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 found that decommissioned mines offered a cost-effective and long-term solution for storing energy as the world transitions to renewable solutions.
The scientists estimate that using gravity battery technology within mines has an estimated global energy storage potential of up to 70TWh – 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 (such as sand). When the energy is needed during periods of low production, the weight is released and used to power a turbine as it falls.
The proposed system would also convert the potential energy of sand as it is lowered into a mine shaft via regenerative breaking.
All put together, it's a remarkably simple solution that's also very cost effective as mines already have the necessary basic infrastructure and are connected to the power grid. We can expect to hear a lot more about UGES (Underground Gravity Energy Storage) in the coming months and years.