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posted by martyb on Monday June 02 2014, @06:08PM   Printer-friendly [Skip to comment(s)]
from the the-answer-is-blowin-in-the-wind dept.

A Dutch company has launched a new type of wind turbine that is small enough to fit onto the roof of a house. The turbine looks like a Nautilus shell, and their website explains how it works:

Most today's wind turbines require that a difference in pressure between the front and the rear side of the rotor blades be maintained in order to be effective. However, this difference in pressure also has a negative effect called "drag".

Our turbine rotor captures the kinetic energy of the wind due to its speed, and, by reversing the wind and reducing it to almost zero Beaufort converts it into mechanical energy. By doing this the wind speed's effect (in kinetic energy) on the rotor is maximized and "lift" is obtained by the wind's acceleration over the rotor plane.

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  • (Score: 2) by Angry Jesus on Monday June 02 2014, @06:27PM

    by Angry Jesus (182) on Monday June 02 2014, @06:27PM (#50347)

    There isn't much windspeed at the height of the average house. That's why whenever you see windmills they are almost always up on a high tower. Still, it might be useful on taller apartment buildings, and as they have on their website, industrial buildings.

    • (Score: 1) by jmc23 on Monday June 02 2014, @07:12PM

      by jmc23 (4142) on Monday June 02 2014, @07:12PM (#50369)

      Did you take a look at how efficient this design is at low wind speeds and/or the average wind speed at 1-2 stories.

      No, you didn't.

      • (Score: 0) by Anonymous Coward on Monday June 02 2014, @09:23PM

        by Anonymous Coward on Monday June 02 2014, @09:23PM (#50412)

        Average 20ft windspeed in american suburbs is 0.6mph -- not much to speak of. Guess you didn't take a look either.

        • (Score: 2) by lhsi on Tuesday June 03 2014, @09:34AM

          by lhsi (711) on Tuesday June 03 2014, @09:34AM (#50575) Journal

          Why do you assume that the only place this is going to be used in is an "american suburb"? You are aware that people live in other places in the world, right?

          • (Score: 0) by Anonymous Coward on Tuesday June 03 2014, @03:23PM

            by Anonymous Coward on Tuesday June 03 2014, @03:23PM (#50658)

            Why do you assume that I think it would only be used in american suburbs?
            That would be stupid, wouldn't it?
            Much more sensible - numbers for american suburbs, which cover a vast range of geographic variability, were simply the most accessible. When the OP didn't have any numbers at all, should I have assumed that he thought they would be used in no place at all?

  • (Score: 2) by egcagrac0 on Monday June 02 2014, @06:28PM

    by egcagrac0 (2705) on Monday June 02 2014, @06:28PM (#50349)

    I don't understand how you can have an airfoil that doesn't exhibit drag.

    This design may exhibit less drag than other types, but my simpleton mind doesn't understand how you can get "lift" without "drag".

    • (Score: 5, Funny) by evilviper on Monday June 02 2014, @06:56PM

      by evilviper (1760) on Monday June 02 2014, @06:56PM (#50358) Homepage Journal

      I don't understand how you can have an airfoil that doesn't exhibit drag.

      Well, Stupid...

      You can't understand how their device works, because you missed where they explained that they developed and used alternative laws of physics to design it:

      [We] "developed new theories and techniques that more closely follow the natural laws of physics for energy."

      http://dearchimedes.com/who-we-are/ [dearchimedes.com]

      See!!! When you develop your own theories, that outperform everyone else's laws of physics, it's easy enough to build friction-less airfoils.

      --
      Hydrogen cyanide is a delicious and necessary part of the human diet.
      • (Score: 3, Funny) by egcagrac0 on Monday June 02 2014, @07:10PM

        by egcagrac0 (2705) on Monday June 02 2014, @07:10PM (#50368)

        When you develop your own theories, that outperform everyone else's laws of physics, it's easy enough to build friction-less airfoils.

        Can't wait to see how they harness perpetual motion theory to make the world a better place.

        • (Score: 2, Funny) by Alfred on Monday June 02 2014, @08:50PM

          by Alfred (4006) on Monday June 02 2014, @08:50PM (#50400) Journal

          With perpetual power comes perpetual responsibility and nobody wants perpetual responsibility.

