This work is on the study of renewable energy system with proton exchange membrane fuel cell and electrolyzer using the photovoltaic energy for producing hydrogen. The input energy of this system is based on the transformation of photovoltaic cell from solar radiation and the output energy is sent to user based on instantaneous requirement. The energy system mainly consists of the charging battery for storing electric energy in a short-term manner and the electrolyzer/fuel cell devices for energy storage in hydrogen formation for mid-term usage. The investigated issues mainly include the optimal specification for the principal components in the energy system, and the design of an exemplary energy system for demonstration.