http://www.househacker.com/ househacker/tags/windmill
Perhaps the most fascinating feature of this new design is the fact that it not only gathers energy from the push on the front side, but actually is pulled forward on the back side through a lift effect, similar to the principle that causes lift on a wing. "The back pressure creates a vortex that pulls it around, turning drag into lift," says Taylor.

The result is that the turbine spins just slightly faster than the wind speed -- 1/100ths faster on average, beginning with winds of about 5 miles per hour.

This facet is the "technology breakthrough" that makes it unique, according to Taylor.

Very cool.]]> http://www.househacker.com/permanent/New-Wind-Power-Design