Abstract: An apparatus for generating electric power using wind energy includes a structural frame configured with a vertical array of accommodating spaces and having two pairs of sides. Each pair of the sides are opposite to each other. Each of a plurality of electric generating units includes a windmill mounted rotatably in a respective accommodating space and operable to face wind and to convert wind energy into a mechanical rotary power output, and a generator coupled to the windmill to convert the mechanical rotary power output into electric power. Each of four wind guiding units is disposed on a respective corner of the structural frame, and has a wind guiding member. The wind guiding members of any two adjacent wind guiding units define a wind channel that converges toward a corresponding side of the structural frame.