Glossary of Terms -- Access Energy, Inc.

About Wind Energy

**Glossary of Terms**
Anemometer	Used to rotate the wind speed. It then transmits that data to the controller.
Blades	Most wind turbines have three blades. Smaller versions may have two. Wind blowing over the blades cause them to lift and rotate.
Controller	Starts the rotation of the turbine blades at the desired wind speed ad stops them when wind speed becomes too excessive.
Gearbox	One of the most important main components of the wind turbine is the gearbox. Placed between the main shaft and the generator, its function is to increase the speed of the rotor blades to the generator's required rotation speed, which is about 1,000-1,500 rpm.
Generator	Transforms mechanical energy into electrical energy.
High-speed shaft	The shaft that drives the generator.
Low-speed shaft	The rotor turns the low speed shaft (usually about 30 to 65 rotations per minute.
Nacelle	The structure on top of the tower attached to the rotor and houses all of the generating components (i.e., the gearbox, low and high speed shafts, generator, controller and brake).
Pitch	Controls the blades of the turbine with respect to the wind flow. The blades are turned, or pitched, out of the wind to keep the rotor from turning in winds that are too high or too low to produce electricity efficiently.
Rotor	The rotor is the noticeably spinning part of the turbine that includes the hub and the blades.
Tower	The tower holds the nacelle and the rotor. Towers for large wind turbines are usually made out of tubular steel, lattice, or concrete. The taller the tower, the greater the availability of steady winds and operating efficiency.
Wind Direction	There are different types of wind turbines. Those which are designed to operate whilst facing the wind are called upwind turbines. And those turbines which operate facing away from the wind are called downwind turbines.
Wind Vane	Used to measure wind direction.
Yaw Drive	Used to keep the rotor facing the wind as the wind direction changes, in order to ensure the maximum amount of electrical energy is being produced at all times.
Yaw Motor	Powers the yaw drive.
Yaw System	Most wind turbines which generate over 500 kW have an active yaw system. A controller checks the wind direction measurement that is supplied by the wind vane.