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Microwind Generator For Low Power Systems 243

Posted by CmdrTaco
from the welcome-to-sunday dept.
An anonymous reader wrote in to say that "Shawn Frayne, has developed Windbelt, efficient, cheap lowpower wind generator built out of taut kite fabric." Everyone has seen the video where the suspension bridge is ripped apart by wind- his idea was to use the same thing to generate power. I doubt I'll be running my desktop off it any time soon, but it's a cool idea.
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Microwind Generator For Low Power Systems

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  • by Sub Zero 992 (947972) on Sunday October 14, 2007 @09:10AM (#20973099) Homepage
    And now for a really interesting renewable energy concept: kite gen [kitegen.com]. Would have made Newton smile :)
    • by LingNoi (1066278)
      What happens to the kite when it's not windy? Someone would have to drive up to the plant and relaunch the kite. : /
      • by slim (1652)

        What happens to the kite when it's not windy? Someone would have to drive up to the plant and relaunch the kite. : /
        My guess is that at the altitudes they're talking about, it's always windy enough to keep a kite aloft. An appropriately designed kite can stay up in very little -- or no -- wind. Search youtube for "indoor kite" for demonstrations.
        • Re: (Score:3, Funny)

          by LingNoi (1066278)
          Awesome. This could also be used to capture electricity from lightning strikes!?!
    • by StarfishOne (756076) on Sunday October 14, 2007 @11:01AM (#20973691)
      They are certainly not the only ones doing pioneering work in this field:

      Laddermill from the Technical University of Delft is also working on it for a number of years now:
      http://www.lr.tudelft.nl/live/pagina.jsp?id=8d16d19a-e942-45aa-9b52-48deb9312e92&lang=en [tudelft.nl]

      Publications:
      http://www.tudelft.nl/live/pagina.jsp?id=fe263f84-29af-4010-8222-2f1112c8f223&lang=en [tudelft.nl]

      The more alternatives for environmentally friendly energy sources the better! :)
    • Re: (Score:2, Interesting)

      I like the idea, it's nifty but I see at least one major flaw in it.

      This would cause a circle of death above the power plant. Nothing could fly there (birds, planes, etc.) without getting chopped to pieces by extremely high speed wires flying about. I know some people who have experience with wind farms and they always mention the problems with birds - and yes, I've heard the statistics on these numbers but look a little closer and with a grain of salt - so uncontrolled, high speed wires in my opinion
      • Re: (Score:3, Informative)

        by wvmarle (1070040)

        Traditional wind farms (using wind turbines) are apparently not much of a problem for birds. I recall a study done years ago in The Netherlands, where some environmental protection group wanted to see how much damage the wind turbines were doing. The startling result: nearly nil! The explanaition: birds will not fly into the turbines because they are warned by the noise.

        Now how that would hold up with the kites I don't know. My only experience is with kiting at the beach: we could sometimes see seagulls ma

        • Re: (Score:3, Funny)

          by StikyPad (445176)
          In the case of giant kites, one would hope they'd be warned by their eyes. But even if birds are getting killed by windmills and kites, at least they're mainly killing off the dumb and the weak. Sort of like air sharks. Eventually only the smart and/or skilled fliers will be left, aside from the odd case of down syndrome (pun intended), and this whole issue will be moot.
      • I don't know about less green that coal but I agree it would be like a kilometer high razor netting. Modern windmills OTOH are not a problem to birds any more than tall buildings are, (hint: big blades move slow).
  • by DamonHD (794830) <d@hd.org> on Sunday October 14, 2007 @09:17AM (#20973133) Homepage
    ...but it is not at all clear what their efficiency or $/Watt or manufacturing cost will be. Although absolute efficiency is maybe not critical for many applications given that the wind is free, cost is important in, for example, third-world deployments.

    See the discussion here for example: http://www.fieldlines.com/story/2007/10/13/9445/4984 [fieldlines.com]

    Much as I'm intrigued by this let's not get into perpetual motion machines nor "beating Betz" just yet! In particular the "30x as efficient as the best microturbines" claim in TFA is particularly suspect: I have a VAWT made from a cardboard cereal packet in my back garden that probably extracts 10% of the available energy.

