Natural hydrogen exploration in Australia – state of knowledge and presentation of a case study

Hydrogen will play a major role in Australia’s transition to a net zero emissions energy future. The hydrogen industry and technology are scaling up with hydrogen produced via two pathways, thermochemical and electrochemical, that involve the use of fossil fuel feedstock or the use of an electrical current to split water into hydrogen and oxygen. Exploration for and production of natural hydrogen is one of the most promising ways to get large quantities of green hydrogen cheaper than the ‘blue’ hydrogen produced from methane. Some predictions from this growing industry even estimate that the production of natural hydrogen can quickly become economically viable. We propose to review the state of knowledge of natural hydrogen exploration and production in the world and focus on the exploration of the Australian natural seeps in the frame of the incredible exploration rush we are currently experiencing. Surface emanations often referred to as ‘fairy circles’ are often associated with high hydrogen soil-gas measurement and have been described in numerous countries. In the frame of our research, we recently showed that similar hyrdrogen-emitting structures are present in Australia. New regional scale soil-gas measurements reveal persistent hydrogen concentration along the Darling Fault, in the Perth Basin and on the Yilgarn Craton. Those geological settings promote processes such as deep serpentinisation of ultramafic rocks as potential hydrogen sources that are of massive potential economic value. We review the results of different techniques to explore and quantify the presence of natural hydrogen leakage.