Researchers believe that abandoned mines could be the key to tackling the energy crisis, as they could be repurposed to store enough electricity to power the entire planet. Experts have called on an accelerated rollout of energy storage sites like large-scale batteries and pumped hydropower, particularly as the world shifts away from fossil fuels and towards renewable sources of electricity like wind and solar. These sources of electricity do not emit harmful greenhouse gases and have even proved to be cheaper thanks to advancing technologies and soaring gas prices.
However, one of the biggest drawbacks of solar and wind energy is that they are intermittent, meaning that during times when the wind doesn’t blow and the sun doesn’t shine, power output could fall dramatically.
Now, an international team of researcher have said that they have found a solution, by repurposing abandoned underground mines to store vast amounts of energy using gravity batteries.
In a new study led by the International Institute for Applied Systems Analysis (IIASA), researchers found that decommissioned mines could offer a cost-effective and long-term solution for storing electricity.
They calculated that using gravity battery technologies in these mines could help store an estimated potential of up to 70TWh, which is roughly the equivalent of global daily electricity consumption.
The principle behind a gravity battery is that during times when there is a lot of renewable energy generation, the battery will use some of this excess power to move a heavy weight to the top of a deep shaft.
Later when power is needed, winches gradually lower the weight, which produces electricity from the movement of the cables, sending it back to the grid.
The authors of the study also believe that converting these old mines into house gravity batteries would also have a broader economic benefit for the local community.
Julian Hunt, a researcher at IIASA Energy, Climate, and Environment Program said: “When a mine closes, it lays off thousands of workers. This devastates communities that rely on the mine for their economic output.
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“Turning abandoned mines into energy storage is one example of many solutions that exist around us, and we only need to change the way we deploy them.”
Meanwhile, in a study published last year, researchers developed a gravity battery concept which could particularly ensure a stable power supply in urban areas, by turning skyscrapers into giant batteries.
This system would store power by lifting wet sand containers or other high-density materials, which are then transported remotely in and out of a lift with autonomous trailer devices.
The Lift Energy Storage Technology (LEST) could prove to be a very cost-effective solution, as high-rise buildings already have lifts installed, thus removing the need for additional major infrastructure.