          • (Score: 2) by Gaaark on Monday June 02 2014, @09:49PM

            by Gaaark (41) Subscriber Badge on Monday June 02 2014, @09:49PM (#50430) Journal

            Another reason there is no God! :)

            --
            --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
            • (Score: 0) by Anonymous Coward on Tuesday June 03 2014, @12:18AM

              by Anonymous Coward on Tuesday June 03 2014, @12:18AM (#50470)

              nobody

              God is without a body, dumbass...

              • (Score: 2) by evilviper on Tuesday June 03 2014, @04:00AM

                by evilviper (1760) on Tuesday June 03 2014, @04:00AM (#50516) Homepage Journal

                God is without a body, dumbass...

                Well, he has an "image," upon which humans are based. I would have to presume that "image" is some variation on the concept of a body of some sort.

                --
                Hydrogen cyanide is a delicious and necessary part of the human diet.
              • (Score: 2) by evilviper on Tuesday June 03 2014, @10:44AM

                by evilviper (1760) on Tuesday June 03 2014, @10:44AM (#50582) Homepage Journal

                God is without a body, dumbass...

                Well, he HAD one, but all those crazy Catholics kept EATING it...

                --
                Hydrogen cyanide is a delicious and necessary part of the human diet.
        • (Score: 2) by FatPhil on Monday June 02 2014, @09:43PM

          by FatPhil (863) <pc-soylentNO@SPAMasdf.fi> on Monday June 02 2014, @09:43PM (#50426) Homepage
          If we can turn human stupidity into an energy source, we'll be set for a very long time.
          --
          Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
        • (Score: 2) by evilviper on Tuesday June 03 2014, @04:20AM

          by evilviper (1760) on Tuesday June 03 2014, @04:20AM (#50521) Homepage Journal

          Can't wait to see how they harness perpetual motion theory to make the world a better place.

          They're going to strap magnets to the corpse of Sir Isaac Newton, and put a stator coil in his casket, so they can generate all the electricity they could ever need, from the process of him spinning in his grave.

          --
          Hydrogen cyanide is a delicious and necessary part of the human diet.
    • (Score: 2, Informative) by Zinho on Monday June 02 2014, @07:06PM

      by Zinho (759) on Monday June 02 2014, @07:06PM (#50363)

      The write-up provided is useless to an engineer (or anyone willing to spend two seconds thinking about what was said). There is no way to eliminate drag and still extract energy from the air stream. If you take Kinetic Energy (1/2 mV^2) out of the wind you slow it down, so there is going to be drag involved.

       

      The most informative statement they made was that their turbine has "80 percent of the maximum that is theoretically feasible." The theoretical maximum referred to is Betz's law [wikipedia.org], "no turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind." So this new design will extract .593*.8 = .474 -> 47.4% of the kinetic energy from the incoming wind.

       

      That's not bad, actually; in fact, that's the sort of efficiency you get on large wind installations. It's obvious to me that the designer either doesn't really understand the physics of what they're involved in, or that they've been told to shut up and let the marketroid talk to the Eloi. That's kind of tragic, since it seems to me that they have a good product and it can probably stand on its own without hyperbole or outright lies to support it.

       

      I should also note that the 1300 KWh rating they gave is per year, and that they're estimating that two or three of these would satisfy the needs of a typical Dutch household. I should really get on whatever efficiency program they're using, since my consumption is about that much per month (more in the summer). This would be cool to put on my roof as a way to start loud conversations with my neighbors, but it wouldn't be very cost-effective as a way to offset my power usage.

      --
      "Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
      • (Score: 2) by HiThere on Monday June 02 2014, @08:05PM

        by HiThere (866) on Monday June 02 2014, @08:05PM (#50389) Journal

        Well, they said two or three plus solar cells. Didn't mention batteries for some reason. Even if I assume that everything the said is accurate, and that two or three plus solar cells (how many?) would generate enough energy, there's no mention of how you deal with when the sun's not shining AND the wind's not blowing.

        So, yes, it's marketdroid speak. Any engineer would have known that it was misleading no matter HOW poor an engineer he was. Either that, or it's an incredibly bad translation that just happened to be grammatical.

        --
        Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
      • (Score: 2) by hankwang on Monday June 02 2014, @09:52PM

        by hankwang (100) on Monday June 02 2014, @09:52PM (#50431) Homepage

        "1300 KWh rating they gave is per year, and that they're estimating that two or three of these would satisfy the needs of a typical Dutch household. I should really get on whatever efficiency program they're using, since my consumption is about that much per month (more in the summer)."

