alt.energy.homepower

Eeyore wrote:

>> >I phoned the Met Office. The daily average yesterday for NW10 was 9 knots
>> >or m/s. At that speed those turbines might be providing maybe as much
>> >as 500W ea (absolute maximum).
>>
>> P=kV^3.

The point was that you can't use the average windspeed.
Use the average of its cube or a Rayleigh distribution.

>What's your value for k ?

Paul Gipe's Wind Power book says wind power density is ^3 W/m^2,
with V in mph. He says the best rotors achieve 40% efficiency (vs the 60%
Betz limit... 90% efficiencies for the transmission, generator, and power
conversion would make the power density ^3 W/m^2.

Nick