Small Wind Turbine

A small wind turbine, also called a micro wind turbine or urban wind turbine, generates electricity for small scale use, typically between about 500 watts and 10 kilowatts though some models produce as little as 50 watts, and it usually relies on a passive tail fin to keep it facing the wind and a direct drive generator rather than the active yaw systems and gearboxes of utility scale turbines. Definitions of the category vary: the international IEC 61400 standard sets the boundary at a rotor area under 200 square meters and a generating voltage below 1,000 volts AC or 1,500 volts DC, while the Canadian Wind Energy Association treats turbines up to 300 kilowatts as small; most designs are horizontal axis machines with blades 1.5 to 3.5 meters across, though less efficient vertical axis versions also exist, and they typically need a wind speed of about 4 meters per second to start generating and perform best mounted at least 30 feet above nearby obstacles. Hobbyist, do it yourself small turbine designs emerged in the early 1970s and became popular during the back to the land movement of the late 1970s in the United States and Europe.