        We (2 person household in Netherlands, 95 m2/1000 sq.ft house) use around 1800 kWh/yr, of which we generate about 600 kWh from a small solar panel. How? We rarely use airconditioning, which is bearable because daytime temperatures exceed 30 C only a few days per year and because this house is well insulated both for keeping the heat in during the winter, and out during the summer. Fridge/freezer is energy class A+++ (150 kWh/yr), washer is about 0.6 kWh per 7 kg cycle (1x per week), dishwasher 1 kWh/cycle (3x per week), nearly all lighting is CFL and LED, and generally I pay attention to idle/standby power use of various electronics (including fileserver), keeping in mind that every watt-year costs 2 euros, so many things are switched off when not in use or are purchased with energy use as a criterion. The tv is only on if we're actually watching; it's not used as a moving wallpaper (I've the impression that that is common in the US). For heating and cooking we use natural gas. I suspect that the water pump for the central heating system takes a big chunk of those 1800 kWh. Our computing needs are served by various mobile devices and smallish laptops, and a small server (14 W idle).

        It also helps that we both have fulltime jobs.

        • (Score: 0) by Anonymous Coward on Monday June 02 2014, @11:15PM

          by Anonymous Coward on Monday June 02 2014, @11:15PM (#50450)

          "For heating and cooking we use natural gas."
          There's your problem. Your energy accounting is dishonestly hiding a sizable chunk of your use in a fossil fuel you forgot to account for.

          • (Score: 1) by Zinho on Tuesday June 03 2014, @12:40AM

            by Zinho (759) on Tuesday June 03 2014, @12:40AM (#50475)

            In the context of reducing electrical usage I think it's fair to consider natural gas use as a viable alternative. I cook year round and heat in the winter with gas, too; I'd use a gas clothes dryer as well if I could. We recently switched to using a clothesline to dry clothes, and we're down to about 1,000 kWh/month if we don't run air conditioning.

            I think the biggest difference between us is location - I'm in south central United States, and hankwang is in the Netherlands. Where I live we average 18 days above 100F (37.5C), and in 2011 we had 71 days above that temperature. I'm curious about the water pump for the heater, is that radiant flooring?

            In any case, hankwang is using close to 10% of the electricity I am. That's astounding to me. I'll have to look at my appliances to see if there are savings I could make there.

            --
            "Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
            • (Score: 2) by carguy on Tuesday June 03 2014, @11:52AM

              by carguy (568) Subscriber Badge on Tuesday June 03 2014, @11:52AM (#50597)

              Another data point, we are two people working from home, a couple of laptops on all the time. The water boiler (baseboard heat) and hot water heater run on gas, everything else is electric. Location is downwind of Lake Erie in a 1963 brick ranch. The only insulation that it was easy to add was to take the attic floor up to a total of 18" (~0.4 meter) of fiberglass. It has never hit 100F here, although with warming it may get there soon. These factors both moderate summer temps and usually limit A/C (a smaller unit, but not energy star) to a few hours in summer evenings. The basement has a small de-humidifier running about half time in the summer to control mold. We mostly cook meals at home, eat dinner out once or twice a week. A recent "energy star" fridge made a big difference compared to the previous fridge from the 1980s. We are both good about turning lights off, but for reading in the evening hours still use 100W incandescents (eyestrain from CFLs); looking forward to trying brighter LED "bulbs". We dry about half the clothes on a rack indoors, more in winter for the humidifying effect.

              I'm looking at putting the cable box (a constant draw) on a timer, so it boots up before our typical TV watching in the evenings--but it would be more convenient if the cable company had a box that idled at lower power. If we renovate the kitchen/utility area we will change over to a gas range (cooktop) and oven, as well as a gas clothes dryer.

              We're currently around 400 kWh/month (yearly average) including A/C for a few months in summer. If we average the 8 or 9 "non-A/C months" it's just under 300 kWh/month. It would be hard to get down to the hankwang / Netherlands level here, but we do have room for improvement.

            • (Score: 2) by hankwang on Wednesday June 04 2014, @09:42AM

              by hankwang (100) on Wednesday June 04 2014, @09:42AM (#50994) Homepage

              I'm curious about the water pump for the heater, is that radiant flooring?