    Rgds

    Damon
    • Re: (Score:2, Interesting)

      by conureman (748753)
      Are you kidding? I could build one of those! Well, maybe. Anyways the cost is magnitudes different from what I saw, and it looks to be user-repairable. Probably doesn't kill birds, either. Regarding the claimed efficiencies, I am not a scientist, but I learned from Tesla that efficiency increases with frequency. That thing was humming.
      • ... but I learned from Tesla that efficiency increases with frequency.

        So that just means that if we can make it run on microwaves we'll be in great shape.
    • by Smidge204 (605297) on Sunday October 14, 2007 @12:01PM (#20974059) Journal
      I'll steer clear of the efficiency claims, but the cost would definitely be a bargain.

      All thing else being considered equal, compare a modern turbine:
      -Mast
      -At least two (Usually three) airfoil blades (engineered composite materials)
      -Gearbox (fairly complex device)
      -Generator head (fairly complex device)

      To this thing:
      -Mast with gap in middle
      -Length of strong, flexible material (metal, plastic)
      -Permanent magnet
      -Coils of wire

      That's dead simple and could probably be supplied in kit form and assembled with absolutely minimum tools... like nothing but a large hex wrench.
      =Smidge=
      • by DamonHD (794830)
        Well, one reason that I'd dearly like to get a simple VAWT (Vertical Axis Wind Turbine) working is to eliminate two expensive parts for low-power applications: the mast (or at least most of it) and the yaw brearing.

        No gearbox required, and the blades can be cut out of a strong weatherproof box.

        But, yes, the generator is still expensive. Two costs (the strong magnets, and the wound coils) is shared with the Microwind.

        Rgds

        Damon
      • by flyingfsck (986395) on Sunday October 14, 2007 @03:32PM (#20975413)
        Well, the simplest way to build a wind generator, is to buy a 3 foot diameter 36V cooling fan for a large stationary diesel motor and mount that on a post. Add a big diode and hook it to a 12V battery. If you are a bit more careful, then add an over-voltage cut-out switch. To power a sea/lakeside cottage, this is all you need. A 36V fan will charge a 12V battery better in low wind (It won't ever get to 36V, not even in a storm with no load). The post bearing is just a pipe slid over the mast, it can be a loose fit, add some grease to eliminate squeaks, add a vane at the back and run the cable down loosely with a plug, so you can unwrap the wire once a month. KISS.
      • Re: (Score:3, Interesting)

        by DerekLyons (302214)
        A modern wind turbine can also be supplied in kit form and assembled with absolutely minimal tools... like nothing but a large hex wrench.
         
        Yes, the parts are complex, but the interconnections between them are not.
    • The claim is not "30x as efficient as the best microturbines" as all speeds, but at the low speeds (10 mph) where energy loss to friction is paramount & some microturbines won't even spin up.
      • by DamonHD (794830)
        Again, not all turbines, and the text seemed to be claiming 30x better than the *best*, which for honesty/fairness had better be the best at the same windspeeds.

        Look at designs like simple VAWTs and the MotorWind HAWT for low wind speeds, rather than the more conventional HAWTs.

        *All* designs suffer from the wind's power varying with the cube of the wind-speed.

        And unlike a VAWT or yawed-HAWT, the Microwind looks like it needs a fixed wind direction *and possibly a narrow fixed speed range* for the vibrations
    • by Jartan (219704)

      In particular the "30x as efficient as the best microturbines" claim in TFA is particularly suspect: I have a VAWT made from a cardboard cereal packet in my back garden that probably extracts 10% of the available energy.


      I don't think the claim was just a straight % efficiency comparison. It was probably meant as a cost/efficiency comparison to whatever is on the market now.
      • by DamonHD (794830)
        Which might be true, and is very interesting if so, but then they should say that and/or back it up!

        I really do think that there is a dearth of solutions in the sub-100W range, and this looks potentially interesting.

        Not everyone is wanting to run a 3kW electric oven in their off-grid shack...

        Right now I'm working by a single 3W LED in my office, and I only need ~20Wh/day to cover its consumption for example.

