Local force for change Green Gravity wins state sustainability award

Green Gravity just keeps pulling in the awards. Capping off a big year of accolades – including at the Illawarra Business Awards – the local company recently won the Climate Technology for Impact prize at the Banksia Foundation’s 2025 NSW Sustainability Awards. 

Presented at the Australian National Maritime Museum on December 9, the Banksia Award celebrated Green Gravity’s efforts to “radically accelerate the world’s renewable transition” via its mission to repurpose old mine shafts as energy storage hubs and provide a long-life alternative to chemical batteries.

Tania Jones, Green Gravity’s sustainable development manager, said that when it comes to finding "innovative, sustainable and smart solutions", the Illawarra has both the capability and knowhow.

"That is why I am so proud to work for Wollongong-founded energy storage developer Green Gravity," Tania said.

"Green Gravity’s Wollongong team is made up of engineering and business professionals that started their careers at BlueScope (back then BHP), attended UOW, held global roles and have now returned to the region to base their families and focus their careers for impact. 

"We are members of local community groups, business networks and boards and our region's STEM education network because we believe in this region and its ability to demonstrate what can be achieved when we include, collaborate, and innovate." 

Tania said the Sustainability Award – presented by the Banksia Foundation with support from the NSW Government – recognises this approach, as well as the team's circular vision in repurposing mining assets.

Trialled in the Illawarra

Founded in 2021 by former BHP executive Mark Swinnerton as a response to climate change, Green Gravity's storage system is on the rise at the same time as Australians are charging ahead of the rest of the world to install rooftop solar. About 4 million households – or one in three homes – now have solar on their roofs. 

Last year on a tour of the Gravity Lab – a shed in the Port Kembla steelworks complex with a prototype tower – Mark explained how gravitational energy storage works.

“This is about lifting very heavy objects up a legacy mine shaft, when we have excess renewable energy," he said, "and then lowering those weights back down again through the mine shaft when we want to release the energy back to the grid, which means we can take solar energy and we can reproduce it at night.”

In 2025, Green Gravity announced the first demonstration trial of its Gravitational Energy Storage System (GESS) would take place in an Illawarra coal mine – at Number 4 Shaft at Russell Vale Colliery, which is owned by Wollongong Resources.

Tania said this trial was one of the year's highlights, along with winning 2025's Business NSW State Award for Sustainability and completing the prototype development of Green Gravity's 'Gripper and Weighted Object', with the support of a NSW Government grant.

"But the real highlight for 2025 for me has to be the opportunity to share this clean energy technology with over 1100 members of our community through Inside Industry’s Clean Energy Tours," Tania said.

"We have seen countless primary and secondary STEM students, community groups, First Nations leaders, university students from across the globe, government and investment/policy bodies, and interested residents visit The Gravity Lab at Port Kembla (in a repurposed BlueScope Warehouse)  and see the mechanical/electrical mechanism up-close. 

"It is an honour to be able to share the development of this technology with our community, many of which worked in industry sectors that refined the very technology that we are now repurposing."

Also showcasing Illawarra ingenuity at the Banksia Awards were the team from the Electrify 2515 Community Pilot. The community-led electrification research project was a finalist in the Placemaking category; Eurobodalla Shire Council took out first prize for its Wagonga Inlet Living Shoreline project.

What's next for the award winners

"Green Gravity’s goal for 2026 is to complete the commissioning and commence the operation of the first-of-a-kind demonstration trial of the Gravitational Energy Storage System (GESS) here in the Illawarra," Tania said.

Again, it could be a team effort by local talent driving innovation, she added.

"Working with local partners, government, suppliers and networks – like Wollongong City Council, UOW Energy Futures, i3net and Business Illawarra, BlueScope, Inside Industry, Hi Neighbour, Renew Illawarra, Endeavour Energy, EnergyCo, Wollongong Resources & GM3 – to showcase how we can use the Illawarra’s mining legacy to accelerate its renewable energy future."

Inside Industry's Clean Energy Tours

Clean Energy Tours are for all ages and operate on the 3rd Saturday of every month, starting from the Inside Industry Visitor Centre at BlueScope's Northgate entrance and taking in the Port Kembla Hydrogen Hub and Renewable Energy Zone (REZ). The cost ranges from $22 for children to $40 for adults. Tours of the port and the steelworks are also available. For more information, visit the Inside Industry website