
Disclosed is a horizontal axis wind turbine of an downwind type having a rotor disposed downwind of a tower, comprising: a rotor having a hub and a blade; a nacelle to support the rotor rotatably through a main shaft connected to the hub; a cylindrical tower supporting to enable free yaw rotation of the nacelle; and an exhaust fan disposed on the nacelle, to exhaust an air inside the nacelle, wherein the cylindrical tower has a plurality of through-holes which are formed in a wall of the tower a...











