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Earth Power

Study Suggests Generating Capacity of Wind Farms At Large Scales Overestimated 209

Posted by samzenpus from the battery-half-empty dept.
First time accepted submitter AchilleTalon writes "Research by Harvard professor David Keith suggests that the global capacity for energy generation from wind power has been overestimated, and that geophysical / climate effects of turbines will reduce the benefits of large-scale power installations. 'People have often thought there's no upper bound for wind power—that it's one of the most scalable power sources," he says. After all, gusts and breezes don't seem likely to 'run out' on a global scale in the way oil wells might run dry. Yet the latest research suggests that the generating capacity has been overestimated."
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Study Suggests Generating Capacity of Wind Farms At Large Scales Overestimated More

Study Suggests Generating Capacity of Wind Farms At Large Scales Overestimated

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  • 'People have often thought there's no upper bound for wind power—that it's one of the most scalable power sources," he says.

    What?! I've been lied to! My father poured foundations for windmills in my hometown and I've been going around saying that they're a great resource for us to have and boy do I feel like I've been duped! Let's read this whole news article and find out all the other lies I've been spouting!

    "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."

    Okay so you write that as your last sentence in the entire article? Crawl in a hole and die. Please. Whoever wrote this news article and summary, please go die. I'm sure the professor's research is sound but the way this press release of it was laid out painted wind as a mythical source of energy so please just do us all a favor and die.

    So a few terawatts is what, like 7% of our total energy needs? Okay, let's scale it up to there and then we'll have empirical evidence to support how far we should go.

    I don't think anyone suggested we blanket the Earth in windmills or even that wind is the basket into which all of our apples should go but, looking at the high wind areas next to metropolises, you have to admit there's some low hanging fruit out there, yeah?

    • > looking at the high wind areas next to metropolises, you have to admit there's some low hanging fruit out there, yeah?

      Um, typically metropolises aren't built next to high wind areas. Usually high wind areas are where people don't want to live.

      Also, what happens when there's fine weather for a week... You just get people to switch everything off? You can't just turn off and on nuclear/thermal all the time.

      Wind is OK when you can balance it with hydro power, otherwise, it's crap.

    • Re:Ah, Let's Read the Whole Article, Shall We? (Score:5, Informative)

      by jamesl ( 106902 ) on Monday February 25, 2013 @06:03PM (#43009293)

      The costs for a utility scale wind turbine in 2012 range from about $1.3 million to $2.2 million per MW of nameplate capacity installed.
      http://www.windustry.org/resources/how-much-do-wind-turbines-cost [windustry.org]

      Say, a dollar per watt (nameplate).

      An installed nameplate terawatt would cost about $1,000,000,000,000. That's a pretty expensive experiment. And wind turbines' real world average output is a fraction of their nameplate rating.

      The total levelized cost of an advanced combined cycle natural gas fired plant is about one third less than onshore wind and 80% less than offshore wind.
      http://en.wikipedia.org/wiki/Cost_of_electricity_by_source [wikipedia.org]

      • Yes, but that doesn't include the cost of obtaining fuel.

        • Re: (Score:2)

          by jamesl ( 106902 )

          Yes, but that doesn't include the cost of obtaining fuel.

          And that's why we link to sources. But rather than follow the link, some people prefer to showcase their ignorance.

          Levelized Energy Cost (LEC, also known as Levelised Cost of Energy, abbreviated as LCOE) is the price at which electricity must be generated from a specific source to break even over the lifetime of the project. It is an economic assessment of the cost of the energy-generating system including all the costs over its lifetime: initial inve

          • Note, "cost of fuel."

            And by what means does that calculation include the external costs of burning fossil fuels such as natural gas, releasing CO2, and the hydraulic fracturing that made the gas artificially cheap to begin with?

            • Re: (Score:2)

              by jamesl ( 106902 )

              I know this was an oversight on your part, but you failed to include a link to an authority on those external costs, including numbers. What does "artificially cheap" mean?

              While you're working on that, you might think about what raising the cost of energy will do to the world's poor -- those living on less than one US dollar per day.

