In a power generation system of this invention, the outputs from power generation layers electrically connected in series are input to corresponding power conversion devices, and boosted outputs are connected in parallel and fed to a load. Alternatively, the output from one of power generation layers electrically connected in series is input to a first power conversion device, and the serial output and the boosted output from the first power conversion device are connected in parallel, input to a second power conversion device, boosted, and fed to the load. Since the two power generation layers can be individually output-controlled, each power generation layer can be optimized basically without considering current balance. Since the optical spectrum utilization efficiency increases, the power generation efficiency increases. In addition, since the power can be fed not to separate loads but to one load, the convenience largely increases.