That the wind fluctuates is common knowledge. But these fluctuations are grossly magnified to an
extent that is not immediately obvious – and has nothing to do with the technology of the wind
turbine. The energy of the wind is that of the moving air, and, as every student knows, such energy is
½Mv2, where M is the mass of air and v the speed. The mass of air reaching each square metre of
the turbine in a second is M=ρv, where ρ is the density of air, about 1.2 Kg per cubic metre. So, the
maximum power that the turbine can deliver is ½ρv3 watts per square metre.