The rotor on an upwind is in the front of the unit, positioned similar to a propeller driven airplane. This is the most common type of wind turbine. To keep it oriented into the wind, a yaw mechanism such as a tail is needed.

Advantage: The reduced tower shading.

Disadvantage: The extended nacelle that is required to position the rotor far enough away from the tower avoids any problems with a blade strike. The blades themselves must be somewhat stiff to avoid bending back into the tower. This will mean the point where the blade attaches to the rotor hub will be stressed during high and gusty wind conditions.

References & Resources