Horizontal Axis Wind Turbine HAWT

This type of wind turbine is the most common and seen across Europe. In simple terms it is 'a wind turbine whose rotor axis is substantially parallel to the wind flow.' (Wind Energy - The Facts. March 2009. A European project financed by the Intelligent Energy).

In general HAWTs used on an industrial scale, such offshore location are most commonly placed upwind, that is to say that the rotor bladed are positioned in front of the tower to face the wind, with the gear and generation system behind. These upwind HAWTs are most popular as the offer higher energy efficiencies because the wind hits the blades directly as opposed to hitting the mechanism first and then the blades as is the case with downwind turbines. The advantage of down wind turbines is that they can pivot in the direction of the wind by using only the wind, as a sail might do by catching the air behind, upwind turbines need to be mechanically turned to face the wind.

Both upwind and and downwind HAWTs can have varying numbers of blades, normally two or three spaced evenly, but single blade turbines do exist as well as small fan turbines with a higher number of blades spaced evenly around the central nose.