    • Low hanging fruit indeed, and a possible source of PRIMARY power for rural residents, there's just one downside... the financial feasibility. The problem with wind power is there's not always wind, and if there's no wind for a week and the batteries drain, you need a fallback, which means regular electricity needs to get laid out to the rural houses anyways, costing the builder of the windmill, & the electric company, who are then going to pass it on to the owners.

      Would you add $50 to your electricity

      • Re: (Score:3)

        by dwywit ( 1109409 )

        It's not that black and white. Each installation needs its own specification. You go for a mix of technology. It's not JUST wind - you can put in some PV panels, and a wind turbine, maybe even a water turbine, maybe a fuel cell. Some places have good wind, many don't. Most places in tropical/temperate zones have reasonable or good solar resources, and some don't. Some places have permanent running water, most don't. And you don't design an off-grid system without a backup generator - yes, they use fossil fu

  • Old news (Score:4, Interesting)

    by Tailhook ( 98486 ) on Monday February 25, 2013 @05:12PM (#43008663)

    The UK already figured out that wind power claims are exaggerated [bbc.co.uk]. By a lot. "Fuel poverty" [bbc.co.uk] is now an 'issue' that appears regularly in the UK press. It's killing people [thesun.co.uk].

    Don't believe any of it; they're all oil company shills. Yay saving the planet.

    • Re: (Score:2)

      by tragedy ( 27079 )

      The UK already figured out that wind power claims are exaggerated [bbc.co.uk].

      The article you quote there says:

      Statements made by the wind industry and government agencies commonly assert that wind turbines will generate on average 30% of their rated capacity over a year, it said.

      But the research found wind generation was below 20% of capacity more than half the time and below 10% of capacity over one third of the time.

      This seems like an exercise in how to lie with statistics. If you're below 20% half the time, you're obviously not below 20% the other half of the time, which makes your average necessarily higher than 20%. Of course, it does say "more than half the time", but how much more? Also, it doesn't actually directly contradict the 30% average figure, which you would think it would if it had actual findings that contradicted that figure. About the best this study seems to be able to

  • In other news (Score:3)

    by Dishwasha ( 125561 ) on Monday February 25, 2013 @05:12PM (#43008671)

    A new study confirms that coal and petroleum are in fact still finite resources.

  • Boundary effect (Score:3)

    by mudshark ( 19714 ) on Monday February 25, 2013 @05:17PM (#43008701)

    Given the fact that power generating wind turbines only poke up 30-50m from the surface, I fail to see how the effects are going to be as significant as Keith suggests. Surface winds are already moderated by friction and topographically generated turbulence, while the vast bulk of wind energy exists above the boundary layer. We're unlikely to deploy large wind farms in a linear sequence anyway, so atmospheric coupling means surface winds will only be affected for a finite distance downstream of a given facility.

    • The problem you're running into is the difference between energy and power. While it's true that the moving air above the surface contains energy, what is actually useful is the power that is taken up by the air mostly from solar heating, and is ultimately dissipated to friction at the boundary layer. This is the resource that is limited.

    • "Given the fact that power generating wind turbines only poke up 30-50m from the surface, I fail to see how the effects are going to be as significant as Keith suggests."

      This is the guy who suggested injecting a huge cloud of ash into the atmosphere to deflect sunlight and heat.
      He has many strange ideas.

      http://www.ted.com/talks/david_keith_s_surprising_ideas_on_climate_change.html [ted.com]

    • Given the fact that power generating wind turbines only poke up 30-50m from the surface, I fail to see how the effects are going to be as significant as Keith suggests. Surface winds are already moderated by friction and topographically generated turbulence, while the vast bulk of wind energy exists above the boundary layer. We're unlikely to deploy large wind farms in a linear sequence anyway, so atmospheric coupling means surface winds will only be affected for a finite distance downstream of a given facility.

      I didn't see where he made any dire predictions about the effects, other than an out of hand comment about what might happen if you covered the entire earth with windmills. Clearly he is not suggesting we are anywhere near that.

