date science. By up to date science I mean studies etc that take the fact that technology changes into account. For example if you say that the speed of a CPU is 100 MHz because it was once that speed, then it is every bit as wrong and anti-science as saying that GM kills everybody. 



    This is one of several references showing how wind has now become competitive with fossil fuels in many situations, even when fossil fuels don't have to pay any pollution tax.
    http://about.bnef.com/press-releases/renewable-energy-now-cheaper-than-n...


    This reference also clearly shows wind as being cheaper than nuclear.

    http://en.wikipedia.org/wiki/Cost_of_electricity_by_source

    Because of technology improvements that you are obviously not aware of, the LCOE of wind has dropped significantly in recent years, meaning that prior beliefs need to be questioned instead of just repeated.


    This isn't just the west, China is building wind far faster then nuclear now:

    http://www.ewea.org/blog/2013/02/chinas-wind-energy-sector-generates-mor...

    Thor Russell
    Hank
    Nothing is impartial if someone wrote it, at least in your postmodernist fantasy land, and yet you think the European Wind Energy Association, an advocacy group, is impartial. Really, there is no point talking to you. I don't care if you hate nuclear power. By all means, put a windvane in your backyard.  I certainly am not going to rewrite an entire chapter in a book for one commenter on the Internet, who is never going to accept the science anyway.
    Thor Russell
    That is ridiculous. I am not post modernist and I am the one that provided multiple references including China which is nothing to do with European advocacy. Wind turbines in the ground producing more power than nuclear in China is not an opinion. To say that it is, is postmodernist. If you think that data is incorrect then show it.
    The whole point about conclusions is that they are based on assumptions and science updates itself to take into account modern data, it is not fixed like a book that is once written, never changed and then "defended" against modern data. I am sure that you are not going to rewrite a chapter in your book, so instead it will give an incorrect conclusion based on yesterdays numbers. 

    My conclusions and ideas are continually updated. For example at present I believe that AGW is worth doing something about, but if worldwide temperatures are flat or go down for two decades then it would obviously change my opinion somewhat. If someone can build a cheap nuclear reactor quickly that there is every indication to believe is safe, I will get behind it. 

    So the question is, how do you update your ideas? What would it take for you to change your mind. If many major sources quote wind as being cheaper than nuclear, in the coming years wind turbines pop up in many countries with different ideologies all around the world in ever increasing numbers and wholesale electricity prices drop then would that change your mind? If you claim your opinion is based on evidence and science, then you need to specify what evidence would cause you to change your mind and what evidence it currently depends on.
    Thor Russell
    MikeCrow
    My conclusions and ideas are continually updated.
    I would find this hard to believe.

    For example at present I believe that AGW is worth doing something about, but if worldwide temperatures are flat or go down for two decades then it would obviously change my opinion somewhat.

    Somewhat? what does that mean? And we're already at 17 years, shouldn't that start to change your opinion already?
    Never is a long time.
    Thor Russell
    It has changed my opinion somewhat. My estimate for the temp affect of 2*CO2 would be higher if it wasn't for that. However the trend is not flat, (the 10 year mean has not been flat for 17 years) the earth is probably still absorbing heat and it is going into the deep ocean. As I have said before I think it is like sin(x) + x, where sin(x) is natural variation (DPO say) and x is CO2. I expect temps will start to rise again toward the end of the decade, but if they don't then I will change my mind.
    Thor Russell
    And here is a link from the federal EIA explaining why there can be no legitimate cost comparison between intemittent unreliables like wind and conventional baseload thermal generation:

    "The duty cycle for intermittent renewable resources, wind and solar, is not operator controlled, but dependent on the weather or solar cycle (that is, sunrise/sunset) and so will not necessarily correspond to operator dispatched duty cycles. As a result, their levelized costs are not directly comparable to
    those for other technologies (even where the average annual capacity factor may be similar)
    and therefore are shown in separate sections within the table."

    http://www.eia.gov/forecasts/aeo/pdf/electricity_generation.pdf

    Real science understands that "energy" is not a replacement for "power".

    MikeCrow
    I'm just glad my electric company doesn't get their pricing info from Wikipedia.
    Ohio First Energy Rates.
    The good news is wind is only about a half cent more per kilowatt hour than a mix of coal, nuclear and probably gas.
    Never is a long time.
    Now how much of that is subsidized?

    If you put regulation after regulation on coal companies, forcing many out and limiting power output, then yes, you will starve the people enough to make wind energy costs look AWESOME, even with all the brown outs and blackouts. Talk to me after 2016 when your energy prices are through the roof, Mr. Coal Country.

