They are designed for nameplate capacity at about 14 m/s. Above that, the prop has to to be feathered to protect the generator, so no additional power. Power is flat above that design speed. About about 25 m/s the prop has to be furled to protect the whole structure. All the big wind turbine producers (GE Wind Turbinbe for example) have specs online. Check it out.
--- On Wed, 3/2/11, Bill Hooper <[email protected]> wrote: From: Bill Hooper <[email protected]> Subject: Re: [USMA:49967] Re: energy flow in watts To: [email protected] Date: Wednesday, March 2, 2011, 8:24 PM On Mar 2 , at 9:38 AM, John M. Steele wrote: (Most windmills need 14 m/s wind for capacity power. That is 50 km/h; how common is that in your neighborhood? At half-wind, you get one-eighth power. How common is 25 km/h?) In the same context, when the wind speed is double, that is 28 m/s, then the electrical output is eight (8) times the value at 14 m/s. It is my understanding that the enormous energy available at higher than average speeds completely overwhelms the deficit when the wind speed is lower, making wind speed feasible in any location where high winds are expected even just occasionally, not necessarily always. It is not the average wind speed that counts; it is the maximum. Bill Hooper 1810 mm tall Fernandina Beach, Florida, USA ========================== SImplification Begins With SI. ==========================
