Green Gravity says former Wollongong Resources coal mine to host world’s first demo deployment of “breakthrough technology”

Green Gravity and Wollongong Resources have announced execution of a binding agreement for gravitational energy storage trials at the Russell Vale mine.

The pair previously signed a Memorandum of Understanding, announced December 2023, and have since worked closely to assess the Russell Vale site for suitability in accommodating gravitational energy storage. 

According to a statement from Green Gravity on Thursday, there are multiple mineshafts at the site well-suited, “with the #4 mineshaft confirmed as the site of the world’s first deployment of the breakthrough technology.” It is currently completing completing engineering study and regulatory approvals for the deployment at #4.

CEO and founder Mark Swinnerton said the planned demonstration plant could provide world-class testing data. 

“By placing and retrieving multiple weights 400 metres underground using fully autonomous systems, we will have the opportunity to validate the incredible safety and environmental credentials of Green Gravity’s technology,” said Swinnerton.  

The Russell Vale mine at Wollongong was an active coal mine from the late 1800 until entering care and maintenance in 2023. Wollongong Resources has eight mineshafts in the Illawarra, which according to Green Gravity “have with the potential to deliver more than 100 [megawatt hours] of clean energy storage”.

Green Gravity describes its invention as offering a “long-duration, low-cost, and environmentally sustainable form of energy storage” and using the “gravitational potential of heavy weights lowered and lifted in legacy mineshafts” to store and release energy.

The site is to remain non-grid connected during trials, according to the release, with energy storage tests at 150 kilowatts of power. 

While trials will be conducted at that level, “the mechanical components and key control systems will be tested at a scale sufficient to underpin future commercial deployments of the technology”, it added.

“Commercial application of Green Gravity’s gravitational energy storage technology is expected to deliver increments of up to 10 megawatts (10 MW) of between 8 and 20 hours of duration at individual mineshafts.”

The news follows an MoU signed between the company and Wollongong City Council, covering a 24-month period and aiming “to position Wollongong and the broader Illawarra as a hub for world-leading clean energy solutions.”

Green Gravity was established in 2021 and opened an R&D site, the Gravity Lab (pictured) in 2023 at the Port Kembla Steelworks.

Picture: supplied

Further reading

Green Gravity, Wollongong deal aims to position region as “global centre for innovation in clean energy storage”

Investors weigh in behind Green Gravity energy storage

Green Gravity partners for mineshaft energy storage

The Gravity Lab complete at Port Kembla

Green Gravity to test mineshaft energy storage system