Introducing, the "Energy Ball"

Energy Ball, by Home Energy International. These windmills are claimed to be 40% more efficient than regular propeller windmills of similar size. The two meter version can supply 1,750 KWh per year, which would supply a little over 15% of the average US households energy usage. They cost anywhere from 3 to 7.5 thousand dollars each (without installation). The catch, they should be installed about 40 feet above ground level and away from trees. No telling whether the loss of tree cover during the summer time -- which helps shield your house and thereby cools it down resulting in less energy usage -- would offset the energy balls usefulness.