The Energy Ball wind turbine looks like an egg beater. The ball is aerodynamically designed to create a wind flow pattern that uses principles of the Venturi effect to increase efficiency. It is quiet and produces power at a wind speed of just 4 MPH.
The Energy Ball DIY power was marketed by Swedish Home Energy with manufacturing in the Netherlands in 2008. In 2009 it established a manufacturing plant in McKinney and an office in Fort Worth, Texas.
A complete home system including installation is in the $11,000 range.