Research and development of solar hydrogen production

— Toward the realization of ingenious photocatalysis-electrolysis hybrid system —

Abstract

It is important to carry out research strategically and in a step-by-step manner in order to put new solar energy conversion technologies into practical use and to realize a society based on renewable energy. In this paper, we clarified the meaning of “solar hydrogen, ” compared various solar hydrogen production technologies, and discussed their feasibilities. Specifically, we showed the effectiveness of the “photocatalysis-electrolysis hybrid system, ” which was invented by AIST, as a promising candidate technology for low cost solar hydrogen production, based on preliminary cost estimations. The scenario toward the realization of the hybrid system is also discussed.