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Power Earth

12 Small Windmills Put To the Test In Holland 510

tuna writes "A real-world test by the Dutch province of Zeeland (a very windy place) demonstrates that small windmills are a fundamentally flawed technology (PDF of tests results in Dutch, English summary). Twelve much-hyped micro wind turbines were placed in a row on an open plain. Their energy yield was measured over a period of one year (April 1, 2008 — March 31, 2009), the average wind velocity during these 12 months was 3.8 meters per second, slightly higher than average. Three windmills broke. The others recorded ridiculously low yields, in spite of the optimal conditions. It would take up to 141 small windmills to power an average American household entirely using wind energy, for a total cost of 780,000 dollars. The test results show clearly that energy return is closely tied to rotor diameter, and that the design of the windmill hardly matters."
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12 Small Windmills Put To the Test In Holland

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  • by zonky ( 1153039 ) on Sunday April 19, 2009 @04:41PM (#27639151)
    rather than 141, if you used the Montana.
    • by Kjella ( 173770 ) on Sunday April 19, 2009 @05:32PM (#27639547) Homepage

      Which is also the biggest by far, 5m in diameter. The trend was very clear, despite the obfuscation with efficiency, cost and integer number of windmills all rolled into one. The bigger they are, the better they work.

      Commercial 18m: 190000 / 143000 = 1.3 Euro/kWh
      Montana 5m: 18508 / 2691 = 7 Euro/kWh
      Skystream 3.7m: 10742 / 2109 = 5 Euro/kWh
      Passaat 3.12m: 9239 / 578 = 16 Euro/kWh

      And the crappiest were even smaller, though I'm not going to bother to do the math for them. In other words, none of these are worthwhile unless you absolutely can not throw up one big windmill instead of five small.

      • by TinBromide ( 921574 ) on Sunday April 19, 2009 @05:52PM (#27639733)
        *cough* Hmm, sounds interesting, but don't current US customers pay 5-20cents per kWh?

        I'm just gonna set this [] down and back away while people flame me for endorsing coal/oil/nuclear based electricity.
        • Re: (Score:3, Insightful)

          by pimpimpim ( 811140 )
          In europe you pay 20 eurocent per kWh at least. This is only going to go up in time. Cost per windmill-kWh will go down due to higher efficiency of future models and longer lifespan. This will converge eventually.
      • Re: (Score:3, Insightful)

        Hmm, maybe I'm missing something since I can't read Dutch but why is this not completely obvious even without this experiment? The bigger they are, the more wind they catch. Sure the small ones are going to be somewhat cheaper but it seems like it's only a matter of the scale of the parts (such as bigger blades or whatever) so the cost is not going to be all that different.
      • Re: (Score:3, Informative)

        by polar red ( 215081 )

        Commercial 18m

        currently, windmills of 2Mw are being installed everywhere. those have 80m diameter, So that 18m one is a very small one.

      • by Anarchitect_in_oz ( 771448 ) on Monday April 20, 2009 @04:05AM (#27642769)
        So the Skystream at 3.7m and 5 Euro/kWh produced enough energy to power 2/3 of an average house. So how close does that come to powering a full remote house who are use to being careful about power. So remote farmhouse in Australia where the neighbour aren't close enough to share a single tower it sounds like this might be an ideal product. Add say gas or good old plain timber burning to cover demand load like cooking and heating a small generator to cover shortfall or emergencies and you have a solution this product suits. Yes wind in built up areas isn't a solution. Yes small turbines when you have distribution density to work with ins't a solution. But doesn't mean these products are useless.
  • While I agree... (Score:5, Interesting)

    by Maxo-Texas ( 864189 ) on Sunday April 19, 2009 @04:42PM (#27639159)

    and even argued that sea based windmills would be inefficient recently (I think they will be attacked for their parts and be big targets if there was a war and I think maintenance in a high saline environment will be higher than they think)...

    I do have to point out that
    * any supplemental power comes off of the most expensive part of your bill (I pay more over 250kwh, and a whole lot over 750kwh).
    * the more windmills we build, the cheaper it will get to make them.

