Microwind Generator For Low Power Systems

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.

Comments

Macro wind power: Kite Gen

[Sub Zero 992]

And now for a really interesting renewable energy concept: kite gen. Would have made Newton smile :)

Re:Macro wind power: Kite Gen

[StarfishOne]

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

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

The more alternatives for environmentally friendly energy sources the better! :)

Re:Macro wind power: Kite Gen

[0111 1110]

Birds are not noted for their advanced intelligence.

Au contraire mon ami Aussi. Convinced yet?

Sub-100W generators are very interesting...

[DamonHD]

...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

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:Sub-100W generators are very interesting...

[Smidge204]

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=

Re:Sub-100W generators are very interesting...

[flyingfsck]

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.

'Taught' material?

[Alicat1194]

What did they teach it? Um, Editors, I think the word you're looking for is 'taut'.

Units

[springbox]

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?

Wrong solution

[bogaboga]

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:Wrong solution

[Anonymous Coward]

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.

Re:Wrong solution

[Belacgod]

Or, as C.S. Lewis put it, the world is "divided between wolves who do not understand, and sheep who cannot defend, the things which make life desirable."

Re:Wrong solution

[ScrewMaster]

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.

A bit more detail

[AndroidCat]

Shawn Frayne's Windbelt Wins Popular Mechanics 2007 Breakthrough Award

Re:Nah, this is dumb

[confused one]

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...

Not a Single Engineering Reply

[BoRegardless]

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.

Re:Not a Single Engineering Reply

[Bucc5062]

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.

Re:Nah, this is dumb

[ezavada]

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.

Sure, but this will only run when there is wind. In any case you are going to need some kind of energy storage, whether batteries for small scale use, or pumped water for larger scale.

With a small scale system like this, you could also combine it with solar panels and a battery and get luggable power generation that would work in most places.

I'm thinking about building one myself to get some numbers and see how well it scales

Cool! I'm sure a lot of people would love to see a project page for a DIY wind generator of this sort!

Re:And how exactly does the science work?

[ashitaka]

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?