Revisiting the cost analysis of importing liquefied green hydrogen.

Hydrogen emerges as a promising energy carrier in achieving carbon neutrality, especially in countries such as South Korea and Japan, where renewable energy resources are scarce. Consequently, economically importing hydrogen from overseas is paramount to a stable supply. However, previous studies have often oversimplified the estimation of hydrogen import costs with optimistic assumptions, raising doubts about their reliability. This study comprehensively assesses costs incurred from green hydrogen production to liquefaction and transportation. The cost analysis includes detailed design considerations for hydrogen liquefaction and re-conditioning plants, alongside thermodynamic simulations to estimate the boil-off gas rate of liquid hydrogen during transport. Focusing on a case study of importing liquefied green hydrogen from Australia to South Korea, our findings reveal that the levelized cost of hydrogen is approximately 30.2 USD/kgH 2 as of 2023. Projections suggest a decrease to around 18.3 USD/kgH 2 by 2050, assuming technological advancements, significantly exceeding values reported in the existing literature. Sensitivity analysis highlights the renewable electricity price in Australia and the boil-off rate during shipping as key factors that significantly influence the levelized cost of hydrogen. • Costs for producing and transporting liquified green hydrogen are rigorously analyzed. • Detailed process design and thermodynamic simulation are conducted for realistic analysis. • A case of importing hydrogen from Australia to South Korea is studied. • LCOH for 2023 and 2050 are 30.2 and 18.3 USD/kgH 2 , which exceed literature values. [ABSTRACT FROM AUTHOR]