Battery-assisted low-cost hydrogen production from solar energy: Rational target setting for future technology systems

The massive implementation of renewable energy requires sophisticated assessments considering the combination of feasible technology options. In this study, a techno-economic analysis was conducted for hydrogen production from photovoltaic power generation (PV) utilizing a battery-assisted electrolyzer. The installed capacity of each component technology was optimized for the wide range of unit costs of electricity from the PV, battery, and proton-exchange membrane electrolyzer. Leveling of PV output by battery, the necessary capacity of electrolyzer is suppressed and the operating ratio of electrolyzer increases. The battery-assist will result in a lower hydrogen production cost when the benefit associated with the smaller capacity and higher operation ratio of the electrolyzer exceeds the necessary investment for battery installation. The results from this study indicated the cost of hydrogen as low as 17 to 27 JPY/Nm³ using a combination of technologies and the achievement of ambitious individual cost targets for batteries, PV, and electrolyzers.