    Still- I think nano-solar type approaches are the most likely to work out.

    • by narcberry ( 1328009 ) on Sunday April 19, 2009 @06:36PM (#27640087) Journal

      Or nuclear. It's proven, it's working today, and there's phenomenal amounts of energy.

      When did America become so retarded?

  • by Roogna ( 9643 ) on Sunday April 19, 2009 @04:44PM (#27639175)

    Apparently it does matter, and these were obviously very poorly designed if three of them straight up broke.

  • Slow (Score:4, Informative)

    by Anonymous Coward on Sunday April 19, 2009 @04:48PM (#27639199)
    3.8 meters/second average is not a windy area, infact it's a Class 1 [] wind speed. There are many places in the U.S. that are Class 3 or better, and you'd get much different results from those areas.
    • Re:Slow (Score:5, Funny)

      by YrWrstNtmr ( 564987 ) on Sunday April 19, 2009 @04:53PM (#27639245)
      3.8 meters/second average is not a windy area, infact it's a Class 1 [] wind speed. There are many places in the U.S. that are Class 3 or better, and you'd get much different results from those areas.

      Yeah. You'd have ALL of them break.
    • Re:Slow (Score:5, Interesting)

      by radtea ( 464814 ) on Sunday April 19, 2009 @05:35PM (#27639583)

      3.8 meters/second average is not a windy area

      No kidding! This is a "study of wind power in an area that anyone who knows anything about wind power knows is unsuitable for wind power." Duh.

      The Government of Ontario has an excellent resource on available wind in the province: []

      The legend doesn't even go down to 3.8 m/s!

      On my block, which is downtown in a lake-shore city, at 100 magl (metres above ground level, an acronym that does not appear to be defined anywhere on this otherwise excellent site) the average wind speed is 6 m/s, which is in the acceptable range. Because available power goes as the cube of wind velocity 6 m/s is nearly a four times increase in power over 3.8 m/s!

      Small windmills are not for everyone, but this study is simply bogus if they're reporting the wind velocity correctly.

      • wrong wind speed (Score:3, Informative)

        by kwikrick ( 755625 )

        The reported average wind speed seems rather slow, for that area. The average wind speed is normally more like 6 m/s. Here' s a wind speed map of the Netherlands: [].

  • by caluml ( 551744 ) <slashdot@spamgoeshere.calu m . o rg> on Sunday April 19, 2009 @04:52PM (#27639229) Homepage
    But the electricity needed to power the average American household would power a medium-sized Dutch city, right?
    • by Idiomatick ( 976696 ) on Sunday April 19, 2009 @05:08PM (#27639377)
      I was curious (in kWh):
      Dutch: 6310
      USA: 13,388
      • by gstovall ( 22014 ) on Sunday April 19, 2009 @09:59PM (#27641169) Homepage

        I run about 30,000 KWH per year in my house. I was pretty distressed by this amount compared with both the Dutch and US averages, until I factored in:
        1) All electric -- no gas
        2) Climate where Heating Degree Days outnumber Cooling Degree Days 3 to 1
        3) This house, even though it's all electric, consumes only half the electricity of my PREVIOUS house, which was not all electric
        4) 6 people live here
        5) I work at home, so the house is always occupied
        6) I run a small datacenter at home, so not only does all the equipment have to be powered, it has a separate cooling unit.

        Given that, I don't feel AS bad. However, it's still a lot of electricity. Yes, I replaced all incandescents with fluorescent about 10 years ago, so that helps.

  • by SupremoMan ( 912191 ) on Sunday April 19, 2009 @04:52PM (#27639235)

    Why don't the Dutch install tidal turbines in their fields instead, and wait for their country to flood.

    Oh I kid, I kid

  • A little sad. (Score:5, Insightful)

    by haeger ( 85819 ) on Sunday April 19, 2009 @04:53PM (#27639241)

    It would take up to 141 small windmills to power an average American household entirely using wind energy...

    I think this sais more about American household power consumption than it does about small windmills. Doesn't it?

