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The Windbelt – a Cheap Wind-Power Generator
dominique_cimafranca writes "Shawn Frayne, a 28-year old inventor, has developed a small wind-powered generator that can be used to power small appliances in developing countries. Unlike the typical propeller design one expects of wind generators, the windbelt uses the oscillation of a membrane that follows the vibration of bridge. The oscillation drives small magnets which generate the electricity. From the article: 'Frayne's device, which he calls a Windbelt, is a taut membrane fitted with a pair of magnets that oscillate between metal coils. Prototypes have generated 40 milliwatts in 10-mph slivers of wind, making his device 10 to 30 times as efficient as the best microturbines. Frayne envisions the Windbelt costing a few dollars and replacing kerosene lamps in Haitian homes.'"
The air needs to pass over this resonating piece at a particular speed to start it resonating (flapping). Is there some sort of way to adjust the tension of the band during use to account for faster / slower winds or is it only good at 7.9563 mph winds?
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Some things can scale, but there are other things that really can't be enlarged. For example, ionizing air currents. Yes, it works on a small scale to move air through a Sharper Image filter, but you couldn't effectively push the air through a house's HVAC system with just thin wires and a high potential difference.
If this belt technology can be scaled up to generate kilowatts as opposed to milliwatts, it would have a real use. Otherwise, its similar to small solar panel technology in the 1980s -- will power a small motor or a clock, but that's basically it. It may at best end up a niche product as something to power remotely located low-wattage computers, such as weather stations in heavy forest.
Ah, yes. But if you were actually a member of his target audience (dirt poor people in countries like Haiti making $2-$4 per day) then you couldn't afford that fancy $3000 turbine in your wildest dreams. Smaller, more affordable turbines grow dramatically less efficient due to friction forces at small sizes. In order to actually make your point valid, you'd have to find a wind turbine of the same wattage range that is cheaper.
The whole point here is very specific. Poor people, like the ones in Haiti don't have many things that need electricity. The problem is, the only source of light they have is fire based causing an increases risk of burning to death in a hovel fire. The problem is compounded by the fact that third world shanty towns usually don't have much in the way of municipal fire codes. Assuming LED bulbs come down in price far enough (which the look to do eventually) they have the energy efficiency needed to run off this thing, the ruggedness to last in that kind of environment, and the long life to make themselves truly economical. They could, completely, replace oil lamps, candles, and other fire based light sources. It has the added bonus of eliminating one of the motivating factors in the deforestation of Haiti, which, in turn, is one of the reasons they've had such horrible flooding in this last hurricane.
This thing still has a lot of things to prove before it can be said to be useful (durability is one of them) but cost/watt isn't an issue for the application being envisioned. As for first-world applications he can use to fund his third-world goal, he just has to look long enough for similar places where a microturbine might have, otherwise, been the only option.
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So basically this is a large scale version of a ribbon microphone? Except backwards? Wouldn't it work much better if it actually worked exactly like a ribbon magnet, i.e. fixed magnetic bars on either side of a conductive ribbon? You'd certainly get less drag on the ribbon if it isn't trying to move heavy magnets around. Who wants to build one and find out? :-D
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I know that he talked about scaling up. Put that down to usual inventor exuberance. All of us who've gotten an invention working have experienced that. What matters is that is entire apparatus of about ten parts can be built of scrap, in a couple of hours.
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Yeah, sure, he's using optimized materials. But anything thin and flexible could be tested, have its optimal shape for flutter in a given environment determined, and used to make these. I knew some guys who did the sensors for their thesis using strips of mylar from potato chip bags.
Magnets are the one hard part and even those can be pulled from dead speakers or whatever.
Wound wire? We've all built our own generators as kids, yes? Winding enough for an electromagnet like that is no big deal. And wire turns up in waste streams all over the place. That's why so many baskets and such from rural craftspeople are made of it.
Rigid frame? Whatever's around. I'm not entirely sure just how rigid that frame needs to be but worst case scenario we're talking about a chunk of iron cut out of a dead car.
And so on.
What this does is enable illiterate people with a few hours of training to make a device from things they don't have to pay for that can power basic things like lights. And from what I'm seeing, it's the kind of thing that will propagate. UNESCO staffer teaches Jose. Jose's brother comes by and asks about it; Jose teaches his brother. Brother's wife wants one to sew better; she makes one for herself. The wife's friends drop by . .
Excellent. All we need to do is provide superbright LEDs and whatever parts turn out to most be in demand and soon, count on it, there will be innovations by the dozens turning up that the inventors and NGO folks never even knew about.
It's all about the information. And what we do with it.
These things seem pretty well scalable for only the cost of the parts. The little desktop one he's got generates milliwatts, imagine what several of these, lined up on a roof would do. Put in just as many at 90 degrees to those just above them, and you're covered for winds from four directions. Work out a weather vane system that keeps the fabric edge-on into the wind all the time, and it can use any light breeze from any direction. I'd probably put up with those to light my house just to lower my power bill. Considering the size of the average roof in the developed world, I'd probably have power to spare if I lit my house with LED nests.
Another factor to consider is that it's another power source for a Mars colony. The dust storms could blot out the sun, and these would still work, assuming the coils are protected and the fabric is strong enough. I don't think the inventor has considered just how important this could be to the whole world, not just the third world countries.
Admit it. You post strawman arguments as AC so you get modded Insightful for refuting them, rather than Troll
One of these windbelt machines will light up only two 20 milliamp LEDs
That's only in the current configuration he's using.....
What happens if:
1) you put magnets at both ends, does it double the output?
2) you make coils "all along" the belt? Does that drastically increase output?
3) you lengthen or shorten the belt? It changes the harmonics, but how does it affect the output?
Other questions:
He's using a desk fan *ON HIGH*. What are the wind requirements needed to generate what level of output? What is the minimum wind speed to initiate the harmonics (watching the video, you see simple vibration until a point where it breaks out into the full "tear up the bridge" mode). How does faster or slower wind affect it? Is there a point where too much wind causes it to lose the harmonic generation mode? Does a commercial system need to be able to adjust tension based on wind speed (added complexity and added cost).
It's a very good start of something, but there are a lot of things not really covered in the short video. I'd love to see this taken several steps more.
Layne