Estimate your site's wind resource; it can vary significantly over an area of just a few miles, due to changes in local terrain. Wind installers generally recommend an average wind speed of at least 12 miles per hour. Consult the U.S. Department of Energy's (DOE) wind resource maps to estimate average wind speeds in your area, or obtain wind speed data from a local airport or weather station.
The size will depend on your energy use, the average wind speed at your site and the height of the wind turbine, all of which will affect the amount of energy it generates. A typical home uses approximately 9,400 kilowatt-hours of electricity per year, according to the DOE. Based on the average wind speed in your area, a turbine rated in the range of 5 to 15 kilowatts (kW) would be required to make a significant contribution to this demand.
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