Drawing Power Charts

Discussion in 'Windtura Generators' started by Minnesota, Nov 27, 2010.

  1. Minnesota

    Minnesota WindyNation Engineer

    I've posted a few vids lately on Power Chart creation. You might enjoy them. Here is the latest one on a 12.5-foot Axial Flux unit based in Oregon.

    http://www.youtube.com/watch?v=jXgUOYuj9iE

    It would be nice to have a WN test site that logged daily data. I think it would help the business in the long run. It requires installing an APRS World logger.
     
  2. murray2paddles

    murray2paddles WindyNation Engineer

    Minnesota, I went back to your UTube power chart testing & although the Berkey was not the top producer in watts, it did preform well where most of us need it, in the low to mid range .

    So how would it be wired or a difference in magnets compared to the Windy turbines that allows it to preform well in the lower winds ?

    I know the 28-35 mph ratings look impressive but how often does that happen compared to the 8-20 mph winds !!.
    That is the range I want .

    For approximately the past year I have been searching out a better match between turbine and grid tie inverters.
    Windy has been assisting me on this project also. It seems that on the questions asked so far there is an option to request from the turbine manufacturer to set / build the operating volts on the turbine. If this is correct how would we request that the turbine be built to best preform in the lower winds....... Would any of your testing so far give us a heads up on this ?

    Also on the Alibaba.com search site you will find complete turbines that are rated at for example (2 kw)
    And this is based on their rated wind speeds of 12 mph or some are at 12 mp/sec.
    There are a number of low wind units available fro China and with no argument they are leading in micro wind technology , so what do they know on how to produce high watt from the low to mid range winds ?

    If you could help in anyway on this I know there would be so many thankful persons.
     
  3. Minnesota

    Minnesota WindyNation Engineer

    Hi Murray,

    One key factor is the Bergey and many of the Chinese units use purpose build PMGs - good power production at lower RPMs that non-purpose built PMGs. This allows them to target the 12MPH nominal wind speed with the right diameter rotor.

    The second key factor is in the blade design. They use true semisymmetrical airfoils - much superior to anyone's bend and twisted sheet-metal blades.

    My Youtube vid on efficiency is where this comes together. The WN units are good but not as good to these other purpose built offerings. That is clear in my chart. That said, I think an advancement in the blades are the next step for the Windtura. I do have a way to design rotor wings and will post something when done.
     
  4. TomT

    TomT WindyNation Engineer

    I may be a little wrong but I think that the metal blades like windy nations work good. But they also present a lot of drag when they spin right from the start up. Where an airfoil blade cuts through the wind better. I just started my wood blades and will post pictures and figures as soon as I can. I am going to go with a 2 blade 6 ft setup just for testing.
     

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