Quantifying onshore salt deposits and their potential for hydrogen energy storage in Australia

Hydrogen energy will remarkably aid the global energy transition from fossil fuels to renewables. Hydrogen is the lightest molecule. It requires large volume storage facilities only found in geological formations. Salt caverns are a potential geo-storage medium that has been used in practice at a commercial scale. In Australia, several basins, i.e., Advalae, Carnarvon, Amadeus, Officer, and Canning, have been identified with notable salt deposits. The feasibility and potential of storing hydrogen in these salts have yet to be determined by geology, salt thickness, or salt type data. Here, we identified potential hydrogen storage sites. Additionally, hydrogen storage volume was estimated in Mallowa and Minjoo salts (Carribuddy salts:-95 % halite and-1 % anhydrite) in Willara Sub-basin, Canning Basin, Western Australia (WA). The results show a high potential for constructing salt caverns for hydrogen storage in these areas. The geochemical data suggest the presence of Bromine (90 to 670 ppm and <150 ppm in some wells), which are favorable for the solution mining process for the development of salt caverns. Our study demonstrates that approximately 28,282 onshore salt caverns (500,000 m3 each) could be constructed in the Willara Sub-basin salt in WA. The estimated number of caverns can store 14,697 PJ of hydrogen energy. The proposed site would be in the Northwest of WA,-70 to 80 km from the Indian Ocean, with access to the shore and transportation. The estimated H2 storage capacity in the salt caverns satisfies Australia's energy consumption (5790 PJ in 2020-21), providing 8900 PJ of H2 energy for export to ensure a sustainable hydrogen value chain.