This turbine is the Energy Ball. It is a Darrieus style wind turbine. It is made by the Swedish company Home Energy. It is a very efficient design. There are currently 2 models, the V100 and the V200. Both feature 6 blades, that work with very low wind speeds. The much improved venturi blade design funnels air through the blades significantly increasing blade speed. Noise levels are very low, usually background noise is louder. For residential use this design is a very good choice.