Hybrid power-supply system composed of photovoltaic and fuel-cell systems

This paper describes a hybrid power-supply system that combines a photovoltaic system with a fuel-cell system for use as an auxiliary generator for long-term backup. The hybrid system exhausts no harmful gases such as NO _x and SO _x, and noise and vibration levels are much lower than those of conventional systems that combine a photovoltaic system with an engine generator. The hybrid system is environmentally friendly and requires little maintenance. We have developed two grid-connected hybrid power-supply systems and a stand-alone hybrid power-supply system. The former has been introduced experimentally into on-line computer systems for data communications, and the latter has been introduced into a repeater station for wireless communications.