              Regular radiators/convectors; the pump to get the water from the heater (Boiler? Not sure about the US/English terms) to the radiators takes about 100 W when it's running. The heater recovers heat by condensing the water out of the exhaust gases, but this will work best if it operates at low temperatures. I try to maximize efficiency by keeping the water temperature as low as possible (70 C/158 F when it's freezing, 50 C/122 F during spring/autumn). The penalty is that the pump has to run for more hours. When we use hot tap water, the same heater will heat up the water in the closed heating circuit, and use a heat exchanger to heat up tap water; also then, the pump will run. No hot water is stored when the tap is not running. This is a very common setup here in Netherlands; I'm not sure how domestic heating works in the US. Coming winter, I'll try to do some optimization on the electricity/gas usage of the heater. :-)

              In any case, hankwang is using close to 10% of the electricity I am. That's astounding to me. I'll have to look at my appliances

              An energy meter (I think they're called Kill-a-Watt in the US) and a notebook can be very revealing. A colleague of mine discovered that his fancy espresso machine, which was switched on all day during the weekends, was a huge power drain. Our home is exceptional as it has an a/c system (inherited from the previous owner); when I discovered that it uses 130 kWh/yr on standby, I installed a 4-euro switch and saved 26 eur/yr in electricity.

      • (Score: 2) by demonlapin on Tuesday June 03 2014, @12:07AM

        by demonlapin (925) on Tuesday June 03 2014, @12:07AM (#50466) Journal
        It's difficult for most North Americans to envision just how efficient you can be in NW Europe because most of us have significant heating and cooling expenses. They almost never need cooling and can rely on heavy insulation and waste heat to substantially warm their houses in winter. It's like living in Santa Monica.
      • (Score: 2) by evilviper on Tuesday June 03 2014, @04:15AM

        by evilviper (1760) on Tuesday June 03 2014, @04:15AM (#50519) Homepage Journal

        I should also note that the 1300 KWh rating they gave is per year, and that they're estimating that two or three of these would satisfy the needs of a typical Dutch household. I should really get on whatever efficiency program they're using, since my consumption is about that much per month (more in the summer).

        1) Their climate is much milder than you'd expect, compared to ANYWHERE in America. The Atlantic ocean does miracles for Europe's climate...

        2) The more people you cram into a smaller space, the less active heating you need (and the more active cooling). Cheaper land/housing costs in the US have lead to a proliferation of larger homes. If we just had smaller houses like Europe, it would go a long way towards reducing heating costs.

        3) Heat-pumps cost as little as $600 (basic split system), and can QUADRUPLE (COP=3.9) the efficiency of (electric) heating, versus old resistive heating coils. It can be cheaper than natural gas, and split systems make it extremely easy to retrofit old buildings. For cooling, a swamp cooler can be drastically cheaper in any location where humidity isn't high.

        4) More insulation helps a lot. Big, unshaded, south-facing windows can add a LOT of heat to your house. etc.

        --
        Hydrogen cyanide is a delicious and necessary part of the human diet.
  • (Score: 5, Informative) by frojack on Monday June 02 2014, @06:36PM

    by frojack (1554) Subscriber Badge on Monday June 02 2014, @06:36PM (#50351) Journal

    Quote TFA

    easily fits on the roof of a house just as would solar panels. The Liam F1 generates an average of 1,500 kilowatt-hour of energy at a wind-speed of 5m/s.

    So that's about a 12mph wind speed, which is pretty unusual in residential districts. The average at Airports is here. [currentresults.com]. Most places don't show 12mph even around airports which sit in wide open areas.

    You just don't find that much wind in your typical residential neighborhood. I live on top of a hill in Washington State, and gazing at my roof mounted anemometer on what seems like a windy day to me, I am reading a peak of 3mph, average of less than 1mph. Hawaii? Probably a much better fit. [usa.com] The trade winds blow just about year around.

    I think for the typical house, Solar would be a better bet, especially if you tied it directly to the AC system> Solar usually comes with zero moving parts. Once you mount something on someone's roof, the next maintenance it will get is when it falls down.

    --
    No, you are mistaken. I've always had this sig.
    • (Score: 3, Interesting) by VLM on Monday June 02 2014, @06:47PM

      by VLM (445) Subscriber Badge on Monday June 02 2014, @06:47PM (#50355)

      "zero moving parts"

      There is the noise and vibration issue, which I've never understood WRT residential-ish wind. Nice silent solar, sure. But wind?

