Year-long demonstration of green hydrogen supply chain with portable and fast-charging metal hydride tanks

A year-long demonstration of a green hydrogen (H 2 ) supply chain using portable metal hydride (MH) tanks was analyzed to clarify the system-level impacts of seasonal ambient temperature variations. H 2 was produced by a photovoltaic-powered water electrolyzer and stored in fast-charging MH tanks operated under active temperature control. Over the year, the H 2 charging rate and the required cooling energy showed only weak dependence on ambient temperature. Instead, the buffer tank pressure was identified as their dominant factor. A maximum absorption rate of 59 NL-H 2 (h kg MH ) −1 was achieved, enabling full charging within 2 h regardless of season. The thermal energy required for H 2 desorption was fully supplied by fuel-cell waste heat during the demonstration period. The annualized power-to-power efficiency of the system was 27%, comparable to alternative H 2 logistics options. These results demonstrate that MH-based H 2 supply chains can operate stably throughout the year with appropriate pressure and thermal management. • Year-long demonstration confirms stable operation of an MH-based green H 2 supply chain. • Maximum absorption rate of 59 NL-H 2 (h·kgMH) −1 enables full charging within 2 h. • Charging rate governed by buffer tank pressure under active temperature control. • Seasonal ambient temperature has minimal impact on system performance. • Annualized power-to-power efficiency reaches 27%, comparable to alternative H 2 logistics.