Techno-economics of renewable hydrogen export: A case study for Australia-Japan

The shift from fossil fuels to clean energy carriers, such as renewable H2, is imminent. Consequently, a global H2 market is taking shape, involving countries with limited or insufficient energy resources importing from renewable-rich countries. This study evaluates the techno-economics of renewable hydrogen (H2) export in a globally significant scenario in which Australia exports to Japan. To gain insight into the immediate, realisable future, the base year was selected as 2030, with a consequently small (in export terms) hydrogen production rate of 100 t/day landed capacity. Electricity was generated by photovoltaic arrays (PV) connected directly to proton exchange membrane (PEM) electrolyser plant, allowing for flexible gaseous hydrogen (GH2) production. To enhance the fidelity of the technoeconomic model, we incorporated rarely applied but impactful parameters, including dynamic efficiency and the overload capacity of PEM electrolysers. The GH2 produced was assumed to be converted into condensed forms suitable for export by sea: liquid hydrogen (LH2), and the chemical carriers liquid ammonia (LNH3), methanol (MeOH), methylcyclohexane (MCH). These were assumed to be reconverted to GH2 at the destination. LNH3 and MCH emerged as promising carriers for export, yielding the lowest landed levelised cost of hydrogen (LCOH). LH2 yielded the highest LCOH unless boiloff gas could be managed effectively and cheaply. A sensitivity analysis showed that a lower weighted average cost of capital (WACC) and scale-up can significantly reduce the landed LCOH. Increasing the production rate to 1000 t/day landed capacity very significantly lowered the landed LCOH, providing a strong incentive to scale up and optimise the entire supply chain as fast as possible. •Incorporated into the system are overload capacity and power-dependent efficiency of the electrolyser•The LNH3 and MCH pathways are the most cost-effective among the studied carriers•To achieve the target value of LCOH, scaling up should be coupled with financial improvements