most energy you can extract is 16/27 - the Betz limit - aka - 59% - if you try to get more, the wind just goes around you. Energy is the density times the area times the [input velocity squared minus the (slowed) exit velocity squared] all divided by two (half from upwind, half from downwind)
the full answer
most energy you can extract is 16/27 - the Betz limit - aka - 59% - if you try to get more, the wind just goes around you.
Energy is the density times the area times the [input velocity squared minus the (slowed) exit velocity squared] all divided by two (half from upwind, half from downwind)