With countries and economies around the globe increasingly relying on non-dispatchable variable
renewable energy (VRE), the need for effective energy storage and international carriers of
low-carbon energy has intensified. This study delves into hydrogen’s prospective, multifaceted
contribution to decarbonizing the electricity sector, with emphasis on its utilization as a scalable
technology for long-duration energy storage and as an international energy carrier. Using Japan as
a case study, based on its ambitious national hydrogen strategy and plans to import liquefied
hydrogen as a low-carbon fuel source, we employ advanced models encompassing capacity
expansion and hourly dispatch. We explore diverse policy scenarios to unravel the timing, quantity,
and operational intricacies of hydrogen deployment within a power system. Our findings highlight
the essential role of hydrogen in providing a reliable power supply by balancing mismatches in VRE
generation and load over several weeks and months and reducing the costs of achieving a
zero-emission power system. The study recommends prioritizing domestically produced hydrogen,
leveraging renewables for cost reduction, and strategically employing imported hydrogen as a risk
hedge against potential spikes in battery storage and renewable energy costs. Furthermore, the
strategic incorporation of hydrogen mitigates system costs and enhances energy self-sufficiency,
informing policy design and investment strategies aligned with the dynamic global energy
landscape.