■ Example of research topics ■
Solar to Hydrogen Energy Conversion System
D. Yamashita, K. Fujii (RIKEN), K. Nishioka (Miyazaki Univ.), Y. Nakano and M. Sugiyama
Photovoltaic power generation is attracting attention around the world as one of the most important renewable energy source. Many solar power generation facilities have been introduced in Japan in recent years. However, stabilization of the power output, which is imposed by the fluctuation in solar irradiation, relies on the electricity grid. Because of this huge burden to the grid, the amount of acceptable solar power generation is approaching the limit. Some attempts have been made to stabilize the output of power generation by using batteries, but they still have a problem in terms of cost and capacity for practical use. We are researching a system that stores electricity as hydrogen which is generated from water splitting by water electrolyzers. The storage capacity can be expanded by increasing the size of the hydrogen tank, so it is expected that we can obtain sufficient capacity to stabilize the power fluctuation with lower cost. Many solar to hydrogen conversion systems have been proposed, but system design is not conclusive yet. This research can contribute to both a renewable energy field and hydrogen society.
Fig. A schematic of solar to hydrogen energy system
A prototype circuit of solar-hydrogen energy management system