      His whole point is that these turbines are packed too densely, and the front ones are shadowing the rear ones, and this fact seems to have been missed when people were making promises about the efficiency of large wind farms. Yet it is easily measurable by reading the output power

    • Re:Boundary effect (Score:4, Informative)

      by Charliemopps ( 1157495 ) on Monday February 25, 2013 @06:02PM (#43009287)

      Your conception of large wind-farms is out of whack. Modern turbines are pushing 200 meters tall now, with rotor diameters of up to 150 meters. Turbine farms are limited by the area of land they're placed on, and the wake of other turbines greatly affect placement. On small farms they can get them as close to each other as 4 to 10 rotor diameters, but on bigger farms the minimum is 15x the size of the rotors. So if we're talking about real industrial scale wind farms where the turbines are in the 200 meter tall range... then they have to be placed over a mile apart!

      A single one of these modern giant turbines produces about 7MW of power and costs about $14 million to build. The smallest reactor in the US (not counting test reactors and such) is in Fort Calhoun, Nebraska and produces 478MW. It would cost close to a Billion dollars and take up nearly 70 square miles of land to use wind to produce the equivalent amount of power as the smallest nuclear reactor in the country.

      We have absolutely no idea what affect a windfarm of that size would have on the environment. If we had enough farms to power the entire country? Again, we have no idea, but the effect would likely be dramatic. You can't take that kind of energy out of our weather systems and expect mother nature to roll over and take it.

      • Re:Boundary effect (Score:4, Informative)

        by TubeSteak ( 669689 ) on Monday February 25, 2013 @09:21PM (#43010819) Journal

        It would cost close to a Billion dollars and take up nearly 70 square miles of land to use wind to produce the equivalent amount of power as the smallest nuclear reactor in the country.

        We have absolutely no idea what affect a windfarm of that size would have on the environment. If we had enough farms to power the entire country? Again, we have no idea, but the effect would likely be dramatic. You can't take that kind of energy out of our weather systems and expect mother nature to roll over and take it.

        We've deforested far larger chunks of land without causing blood to rain down from the sky,
        and there are multiple countries that have re-forested areas larger than 70 square miles.

        China is aggressively planting trees everywhere it can. Since Y2k, they've added ~11,500 square miles of forest per year.
        Part of those 11,500 square miles of forests are an attempt to stop the Gobi desert's southern and eastward creep.
        China's been doing a shitty job with their foresting efforts, but 70 square miles is childs play compared to what's happening around the globe.

        • Last time I checked, trees weren't 200 meters high and scientifically engineer to suck as much energy out of wind gusts as physically possible.

          Also... have you ever heard of the dust bowl? That was just grass we pulled up... and that turned into the greatest ecological disaster in human history.

        • Re: (Score:2)

          by jez9999 ( 618189 )

          So your logic is, "we cut a bunch of trees down and got away with it so it must be OK to do more of it. This effect is further mitigated by the fact that elsewhere, things are even worse"?

      • Re: (Score:2)

        by tragedy ( 27079 )

        So, a few questions spring to mind. How expensive was the nuclear reactor in question? Was it more or less expensive than the equivalent capacity in wind turbines? What are the fuel and operating costs of the nuclear reactor, and are they greater or less than the operating expenses for the equivalent capacity in wind turbines. What, aside from generating power, is done on the two square miles of land the Fort Calhoun plant takes up and how does that compare to the 70 square miles for the wind turbines on wh

    • Re: (Score:3)

      by fermion ( 181285 )
      It depends what large scale deployment means. In many areas the near ground level wind energies are not significant. If we are to harness wind energy, it will have to be at higher altitudes.

      Which is really why as we move forward we have to have a much more diverse view of energy. Right now most countries have a majority producer, be it coal or nuclear or natural gas or whatever. This is most likely due to political pressures, rather than rational thought. In large countries like the US there is going

  • 1-2 watts per square meter of land? (Score:5, Informative)

    by Animats ( 122034 ) on Monday February 25, 2013 @05:24PM (#43008779) Homepage

    I had no idea wind power produced that little power.

    Biggest single wind farm in the world: Alta-Oak Creek Mojave Project, 320 wind turbines, 36 km^2 area, 800 MW. That's 800MW for 36 million square meters, or 22W/m^2. That's peak power, though; yearly average for most wind sites runs about a quarter of peak.

