What seems like a simple plan — sending a large weight down a deep hole — could help Australia towards net zero emissions.
Housed in an old mine shaft and suspended by a strong cable, a weight is lowered 500 metres down a long drop and in doing so, turns a turbine that creates electricity.
It is the same technology that drove grandfather clocks in the 1600s, and it uses gravity to create electricity in the same way as a hydro-electric scheme.
"We're trying to do the same thing, but we don't need the water," Green Gravity chief executive Mark Swinnerton told Lindsay McDougall, on ABC Illawarra Drive.
"We have nearly 100,000 legacy mines in Australia from all around and we have all these big holes in the ground, so rather than use water, we use dense objects."
How it works
In practice, the suspended weight might be lifted during the day when renewable solar energy is plentiful, then lowered at night when power is needed.
Mr Swinnerton said most old mine shafts were still connected to the grid, which meant the system could help deliver power directly to communities near the shaft.
"Only 3 per cent of our legacy mines have been fully rehabilitated or relinquished," he said.
"As a country, we're not using it and it's a great opportunity to reuse infrastructure."
Unused industrial building provides research space
Green Gravity has partnered with BlueScope to a build a 12m tall prototype in an unused building at Port Kembla in Wollongong on the NSW South Coast.
"Its purpose is to … fine tune [the] physics and the electrical wave forms and make sure we have everything right in our control systems," Mr Swinnerton said.
"This allows us to have great confidence in the mine site and convince the mining operators to say, 'It's working over here', and that's a way of building confidence."
BlueScope is currently working through a plan to repurpose and reuse more than 200 hectares of unused land.
"We are very excited that Green Gravity chose to establish its Gravity Lab here on our site by repurposing one of our industrial-sized buildings," BlueScope head of corporate affairs Michael Reay said.
"It's a great fit and a tangible example of what we are trying to create — a modern, high-tech research and development precinct that builds upon our strengths in advanced manufacturing."
Mr Swinnerton said the prototype's results could see the company become world leaders in the technology.
"That's also an opportunity for regions seeing a reduction in mining activity," he said.
Artificial intelligence used to build 'digital twin'
Green Gravity is also building a digital replica of the Gravity Lab at Port Kembla using artificial intelligence.
The replica will be fed with data from the physical lab to help calculate how the technology can be quickly scaled up.
"What we've been able to do is build the Gravity Lab physically and digitally in such a high resolution world that it will behave the same way," Mr Swinnerton said.
"One of the purposes is to calibrate and train its digital twin so you can see how we can find ways to accelerate our technology."
The physical Gravity Lab is expected to be built by the end of this year.