    I agree with you so much, Hank, I purchased your book. It looks like that book you co-authored is a book I've been looking for for a long time.

    We know what the human impacts of wind energy can be when sited according to alleged "industry standards":

    http://www.youtube.com/watch?v=5F1cm5I_Ehc

    Didn't any of the proponents of wind turbines ever see a flock of ducks or gees fly? Do they not know why they fly in that fashion? Even the military flies in the slip stream. I will never forget the first time I pulled in behind a semi on a motorcycle. I quickly learned of that effect. Worse yet, there was a recent story about how the wind farms act like a blender and mix up the surface air with the lower atmospheric air creating clouds down wind of the farm. A wind mill on a cabin by the lake miles from the grid is a good idea, one for every home in the city is DUMB.

    Hank
    Yes, that 'night warming effect' is a concern. It isn't that scientists didn't know about these issues, it is just that no one listened. That is the problem when advocacy supplants science.
    This study errs in its assessment of potential wind energy resources by ignoring real-world data and experience and instead relying on crude theoretical modeling techniques. In reality, wind project developers and investors work closely with atmospheric scientists and other experts to make sure that their projects will produce as much as expected, and real-world data from large-scale wind installations in the US and Europe confirms that they do. Regardless of who is correct, the inescapable fact is that America's developable wind energy resources are many times greater than our country's energy needs.

    For more, see:
    http://www.awea.org/blog/index.cfm?customel_dataPageID_1699=21714

    Michael Goggin,
    American Wind Energy Association

    Hank
     by ignoring real-world data and experience and instead relying on crude theoretical modeling techniques.
    We can let the study author tackle that. It is a good thing we have paid lobbyists to show science the error of its ways.
    You wind power lobbyist really have the propaganda down pat, don't you? How much does it pay to send propagandists, like yourself, out to sterilize these different websites? Hopefully your salary comes from some other source than your monstrous machines...although I guess we could just keep printing money. It worked well for Zimbabwe.

    I'll assume from the ad hominem attacks that you have nothing of substance to say on the points I made.

    I understand why you would say such ridiculous things. Money can make people say and do alot of terrible things. Make a community full of turbines, and homes, and invite people to live there of their own free will. Only then, can we get a true assessment of health concerns,( if your tales are to be believed about people "faking it", or the nocebo effect.) Till the pro-wind people do this, and volunteer to be the guinea pigs, you can expect, and deserve in fact, to be fought every step of the way.

    http://www.awea.org/blog/index.cfm?customel_dataPageID_1699=21714

    Fact check: Harvard study misses real-world facts about wind power
    Posted: 2013-02-27 Michael Goggin, AWEA Manager-Transmission Policy

    A recent study errs in its assessment of potential wind energy resources by ignoring real-world data and experience and instead relying on crude theoretical modeling techniques. In reality, wind project developers and investors work closely with atmospheric scientists and other experts to make sure that their projects will produce as much as expected, and real-world data from large-scale wind installations in the US and Europe confirms that they do. Regardless of who is correct, the inescapable fact is that America's developable wind energy resources are many times greater than our country's energy needs.

    Real-world data confirms large wind installations live up to expectations

    The question posed by this research has already been answered with real-world experience, and the answer is that wind works.

    While the study is interesting from a theoretical perspective, it wasn’t necessary to use models when real-world data is available from large-scale wind installations that have been operating and producing as expected for some time.

    In areas like Sweetwater, Texas; the Columbia River Gorge in the Pacific Northwest, and Buffalo Ridge in Minnesota, thousands of utility-scale wind turbines have been installed in relatively densely clustered areas, and wind energy output has not suffered significantly.

    As documented in great detail on pages 41-46 here, the output of wind projects in these and other areas has remained high, despite temporary transmission constraints causing curtailment of some wind generation and also causing wind developers to build in locations with lower wind speeds. As long-needed grid upgrades are completed over the next several years, wind project capacity factors are likely to continue their long-term growth.

    Experts already take wind farm interactions into account

    For a typical wind project, hundreds of millions of dollars in revenue hinge on accurately predicting what the wind output of a potential project will be. As a result, wind project developers and investors work extensively with atmospheric scientists and other experts to develop very precise estimates of wind project output.

    In fact, the American Wind Energy Association (AWEA) hosts a major conference every year devoted entirely to the topic of wind project resource assessment, and it is attended by hundreds of experts who are working on wind project resource assessment. Concerns about some wind turbines potentially reducing the output of other turbines are analyzed carefully in the wind resource assessment process before the project is built, and any concerns are typically addressed by choosing a different placement for the wind turbines.

