Forgot your password?
typodupeerror
Power

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.
This discussion has been archived. No new comments can be posted.

Microwind Generator For Low Power Systems

Comments Filter:
  • by Sub Zero 992 (947972) on Sunday October 14, 2007 @08:10AM (#20973099) Homepage
    And now for a really interesting renewable energy concept: kite gen [kitegen.com]. Would have made Newton smile :)
  • Noise issue (Score:1, Interesting)

    by Anonymous Coward on Sunday October 14, 2007 @08:22AM (#20973159)
    I recently was looking at microturbines for my urban house recently and decided it was a bad idea because of the noise they make when the wind isnt going fast and people are trying to sleep - woosh...woosh...woosh...woosh...

    I wonder if this makes a noise. buzzzzzzzzzzzzzzzzzzzzzzzzz
    I have decided to use these instead of microturbines and added a pivot and tail so it can turn with the wind direction, and put 20 up on my roof. Would be interesting to see how the buzz multiplies. Would I be living under a swarm of bees?
  • Prior Art, 1964 (Score:2, Interesting)

    by AndroidCat (229562) on Sunday October 14, 2007 @08:27AM (#20973185) Homepage
    (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!
  • by conureman (748753) on Sunday October 14, 2007 @08:28AM (#20973189)
    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.
  • Wrong solution (Score:4, Interesting)

    by bogaboga (793279) on Sunday October 14, 2007 @08:35AM (#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:Nah, this is dumb (Score:5, Interesting)

    by confused one (671304) on Sunday October 14, 2007 @08:47AM (#20973287)

    Not too dumb. He was designing it for use in Haiti. While I suspect there are places where nothing is tenable, a thin ribbon under tension is a whole lot simpler and cheaper to manufacture and maintain than a rotating wind turbine. It doesn't have to be mylar, you could use scrap cloth, although mylar may last longer and be easier to keep under tension. LED's were for the demo. You could use the thing to run any light; or better yet charge a small battery so you have power on demand.

    He made another good point in the article: If you break this you have something that a local can fix. If you break a solar panel, your stuck with a broken panel (which is trash). What he didn't mention is that this would run at night too, as opposed to a solar panel that only works during the day.

    while I agree with another poster's comment that the 30x improvement in efficiency over a microturbine is probably not real, I think it's fairly interesting. Enough so that, since IAAAP (I am an applied physicist), I'm thinking about building one myself to get some numbers and see how well it scales. I know some people in Africa who might be interested in something like this...

  • Re:Wrong solution (Score:3, Interesting)

    by blahplusplus (757119) on Sunday October 14, 2007 @08:48AM (#20973295)
    "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 "protectionism" the US was BUILT by protectionists. They understood from gaining their independence that you need to have control over industries that are of strategic value in case of war/disagreement/embargo/etc.
  • Re:Wrong solution (Score:2, Interesting)

    by Kadin2048 (468275) * <slashdot.kadin@[ ]y.net ['xox' in gap]> on Sunday October 14, 2007 @09:13AM (#20973411) Homepage Journal

    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 vtcodger (957785) on Sunday October 14, 2007 @09:22AM (#20973451)
    Didn't read the article, did we? Come on, admit it.

    The device is specifically aimed at powering very low power devices in poor and developing countries -- radios, (very) low wattage lights, etc. The generators are projected to be relatively small and the illustration seems to show one hung on the side of a building. The major point is that conventional turbines are inefficient at very low power levels because of frictional losses whereas these windscreens are projected to be an order of magnitude or more better (10-30x according to the article).

    You're correct, the device might not scale up to windfarm scale although it's hard to see it as more of a hazard to birds and aircraft than a rotating blade. I have my doubts that a big windscreen will be as efficient at the high end as a turbine, but that's just a guess.

    Anyway, it looks to be a cute idea, and I hope it works out.

  • Re:Wrong solution (Score:3, Interesting)

    by edwardpickman (965122) on Sunday October 14, 2007 @09:43AM (#20973573)
    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. The irony is if the US increased food imports from third world countries the complaint would be we were buying food that the country of origin needed. I've already heard this complaint about some crops. It's a no win argument but the US is an easy target and saying the US could do more doesn't get the rest of the first world off the hook. Most of the first world has subsidies. That was actually the biggest sticking point to creating the European Union was all the pet subsidies each country had.
  • Re:Wrong solution (Score:3, Interesting)

    by ChrisMaple (607946) on Sunday October 14, 2007 @09:46AM (#20973601)
    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.

  • by ChrisMaple (607946) on Sunday October 14, 2007 @10:03AM (#20973701)
    TFA shows LEDs lit by a single generator. Output voltage is proportional to (magnet strength) times (magnet velocity) times (number of turns in the coil). Pick your output voltage and build accordingly.

    My guess is that generators in series can't easily be synchronized, but generators in parallel would tend to self-synchonize (assuming near-identical construction and side-by-side location).

  • by lostsatellite82 (1153629) on Sunday October 14, 2007 @10:23AM (#20973813)
    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 are far less green than modern coal plants.
  • by Animats (122034) on Sunday October 14, 2007 @10:34AM (#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:Wrong solution (Score:3, Interesting)

    by Dunbal (464142) on Sunday October 14, 2007 @10:39AM (#20973921)
    No, I was just using metaphor to point out WHY we can't all get along. This world consists of those who want to fuck, and those who get fucked (even if they don't want to be). THAT is why we can't get along.
  • Re:Wrong solution (Score:5, Interesting)

    by ScrewMaster (602015) on Sunday October 14, 2007 @11:50AM (#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.
  • by linuxvolts (1173693) on Sunday October 14, 2007 @02:27PM (#20975397)
    Wind power is very well understood. The power in the wind is (1/2)*p*A*v^3. Where p is air density in units (kg/m^3), A is the swept area in units (m^2) and v is the velocity of the wind in units (m/s). This is intuitive from a physics perspective if the energy of a moving object is (1/2)*m*v^2 then p*A*v is mass. Albert Betz proved that the maximum efficiency of a wind generating device is 59%. Many small wind turbines can achieve an efficiency of over 30%. From the article it says "his device [is] 10 to 30 times as efficient as the best microturbines" That would put the efficiency of the device at at least 300%. Not only is that higher than the betz limit it is higher than the energy available. A quick example. Lets use an air density of 1 and a swept area of 1 (for a rotary turbine this would be a blade radius of .56m), a wind velocity of 10mph (4.47 m/s) and an efficiency of 30%. This will make 13.4 watts of power. That would be enough to power several small led light.
  • by flyingfsck (986395) on Sunday October 14, 2007 @02:32PM (#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:Nah, this is dumb (Score:2, Interesting)

    by Invidious (106932) on Sunday October 14, 2007 @11:19PM (#20978789)
    One of the neater aspects about this project is that you can build it out of trash you have laying around. Salvage magnets from headphones or speakers, salvage magnet wire from a motor, build the frame out of whateverthehell you have laying around, and use a strip of waxed silk or something for the ribbon. You need a little bit more know-how to turn that into DC, but that's also very basic, and the components could also be salvaged from just about anything. Hell, same thing with LEDs. Let's face it, people in the third world are superb scavengers -- look at the sudden proliferation of satellite dishes made from hammered-out cans that popped up in Afghanistan after we toppled their regime.
  • 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 most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny ..." -- Isaac Asimov

Working...