Abstract: A photovoltaic power generation apparatus includes a support frame, on which solar cell modules are mounted such that neighboring solar cell modules are spaced apart from each other by a predetermined gap set in a lateral direction. A pair of guide rails is mounted on the support frame in a parallel manner at opposite sides of the solar cell modules. A cleaning unit reciprocates on the guide rails in a horizontal direction to clean upper surfaces of the solar cell modules by rotation. Interference frames are mounted on the support frame in the predetermined gaps or at opposite ends of the solar cell modules. The interference frames are arranged at a height at least equal to or higher than the upper surfaces of the solar cell modules such that the cleaning unit contacts the interference frames while rotating or reciprocating.