Rated power of wind turbine: Assume wind speed v air density ρ generator blade radius R, air mass hitting the fan blade within t time m = ρπR^2Vt, energy obtained by the fan blade E = 1/2mv^2 =1/2ρπR^2V^3t
P0=E/t=1/2ρπR^2V^3
Suppose the generator efficiency η
Wind turbine The generated power P=1/2ηρπR^2V^3