The ‘nova-wind 12’ has a gearbox which reduces start-up torque in the generator and contributes to higher overall efficiency. This allows the generator to run at a lower speed to suit all wind conditions rather than having to run at a continuous high speed to generate electricity. A lower rotating speed also generate less noise, and allows the blades on the ‘nova-wind 6’ to be designed for maximum aerodynamic efficiency and reduced wear.

http://www.nova-wind.de/en/customer-benefits.html