Gravity storage technology mooted for Mount Isa mine shafts to back up vast wind and solar projects

Wollongong start-up Green Gravity says has begun initial work on a potential 2GWh gravitational energy storage project using disused mine shafts in Mount Isa, in north west Queensland.

A fortnight after the company secured $9 million in funding to advance its novel technology, Green Gravity says it has commenced regional studies, minesite concept engineering, and local community engagement in Mount Isa and is working with the local council and mine owner Glencore.

It says it has signed a memorandum of understanding with the Mount Isa City Council and agreed on “concept engineering study work” at the Mount Isa mines, including assessing the potential to repurpose multiple mineshafts within the copper operations after they cease to be used for mining operations.

“Mount Isa is an ideal location for the deployment of gravitational energy storage,” said Mark Swinnerton, founder and CEO of Green Gravity.

“The region has an abundance of solar energy resource, matched with a long history of deep underground mining leading to a large population of high-quality legacy mineshafts.

“Our collaborative work with Glencore at the Mount Isa Copper Operations is a great example of how Green Gravity technology has the potential to create new economic pathways as mines approach closure.”

The development of the project will presumably depend on the progress of the proposed Copperstring 2.0 transmission line from Townsville to Mt Isa, which has the potential of unlocking large new mineral resources and vast wind and solar projects.

It is not clear if the newly elected LNP government support this project, given their promise to de-legislate the state’s renewable energy targets, but the Katter Party, which has likely won at least three seats in north Queensland, is a big supporter, and has family connections to the proposal.

Green Gravity’s energy storage system moves heavy weights vertically in legacy mine shafts to capture and release the gravitational potential energy of the weights and is intended to be low-cost, long life, and “environmentally compelling”.

In their Tuesday announcement, Green Gravity claimed that gravitational energy storage technology represents a “significant economic option” for Mount Isa, “with the potential to attract over $1 billion in private capital over the next decade.”

“By repurposing existing mining infrastructure, deploying gravitational energy storage to the region will provide low-cost, firmed green energy, supporting new industrial developments and ultimately contributing to the National Energy Market via the proposed CopperString project,” the company added.

“This initiative will play a crucial role in addressing the region’s energy challenges and promoting sustainable economic growth.”