How Wind Works

Home wind turbines are simple machines with only a few moving parts. The wind turns the blades which turn the shaft which drive the generator, creating electricity.
Turbine systems generally include:

• Blades (or rotor) which convert the wind's kinetic energy into rotational energy;
• Nacelle (an enclosure) which contains a drive train, usually including a gearbox and a generator. This is where the rotational energy is converted to electrical energy;
• Tower to support the blades and nacelle;
• Electric equipment such as controls, electrical cables, ground support equipment, and interconnection equipment.

The faster the wind speed, the higher the tower and the larger the area covered by the blades, the more electricity generated. A 2.5-kW wind turbine with a 100 foot tower (with rotors four to five meters or 14 feet in diameter) can generate about 3,000 kWh annually at a site with wind speeds averaging 10 miles per hour, or about enough to meet half the electricity needs of a typical household. It takes five 30 foot turbines to generate the same amount of electricity as one 100 foot tower. A 2.5-kilowatt machine atop a 100 foot tower might cost $25,000 to $30,000, installed. However many states offer tax credits or other incentives and policies (such as net metering) to make home wind more affordable.