Australia Explores Outback Salt Deposit for Hydrogen Storage
Geoscience Australia has identified a thick salt deposit in Queensland's Adavale Basin as a potential underground hydrogen battery. This ancient rock formation, predating dinosaurs, is being investigated as a solution to Australia's green energy storage needs. The project has the potential to power millions of homes across eastern Australia, aiming to address a looming renewable energy storage gap.
This ancient rock formation, predating dinosaurs, is being investigated as a solution to Australia's green energy storage needs, with the potential to power millions of homes across eastern Australia.
The Adavale Basin: A Deep Dive into Storage Potential
The Adavale Basin is strategically located beneath the towns of Quilpie, Blackall, and Charleville, and also beneath the Great Artesian Basin (GAB). Discovered in 1958, the basin remains largely under-explored and presents significant study challenges. It has no surface evidence and is buried under other large rock formations.
The Boree Salt deposit within the Adavale Basin stands out as the only known rock salt layer in eastern Australia potentially thick enough for deep-earth hydrogen energy storage. Mitchell Bouma of Geoscience Australia explained the innovative method: rock salt can be dissolved to create artificial caverns for storing hydrogen gas or compressed air, effectively creating an "on-demand battery."
Global Precedents and Enormous Potential
Storing hydrogen gas in underground salt caverns is a well-established practice globally, with successful operations dating back decades. A notable example is a site in Teesside, UK, which has been operating continuously since 1971.
Mark Bunch, an independent energy geoscientist from the University of Adelaide, highlighted the "enormous potential" of underground storage. He emphasized its vast scale, capable of holding hundreds of cubic kilometers of gas, far surpassing the capacity of surface tanks. For instance, the Advanced Clean Energy Storage hub in Delta, Utah, utilizes two salt caverns, each equivalent in megawatt-hours to over 40,000 shipping containers of lithium-ion batteries.
Dr. Bunch's calculations suggest a transformative impact: just a few artificial caverns within the Adavale Basin could power 20 million homes daily, based on Brisbane's average household demand. Furthermore, underground energy storage offers significant cost advantages, being substantially cheaper than above-ground alternatives due to reduced surface infrastructure costs. A single cavern alone could potentially store approximately 6,000 tonnes of hydrogen, equivalent to about 100 gigawatt hours of energy or 50 of Australia's largest super batteries.
A few artificial caverns within the Adavale Basin could power 20 million homes daily, offering significantly cheaper and vastly larger energy storage solutions than above-ground alternatives.
Deep Drilling and Community Concerns
In a significant step, geologists drilled a 3-kilometer deep borehole into the Boree Salt deposit in November, setting a depth record for Geoscience Australia. This extensive operation yielded a 976-meter solid rock core, over 500 rock chips, and several valuable groundwater samples. The initial findings from this comprehensive research are eagerly anticipated mid-year.
Despite the project's immense potential, residents living above the proposed site have voiced concerns, particularly regarding the safety and integrity of the Great Artesian Basin (GAB), their primary water source. Blackall-Tambo Shire Mayor Andrew Martin articulated a "precautionary principle," expressing apprehension about potential jeopardization of the water supply due to increased pressure or subterranean movements.
Dr. Bunch, however, sought to alleviate these fears, stating that pumping hydrogen gas into underground salt caverns is unlikely to harm the GAB. He provided a geological explanation: salt, unlike brittle rock types, acts like a "toothpaste-like substance" that naturally adjusts to pressure changes even in a "worst-case scenario" of a fault, thereby preventing further damage. This crucial process would occur approximately 2 kilometers below the groundwater used for drinking and agriculture. Mayor Martin has subsequently requested more conclusive evidence to ensure the project is fail-safe and to ensure the community is actively involved in future exploration decisions.