    I think it's a little sad and I would love to see a power-meter that shows exactly how much power you use when you use it. I think that would make people think.
    Also it's a little amusing to read this site on how "bloated" KDE and Gnome are, or how bloated the linux kernel is, but still people use their terrible inefficient cars and houses that are energy-hogs.
    Why isn't everyone here trying to make their home and car as efficient as comfortably possible? It's the "techie" thing to do.
    And the tech is already available.
    Remember that the cheapest energy unit is the one that you don't use.

    • Re: (Score:3, Informative)

      by timeOday ( 582209 )

      I would love to see a power-meter that shows exactly how much power you use when you use it.

      You mean this []?

      What I would like is "smart electronics" so I can push a single button on my way out and be sure I am not wasting electricity, without shutting off my fridge, alarm clock, and PVR. Maybe somebody can point me to that?

    • HMmm. I am curious (Score:4, Insightful)

      by WindBourne ( 631190 ) on Sunday April 19, 2009 @05:46PM (#27639691) Journal
      When I spent time in Germany, I noticed that their homes really are quite similar to ours. The real issue was that EU has MUCH nicer climate throughout. With that said, I would like to see a comparison of electrical/Gas usage of a HOME, as opposed to a region. The reason is that most places try to compare regional uses which adds in manufacturing as well as travel.
    • Re:A little sad. (Score:5, Insightful)

      by rossdee ( 243626 ) on Sunday April 19, 2009 @05:46PM (#27639693)

      If americans lived in Holland, rather than California, Texas, or Florida, then they wouldn't need A/C for 90% of the year.

    • Re:A little sad. (Score:4, Insightful)

      by clarkkent09 ( 1104833 ) * on Sunday April 19, 2009 @06:24PM (#27639997)
      I would like to see some examples of how Americans consume so much more power then Europeans? Not saying that it doesn't happen, but I lived in both places and didn't really notice much difference in how people behave towards electrical consumption. Gasoline is a different matter of course, it's obvious that Americans drive bigger and less efficient cars, but electricity? Could it be that there are more extremes in climate in the US and so cooling/heating is the big culprit? For example, I bet power usage for air conditioning in the southwest is pretty astronomical. Phoenix or Las Vegas average temperature in the summer months is around 40C (104F). The hottest places in southern Europe are nowhere near that.
      • Re:A little sad. (Score:4, Insightful)

        by caluml ( 551744 ) <slashdot@spamgoeshere.calu m . o rg> on Sunday April 19, 2009 @06:51PM (#27640157) Homepage

        Phoenix or Las Vegas average temperature in the summer months is around 40C (104F). The hottest places in southern Europe are nowhere near that.

        Call me stupid, but perhaps it's a little short-sighted to build cities where humans can't naturally survive. Why do you think Europe has developed so fast over the last few millenia - perhaps because they didn't need to struggle against the elements to grow crops and survive.

        • Re:A little sad. (Score:4, Insightful)

          by hwyhobo ( 1420503 ) on Sunday April 19, 2009 @07:19PM (#27640359)

          Call me stupid, but perhaps it's a little short-sighted to build cities where humans can't naturally survive

          I wonder if you logically extend this attitude to starving Africans?

          • Re: (Score:3, Insightful)

            by Kjella ( 173770 )

            I wonder if you logically extend this attitude to starving Africans?

            I would. Not as in I'd let them starve to death, but as an opposite "teach a man to fish":

            Find a way to migrate them/end their dependence, and you only need to sustain that.
            Find a way to sustain the unsustainable, and you must continue to sustain them forever.

      • Re:A little sad. (Score:5, Informative)

        by Clover_Kicker ( 20761 ) <> on Sunday April 19, 2009 @06:55PM (#27640185)

        bigger houses in USA = more air to heat/cool

        I think there are a lot more gas ranges/water heaters in Europe

        I think front load washing machines are much more common in Europe

        Let's not forget the stereotypical smelly Frenchman, it is perfectly possible to have first-world societies where everyone doesn't shower each and every day.

        Just a comment but from what I see on the TV renovation shows, every window in California is single-pane and insulation is a liberal myth. In Canada you'd freeze to death, in Cali apparently you just crank the AC a little higher and wonder why the power bill is so high.

