Wind turbine generators and PV system generate fluctuating power condition. Therefore, the fluctuating power causes frequency and voltage fluctuations. To solve this problem, we propose a new power supply system with using renewable energy in isolated island. The feature of this system is to use an aqua electrolyzer and fuel cell. The operation of suggested system absorbs fluctuating power of renewable energy. Furthermore, the proposed system is able to generate reactive power and active power with using three-phase inverter. The effectiveness of the proposed power supply system is shown through simulation results in this paper.