    The wind industry continues to move to larger wind projects, driven by the economies of scale associated with larger wind projects. Would wind project developers and their investors be risking hundreds of millions of dollars if their experts thought there was any chance that these large wind projects would suffer from significantly lower wind output?

    Other analyses and real-world experience confirm wind is an important clean energy solution

    Other theoretical assessments of global wind energy resources have accounted for wind turbines potentially reducing wind speeds at other turbines, and still found that there are sufficient wind energy resources to meet humanity’s energy needs many times over. The new paper cites two such analyses.

    A potential source of error in the new paper is that its atmospheric model is based on coarse grid cells that measure 10 km by 10 km, which the paper notes tends to underestimate actual wind plant output by: 1) Ignoring that wind turbines will be sited at optimal locations within that 10 km by 10 km cell, and 2) Calculating the sum of the wind energy production for the cell based simply on the average wind speed for the entire cell, when in reality the sum of the wind energy production for the cell would be higher--because wind output is proportional to the cube of wind speed, wind turbines exposed to above-average wind speeds would produce disproportionately more than turbines exposed to below average wind speeds.

    As a hypothetical example to illustrate this second factor:

    Their method: 8 meters/second average wind speed = 8cubed = 512 energy output

    More realistic: Half of turbines at 6 meters/second, half of turbines at 10 meters/second = (6cubed + 10cubed)/2 = 608 energy output

    Even if the analysis in the new paper is correct and the hundreds of experts and real-world data are not, there would still be enough wind energy resources to meet all of humanity’s energy needs. Analysis by the Department of Energy and National Renewable Energy Laboratory conservatively calculates that the U.S. has enough developable, high-quality wind energy resources to meet U.S. electricity needs more than a dozen times over. Even if this conservative calculation were actually optimistic by a factor of several times over, U.S. wind energy resources would still be sufficient to meet all of our energy needs.

    European countries like Denmark, Germany, Spain, Portugal, and Ireland now obtain 10-30% of their electricity from wind energy, without experiencing significant declines in wind output. Most of these countries began with wind energy resources that are 20-50% less productive than the average wind resources in the U.S., and with total wind resources that are dozens if not hundreds of times smaller than the total wind resources in the U.S. These countries currently obtain 3-8 times more of their electricity from wind than the U.S. does, and they are in the process of developing new wind projects that will push their wind use even higher. With the far superior wind resources in the U.S., the sky is the limit.

    Readers should be careful not to draw erroneous conclusions from the paper’s analysis of how massive deployments of wind turbines could slightly affect the mixing of air in the atmosphere. The paper makes it very clear that this localized movement of air “is very different than warming due to greenhouse gases, in that the warming is primarily local, depends on the stability of the atmosphere, and has a finite limit locally in magnitude due to the depth of mixing occurring.”

    Most importantly, readers should not confuse the simple act of moving air around, which has no impact on the heat balance of the Earth, with global warming that is caused by the introduction of long-lasting greenhouse gases that continually alter the Earth’s energy balance. It is also important to keep in perspective that nearly all human activities, such as planting crops, building cities, managing forests, and even operating nuclear power plants, can have localized impacts on movements of air.

    Regarding land use, DOE has conducted detailed analysis that found that obtaining 20% of U.S. electricity from wind energy would use less land than is currently occupied by the city of Anchorage, Alaska. In fact, the report noted that the 100,000 to 250,000 hectares of land that would be used to obtain 20% of our electricity from wind is significantly less than the 400,000 hectares of new land that is disturbed every year in the U.S. to mine coal for electricity production.

    Related articles:

    Study's lead author: News reports on wind and temperature 'misleading', May 1, 2012

    Fact check: Flawed science journalism on wind energy, April 30, 2012

    Fact check: Forbes blog notes study on wind's limits, but not detailed critique, July 14, 2011

    Hank
    Yes, yes, yes, you get paid to make sure you get your subsidies stay in place and go up. None of this rebuttal is even remotely scientific. Casting doubt on a study is easy, just say the conclusions are 'erroneous' and that's that. But what none of you do is create any actual studies of your own, you just cherry pick data you already have. 

    I have defended wind power from claims it causes health issues, etc. because that is also not evidence-based. But goofy claims like 'Awesome X country subsidizes wind a lot more than we do, we need to fix that' is not really helping your cause.