    A real problem with wind power is that it's like water power - there are a limited number of good sites. There are four really good wind power sites on shore in California, and there are big wind farms on all of them. Anywhere else is less cost-effective. There's good wind from the Texas panhandle north to the Canadian border, but not much there to use the power. (Basic truth: if it's a good wind power site, it's too windy for most people to live there.)

    And, of course, there's the intermittency problem. Here's California's wind power graph for today. [caiso.com] Note that total statewide wind output went up by a factor of 7 in 2 hours, after dropping by a factor of 4 in 5 hours. California buffers some of this by using the dams and pumps of the California Water Project as energy storage, but still, that's a huge variation. Extra generating plants have to be on standby for when the wind dies down. Up to about 15% wind, there's enough slack in the system to handle that. Beyond that, somebody has to build extra plants or energy storage.

    Solar is more predictable. Solar energy and peak air conditioning load track closely. A reasonable goal is to get most of the world's air conditioning load onto solar power.

    • "Solar is more predictable. "

      Indeed, half the time it's pitch black and we know the exact minute it happens, not that it helps energy-wise knowing that in advance.

  • Quote TFA:

    Keith's research has shown that 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.

    Seriously, you have to wonder how this effect was over-looked by the original engineers.

    Yet there appears to be hope. When you look at large windfarms [google.com], you will see the older ones were built much more densely than the modern ones, which endeavor not only to place turbines in the gaps between other turbines, but also leave more room between the towers as well as using towers of varying heights.

    It would appear that simply reading their meters, the engineers are realizing that densely packing turbin

    • Re: (Score:2)

      by bbn ( 172659 )

      Those pictures of wind farms in California are interesting. Compare to pictures of danish wind farms [google.com]

      Totally different strategy.

      However I would like to believe that neither american nor danish engineers are idiots. The windmills are likely placed in the most optimal way according to the landscape and economics.

  • We're not going to replace all our generating capacity with wind. Or solar. Or wave. Or hydro. Or biofuels. None of them are even close to the scale of hydrocarbon energy as we use it now, nor will they ever be.

    If we manage to build about 2500 nuclear plants ( http://en.wikipedia.org/wiki/Cubic_mile_of_oil [wikipedia.org] ) over the next 50 years, and get batteries worth a shit, we might be able to replace hydrocarbon energy in a useful way, particularly if new nuke plants run on relatively safe, common, thorium, however,

    • Even if that nuclear option happens you'd get a electricity availabilty curve that looks like a great big staircase as very large units come on and off line due to demand. A small unit, such as a windmill, may be more expensive per MW but it's a hell of a lot cheaper than bringing a large steam turbine online in a nuclear plant or whatever when you only need a few MW.
      Wind etc are competing in the peak load space with things like gas turbines and even diesel instead of in the base load space with hydro, coa
  • That's the whole proposal of a Dyson Sphere is to capture all of a sun's energy because it is limited. At present there are three primary sources of power, nuclear decay, solar and gravity. Nuclear decay has issues and it will run out one day whether it's several hundred or several thousands years. Solar is limited mostly by the Earth's surface area and cloud cover. Orbiting mirrors and collectors could potentially expand it in the future making it the only source that can be increased without off world min
  • Notice it didn't state above what his field actually is, so keep in mind that this is coming from a Professor of Public Policy and not an expert on air flow, wind powered electricity generation, or really anything to do with the topic at all. He may have picked up a few things but I'd say take his advice with a truckload of salt and get a second opinion from somebody that has put their feet on that bit of ground.
    There's a tendency to accept words from anyone with an important title in anything so long as i

  • "Research by Harvard professor..." Who cares where he does his armchair science from? The real research is being done by building windmills around the world. Has there been a documented lessening of windflow anywhere as a result?

    "as wind farms grow larger, they start to interact"
    So don't build them too close together?

    "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,

  • In many cities and suburbs drying clothing and linen outdoors is forbidden due to esthetics. Instead the electric driers are used, which convert water is vapor first and then condensing vapor on a refrigerated greed. It takes a lot of energy as the physical state of water changes twice: liquid into gas, and then again gas (vapor) into liquid.

    The problem of esthetics could be solved by designing an esthetically acceptable outdoors drier. It means 7 billion people could daily dry clothing and linen outside

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