HelixWind

It is 6 feet high x 4 feet diameter. From the site: “Inexpensive, reliable, simple, the hallmarks of the Helix system make it the best choice for low wind speed residential and commercial applications. The Savonius turbine based design catches wind from all directions creating smooth powerful torque to spin the electric generator. Mounted up to 35 feet high, in winds as low as 10 mph the Helix system creates electricity (up to 2 kilowatts) to power your home or business.”

For more info see: How Wind Power Works