output

SystemSystem Posts: 2,511 admin
when a wind turbine is rated at lets say 1200 watts, does that mean that at a givin speed it will produce 1200 per hour?

Comments

  • Ralph DayRalph Day Solar Expert Posts: 953 ✭✭✭✭
    Re: output

    yes, but not likely!

    Really sustained winds to produce rated power hourly, you wouldn't want to be around...the noise would drive you crazy! I've only ever seen my H80 (1kw) produce that for less than a minute at a time sustained, in over 3 years. Is that false advertising, or false hopes?

    ralph
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: output

    There is a reason why we put this on our website:

    "A note about wind generator power ratings.

    All wind generators (from all manufacturers) have somewhat "generous" ratings, as the power output is usually specified as the MAXIMUM output. In real life in most cases you will be lucky to get even half of that. Also, most people tend to over-estimate how much wind they actually get. Most wind generators require winds in the 15 to 25 MPH range - and 25 MPH is Beaufort 6 - the stage where the wind starts to "whistle" on wires and structures."
  • System2System2 Posts: 6,290 admin
    Re: output

    A few years ago I was foolish enough to partly listen to a vendor and bought a "750 watt" Hornet. I knew enough to know there was no way that thing was going to output anything close to 750 watts, but was expecting probably 100 or 200 watts. Well the most I ever saw it put out was 250 watts during a violent tropical storm that had me believing I would find pieces of that thing scattered across the country come morning, but somehow it did survive. The most common output other than ZERO, was about 20 watts some of the time. I've since taken it down.
    I only wish now that I had put that money into more solar. Oh well, live and learn.
    Wayne
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: output

    wayne,
    you may have benefitted from larger blades, but as i recall, correct me if i'm wrong, but i believe it was you that said you had bought the 24v version instead of the 12v version or something to that effect did you not? not up on it lately, but there was a compromise in there somewhere.
  • System2System2 Posts: 6,290 admin
    Re: output

    Yes, you're right, I had forgotten it was a 24 volt unit operating on 12 volts. Having a lot to learn about wind power (even tho I had built a 10 foot and a 14 foot prop and had the bigger one belt driving an automotive alternator many years ago) I took the word of the sales person that the higher voltage unit "would charge more with less wind" so I went that route. In reality, the result was an overloaded prop that tended to run in stall, or semi stall mode.
    Thanks for reminding me.
    When I think back, the 14 foot unit would run away with the 60 amp 12 volt alternator as if it was free wheeling. As if it didn't even know the alternator was there putting out full power. Unfortunately, it was a 2 blade prop, not 3. The result was very choppy, jerking vibrations when it changed direction with the wind. One day, during a wind storm, it shook the alternator off it's mounting, which still attached to it's heavy cables, swung down into the high speed blade. One piece of the blade was stuck through the barn roof like someone had stabbed it with a giant knife, part of it was still on the shaft, most of it, I have never found. When I think back, in high wind, the roar of it could be easily heard 1/4 mile away. It was an awesome thing for a kid - while it lasted. But that was then and this is now.
    Cheers
    Wayne
  • System2System2 Posts: 6,290 admin
    Re: output

    Bill,

    The alternator on your hypothetical turbine may be very capable of producing a sustained 1200 watts, but there are many factors which make that scenario highly unlikely. On a turbine flying in the real world, the slightest variations in turbine yaw, or any changes in wind speed or density will cause alternator output to rise or fall....constantly.
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