Geoscience Australia is evaluating a thick salt deposit in Queensland's Adavale Basin as a potential site for large-scale underground hydrogen storage. The project aims to address energy storage needs by creating artificial caverns within the rock salt formation.
Geological Context
The Adavale Basin is located beneath the towns of Quilpie, Blackall, and Charleville, and sits under the Great Artesian Basin (GAB). Discovered in 1958, the basin is described as under-explored, with no surface evidence due to burial under other rock formations.
The Boree Salt deposit within the Adavale Basin is the only known rock salt layer in eastern Australia considered sufficiently thick for deep-earth hydrogen storage. Mitchell Bouma of Geoscience Australia stated that rock salt can be dissolved to create artificial caverns for storing hydrogen gas or compressed air.
Research Activity
In November, geologists drilled a borehole approximately 3 kilometers deep into the Boree Salt deposit, marking a depth record for Geoscience Australia. A 976-meter solid rock core, over 500 rock chips, and several groundwater samples were collected. Initial findings are expected mid-year.
Global Context and Application
Storing hydrogen gas in underground salt caverns has been practiced internationally for decades.
A site in Teesside, UK, has operated since 1971. The Advanced Clean Energy Storage hub in Delta, Utah, uses two salt caverns, each reportedly equivalent in energy capacity to over 40,000 shipping containers of lithium-ion batteries.
Independent energy geoscientist Mark Bunch from the University of Adelaide stated that underground storage can hold hundreds of cubic kilometers of gas, compared to surface tanks. He estimated that a few artificial caverns within the Adavale Basin could power 20 million homes daily, based on Brisbane's average household demand. A single cavern could store approximately 6,000 tonnes of hydrogen, equivalent to about 100 gigawatt hours of energy.
Community and Water Safety Concerns
Residents living above the proposed site have expressed concerns regarding the safety of the Great Artesian Basin, their primary water source. Blackall-Tambo Shire Mayor Andrew Martin cited a "precautionary principle," citing potential risks such as pressure increases or subterranean movements affecting the water supply.
Dr. Bunch stated that pumping hydrogen gas into underground salt caverns is unlikely to harm the GAB.
He explained that salt, unlike brittle rock types, behaves as a malleable substance that naturally adjusts to pressure changes in a fault scenario. This process would occur approximately 2 kilometers below the groundwater used for drinking and agriculture. Mayor Martin has requested additional evidence to confirm the project's safety and has called for community involvement in future exploration decisions.
Natural Hydrogen Exploration in South Australia
Separately, natural hydrogen is being explored in South Australia as a potential zero-emissions energy source. The state government has awarded exploration licenses in the Otway Basin. Companies including Thor Energy and Gold Hydrogen are conducting exploratory drilling. Thor Energy reported a 1915 oil well containing 25% hydrogen concentration. Gold Hydrogen found hydrogen with 97% purity on the Yorke Peninsula.
Adelaide University researcher Rachelle Kernen noted hydrogen's potential to reduce emissions. South Australia Energy Minister Tom Koutsantonis described it as a potential significant development but stated that questions remain about extraction, storage, and market delivery. The industry is nascent, with one known production example in Mali.