Homeowners can knock 20 to 40 percent off their electricity bills with a new wind turbine that can be mounted directly on a building. The seven-foot-wide plastic turbine has a ring around its rotors that diffuses noise and limits vibration. The company, Cascade Engineering, Grand Rapids, MI, claims that the turbine is no louder than a whisper. In windy locations, its power output should be about 2,000 kilowatt-hours a year.
In a normal residential application, a home is served simultaneously by the wind turbine and a local utility. If the wind speed is below the minimum speed to spin the blades – there will be no output from the turbine and all of the needed power is purchased from the utility. As wind speeds increase, turbine output increases and the amount of power purchased from the utility is proportionately decreased. When the turbine produces more power than the house needs, many utilities institute a policy called “net metering” whereby the extra electricity is sold back to the utility. All of this is done automatically.
Source: Cascade Engineering