2012-06-27

Co.Exist

Size Does Matter: Bigger Windmills Are Better

A new study finds that building one giant wind turbine is a lot better than building a whole field of small ones. Prepare for a future of monster wind power.

Thirty years ago, before wind power was considered a viable alternative to coal, gas, and nuclear, the average turbine measured something in the range of 50 feet in diameter. These days, wind turbines approaching 500 feet are common, and the plan in the next few years is to take the engineering beyond 1,000 feet.

The reason for this expansion is simple: economics. Bigger turbines produce more electricity. And it’s cheaper to build, install, and maintain one big machine than several smaller ones. Moreover, the opening of offshore sites, particularly in Europe, means there is more space for bigger machines, and hence more demand for manufacturers to think big.

General Electric is currently working on a 15 MW turbine with three times the capacity of most large turbines in operation (most are smaller than that). Part funded by the Department of Energy, the design uses superconducting magnets usually seen in MRI systems in hospitals.

Economics may not be the only reason to go big, though. A new study from researchers in Switzerland argues that larger turbines are also more environmentally sound, because you get more electricity for less manufacturing, transportation, and installation effort (and hence fewer carbon emissions).

Reviewing 12 previously published turbine lifecycle assessments, and European power statistics, the paper finds that for every doubling of turbine capacity, "global warming potential per kWh was reduced by 14%."

"You get a scaling factor that’s been known to happen for the financial aspects," says lead author Marloes Caduff, at ETH Zurich. "The less material you have, the less environmental impact you’ve got from producing the steel, the concrete, and so on. And you’ve got less disposal impact as well."

The paper notes that manufacturers are generally able to produce larger turbines more efficiently than before, lowering the environmental impact. "The more turbines that are produced over the years, the better they are produced. There are fewer carbon emissions," Cuduff says.

Before concluding that bigger wind turbines are always greener, though, there are several reasons for caution.

First, the study only looks at on-shore machines, and then only of a certain size--between 12.5 meters and 90 meters (41 to 295 feet).

Second, the researchers’ model uses "generic" distances for the transportation of raw materials to the manufacturing plant (62 miles by truck, and 124 miles by train), and for the finished product to the installation site. In real life, of course, these distances vary greatly. (The study also makes important assumptions about wind shear).

Cuduff says bigger and bigger turbines could, in fact, turn out to be relatively less environmental.

"There may be other factors that make it not so good. For example, maybe you need much larger foundations, because the force working on the turbines is much larger. That may mean you might get less green again, because you need more materials in the foundation, and more structural stability," she says.

"There is probably an environmental optimum, though we didn’t look into that in the study."

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6 Comments

  • Croatoan2

    The power of a capitalist system is in the inevitable redundencies.
    Our transportation systems in large urban areas usually rely on several distinct public transportation systems so a workers strike does not have to stop all commerce. Trollies, urban rail, Bus systems, etc. The Soviet system fell because "why should workers do redundent work?" Only need one sysytem. Let the other manpower build toasters. Then, it happens again. The soviets could build plenty of toasters (for example) but they had no infrastructure for distribution because they wouldn't waste there prolateriats in redundent labor. Capaitalism is a system of distribution with several sources all active and WORKING to get the toasters in Grandmom's kitchen.
    My point: Why not allow "mom and pop" electric generation companies occur? Geo thermal, wind, tidal, solar, etc. Its our system. Let it run.
    Lets be redundent and see what the windpower people can do, the solar people etc.
    We have redundent mail with fed ex and UPS and our Postal System. Let one fail and our vigor as a capitalist can take the punch. The Soviet system was incapable because it wouldn't waste its workers potential in redundency.
    Look at the space program now with capitalists AND Russia and more involved? Wouldn't it be better to have just one so when the shuttle crashes Russia (they're in the soup) handles all resupply and transfers of astronauts for five years. Redundency. Thats important.

