small Wind energy systems

Wind turbines can be designed to turn on either a vertical or horizontal axis.  The vast majority of wind turbines  consist of rotor blades which rotate around a horizontal hub. The hub is connected to a gearbox and generator, which are located inside the nacelle. The nacelle houses the electrical components and is mounted at the top of the tower. In a grid-tied configuration the electricity from the generator is routed to an inverter which converts the electricity from direct current (DC) to the alternating current (AC) that electrical grids use.  The AC electricity is then fed into the grid through the home's control panel.  The diagram below shows a typical grid-tied configuration:

Wind turbines can have three, two or just one rotor blade. Most small wind turbines have three. The blades are usually made of fiberglass-reinforced polyester or wood-epoxy. Because the wind speed varies most modern wind turbines have microprocessor controlled governors which adjust the turbine speed.  These governors are essential because extremely high wind gusts can cause the rotors to turn too fast which can damage the turbine due to excessive vibration. Most wind turbines have gearboxes though increasingly manufacturers are turning to turbines with direct drives because they are much simpler and easier to maintain.  Wind turbines have a  wind vane mounted on the housing to keep the turbine facing into the wind. This is also sometimes referred to as a "yaw mechanism".  Wind turbines may also have a small anemometer on them which is a small spinning wind gage which can feed information to the controller on the current wind speed.

Turbines range in capacity from several kilowatts to three megawatts. This means that wind power can be used for small applications like a home, school or farm.