Systems and methods for capturing the energy of wind currents by placing wind-driven turbines at one or more edges of a building's roof, where the wind currents are concentrated by deflection of the wind off the horizontal faces of the building. In one embodiment, a cylindrical wind turbine is placed at the edge of a building's rooftop. The turbine structure drives an electrical generator. The axis of rotation of the turbine is parallel to the ground and to the edge of the building. A concentrator may be used to direct rising winds into the turbine. Turbines can be installed on multiple sides of the building to optimize the system for variations in wind direction with changes in seasons or weather conditions.