  • Some thoughts (Score:4, Informative)

    by Eudial ( 590661 ) on Sunday April 19, 2009 @04:56PM (#27639261)

    The windmills seems to have been erected very close together. This may cause them to interfere with each other through turbulence. Also, some of them did fairly good. The Skystream and the Montana doesn't seem to be a total waste of money.

  • Do the math (Score:5, Informative)

    by Ancient_Hacker ( 751168 ) on Sunday April 19, 2009 @05:03PM (#27639331)

    There are two very simple scaling laws at play here.

    First off the wind power intercepted goes up as the square of the rotor length. So larger is better, a lot larger is a whole lot better. You also get the free benefit of stronger winds as you have to raise the center point as to not hit the ground.

    Next the power goes up as the CUBE of the wind speed. So it really pays big to find a real windy spot.

    So your basic $30,000 small, low windmill placed on your typical house are real big losers.

  • by lnxpilot ( 453564 ) on Sunday April 19, 2009 @05:08PM (#27639379)

    It's physics 101.
    Capturing a larger cross-section of moving air is more efficient.

    The reverse is also true (generating thrust):
    Turbofan engines are more efficient at lower air-speeds than straight turbojets.
    Moving a small amount of air at a higher velocity will create more wasteful eddies than moving a larger cross-section of air at a lower speeds.

    Helicopters are the extreme case WRT aircraft.
    You need a lot less power to make a helicopter hover than a ducted-fan or jet VTOL aircraft (like the Harrier or the JSF).

    It reminds me of people who are surprised that electric cars / hybrids take up the most energy when they accelerate.
    Duh, that's when you're actually gaining kinetic energy.
    In cruise, you're just fighting drag (air) and friction (road).

  • by Zero__Kelvin ( 151819 ) on Sunday April 19, 2009 @05:22PM (#27639475) Homepage
    Dutch experiment proves theory doesn't map to practice. Film at 11 ...
  • by iamflimflam1 ( 1369141 ) on Sunday April 19, 2009 @05:24PM (#27639493) Homepage
    This has to be the worst summary ever. Please take the time to look at the article and do the maths yourself.
  • by jeroen8 ( 1463273 ) on Sunday April 19, 2009 @05:52PM (#27639737)
    On the Renewable Energy website OliNo there is an article Test results small wind turbines [] website with some more background on this test. The first test results show that a PV system (Solar Energy) is more cost effective than these small windturbines. The Dutch article [], which is more up-to-date, show also the last measurement results of the windturbines (11 months of data). The conclusion is the same. However, it was found out, that an official wind measurement station of the KNMI only 14 kilometers (8.8 miles) away form the test site has an average windspeed which is twice of of the test field. This could explain the low yield of the windturbines.
  • by Daimanta ( 1140543 ) on Sunday April 19, 2009 @06:01PM (#27639815) Journal

    not in Holland. Holland is the combination of North-Holland and South-Holland, both provincies of the Netherlands. The Netherlands is the country as a whole. The Kingdom of the Netherland is the Netherlands plus the Netherland Antilles and Aruba. Zeeland(Sealand) is a provincy seperate from Holland.

  • VAWTs anyone? (Score:3, Informative)

    by Rooked_One ( 591287 ) on Sunday April 19, 2009 @06:10PM (#27639891) Journal
    If this is real... then its real cool. []

    I know that where I live, if I had one of those, I wouldn't need to be plugged into the grid (most of the time at least.)

    And there are so many other hobbyists who have vawts on youtube - interesting stuff. The dutch just took the wrong approach to it ;)
  • Well duh (Score:3, Insightful)

    by zogger ( 617870 ) on Sunday April 19, 2009 @06:53PM (#27640175) Homepage Journal

    No one in the industry I am aware of would say one of those tiny (those montana and skystream models are the exception there, as they are more realistically sized) windchargers would power a household. And further, no one credible who sells or installs realistically sized residential windchargers would recommend it be installed on a household roof. I have a very small windcharger, 300 watts max output in ideal conditions, it is designed to provide a small amount of battery recharging capability for like sailboats or a small weekend cabin or something, and that's it. Same as no one solar panel is going to power your home. This is the duh part, I mean, read the dang specs before you buy and try to keep in mind what your demand would be. There are still a lot of decent windchargers out there that fall between these tiny models and those megawatt sized hugemongous models.

