Abandoned underground mines could be repurposed to store vast amounts of energy using gravity batteries, according to an international team of researchers.
A study led by the International Institute for Applied Systems Analysis (IIASA) found that decommissioned mines offered a long-term, cost-effective solution for storing energy as the world transitions to renewable solutions.
Scientists estimate that the use of gravity battery technology within mines has an estimated global energy storage potential of up to 70 TWh, roughly the equivalent of global daily electricity consumption.
A gravity battery works by taking excess energy produced from renewable sources like wind or solar and using it to lift a heavy weight.
When the power is needed during periods of low production, the weight is released and used to drive a turbine as it falls.
Repurposing old mines to house gravity batteries would also have broader economic benefit for the local community, according to the study authors.
“When a mine closes, it lays off thousands of workers. This devastates the communities that depend on the mine for their economic production. Underground Gravity Energy Storage (UGES) would create some openings as the mine would provide energy storage services after it ceases operations,” said Julian Hunt, a researcher at the Energy, Climate and Energy Program. IIASA Environment.
“The mines already have the basic infrastructure and are connected to the electricity grid, which significantly reduces the cost and facilitates the implementation of UGES plants.”
The proposed system would convert the potential energy of the sand as it is lowered into the mine shaft through regenerative failure.
Similar systems using gravitational energy are already in use, and an Australian iron ore company last year unveiled what it claimed to be the world’s first ‘Infinity Train’. The technology allows the battery electric train to transport materials without the need to recharge.
The transition to renewable energy sources accelerated last year amid the global energy crisis, although ways to store excess energy are seen as critical to supporting sustainable energy.
“To decarbonise the economy, we need to rethink the energy system based on innovative solutions that use existing resources,” said Behnam Zakeri, co-author of the study.
“Converting abandoned mines to energy storage is one example of many solutions that exist all around us, and we just need to change the way we implement them.”
The study, titled ‘Underground Gravity Energy Storage: A Solution for Long-Term Energy Storage’, was published in the scientific journal energies.