Life cycle global warming impact of a green hydrogen supply chain: A case study of Australia to South Korea

Although hydrogen is regarded as a key strategic factor in decarbonisation and produces no direct emissions when used, its production and delivery processes generate different levels of environmental impacts, with variation dependent on the pathways and methods involved. To effectively employ hydrogen for greenhouse gas (GHG) mitigation, lifecycle assessments (LCAs) of its environmental impacts should be integrated into the design phase of supply pathways. In this work, an LCA was conducted on a hydrogen supply chain between Australia and South Korea. The findings show that, when an entire life cycle is considered, renewable energy contributes the most to the associated carbon emissions. Different electricity supply configurations were evaluated: hypothetically dispatchable renewable electricity (RE), variable RE and RE from a future Powerlink project. The results identified various emission levels across different electricity supply configurations: 3.23 kg CO2e/kg H2 for the dispatchable RE, 3.81 kg CO2e/kg H2 for the variable RE and 6.14 kg CO2e/kg H2 for the Powerlink electricity. Sensitivity analysis was conducted to assess the impacts of different variables on GHG emissions. The findings reveal that the emissions increase with higher shares of photovoltaic (PV) electricity, energy storage system (ESS) contributions, and the GHG intensity of PV electricity. These results provide insights into the environmental impact of different hydrogen supply configurations and inform future decision-making in hydrogen supply chain design.