        Rgds

        Damon
  • 'Taught' material? (Score:5, Insightful)

    by Alicat1194 (970019) on Sunday October 14, 2007 @09:22AM (#20973155)
    What did they teach it? Um, Editors, I think the word you're looking for is 'taut'.
  • Units (Score:4, Funny)

    by springbox (853816) on Sunday October 14, 2007 @09:24AM (#20973169)

    Everyone has seen the video where the suspension bridge is ripped apart by wind- his idea was to use the same thing to generate power.

    So will the power output be measured in bridges per minute?

    • by jetpack (22743)
      Actually, no. If you've ever seen the video you would realize that the proper units would be cars per oscillation.
    • Everyone has seen the video where the suspension bridge is ripped apart by wind- his idea was to use the same thing to generate power.
      So will the power output be measured in bridges per minute?
      Nope, Libraries of Congress per furlong.
  • Prior Art, 1964 (Score:2, Interesting)

    by AndroidCat (229562)
    (In fiction at least) The Subways Of Tazoo, Colin Kapp, 1964. [ansible.co.uk] In the story, it was strings rather than ribbons. The story involves an alien race that killed themselves by climate change. Tsk, what science-fiction twaddle!
    • (In fiction at least) The Subways Of Tazoo, Colin Kapp, 1964. [ansible.co.uk] In the story, it was strings rather than ribbons. The story involves an alien race that killed themselves by climate change. Tsk, what science-fiction twaddle!

      You laugh but if you've ever been in a subway you know that they certainly generate a lot of air as the trains travel.

      I'm half wondering if you could either have these mounted in the tunnels to charge batteries for emergency power use OR mount them on electric trains themselves to create some sort of regenerative system.

      Wouldn't be the first time Science Fiction has lead the way...

      • by FLEB (312391)
        I'm out of my realm of experience here, but I'd think that mounting them on trains would just be converting the air drag that the devices themselves created. Now, as for wall mounting, there might be something there.
        • Mounting them on the tunnel walls would have the same effect. They'd slow the air moving through them, which would exert drag on the train.

          There's no free energy.
      • by tylernt (581794)

        You laugh but if you've ever been in a subway you know that they certainly generate a lot of air as the trains travel.
        Hence Evacuated Tube Transport [google.com].
  • Could someone explain the science behind this? I remember from high school physics that the collapse of the Tacoma Narrows Bridge was used as an example of forced resonance, but now I see from the Wikipedia article [wikipedia.org] that resonance has nothing to do with it, and that complicated aerodynamics come in to play. Are there any experts out there who could conjecture on how the Windbelt actually works and explain it in terms of the bridge collapse?
    • by Dunbal (464142)
      IT's a strap with a magnet glued on that vibrates in front of a length of copper wire. There's no magic, and the reference to the Tacoma Narrows bridge is just hype. Everyone knows that stuff moves in the wind. So if you cause a magnet to move in front of a wire, you will induce an e.m.f., which gives you voltage. The real science is probably how much tension you put in the strap, because you want it to move but not too much.
      • by ashitaka (27544) on Sunday October 14, 2007 @12:06PM (#20974091) Homepage
        The reference to the Tacoma Narrows bridge is very relevant. Galloping Gertie showed that even without hurricane-force winds a very heavy ribbon-shaped strip can me made to move in an extreme fashion due to mechanical resonance. Even a small strip would have the same kind of resonance so that large relative movement can be extracted from even light winds.

        Haven't you ever made a blade of grass whistle between your thumbs?
    • "but now I see from the Wikipedia article that resonance has nothing to do with it"

      Did you read the whole article, because you seem to have missed this part,

      "The wind-induced collapse occurred on November 7, 1940 at 11:00 AM(Pacific time), due partially to a physical phenomenon known as mechanical resonance."
  • Dupe, sortof (Score:2, Informative)

    by Snefru2 (663397)
    This turbine was one of the items mentioned few days ago on Slashdot in another post. See: http://science.slashdot.org/article.pl?sid=07/10/11/212243 [slashdot.org]
  • Wrong solution (Score:4, Interesting)

    by bogaboga (793279) on Sunday October 14, 2007 @09:35AM (#20973231)
    I wonder why [some] westerners always come up with their pet projects and think these projects will solve third world problems. To the shown apparatus generates too little power to be of any use at all.

    The only sure way to help countries of the third world is for countries like the US to open up their subsidized markets. The corn market in the US for example is subsidized to an extent of almost 10 billion dollars in 2005!

