Hydrogen storage in depleted gas fields: A techno-economic case study of Moomba, South Australia

Abstract

This study conducted a techno-economic analysis of green hydrogen production, focusing on evaluating the ‘cost of delivering hydrogen to market’, which includes storage and transportation. The analysis evaluates PEM electrolyser hydrogen production at Moomba (South Australia), comparing underground storage (UHS) in depleted gas fields and surface storage for techno-economic performance. Hydrogen transport to Port Bonython is assessed via 659 km of pipelines and 963 km of tube trailer road transport. Delivery capacities are based on ship export categories: small (1500-3000 m³), medium (10,000-20,000 m³) and large (40,000-50,000 m³) carriers. They correspond to hydrogen capacities of 106.2 to 212.4 tonnes, 708 to 1,416 tonnes and 2,832 to 3,540 tonnes, respectively. The requirements correspond to hydrogen production rates of 305.86 tonnes/day and 632.10 tonnes/day for 1.27 GW and 2.54 GW electrolysers, respectively. Increasing electrolyser capacity slightly improves economic performance through economies of scale, reducing the levelized cost of hydrogen production from A$6.95–A$8.87 kg-1 H₂ (1.27 GW) to A$6.92–A$8.73 kg-1 H₂ (2.54 GW), but not a very significant reduction. UHS demonstrates lower costs (A$0.12–A$0.88 kg-1 H₂) compared to surface tanks (A$3.24–A$6.15 kg-1 H₂). Pipeline transport yields the lowest levelized cost of hydrogen transport of A$1.21–A$1.27 kg-1 H₂, while tube trailer shows higher costs for CGH₂ (A$3.45–A$7.79 kg-1 H₂) and LH₂ (A$6.35–A$13.67 kg-1 H₂). The integrated analysis shows a levelized cost of hydrogen delivered (LCOHD) of A$3.74–A$7.15 kg-1 H₂. Hydrogen price, electricity cost, discount rate and utilities are the primary economic drivers. The study recommends reducing renewable electricity costs, prioritising pipeline infrastructure and underground storage, and adopting effective integrated hydrogen supply chain planning.