      I live far north of the peak of tornado alley but we get plenty of t-storms and blizzards with rather high winds, another mystery to deal with roofs and windmills. Usually the sun doesn't decide to be 10 times as bright on a random-ish basis.

      • (Score: 2) by computersareevil on Monday June 02 2014, @08:51PM

        by computersareevil (749) on Monday June 02 2014, @08:51PM (#50402)

        "Usually the sun doesn't decide to be 10 times as bright on a random-ish basis."

        I think I read a short story about that once.

        Ah yes, here it is [wikipedia.org].

    • (Score: 3, Informative) by pe1rxq on Monday June 02 2014, @06:57PM

      by pe1rxq (844) on Monday June 02 2014, @06:57PM (#50359) Homepage

      In the Netherlands we actualy have a large costal area where the yearly average is 5m/s or more.
      But I guess a few large ones will work better still.

      • (Score: 2) by frojack on Monday June 02 2014, @07:09PM

        by frojack (1554) Subscriber Badge on Monday June 02 2014, @07:09PM (#50367) Journal

        Agreed, there are places this would work. Seemingly every ridge in the Western US has sprouted wind farms.
        There are plenty of rural farms where there is virtually no wind-obstruction.

        I wonder if these turbines would be more efficient when scaled up than those huge tri-blade monsters.

        Speaking of wind farms, there is apparently a warming effect [nsf.gov] from a large wind farm, and if these devices
        started appearing on every city roof top, that might exacerbate the heat sink effect in cities.

        --
        No, you are mistaken. I've always had this sig.
  • (Score: 1) by captain_nifty on Monday June 02 2014, @06:36PM

    by captain_nifty (4252) on Monday June 02 2014, @06:36PM (#50353)

    P=1/2*A*V^3 is the theoretical maximum you could ever get from a wind turbine. Your energy is determined by swept area and wind speed, mostly wind speed, putting a small turbine (no matter what amusing shape they make it) on your roof, with low wind speeds, will never generate enough energy to pay of the cost. You need high consistent wind speeds, which in most places means high above the ground on a tower.

    • (Score: 2, Informative) by Zinho on Monday June 02 2014, @07:25PM

      by Zinho (759) on Monday June 02 2014, @07:25PM (#50375)

      It's actually less than that; if you were to completely stop the incoming air (remove all of its KE) then it would pile up on the downwind side of the turbine. We've known for most of a century [wikipedia.org] that you can only really extract ~60% of the KE from the wind before slowing the air down too much hurts your efficiency.

       

      In other words, I totally agree with you, and it's worse than you thought.

      --
      "Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
  • (Score: 5, Insightful) by evilviper on Monday June 02 2014, @06:49PM

    by evilviper (1760) on Monday June 02 2014, @06:49PM (#50357) Homepage Journal

    ANY wind turbine is going to be unsuitable for residential areas. If it spins, it's going to generate noise. Even if designed to be perfectly silent out-of-the-box, you'd still need homeowners to do frequent maintenance, which NOBODY would actually perform.

    For wind power on a house, I'd probably try the vertical-axis 55-gallon barrel design:

    http://www.instructables.com/id/55-Gallon-Drum-Turbine/ [instructables.com]

    --
    Hydrogen cyanide is a delicious and necessary part of the human diet.
    • (Score: 2) by egcagrac0 on Tuesday June 03 2014, @06:31AM

      by egcagrac0 (2705) on Tuesday June 03 2014, @06:31AM (#50545)

      If you're going to do that... use a better bearing than a lazy susan. Look up "pillow block [google.com]". Those bearings are designed to mount a shaft, allow convenient lubrication, and have machined bearing races (quieter and more efficient) rather than stamped sheet metal with a few BB's thrown in.

      A reclaimed automotive wheel bearing would probably work, too, although the shape might not be as useful.

  • (Score: 1) by speps on Monday June 02 2014, @07:07PM

    by speps (4420) on Monday June 02 2014, @07:07PM (#50365)

    This is not really the first time I've heard about wind turbines in urban areas.

    I've seen a couple in Birmingham (UK), here is a picture : http://www.flickr.com/photos/39415781@N06/4636522006 [flickr.com]

    I have no idea who made those but I remember seeing them turn very fast on a non windy day.