Ultra-quiet wind turbine is designed to operate in a site with medium to high wind speed averages of 12 MPH and greater. Provides 100+ kWh per month (3.4 kWh per day) in a 12 MPH average wind. The Whisper 100 is one of the quietest wind turbines ever tested by the National Renewable Energy Labs. Ideal for cabins, 12V battery charging, remote power and backup power. Adjusts from 1248V DC and features overspeed protection. U.S.A.