A rumor in my region states that a wind turbine consumes far more energy while being built and setup than it can produce in a lifetime.
The debate is about modern, freshly built turbines in Southern Germany.
Is there evidence that this is true?
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4I'm not sure this is a "notable" claim– user23048Commented Apr 26, 2017 at 13:43
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10Is your region a coal-producing one by any chance? I've heard recent claims that the costs of coal due to environmental damage, health problems, and early deaths is far greater than the value of the energy produced. I'm sure it matters what kind of coal is burned, though. In any event, this could be an attempt to co-opt that argument and turn it around.– JimmyJamesCommented Apr 27, 2017 at 19:48
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26It's absolutely true, if you forget to build them outdoors.– userLTKCommented Apr 28, 2017 at 11:38
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15Rule of thumb: the energy cost to build something, is passed on in the purchase price. Nobody would buy wind turbines if their purchase cost more than they'd ever be able to earn back.– HobbesCommented Apr 29, 2017 at 8:12
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9@Hobbes You forget we live in a world of government subsidies and decisions based on hope and moral ideals instead of math. Never under estimate the raw power of human stupidity. However, nice and objective as the math is, that doesn't mean we are immune to creative accounting shenanigans. Always look into who did the math.– candied_orangeCommented Apr 30, 2017 at 22:25
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3 Answers
The Guardian cites a 2010 study that found:
the average windfarm [sic] produces 20-25 times more energy during its operational life than was used to construct and install its turbines. It also found that the average "energy payback" of a turbine was 3-6 months.
Wikipedia has a graphic that is based on another 2010 study showing similar numbers:
The German federal environmental protection agency says that wind turbines produce back the amount of energy that was consumed during production after 3 to 7 months.
Siemens analyzed its wind turbines and found that the energy amortization period is about 5 months for onshore facilities and about 10 months for offshore farms. This considers not only the cost to produce the turbines, but the entire lifetime energy cost, including maintenance, dismantling, etc.
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11Have they counted in the additional costs on network due to unforseen changes in energy production? I.e. overproduction when winds come and underproduction when wind calms down? Have they count in the need of backup plan for sudden coverage of power drop (maintaining peak hydro+Coal both ready to switch on)?– CrowleyCommented Apr 25, 2017 at 16:17
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141@Crowley Probably not. Also probably not the incalculable cost of nuclear waste storage for fusion, or the destroyed landsapes for coal. The question was about a wind turbine and the energy being consumed to build and setup that specific windmill Commented Apr 25, 2017 at 17:02
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20In the interests of properly informing comparisons against conventional energy production, note that this is 2010 data. Photovoltaic has improved quite enormously since then. I'm not sure whether the improvements in wind turbines have been quite so meteoric, but they've also definitely improved (bigger usually equals better better for wind, and they're a lot bigger today! ) I'd also like to know what figures are used for the life expectancy of the various types of generating plant. To a fair approximation, double the life and you double the energy return.– nigel222Commented Apr 25, 2017 at 18:09
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36@HagenvonEitzen I think you mean fission, not fusion? (I only wish we had viable fusion power already!)– Doktor JCommented Apr 25, 2017 at 21:08
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7@nigel222 not according to this: goo.gl/mtJ8jp ... a photovoltaic cell's output does decrease over time, depending on UV exposure and physical stresses. At the 50 year mark, a PV cell may only be outputting ~50-80% of its original output regardless of the "seals". Granted, this is still a pretty great ROI, and as we improve the efficiency of PV cells themselves as well as PV cell recycling it only gets better!– Doktor JCommented Apr 25, 2017 at 21:14
Given there's much talk about the 2010 study, here's a 2013 one. It mainly expand the other one, by:
"Tweaking the lifetime": very low ones were assumed for conventional plants (also including deprecated centrifugal enrichment tech for nuclear)
"Counting all output", even if not needed: i.e. including the need for buffering (aka "backup" in case of variable energy sources)
With respect to just wind power, we can see they offer a similar mean figure of around 16~19 (which as Weißbach notes is massively dependent on the place turbines are built). If you consider the aforementioned later caveat, this gets double halved, but still we are quite above "energy sink" levels.
Further anyway (depending on whether your actual point is about wind energy in general, or "to be built new turbines") EROI further scales up, given most common newer installations average size is almost two times an E-66.
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1Your source notes that these are energy costs and outputs, not monetary costs, which can be entirely different. So instead of computing the raw EROI, as in the graph above, it can be more useful to consider the exergy equivalent, by weighting both the energy inputs and energy output by a factor of 3 when the energy type is electrical. Commented Apr 28, 2017 at 9:12
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8Also, using GDP for economical viability is flawed as it ignores environmental damage (and resulting loss of health and tourism). Commented Apr 28, 2017 at 9:43
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5@Cees Timmerman if you open it that was done (called EMROI). It doesn't include externalities, but if any those would just lower fossils I guess. We were talking about raw energy i/o on the other hand so that's why I didn't mentioned it.– mirhCommented Apr 28, 2017 at 12:34
The roi depends on the windmill, and it could be bigger than 3-6 months. For example, if the windmill operates in colder regions, "the additional cost of such a system [de-icing] can be compensated by additional production within 2-3 years of operation." Source http://www.elforsk.se/Global/Vindforsk/Survey%20reports/12_13_report_icing.pdf
Of course, a wind turbine could be deiced by different means, like for example using hot water sprayed from a helicopter, but the savings on the initial building costs are translated to higher operational costs. For a one time de-icing "costs will be recovered within 48 hours compared to a reduced or no production."
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4Welcome to Skeptics! I understand that some wind turbines are going to be slower to pay back than others, but you haven't covered the general case here. From your answer, it isn't clear that any will ever pay themselves back.– Oddthinking ♦Commented Apr 26, 2017 at 13:38
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Interesting article but I wish they sourced the 2-3 years. By waiting for a warm day they could de-ice it for free. Also I thought you were joking about the helicopter hot water spraying Until I saw the pictures in the second document.– danielCommented Apr 27, 2017 at 9:34
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1This answer is pretty cold area centric, one of the links says in the coldest parts of the USA turbines are only effected by icing ~5% of the time. I'm sure if you asked about de icing in Australia they would ask you what ice was. Building in extreme cold or low wind areas could return less energy than invested, but it would not make any money so no one wants to do it.– danielCommented Apr 27, 2017 at 13:03
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1@daniel Not necessarily. Consider the agriculture subsidies link: "The Agricultural Adjustment Act (AAA) was a United States federal law of the New Deal era which reduced agricultural production by paying farmers subsidies not to plant on part of their land and to kill off excess livestock." In essence, a noncompetitive farm would still make a profit. Note that I'm not saying that this is the case here, I am just speculating on both OP's and Jason's questions on why an unprofitable wind turbine would exist.– ctapusCommented May 2, 2017 at 12:45
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1@ctapus I'm talking about a power generation company maximizing their profit by choosing to put a windfarm in a viable area so they can sell power. That said there are cases where the decision makers goof up, or choose feelings over logic: bbc.com/news/uk-wales-24844182– danielCommented May 2, 2017 at 14:06