It’s exploiting energy from the wind and the sun, along with the power of gravity. “Battery storage on its own—or what people call short-duration energy storage—is very important,” said Martin Staadecker, an energy systems researcher at the Massachusetts Institute of Technology and lead author of the new study.
Scientists are looking at a novel new way of utilizing “gravity batteries” built from decommissioned mines around the world for energy storage, in a move that could provide an avenue toward more sustainable energy for future generations.
Companies are figuring out how to store energy underground, too. A company called Hydrostor, based in Toronto, Canada, uses excess renewable energy on the grid to pump compressed air into subterranean caverns filled with water. That forces the water aboveground into a reservoir.
“Unlike battery energy storage, the energy storage medium of UGES is sand,” the study’s authors write, “which means the self-discharge rate of the system is zero, enabling ultra-long energy storage times.”
Because they eventually self-discharge when stored for long periods, batteries, UGES is more efficient on account of there being no self-discharge that occurs, potentially allowing the storage of energy generated by these “gravity batteries” nestled deep within abandoned mines around the world to be stored for periods of several years.
Underground storage for renewable energy resources could be a viable green solution as we transition to a net zero UK. Some renewable energy sources, like wind power, are intermittent and any excess energy can be difficult to store. BGS © UKRI.