Components   The blades of the turbine catch the wind and change the horizontal movement of the wind into a rotational force turning the shaft. The generator then turns this movement into electricity. There are two basic wind turbine designs: HAWTs, in which the rotating axis is horizontal, and VAWTs, in which the asix is vertical. Both designs convert the wind's kinetic energy to mechanical movement or electricity (Figure 2).         Figure 2. Basic wind turbine configurations       As air flows over both surfaces of an air-foil-type blade, the conversion process begins. Air passes more rapidly over the longer (upper side) creating lower pressure above the airfoil than beneath it. The pressure difference results in an upward force known as aerodynamic lift, which causes the blade to rotate about a central hub and shaft.