The present invention is provided with: a power converter (14) connected to a power plant (12) for generating power from renewable energy and having a proportional-control type power adjusting function that outputs the power generated by the power plant (12) after converting a direct current into an alternating current, and that adjusts the outputted power proportionally to a manipulation level; an instantaneous power detector (3) that detects an instantaneous power of the power outputted from the power converter (14); a comparison unit (4) that compares the instantaneous power detected by the instantaneous power detector (3) and a target value set by a generated power setting unit (5) and outputs a comparison signal; a control unit (6) that adjusts the comparison signal outputted by the comparison unit (4); and an output signal unit (7) that outputs the comparison signal adjusted by the control unit (6) to the power converter (14) as the manipulation level. Since the generated power setting unit (5) sets the
