Horizontal Axis Wind Turbines (HAWT's)

HAWT’s have the axis of turbine rotation parallel to the ground (horizontal). They are typically mounted on top of a tower, and must be pointed into the wind. Most HAWT’s have a gearbox, which is used to drive the generator which produces the electrical power. The wind blowing past the tower normally produces turbulence behind it, so this type of turbine is usually pointed upwind of the tower. To prevent interference with the tower, the turbine blades are stiffened, and are placed comfortably in front of the tower.

The number of blades of HAWT’s varies from one to three. The most common of these is the three-bladed variety. HAWT’s have high blade speeds, high efficiency, and good reliability--it is the type of wind turbine that is used to produce commercial electricity today. The blades range in length from 65 to 130 feet (or more). The tower posts range from about 200 to 295 feet high. Current HAWT models have blades that rotate at 16.6 revolutions per minute (rpm). The gearbox increases the speed of generator components to 2,200 rpm. All HAWT’s are equipped with shut down features to protect the turbine during excessively high wind conditions.

To learn more about wind turbines, and other wind-related topics, please visit Wind Turbine Blades.