Green Gravity, which is turning old mineshafts into energy storage, raises $9 million

A Wollongong startup converting disused mining shafts into long-duration energy storage has raised $9 million to turn the idea into reality.

Green Gravity was backed by HMC Capital, BlueScopeX, New Zealand’s Pacific Channel and SCAP H, a subsidiary of Japan’s Sumitomo Corporation.

BlueScopeX’s hosts Green Gravity’s demonstration plant at BlueScope’s Port Kembla Steelworks facility in a unique and world-leading approach to repurposing legacy mineshafts and works with global miners, energy companies and research institutes to scale up its technology.

The energy storage system is low-cost, long life and environmentally friendly, moving heavy weights vertically in legacy mineshafts to capture and release their gravitational potential energy.

The funding will see the startup focus on the engineering and physical testing of the system at scale for commercial deployment decisions, having built collaborative relationships with mine site owners including Yancoal, Wollongong Resources and CEVJ of Romania. 

Founder and CEO Mark Swinnerton said the backing from offshore investors such as Pacific Channel and SCAP H shows global interest for the technology.

“This funding round, backed by a world class syndicate of investors, demonstrates the game changing impact Green Gravity is having on the renewable energy storage landscape,” he said.

“It will strengthen our team and enhance our capabilities, as we propel towards widespread commercial availability.”

Swinnerton said his institutional investors have “a unique blend of global technology knowledge, Australian manufacturing credentials, mining services expertise and large-scale listed infrastructure investment capacity” for his startup to succeed.

“The testing and engineering development Green Gravity has conducted over the past year has validated the attractive cost and sustainability profile of the technology,” he said.

“We expect to configure the gravitational storage technology for mid-duration storage  applications of 4 to 24 hours, deliver 80% energy efficiency and to enable reuse of critical grid infrastructure. With more than 80 deployment options in review, we  expect to make a major contribution to decarbonising the energy grid in the coming  years.” 

BlueScopeX partner Andrew Garey said: “Firmed renewable energy will be a critical part of decarbonising many industries, including steel. We are really excited to partner with companies like Green Gravity on the journey of scaling reliable, low-cost firming technologies.”