Max out put of wind turbine?

Question

What maximum output would you expect from a wind turbine wiht a blade of diameter 20ft in a 15-mph wind?

Answer 1

Bergey Excel
7 m (22 ft.) Diameter

10 kW at 13 m/s (29 mph)

(Battery Charging: 7.5 kW)

35 kWh / Day Nominal

If you cut the wind speed in half, you reduce the power output to 1/8 of the rated power output, if the turbine will operate at that low an rpm. So you would get about 2.5 KW out of a unit like this at a wind speed of 15 MPH