Fact or Fraud

[wdyasq]

There has been a discussion on VAWT and Helix Wind was mentioned. I decided to go over to the site and see the new and exciting.

I went to the FAQ page:

"Q. What are the dimensions?

A. Helix wind turbines currently come in two sizes, the Helix 2kw home for residential applications, which stands 9' feet tall by 4' feet in diameter (2.74m x 1.21m). The commercial turbine, the Helix 5 kw measures 12' feet in height by 4' feet in diameter, (3.6m x 1.21m)."

That gives one the effective swept area of a 2.04m blade-set for the 2kW unit and a 2.34m blade-set if these were HVAT units. Another quote form the FAQ: "Most VAWTs produce energy at only 50% of the efficiency of HAWTs in large part because of the additional drag that they have as their blades rotate into the wind."

According to their FAQ:

"Q.How much power will it generate?

A The Helix 2kw system with an average wind speed of 11 mph (5m/s) will average 2125 kWh per year."

"The Helix 5kw system with an average wind speed of 11 mph (5m/s) will average 5902 kWh per year."

WOW - that is some kind of power!

The next step is to go to the handy wind power calculator Ross W wrote and is on his IRC channel - I convert 11mph to 17.6kph and punch in some numbers:

"!wp 2.04 17.6 - 233.9 watts possible from 2.0 m dia prop (3.3 m^2) in 17 km/Hr wind (density of 1.225000)- 37.4 watts output assuming generator is 80% efficient and Cp of 0.20"

And: "!wp 2.14 17.6 - 257.4 watts possible from 2.1 m dia prop (3.6 m^2) in 17 km/Hr wind (density of 1.225000) -41.2 watts output assuming generator is 80% efficient and Cp of 0.20

Let's see, there are 8766 hours to a year. I multiply that by the output (41.2W), using the highest output and not degrading for efficiency...361,159 Wh/yr. That is equal to 361kWh/yr giving the unit more than twice the possible credit it should be allowed. this gives the little turbine making 15% of what is claimed and the large one about 6%. And actually, 8% and 3% of claimed amount.

This is another successful scam if the proponents avoid prison time, IMO

Ron

[TomW]

Gee, Ron;

Hard enough keeping the peace here lately with the surge in VAWT proponents.

Thanks for lighting the fuse. NOT.

I am outta here on this one.

Cheers.

TomW

[disaray1]

Jeez, Ron! Why are you so pessimistic? Everything was going sooo good until you busted out that obviously defective calculator. Quit harshin' my buzz.

 David  

 ps. home unit = 4'X 9'  commercial unit 4'X 12'  25% increase in size.

     home unit = 2kw  commercial unit =5kw 150% increase output. Yep.

[windstuffnow]

  Just piling some numbers in the calculator I get 45 watts with the 9x4 and 56 watts from the 12x4 or 395kwh and 497kwh respectively.  That's if its in an 11mph wind 24/365.  I think their a bit off on their numbers myself... buyer beware...

.

[vawtman]

Hi Tom

 I know your outa here on this but if i owned a wind turbine co.and wanted to prove my product i would set it up at your place.Like Zubbly did for ya.

 They must have people following us but never chime in.What better way to sell a product.

 Who knows maybe someday i will if we live long enough.

[richhagen]

It is a disservice to proponents of wind power and renewable energy that so many manufacturers make - at best - unrealistic claims about their products.  I think it is good to bust out the bad ones in a way, although I suspect that most gullible people will never see these posts before plunking down their cash, and will be left with the opinion that renewable energy in general does not work, or is impractical - and that is just too bad.  I should also note that there are plenty of responsible vendors who post generally reliable data about their products, I applaud those.  

There are of course plenty of people who get useful benefit out of having Vawts, and for some locations and applications they may be more practical than Hawts.  In my opinion, if the machine does what it is supposed to do it is good, if it doesn't, it is of course bad.  A machine that is supposed to do the impossible, and of course, can't, is in my opinion bad, and my opinion of people who promote products in such a way, well I'll save Tom or Kurt from having to edit out the language which I generally try to avoid using and leave that to ones imagination.  Rich

[Stonebrain]

Hi Ron,

I don't think it's enough doing unrealistic claims or lying on websites to do prison.

Did you find something about warranty on their site? That's just when you by it.

To get them in prison you must be very smart or very rich,or they must be very stupid.

cheers,

stonebrain

[jacquesm]

as long as being 'green' is synonymous with investors falling all over you with their $ (some funds have a statement that they will actually invest an x %age of their cash in green projects no matter what) these scams will continue to give wind power a bad rap.

[Stonebrain]

I think for most vendors it's a bad strategy to do unrealistic claims.

If you put a lot of money in a windmill you'll first try to inform yourself about windenergy.(On this site for exemple).

But if your product sucks,you might have a reason to change strategy:

the target becomes people who are rich and stupid.

cheers,

stonebrain

[dinges]

I came across this comparison of various wind turbine configurations and thought it might be interesting:

A full-resolution image (116 kB) can be found here:

http://www.anotherpower.com/gallery/energy-stuff-and-more/comp1?full=1

Interesting to compare the weights of the rotors (Wr) of various turbines to achieve a certain power (3.3 kW @ 5.6 m/s). The quality number (Q) is a bit arbitrary/artificial, but indicative nonetheless...

Regards,

Peter.

[DamonHD]

Yes, Q is somewhat dubious as it says nothing about the qualities or cost or even thinkness of the materials required in each case, but that is a very interesting chart nonetheless.

I'm astonished that the Savonius is shown as requiring so much more weight and so much little extra swept area as the left-most HAWT for the same power output: I assume that I've misunderstood something.

Thanks,

Damon

[fcfcfc]

Hi:

DanB mentioned the post so I thought I would look. I should have mentioned about the fact, when I said I thought the engineering was slick, I was not talking about the output energy level, only the visual design. I think it is fair to say that with only a marginal bit of knowledge, their energy output claims are far fetched, unless they have some of those coveted N1000 neos from voyager. I chose it for my design, except that I am adding aerofoil baffles,  because I thought the turbine mechanical design looked good. My to be turbine size of 4' x 16 feet isn't bigger because frankly I really can't make it much bigger for practical reasons, so, whatever I get, I get...

My spot is really a no wind spot except for the Winter time, which is OK since that is when the sun is the worst. What I will eventually end up with is hard to say other than a HAWT won't fly here. In terms of what is simplest to make from all aspects including the wacky gen ideas I have, is to take 3 of the 48VDC stators and build three "standard units", rectify the outputs and hook them in series to triple the voltage. Good by 48VDC, hello 144VDC... there's nothing wrong with stacking for scalability...

Or maybe get a dozen car alts and drive them off the main shaft of the turbine, all in a circle like a clock, and wire them to self excite like a series wound motor from residual flux and hook all the outputs in series, 15VDC x 12 = 180VDC...

Onward...

.....Bill

[richhagen]

Yeah, but if a product doesn't work to start with, then realistic claims will get them no sales. . . . . Rich