Why does not the “Mean power (Pm)” calculated result change when I vary the “Power coeff. (Cp)”?
A. Mean power is an empirical formula (based on in-service measurement on many real existing turbines). Since Cp varies with windspeed it cannot easily be used in the formula (but is probably assumed to be around 0.15 mean) . Also the distribution of windspeed around the mean affects power as the cube of the instantaneous speed! This long term mean power is what other people have actually achieved and you can’t change that result by making your own turbine more efficient. This is your target to beat!
