From a building in the steelworks to the world: How Green Gravity is leading large-scale energy transition

Mark Swinnerton’s first job was at Port Kembla Steelworks so it’s only fitting that the company he founded, Green Gravity, has found its home in a disused steelworks building.

Mark grew up in Canberra but moved to the Illawarra to attend the University of Wollongong. He started at Port Kembla Steelworks as a materials engineering cadet working in the production department at the BOS.

“I always wanted to be a civil engineer, my family had a history of engineers and it kind of appealed to me,” Mark said.

“I liked infrastructure and the built environment so I figured civil/structural engineering was right for me.

“Of course, in the end my dad convinced me that getting paid by BHP to go to uni was a better idea than being a full-time student!”

Mark, the founder and CEO of Green Gravity, will be guest speaker at The Illawarra Connection’s (TIC) first dinner meeting of the year, on Tuesday 4 February.

He’ll be talking about some of the challenges of the renewable energy transition and demonstrate how the Illawarra has a rare set of circumstances to lead the world in new technology at scale.

Green Gravity opened its research and development facility Gravity Lab at the steelworks in July 2023, including the construction of a 12-m prototype.

“Green Gravity exists to radically accelerate the world’s renewable transition,” Mark said.

“Our simple technology lets us store excess energy by lifting heavy objects up a mine shaft during the day, then releasing that energy by lowering them down at night.

“The energy just changes its form from potential energy when we lift the object, to kinetic energy when we lower the object.

“Solar energy is cheap and plentiful, but it is only available when the sun is shining.

“We need to take part of the solar production and store it to use at night. Green Gravity has a technology that is low-cost, long life and very sustainable to move solar to when we need it.

“We’ve spent two years in Wollongong developing a technology that we are now increasingly convinced can make a radical change to our future climate.”

After eight years at Port Kembla where Mark worked across the steelmaking and slab yards, he moved to WA and worked in the iron ore mines for a few years.

In WA’s Pilbara he helped solve logistics problems for the iron ore division by changing the shape of ship hulls.

He held senior white-collar roles in BHP’s Singapore marketing and economic analysis teams, before returning to Australia to manage one of BHP’s Queensland coal mines.

It was while he was BHP’s chief economist based in Singapore that he became deeply interested in green energy.

“It was at that time I had access to incredible depths of analytics and there was a simple conclusion to make – the world is way off target for addressing climate change,” he said.

“By the time COVID came around, I determined that the situation was no better, and that more people needed to take more accountability – which should include me.

“Two things came together for me in 2021. There was lots of media about the Snowy Hydro scheme – which is where renewables are stored by lifting water up a hill.

“There was also a Senate enquiry into the national status of mine rehabilitation, and it found that only five of about 100,000 legacy mines have been fully rehabilitated.

“This got me wondering what all of the other 99,995 old mines were doing – but also what other ways could you apply the principles of Snowy Hydro but not need to flood vast valleys.”

In well under five years, Green Gravity has made huge inroads in both the domestic and international markets.

“We’re working with the Federal Government of Romania to help the transition of coal mining regions using our technology, right through to Far North Queensland where we are working with the city of Mount Isa and Glencore to understand how we can repurpose mine shafts in that region to bring renewable energy to northwest Queensland,” Mark told Invest Wollongong’s #MadeInWollongong Business campaign in December.

“We’ve been able to show that clean energy technology can be developed in regional Australia, can be deployed in regional Australia, and ultimately we can change the world with these technologies.”

Mark said the company was about two-thirds of the way through preparing the technology for commercial application.

“We are gearing up to do our final demonstrations, which will be in a deep mineshaft, and are working with our first customers on the feasibility studies to be able to deploy the tech at large scale into the grid,” he said.

“We are working with 45 mining companies globally and have access to 75 mineshafts currently. We are actively engaged in five countries, but we are focussed on getting the technology launched first in Australia.”

And the future is bright for the company, which last year was named on Cleantech Group’s prestigious 2024 Cleantech 50 to Watch. The annual list highlights 50 early-stage companies from across the globe that are creating groundbreaking solutions to address some of the world’s most pressing environmental and sustainability challenges.

“In five years, Green Gravity will have large-scale energy storage systems working in the grid across east Australia,” Mark said.

“We will be making investments in assets in Europe, North America and India, and we will be exporting technology and key knowhow from the Illawarra.”

While Green Gravity takes up much of Mark’s time, when he does get to relax he enjoys spending time with his wife and four children at home in Bulli.

The Illawarra Connection, which celebrated 30 years in 2023, aims to foster connections, inspire collaboration and drive business innovation in the Illawarra region.

The organisation holds six black-tie events throughout the year, designed to engage, educate and inspire members.

The TIC dinner will be held at the Novotel Northbeach, on Tuesday 4 February, starting from 6:30 pm. For information about the dinner, or membership enquiries, email TIC at [email protected].