1. By, Matt Macrelli

2. Basic Facts A wind turbine is a rotating machine which converts the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill. If the mechanical energy is then converted to electricity, the machine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC), or aerogenerator.

3. Windmill Wind Turbine

4. Windmill Use Wind Turbine Use Grind Wheat to Flower Grind Corn to Cornmeal Making Oil Pumping Water ELECTRICITY

6. Size and Power Ratings The largest machine has blades that span more than the length of a football field, stands 20 building stories high, and produces enough electricity to power 1,400 homes. A small home-sized wind machine has rotors between 8 and 25 feet in diameter and stands upwards of 30 feet and can supply the power needs of an all-electric home or small business.

7. Example Prices A small turbine can cost anywhere from $6,000 to $22,000 installed, depending upon size, application and service agreements with the manufacturer. Homes use approximately 9,400 kilowatt-hours (kWh) of electricity per year (about 780 kWh per month). Depending upon the average wind speed in the area, a wind turbine rated in the range of 5 to 15 kilowatts would be required to make a significant contribution to meet this demand.