Wind power question.

klrskies
klrskies Solar Expert Posts: 30
Greetings,
A bit off the solar topic but perhaps the place to ask it...?

I see plenty of videos and info on how easily a turbin spins , yet when I can find information about output, they don't seem to put out high enough watts till very high wind speeds (20+mph) I want charging voltage at attainable wind speed...what am I missing? Blade design seems to be pretty diverse too..what's proven to work well and hold up in low wind areas of the country? The axial flux (home made) design looks interesting. It would seem building a oversized diameter rotor assembly and generating adequate torque at low wind speeds would produce charging capability. Add more generator load as wind speed increases...build it to endure the stresses imposed on it. Cost for a purchased turbine would not be practical when compared to what's available/advertised currently...quality engineering costs. Probably a project for an enthusiastic do it your selfer with no intrest in marketing!
Regards,
Ken

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind power question.

    Low wind = low power, no matter what the turbine design. The mechanical force available at low wind speeds when converted to electrical power is not very much, especially after the mechanism of the turbine takes its due. This is physics and there is no way around it, no matter what the hyperbole on the internet says. Spinning a turbine against no load in light winds is easy; getting it to make appreciable power at low wind speeds is impossible.

    The first thing anyone considering wind should do is put up an anemometer, preferably one that can record the data. For best performance a turbine needs steady, consistent wind. What feels like a lot of wind to us is not that much when you're trying to squeeze Watts out of it. Turbines do not do well with low wind speeds, inconsistent wind (turbulence - lots of directional changes), nor gusty winds (which tend to tear them apart). This is why they need to be mounted up high (30+ feet) and out in the open. The blasts that knock your hat off when you're walking around your house won't do it. And yes you will see differences in blade and other aspects of design: what's most efficient at one speed will not be at another. This is why they need feathering mechanisms, dump loads, brakes, et cetera to keep them from flying apart (literally) if the wind speed gets up too much.

    Inevitably you will see turbines rated for peak performance at 20+ mph wind speeds because you need that kind of sustained wind in order for there to be enough mechanical force in the moving air to translate into practical amounts of Watts. That isn't to say they won't work at all under other conditions, just that the output will be lowered significantly making the expense of the turbine and tower a pretty poor return in terms of Watt hours produced for money spent.

    For most sites they aren't practical. So always test your site before you lay out the money!
  • jacknife
    jacknife Registered Users Posts: 6
    Re: Wind power question.

    I have a 1600 watt P.M. A. on the way, Ill let you know.
  • klrskies
    klrskies Solar Expert Posts: 30
    Re: Wind power question.

    A large turbine with the ability to be variably loaded to control over-speeding seems complex and expensive...yet there is plenty of work to do isn't there?
  • klrskies
    klrskies Solar Expert Posts: 30
    Re: Wind power question.

    Is there a source for standardized turbine performance comparison thats current?
  • WisJim
    WisJim Solar Expert Posts: 59 ✭✭✭
    Re: Wind power question.

    It is going to be a year or so before there is much available as far as results of testing of turbines by independent testing facilities in compliance with the new standards developed in the last couple of years. This is all new territory, the testing of small wind turbines, and isn't cheap.
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: Wind power question.

    A few test sites:
    Warwick wind trials in the UK: http://www.warwickwindtrials.org.uk/2.html
    The Zeeland trials in the Netherlands: http://ampair-aquair.blogspot.com/2011/04/delta-zeeland-small-wind-turbine.html
  • klrskies
    klrskies Solar Expert Posts: 30
    Re: Wind power question.

    Looks pretty bleak for return on investment to me...add the possible mechanical problems and it would be easy to be a frustrating loss. One best tread cautiously into wind power me thinks.
    I like the concept, and may experiment a bit to get a feel for what's involved. I thinks it's the visual effect that I like...seeing the physical transformation of energy. Anemometer first!

    Ken