Swedish energy products company, Home Energy, is marketing an innovative new small wind turbine, the Energy Ball v100. The Energy Ball utilizes the ‘Venturi’ effect to increase the speed of the wind passing through its spherical design to make it more efficient at low speeds.
The design is a departure from the conventional three blade, propeller-like turbine designs and is said to be almost silent in operation while having a more pleasing visual silhouette. The ‘Ball’ starts generating power at 4.5 mph and has a maximum power of 500 watts (more specs).
Roof, pole or facade mounted.
more info and details re: the U.S @ Home Energy Americas
(Update: links removed)