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Forum Index : Windmills : The Helix Vawt and Construction Ideas

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floodrod
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Joined: 08/07/2009
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Posts: 70

Posted: 02:20am 17 Oct 2009

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I was reading up on several studies about Vawts and best performers. These two bits of information caught my interest..

1... During one year, the Windside Double Helix VAWT in Finland produced about 400 kWh/square meter. It was the best wind machine installed in Finland during that year. The best HAWT type produced about 300 kWh/square meter during the same year.

2.... "Different blade shapes which were tested at the University of Illinois showed a maximum efficiency of about 35 %[5]. More Savonius turbines were tested at Kansas State University, with efficiencies reported of about 25 %[13, 4].
It thus appears that the Savonius, if properly designed, has an efficiency nearly as good as the horizontal axis propeller turbine or the Darrieus turbine. The Savonius turbine therefore holds promise in applications where low to medium technology is required or where the high starting torque is important." By Wind Energy Systems
by Dr. Gary L. Johnson November 20, 2001 http://www.eece.ksu.edu/~gjohnson/

I have been looking at many pictures of these double helix Vawts and trying to come up with construction ideas.. This is when WINDOW WELLS came to mind.. Take a look at the pic..

They could be purchased pretty cheap ($15 USD Each), there made of non-corrosive materials, they are weather proof, they come in all different sizes, they have internal ridges to harness the air, and they have mounting holes already perfectly spaced.. If one would design a center shaft, they may be able to use these window wells by mounting them onto the shaft in a double helix-spiral formation. I would imagine they would be "Newbie" friendly because no cutting/shaping is required..

I was thinking of buying large diameter PVC and chopping it up, but this may be easier and more efficient. Any feedback before I waste another $200?

Downwind

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Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 03:33am 17 Oct 2009

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What the hell is a window well??
and what is one used for.
Just curious??

Sometimes it just works

floodrod
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Joined: 08/07/2009
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Posts: 70

Posted: 04:01am 17 Oct 2009

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they go around basement windows that are lower than ground level. They keep water from running into your basement

electrondady1
Senior Member

Joined: 12/02/2009
Location: Canada
Posts: 208

Posted: 01:44pm 19 Oct 2009

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it wont give you the double helix shape you are looking for.
you would need lots of segments to approximate a stepped version of one.
lots of support structure.
welding skill would come in handy.
if you are willing to settle for a less sophisticated
shape, it could be used for a straight sided version.
but if that is the case then why not use 40 gal.plastic barrels, cut in half.
what are the dimensions?

cutting a piece of large dia . tubing might give you a more aesthetically pleasing result.

anteror
Senior Member

Joined: 06/10/2009
Location: Finland
Posts: 189

Posted: 08:57am 20 Oct 2009

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Look the powercurve of this;

http://www.bettergeneration.com/wind-turbine-reviews/turby-v awt.html

It really does not produce energy untill very heavy winds.
Its diameter is 2,89m !!!
They had a litle while ago big pages saying this and that.
Now they have;

http://www.turby.nl/

Needs very high winds to produce energy, which are very rare on a one year period.

Antero

Edited by anteror 2009-10-21

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