    If third world countries got just half of that market, a lot of lives would be changed.

    • Re: (Score:3, Interesting)

      by blahplusplus (757119)
      "The only sure way to help countries of the third world is for countries like the US to open up their subsidized markets. The corn market in the US for example is subsidized to an extent of almost 10 billion dollars in 2005!"

      Subsidies are necessary, you're not thinking about how the world works. A country should never let a large proportion of it's food production all be outsourced. What happens in case of war or political/trade fallout? Yeah I thought so too. Whle free-market apologists will cry "protec
      • Re: (Score:3, Insightful)

        by bogaboga (793279)

        A country should never let a large proportion of it's food production all be outsourced. What happens in case of war or political/trade fallout?

        Here is the problem: When the Australians, Japanese and Europeans do exactly that, the US screams "subsidies, subsidies, subsidies...", as if the US is any innocent.

        • Re: (Score:2, Interesting)

          by Kadin2048 (468275) *

          A country should never let a large proportion of it's food production all be outsourced. What happens in case of war or political/trade fallout?

          Here is the problem: When the Australians, Japanese and Europeans do exactly that, the US screams "subsidies, subsidies, subsidies...", as if the US is any innocent.

          The U.S. is the bigger market, therefore it can negotiate trade agreements that are in its favor. Chances are, the Australians want access to the U.S. market a lot more badly than the U.S. wants access to Australia's; therefore, the U.S. can keep its subsidies and make other nations get rid of theirs.

          Life is not fair.

          • by Dunbal (464142)
            The U.S. is the bigger market, therefore it can negotiate trade agreements that are in its favor.

                  Not for long. Soon India and China will be the bigger markets. Their economies are growing at phenomenal rates, and will soon be able to afford more complex (and expensive) goods on an unprecedented scale: 3 billion people.
        • by Atzanteol (99067)
          So what? Seriously. Just because the US complains doesn't mean you have to actually *do* something about it you know...
      • Re: (Score:3, Interesting)

        by ChrisMaple (607946)
        The US was created as a rebellion against England's protectionism. The US grew in spite of , not because of, protectionism. Economic efficiency always demands using the least expensive of equivalent alternatives, and that means no protectionism.

        Protected industries grew; their customers failed to grow because of the higher prices. The net effect was inferior to free trade.

        • Re:Wrong solution (Score:5, Interesting)

          by ScrewMaster (602015) on Sunday October 14, 2007 @12:50PM (#20974405)
          What you free trade types eternally fail to grasp is that people aren't nice, don't always play by the same rules, and frequently use their economies to damage each other. To me, it seems like you have a rose-colored world view that is simply not borne out by history and current events. Yes, competition is good, it keeps companies on their toes, and certainly excessive protectionism has negative consequences in that regard. No argument from me there. But you have to understand, the converse also has negative effects. That's especially true when dealing with a culture and economy such as China, which doesn't have the slightest conception of Western business ethic, and sees nothing wrong with eliminating the competition by any means whatsoever. Very efficient from their perspective, downright disastrous for us.

          I have news for you: raw industrial efficiency is not the only measure of a successful economy. How a nation's economy provides for its people, long term, is an equally important metric. I would say, a far more important one. Throwing away domestic manufacturing in favor of cheap imports from inimical foreign powers is not a good way to serve the needs of your people. In fact, free trade, so far as the United States is concerned, is doing exactly the opposite. We are transferring massive amounts of money to China in exchange for cheap imports, while simultaneously losing the ability to provide for ourselves. What good are these customers of whom you speak, when there are no longer any American producers of those products? Explain to me how this is good, how it grows our economy?

          The original poster in this thread was correct: if you have any sense of self-preservation whatsoever you protect your key industries. If you don't, and someone takes them away from you (as is happening with virtually every manufacturing sector in the United States today) you are vulnerable at every level. I'm not saying that means exclude all foreign competition, but it does mean that you make damn sure that foreign competition isn't allowed to operate in a predatory manner. Unfortunately for us, our government and corporate leaders sold us out for a song. Now, I don't know exactly what's going to happen over the next few years, but if what I read about American manufacturing being down to 1950's levels is even close to being true, we are in deep shit.