  • cynthia wick

    Wind in fact is not plentiful onshore in the northeast. If you look at the national renewable energy lab wind map (our government)  we aren't even at the minimum level to use sense of wind turbines. Our governor changed the way that all is calculated. So the fact is the northeast does not have the wind resource onshore. This is all tied up with corporate interests GE, Exxon and foreign corporations coming in for the big subsidies and using their tax breaks for guess what...fossil fuels. On the other hand solar is a smart alternative energy for the northeast and will not devastate our forests. Breezes in the Berkshires do not in fact mean that wind is plentiful for turbine use. Go on our website PreserveOurBerkshires and you will learn so much about it. The trend by the way all over the world is that it is the emperors new clothes. Europe is completely rethinking their use. Activist groups all over the world are reporting the medical effects of living next to them. In Lenox we did a study with three pro wind and three anti, for our ridge and it was unanimous that the resource was not there, that it made no fiscal, environmental or renewable sense. Instead we opted for building a solar field. You can also see that report on our town's website. This is not about not improving our country but finding smart alternative energies that make sense  instead of spending hundreds of millions of tax dollars, filling corporate pockets, and doing nothing to help global warming. Wind power cannot cut down on our dependence on fossil fuels. The impacts and costs far outweigh that as a remote possibility. So important to really understand the facts. I was a surprised as you might be once you start to read not the propaganda, but the true facts about industrial wind. 

  • Judgeforyourself37

    WInd is plentiful, especially here in the Berkshires. Why not make use of this for an additional power source? Why, oh, why is this country and this area, in particular, so backward. Other countries utilize wind and water power to a greater extent than we do.
    I know, some of you will tell me to "get out of the US if I don't like it." I do like it I love this country, and have for over 75 years, but we can improve. We can improve our educational system, which is 17th among other developed countries. We can improve our medical system that does not give our citizens the length or quality of life that is enjoyed in other developed nations. Why do we have to have such a huge military budget, and a huge budget for the CIA? The huge CIA budget pays for obscenely highly paid contractors who are protected with more vehemence than our military personnel and are doing what our military should be doing. Just because you love a country does not mean that the country cannot be improved.

  • cynthia wick

    This article is baloney.  Industrial wind does NOTHING to prevent global warming. Not one coal or gas plant has ever been shut down because of industrial wind. This is more false publicity from the wind industry. The large scale wind turbines have a major environmental impact, health impacts, are not cost effective, and are fueled by massive subsidies from our government. Our tax dollars wasted. I am astonished that Berkshire Daily has published this false article and published none of the important informational articles about big wind in the Berkshires. 

  • ThinkThoughtThunk

    Judge--37

    Only the most gullible amongst us believe the wind industry's propaganda that wind power can cut down dependence on fossil fuels.  Instead of taking that on faith (as though this was a religious pursuit) please cite the scientific study or studies showing that wind power has that capability. (Hint: There aren't any that are based on real data.  The real data shows the opposite.) 

    What you may find whilst vainly searching for those studies is the unfortunate truth about intermittency, capacity factors, capacity values, and density that tell the real story of wind generated electricity's ability to replace fossil fuel generation of electricity and positively impact the fight against human created climate change. 

    With respect to the industrialization of the Berkshires, I am proud to be "backward" if by "backward" you mean that I cherish the natural world for what it is and would never support the wholesale destruction of the wildlife habitat on our ridges for a few measly kilowatts of big-screen-TV juice.

    Cynthia

    You say you are astonished.  I am merely resigned to the superficial coverage of our local media.  Well at least the author of the study, Cudoff, admits that "bigger and bigger turbines could, in fact, turn out to be relatively less environmental. "  In other words, our paper doesn't say anything!! lol

    Here is the scale of a 3-MW turbine put into perspective...

  • Judgeforyourself37

    However, Cynthia, wind power could cut down on our dependence upon fossil fuels, which do pollute. Even the so call clean coal does pollute and it poses huge risks for the miners due to the fact that the owners of those mines eschew the safety standards that are now, and always have been sorely needed.