| A photovoltaic (PV) module-electrolyzer subsystem model was developed to help size components for a stand-alone system. The system provides electrical energy from a fuel cell and energy storage from pressurized hydrogen and oxygen gases. A small system was simulated with Chicago weather data at a nominal 12 volts with a 300 W PV panel. An electrolyzer with ten cells, each of active area 8.4 cm2, provides the optimal match. At atmospheric pressure and a temperature of 80 C, a solid polymer electrolyte electrolyzer directly coupled to PV is just as efficient, 95%, as using a maximum power point tracker. Use of the electrolyzer to pressurize the hydrogen and oxygen gases is predicted to be less efficient than a system with compressors. The efficiency of the electrolyzer in its conversion of electricity to hydrogen and oxygen gas storage is 72%. |