          This is not a joke, this is not some philosophical issue with no real-world effects: when a major economy falls people get hurt. Ours is heading for a fall of Biblical proportions, and it's you Free Traders that will bear a significant responsibility for that event.
    • Re: (Score:3, Insightful)

      by Angostura (703910)

      I wonder why [some] westerners always come up with their pet projects and think these projects will solve third world problems.


        Because said Westerner knows that he can have little impact on international trade policy, but does have a potentially nifty, cheap approach to micro-generation? Don't let me stop you from looking that gift-horse in the mouth though.
    • Re:Wrong solution (Score:5, Insightful)

      by Anonymous Coward on Sunday October 14, 2007 @10:37AM (#20973535)
      I like how you're faulting "western" inventors. Are you American by any chance? Or at least from a western nation yourself?

      I've seen your kind of reaction turn up in the Slashdot discussions about the OLPC project. Here's a summary of what I see as being your argument:

      "This is a waste of time -- a worthless solution -- because it doesn't provide the power and performance that I, as a westerner, demand from technology."

      If that's an accurate summary, I have news for you: if you've spent a lifetime living on the edge of civilization, having a power source that can turn on a few LEDs at night or run a radio, or having a "worthless, underpowered laptop" can mean a real improvement in your life.

      I'm sorry if this windbelt doesn't provide you with enough power to run your home's AC unit, your 62 inch plasma display, your 100+ halogen and assorted incandescent light bulbs, and that server room in your basement. The thing is, this solution isn't meant for you. I know that's hard to handle -- that someone might be thinking about people other than yourself -- but please try to accept that possibility. If you find that overly taxing, just crack open another beer and take your Hummer out for a drive to the gas station.

      Believe it or not, there are people out there who can get by with a lot less than you, and for them, something like this will be a big deal.
      • by jcr (53032)
        Hear, hear! Well said, AC.

        -jcr

      • I like how you're faulting "western" inventors. Are you American by any chance? Or at least from a western nation yourself?

        I've seen your kind of reaction turn up in the Slashdot discussions about the OLPC project. Here's a summary of what I see as being your argument:

        "This is a waste of time -- a worthless solution -- because it doesn't provide the power and performance that I, as a westerner, demand from technology."

        If that's an accurate summary, I have news for you: if you've spent a lifetime living on the edge of civilization, having a power source that can turn on a few LEDs at night or run a radio, or having a "worthless, underpowered laptop" can mean a real improvement in your life.

        I'm sorry if this windbelt doesn't provide you with enough power to run your home's AC unit, your 62 inch plasma display, your 100+ halogen and assorted incandescent light bulbs, and that server room in your basement. The thing is, this solution isn't meant for you. I know that's hard to handle -- that someone might be thinking about people other than yourself -- but please try to accept that possibility. If you find that overly taxing, just crack open another beer and take your Hummer out for a drive to the gas station.

        Believe it or not, there are people out there who can get by with a lot less than you, and for them, something like this will be a big deal.

        Even as a wasteful "Westerner" typing away on my MacBook I find this positively insightful!

        Will someone mod parent up please?

      • I'd like to point out that is global warming is real and we are going to do anything about it, we ALL need to learn to live with less power consumption.

        Heck even if global warming is bunk, if the Chinese keep their head long rush to consume like westerners, then we are ALL going to need to do more with less.

        The other question is how well will it scale?
    • Re: (Score:3, Interesting)

      by edwardpickman (965122)
      I'm against corn subsidies but why is the solution to all the third world problems the gutting of US industries? The point is the Euro is stronger so why doesn't some one ever mention Europe opening up more to foreign markets? The US has exported a large percentage of it's industrial production and it's importing more food from foreign countries than ever before. The US produces more food than any other country in the world and generally countries want more food exports from the US not the other way around.
      • by RAMMS+EIN (578166)
        If I had mod points, I'd mod you up. As it is, I'll just say you are spot on. Oh, and for the record, people do pick on the EU. I know, I live there. And we're (that is, some people are) trying to cut the subsidies and import barriers and all those, but, as you can imagine, the people benefiting from them scream bloody murder every time. It's a huge mess. Such is politics.
    • You are thinking too in the box when you think a pet project can't go and help third world countries. It all must start with a small idea first. How do you think the XO-laptop was developed? I'm sure it started with a really simple mockup prototype at the earliest stages, a "pet project".