      This was sort of a *really* stupid test. Might as well throw a lawnmower engine in your caddy to try and achieve epic mileage, and then see how far you get down the road. It is that dumb to anyone who knows anything about alternative energy.

    There are tens of thousands of people who own and use residential windchargers, all over the planet, but they are all designed for the task, they are all large, and mounted on sturdy tall towers. The mentioned two largest ones there should be considered entry level in size for practical household use. Yes, size matters obviously, and this info has been out there for close to a century now as regards wind to electrical power.

  • by sribe ( 304414 ) on Sunday April 19, 2009 @07:31PM (#27640431)

    Yeah, I try to keep up with this stuff, since I live in a location that has an "above average wind energy density" to put it mildly. Just last week I saw a hyped article about a new small turbine, went to their web site, and they're claiming that their device only costs about $5,000 installed and will generate 500kWh/year. I blinked. I re-read. I went to other pages to see if that figure was a typo or consistently used. But nope, that's what they're claiming: for only $5,000 up-front I can generate $50/year worth of electricity. And to think, some of the founders will probably be surprised when the company is out of business in a very few years.

    So, obviously, I thought that it was ridiculous (and sad) that a company would offer such a low-producing product at that price. But looking at these test results, $5,000 for 500kWh/year is actually hugely better than most!

  • Burj Dubai (Score:4, Insightful)

    by failedlogic ( 627314 ) on Sunday April 19, 2009 @07:43PM (#27640497)

    Tall buildings and skyscrapers are a boring part of the city scape. Nothing ever moves. They are only pretty with Christmas lights.

    I suggest Turning the Burj Dubai building into not only the world's tallest building, but also the world's largest windmill. At that height, one swing should power the whole world for the year!

  • by damn_registrars ( 1103043 ) <> on Sunday April 19, 2009 @07:55PM (#27640547) Homepage Journal
    For those who wondered where the country New Zealand got its name; or more so where the "old" Zealand is:

    Dutch province of Zeeland

    There is your answer.

  • Finding this amusing (Score:5, Informative)

    by evilad ( 87480 ) on Sunday April 19, 2009 @09:40PM (#27641085)

    Having grown up in a household whose total electrical needs were powered by a single 3m wind generator, I'm finding this article summary awfully amusing.

  • Design? (Score:3, Interesting)

    by mutantSushi ( 950662 ) on Sunday April 19, 2009 @10:43PM (#27641391)
    Larger rotor diameter generators obviously are advantageous. But this study/article seems to not acknowledge an interesting approach that was investigated in Britain: (In areas with sufficient regular wind), houses/buildings whose roof pitch is parallel to the common wind direction (i.e. the roof line is perpendicular to the common wind direction) can exploit their aerodynamic shape to boost the efficient of smaller wind rotors. With an additional "wing" form mounted above a row of smaller wind rotors (like a little roof), combing with the increased local wind speed generated by the roof pitch, the smaller rotors can easily achieve efficiencies of >2x the same size rotors not mounted to take advantage of local aerodynamics. This type of approach is of course generated at the site of usage, so has no transmission losses. Design doesn't matter?
  • by ignavus ( 213578 ) on Monday April 20, 2009 @12:06AM (#27641817)

    With all these propellers spinning, don't they make the earth rotate faster?

  • by Animats ( 122034 ) on Monday April 20, 2009 @02:05AM (#27642205) Homepage

    I went to a "Green Expo" last year, and saw one booth with a small windmill, with about a 2 meter diameter 3-blade carbon-fiber blade assembly. The blades were fixed, and there was no overspeed feathering/furling capability. This was $10,000. Using their numbers, payback time was a century.

    The going rate for a 2m turbine is about $1000. [] So I asked the sales rep why their unit was so expensive. He said "this is a status symbol, like a Mercedes". Right.

In the realm of scientific observation, luck is granted only to those who are prepared. - Louis Pasteur