What is the average power density of a commercial wind farm?
We don’t normally talk about wind farm power density in terms of power per cubic meter. It is common to refer to a location in terms of wind Class, where each classification relates to a range of average power density in W/m^2 at a hub height of 50 m. “Good” wind power sites have average power density of 400-500 W/m^2 at 50 m. Of course, the wind is usually statistically described by a Weibull distribution, with parameter k=2. The ultimate value for power denisty is determined by the geography, the specific turbine, and the wind at that location. In wind farms with closely-spaced turbines, it is common to see rows of turbines spaced 10s of rotor diameters apart. Within a row, typical ‘close’ spacing is 4-5 rotor diameters. All of this distance between turbines, especially upwind / downwind, is essential to allow each turbine to have ‘clean’ or ‘nearly clean’ low-turbulence air coming to it. So, a 3 MW turbine with 90 m diameter rotor would have about 450 – 500 m to its next neighbor in