      It all starts with some dude tinkering in his garage, in his office playing with components. Then you go to the engineering/R and D level which applies the PRINCIPLES of the pet project onto a larger scale. Not the same li

    • by Dunbal (464142)
      I wonder why [some] westerners always come up with their pet projects and think these projects will solve third world problems.

            Because the West (and more recently Japan) have clearly demonstrated themselves to be innovators.
    • Re: (Score:3, Insightful)

      by jcr (53032)
      The only sure way to help countries of the third world is for countries like the US to open up their subsidized markets.

      That's not the biggest problem that most of the third world has, not by a long shot. Sure, they'd benefit even more than we would if our tax money wasn't spent on keeping farmers growing more of a given crop than the market wants them to, but the biggest drag on any third world country today is the local kleptocrats who hand out monopolies to their cronies, and use aid money to buy weapo
    • by Atzanteol (99067)

      I wonder why [some] westerners always come up with their pet projects and think these projects will solve third world problems.

      Becuase most of the innovation in third world nations takes the form of "new ways to commit genocide?"

    • Re: (Score:3, Informative)

      by ibbey (27873)
      To the shown apparatus generates too little power to be of any use at all.

      None, huh? So why does he show the device powering a radio and a clock in the video? You're right, 40mW isn't much power, but according to the video the device costs $2-$5. For that price, you can easily build a few of them & you start to get to a more useful amount of power. But even 40mW is enough to do things like maintain the charge on a cell phone or charge a flashlight. I'm sure someone with more knowledge of low power syste
  • From the summary: taught kite fabric.

    Must be some kind of memory fiber that returns to its original shape when the wind stops blowing.
  • It wasn't just the wind, it was also the resonance of the poorly designed structure.

    The wind was just the power to get it to resonate, from that point on it was all vibrations.
  • by Snowgen (586732)
    This was just posted on Thursday [slashdot.org].
    • by OzPeter (195038)
      Apparently in the recent interview, no one bothered to take Taco to task over dupes.
  • This right here is what science and inventing is all about. Forget how things have been done in the past and come up with something better.

    If you think about it, the wind turbine is essentially based on the old windmill design that has been around for centuries. It's reasonable to think that when people people were first thinking of a way to harness wind energy, that was the first thing they thought of for that exact reason.
  • by BoRegardless (721219) on Sunday October 14, 2007 @10:30AM (#20973511)
    There was not any engineering detail to go on from the video, I agree. But trashing the idea without getting the numbers is bad science, more akin to the nightly news.

    The whole concept is interesting, because it can work with wood and cloth instead of mylar and aluminum. The "first world" part would be the magnet, coils and the DC rectifier/converter to allow a user to likely charge a battery.

    How many of these generators and how big they would be to extract a usable 10 watts of charging power in a 5-10 mph wind hasn't been defined, but with a couple models, that can be determined.

    You never learn anything by bitching. Buckling up and testing is the way this & other ideas will be understood and improved. For the 3rd world, just a minimal LED lamp array can make the difference between studying at night or not.

    • by Dunbal (464142)
      There was not any engineering detail to go on from the video

            Engineering detail? It's a strap with a magnet glued on, placed in front of a copper wire. Not much engineering there.
      • by Bucc5062 (856482) <bucc5062@gmail.cPLANCKom minus physicist> on Sunday October 14, 2007 @12:19PM (#20974155)
        Fine, then make one and truly answer the parents post. He/she talks about how people were trashing the idea, but not by applying actual effort to prove or disprove, just unsubstantiated opinion.

        I am not an engineer, I do not think I could build this, but were I capable I'd try it out and start to look at the numbers.

        1 - It was said it would not work in low winds (5/10 mph) because the demo used a fan. Prove it I say. it may be a combination of material tension and mass of the magnet.

        2 - It was said it would buzz. Prove it. Build one and measure the decibels produced. Can the sound be dampened without losing efficiency.

        3 - It was said it was not 30x efficient. Prove it. Build one and compare it to other micro wind generators (though the video indicated there were few out there)

        I know this is /. and most times we don't read the article, we have varying opinions, but it does surprise me that out of all the eggheads on this blog list, there are not some who could duplicate the experiment and show results. until proven differently, my opinion is that this device is a cool idea worthy of more review, and an example of genuine innovation.
        • by Plunky (929104)

          1 - It was said it would not work in low winds (5/10 mph) because the demo used a fan. Prove it I say. it may be a combination of material tension and mass of the magnet.

