Fundamental Study on Solar Hydrogen Energy Systems. System Optimization Based on Hydrogen Production Cost.

Abstract

Hydrogen is regarded as a potential future energy carrier. It is produced by water electrolysis. The power required is supplied by photovoltaic array. The hydrogen has been produced by using the hydrogen generator typed solid polymer electrolyte with photovoltaic module rated 2.4V, 32A. We have designed and constructed the experimental system that photovoltaic module coupled with hydrogen generator directly, and measured and analyzed the basic characteristics, i.e. production of hydrogen, I-V characteristics and cell temperature for photovoltaic module and hydrogen generator. It was found that the variation of cell temperature and irradiance influenced on production of hydrogen. Then the optimum design method of solar hydrogen energy system has been developed from the hydrogen production cost point of view. In this method, the design point is decided by the irradiance intensity when the system is operating under rating capacities. As a result from the basic data of experimental system, the optimum design point of solar hydrogen energy system depends on the ratio of photovoltaic array cost to hydrogen generator cost in system.