Inside a Chinese wind turbine nacelle

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  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Inside a Chinese wind turbine nacelle

    It looks like it produced 108 KWH over a total period of 4.8 months, which is considerably under the manufacturers projection of 2000 KWH per year. Over 5 months it "should" have produced over 800 KWH.

    Not sure where the missing months went, as it appears to have been installed for a period of 7 months. I can only assume that was down time - either from no wind or not working.

    That comes out to 21.6 KWH per month, using the 5 months figures. By contrast, a bicycle equipped with a pedal powered generator run for 2 hours a day would produce about 15 KWH per month. :p

    But this points out what we have been saying for years - just about all wind manufacturers estimated production figures are a fantasy. But from what few hard numbers we have seen from VAWT's indicates they are right up there with Cinderella.
  • WisJimWisJim Solar Expert Posts: 59 ✭✭✭
    Re: Inside a Chinese wind turbine nacelle

    One thing to remember with the Mariah is that the company is the only one building vertical axis turbines that had enough faith in their product to even have their machine tested. Makes you even more suspicious of the other VAWT manufacturers or promoters. Mariah also is a member of the AWEA, I think, and is the only VAWT company that sounds legitimate to me. People just don't realize how difficult the environment is on top of a tower in the wind, and how much wind it really takes to generate electricity.

    Jim, using a 1940s vintage Jacobs since 1978
  • boBboB Solar Expert Posts: 1,003 ✭✭✭✭
    Re: Inside a Chinese wind turbine nacelle

    I just saw a Windspire running and charging batteries 2 days ago. I have been very skeptical of VAWTs for quite some time now, but NOW see that they CAN actually work ! This was a class 6 wind site near the ocean, but still... It was making a fairly consistent 800 or 900 Watts or so to charge a 24V bank through an OutBack FX inverter acting as grid.

    I have a wee bit of a changed attitude for them now, but, probably only for the Mariah so far at this point. Most other ones I have seen were just spinning garden art I think.

    boB
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Inside a Chinese wind turbine nacelle

    BoB,

    Making 8-900 watts in what force wind?

    T
  • boBboB Solar Expert Posts: 1,003 ✭✭✭✭
    Re: Inside a Chinese wind turbine nacelle
    icarus wrote: »
    BoB,

    Making 8-900 watts in what force wind?

    T

    I wish I had an anemometer. I don't know what the "average" wind speed is there either. Will try to find out, somehow.

    It wasn't all that strong though. I mean, not a wind storm by any means. Maybe 20 MPH ? Maybe less. Not 28 MPH fer sure anyway.

    boB :D
  • Bob McGovernBob McGovern Solar Expert Posts: 25
    Re: Inside a Chinese wind turbine nacelle

    Here's specs on the Windspire: their "2000kWh/year" projections are based on 12 mph average wind speeds (Force 3, class 1), and that just ain't happening -- not by a factor of three, that ain't happening. It has a TSR of 2.8 and 80sqft of swept area; the ARE110, a solid-bottomed HAWT of known pedigree, TSR of 6.5, and 110 sqft of swept area, projects only 419 kWh/month at 12 mph.

    That said, the Windspire's stated TSR of 2.8 is by a good whack the highest I've ever seen for a VAWT of any flavor. That's really pretty hot, and it reinforces my belief that Mariah have gotten as close to the ideal design as we're likely to get. A piece of trivia for people who aren't gonzo for wind turbine minutia: In theory, a modified Darrius VAWT (gyro-rotor like the Windspire) could outperform real-world HAWTs. Their advantage is that they place their entire lifting surface at the end of the moment arm. But that's in a world of frictionless planes, where drag and turbulence are just bad dreams, and where tip speed ratios >8.5. Since drag and turbulence do exist, and since the Windspire probably marks the high-water in TSRs, VAWTs are condemned to produce nearly an order of magnitude below HAWTs of equal swept area.

    Still, I know people in Class 7 wind areas who have failed utterly with SWWP and Bergey HAWTs. I bet the Windspire could do pretty well for them, and it would be killer in places like McMurdo Station. See the colorful part of Wyoming in the lower right of this picture?

    WYwindpower50_big.jpg

    Home Sweet Home. Those people ought to talk to Mariah. (For the record, our place is only Class 3, 14.6 mph. We're in that basin surrounded by red and blue; some days, it's like living in a toilet bowl.:D)
  • boBboB Solar Expert Posts: 1,003 ✭✭✭✭
    Re: Inside a Chinese wind turbine nacelle

    Yep, not as good as HAWT per same swept area but that's OK. You're gonna NEED way more swept area this close to the ground !
    It was fairly quiet too, but I would expect this due to the low TSR and necessary "largeness". It's definitely different.

    I am just happy that something like this CAN work, rather than NOT work and give a worse name to wind. BUT, it still can give a bad name (to at least VAWT's) if not placed where there is a fair amount of wind.

    boB
  • halfcrazyhalfcrazy Solar Expert Posts: 720 ✭✭✭
    Re: Inside a Chinese wind turbine nacelle

    Without seing this thing is there a particular reason it has to be so close to the ground? i know it is big but? Hmm i may have to look into this i dont think i have enough to do allready.
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