          I think low winds are just fine. You want this to resonate, and as was apparently demonstrated by the bridge incident, resonation can be induced with low wind speeds. The lines on my sailing yacht resonate if the windspeed is low enough, causes enough hum to wake me on a calm night

          actually, I think a wider or longer belt might work bet

    • Popular Mechanics is just a front for Press Releases most of the time and probably lost most their educated staff many years ago back when I stopped reading the trash it became (not that it was ever a quality source for science news.)

      Look at savonius for cheap power.

      Off the top of my head:
      Take the design from those shake flashlights (aka "jerk off" lights) and balance the thing so it can totter up and down enough for the magnet to slide past the coil. Then hook up just about anything that will flap in the
  • by Animats (122034) on Sunday October 14, 2007 @11:34AM (#20973887) Homepage

    It's so Popular Mechanics. Another resonant oscillating generator.

    This is an old idea, but the usual form is a free-piston engine. [freepistonpower.com] Popular Mechanics was hot about that one back in 2004. For something that will light two LEDs, that thing looks big and expensive. Note the machined aluminum frame. For comparison, here's a toy wind generator kit [amazon.co.uk] ("convert a plastic bottle to a wind generator!").

    Notice how the guy with the vibrating ribbon generator demonstrates it in front of an electric fan. On high. That's probably because it only works in a strong wind. People generally don't live where winds are regularly that high. Wind speed in Port-au-Prince has been between 9 and 12MPH all day, so something that cuts in around 9MPH is needed for use in Haiti.

    The classic cheapie generator is taking an oil drum, cutting it in half, and using that as a Savonius rotor. Then you get an alternator from a car, and there's your actual generator. The axle sticks up into the air, where the halves of the oil drum collect the wind and turn the alternator. Here's a smaller version [angelfire.com].

    • Re: (Score:3, Insightful)

      by Cheerio Boy (82178) *
      You can also make them from Pringles cans:

      http://shorterlink.org/3266 [shorterlink.org]

      Or heating ductwork:

      http://shorterlink.org/3267 [shorterlink.org]

      As for the frame you're referring to that could easily be made of local materials like wood or recycled plastic or almost anything that will put tension on the material. And the repair on this object is considerably cheaper than replacing something like the spindle bearings of a oil-drum wind generator which will wear out over a long period of constant use.
  • by eepok (545733)
    Why doesn't he use the same source of power that's running the fan?
    Common sense isn't so common, is it?
  • To the naysayers: (Score:2, Insightful)

    by SeaDuck79 (851025)
    I'm not saying that this is the greatest thing since sliced bread, BUT... Those who think a thing to be impossible should shut up and get out of the way of those who are doing it. You can waste your time cursing the darkness, but it's probably not going to be as productive as trying to light a candle. Or an LED.
  • The specs are not impressive. He's talking about 0.040 Watts. To even begin to light a house you'd want at least 10 watts, that would take 250 of these devices. At $4 each, that's a cost of $100 per watt. Spendy.

    Or take one salvaged windshield-wiper motor with a three blades. Maybe $15 for 10 watts, or $1.50 per watt. Which is cheaper and easier to install and maintain?

  • This article is a dupe. Here's what I said about Shawn last time:
    ===
    http://science.slashdot.org/article.pl?sid=07/10/11/212243 [slashdot.org]
    Low-tech Inventions That Help Change Lives
    arbitraryaardvark (845916) on Thursday October 11, @07:41PM (#20947701)
    (http://vark.blogspot.com/ | Last Journal: Friday October 12, @03:26AM)
    http://www.wired.com/culture/lifestyle/news/2004/10/65276 [wired.com] [wired.com]
    A MacGyver for the Third World
    http://www.flickr.com/photos/aidg/612856202/in/set-72157600466239024/ [flickr.com] [flickr.com]
    flickr
    http [instapundit.com]
  • nice idea, but I could imagine the noise problem as a major obstacle.

Facts are stubborn, but statistics are more pliable.

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