Faster winds create more lift and thus more power. But there's a little surprise lurking in the physics. It turns out the wind's power increases with the cube of the speed. This means that a ten mile per hour wind has nearly three times the power of a seven mile per hour wind. Seeking out these extra three miles per hour is well worth the effort.
Ideal sites are the tops of smooth hills, where the wind speeds up due to funneling.
Because friction decreases away from the ground, wind speeds at 100 feet are about 25 percent higher than at 30 feet. Hoisting your turbine high also helps avoid turbulence. Turbulence occurs when wind spills and whirlpools around obstacles like houses and trees, leaving a wake of chaotic air. These choppy uneven winds buffet the rotors, putting stress on the tower and turbine. To find a smooth flow, Sagrillo recommends keeping the rotors at least 30 feet above anything within 500 feet.