Windpower with less wind

[ibbman]

Anyone heard of this?

http://www.corpmagazine.com/Departments/...fault.aspx

http://www.earthtronics.com/honeywell.aspx

It looks like they should be out later this year and might work for lower wind areas!

[MarkP]

I wish them well. That being said I don't think they are really revolutionizing the industry. There is less energy in low speed wind. As energy costs go up, it becomes economically practical to design wind turbines for lower wind speeds. When oil was dirt cheap it didn't pay to compete with it, so wind turbines were exclusively designed for windy areas.

My father and I mounted a small 6' diameter wind turbine on the roof of their attached garage. I can tell you that wind is very variable as an energy resource and no turbine design can compensate for lack of a good location with a good wind resource. Smoothness of the wind is a really big deal. Wind turbines are maintenance hogs and turbulence makes it way worse. A steady 5 mph or a steady 100 mph, both would be a snap, but to utilize wind that varies from 0 to 50 is a real challenge.

From experience as well as what I read on the internet, mounting the turbine on the house is bad. It shakes the whole house sometimes. Scary. Then again we had a turbine that was almost antique 20 years ago. I am sure they are better today but there are certain laws of physics you can't get around.

[Rob Tucker]

Somewhere here on Punaweb is mention of a new wind generator type. It is designed as a wing in lieu of a propeller and operates efficiently in low wind. It is, as I recall, going into testing Kona side at the Energy Lab as I write. Very, very interesting. The first test of it was in Santa Barbara, CA. a few years ago.

Think back to that old B&W film of an early airplane with about five stacked wings. It didn't fly but the theory of using a wing to lift in a breeze seems to have ability to drive a cam.

[David M]

We've been reading these teasers for years - and of course the promise is just around the corner. Has anyone found any published real life results? Please post if so, as I'm curious to read good news.

I too was intrigued by the wing thing - where are the results????

David

Ninole Resident

[JWFITZ]

The power of a turbine is primarily a function of its swept volume, not blade solidity(how many blades.)

The power(force) of (the useful range) of wind speed is a a function of the square of the velocity. Temperature is also a factor, as is humidity, and hot dry air has less power. Note: this is a broad generalization and not an equation, and only works for off the cuff generalizations through the most useful and common range of wind speeds. You'll find that at low wind speeds nothing will turn and at high wind speeds, meaning much over 40 knots things sensibly built for 10 knots will fly all apart. A commonly used engineers formula is pounds per square foot = wind in velocity in MPH(.003)^2

If you want more information, google Reynold's number and dive in.

There will be very little power available in such a unit. The reason they scale wind turbines for 10 knots or more as there's just very little juice in low wind speeds and it's near pointless to even try to gather it, so one may as well design to optimize at higher wind speeds.

Anyway, there's the basic physics. Anybody want the real numbers I'll dig them up but you'll find once you plug the whole works together the old guestimate is going to be pretty close. It gets into a whole other can of worms with angle of incidence, yaw, turbulence and the rest, but no wind generator no matter how efficient can create power that isn't there. I think any of us who've carried a sheet of plywood in 5 mph, or 10, or 15, or 20--and have given up, will immediately grasp the issue.

That being said, I've installed wind generators and for many are likely a better option than solar, and deserve more attention than they get. They are noisy, and that is a downside.

[Rob Tucker]

David, My original posting on this was almost exactly one year ago Here. This is not a turbine.

But the HtH link is in archive and they charge a fee. So I looked about and found this site: Kelly WindWing

I haven't heard anything since. If anyone has the time to call N.E.L. it would be nice to know if this testing is really underway, if there are results, and if the results are published or scheduled to be published.

I also found this article about a proposed installation elsewhere which makes mention of Hawaii and the NEL.

It would be great if this was not another Minto Wheel.

[JWFITZ]

There's more money in Minto Wheels than there is in alternative energy, unfortunately.

By the way, it's worth working the whole F/lbs=V(.003)^2 on the surface area of one's south facing wall and ponder a Cat III hurricane at 80 mph. . .

[Rob Tucker]

I've already pondered that. I'm in good shape, thanks.

[ibbman]

I guess we'll see what happens if these ever hit the market and get real world results. The magnets being at the tips of the blades instead of at the hub is interesting.