According to the study, decommissioned mines could be repurposed to operate as “gravity batteries.” The idea is easy: excess energy is utilized to lift heavy objects, like sand, up into the mine. When energy is needed again, the weight is dropped, spinning a turbine and converting the kinetic energy from gravity back into electrical power.
Credit: Nova Scotia Minehunters/Facebook.
This electrical energy can then be used when demands on the grid are high, and at other times, when there is excess energy in the grid, the gravity battery system utilizes some of that energy to pull the load back up, keeping the energy for later usage.
As the world increasingly relies on renewable resource sources like wind and solar, the obstacle of keeping excess energy becomes progressively pressing. But a brand-new study from the International Institute for Applied Systems Analysis (IIASA) in Australia suggests that a not likely solution may be concealing in plain sight: deserted mines.
Saving energy through gravity
The IIASA researchers have proposed an unique kind of gravity battery, understood as Underground Gravity Energy Storage (UGES), that makes use of elevators in existing decommissioned mine shafts and raises and lowers containers full of sand. Electric motor and generator units on both sides of the shaft move the elevator up and down, producing electrical energy through regenerative braking en route down and utilizing some of that electrical power on the way back up.
The IIASA approximates that it would cost roughly $1-10 per kilowatt-hour to transform a mine, and a more $2,000 per kilowatt of power capability. However the potential payoff is substantial: the scientists think that their technique might have a worldwide capacity of 7 to 70 terawatt-hours, with the majority of this possible concentrated in China, India, Russia, and the USA– the nations with the most deserted mines. To put that into point of view, global energy consumption for 2021 was about 25 terawatt-hours.
Among the most typical gravitational energy technologies is represented by pumped-storage hydroelectric systems, where water is launched from a high elevation, creating electrical energy through the spinning of turbines as it flows downhill. The water is pumped back up to the top when there is excess energy.
UGES would produce a couple of jobs as the mine would provide energy storage services after it stops operations,” says Julian Hunt, a researcher in the IIASA Energy, Climate, and Environment Program and the lead author of the research study. The possible benefit is huge: the researchers think that their technique might have a worldwide potential of 7 to 70 terawatt-hours, with many of this prospective concentrated in China, India, Russia, and the USA– the nations with the most deserted mines. To put that into point of view, international energy consumption for 2021 was about 25 terawatt-hours.
The genuine appeal of the idea is that there are already millions of abandoned mines around the world that could be fairly inexpensively transformed for this purpose. Most contain the basic needed facilities and are already connected to the power grid.
The findings appeared in the journal Energies.
The idea is basic: excess energy is utilized to raise heavy items, like sand, up into the mine. When energy is needed again, the weight is dropped, spinning a turbine and transforming the kinetic energy from gravity back into electricity.
The advantages of repurposing abandoned mines for energy storage dont stop there. The researchers likewise believe that operating gravity batteries in these mines might bring back or maintain some of the tasks lost when the mines closed.
” When a mine closes, it lays off thousands of workers. This devastates neighborhoods that rely just on the mine for their economic output. UGES would create a few jobs as the mine would offer energy storage services after it stops operations,” says Julian Hunt, a researcher in the IIASA Energy, Climate, and Environment Program and the lead author of the research study. “Mines already have the standard facilities and are linked to the power grid, which significantly reduces the cost and facilitates the application of UGES plants.”
Among the essential benefits of this approach is that it does not experience the same self-discharge problems that conventional batteries do. The energy is stored in the gravitational potential of the weight itself, instead of in a chemical-based battery that can lose its charge over time.
Its a concept thats still in the early phases of research and development, however its one that might have a huge effect on the future of renewable resource storage. The next step is to investigate the feasibility of the idea on a larger scale, however the IIASAs research study recommends that abandoned mines might be a cost-effective solution that might also supply tasks.
“To decarbonize the economy, we need to reassess the energy system based on ingenious solutions using existing resources. Turning abandoned mines into energy storage is one example of lots of solutions that exist around us, and we just need to alter the way we release them,” concludes Behnam Zakeri, research study coauthor and a scientist in the IIASA Energy, Climate, and Environment Program.