Europe’s deepest mine becomes gravity battery to store renewable energy

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An abandoned mine in Finland is to be converted into a giant battery to store renewable energy during periods of overproduction.

The Pihasalmi mine, located approximately 450 kilometers north of Helsinki, is Europe’s deepest zinc and copper mine, with the potential to store up to 2 MW of energy in a 1,400 meter deep shaft.

Gravity batteries will be installed in disused mines to harness surplus energy from renewable sources such as solar and wind power to lift heavy objects. During periods of low production, the weight is released and used to power a turbine as it falls.

The gravity battery system is being developed by Scottish company Gravitricity, which plans to use a mine in Finland as a full-scale prototype to demonstrate the technology.

Martin Wright, Gravitricity’s executive chairman, said: “This project will enable our company to provide reliable, long-life energy storage that can capture and store energy during periods of low demand and quickly release it when needed. “This will be a full-scale demonstration of what the technology can deliver.”

“This full-scale project provides a pathway to other commercial projects and allows us to incorporate our solution into mine decommissioning activities, providing a potential future for mines that are nearing the end of their original useful life. We provide.”

A study last year by the International Institute for Applied Systems Analysis (IIASA) estimated that gravity batteries in abandoned underground mines could store up to 70TWh of energy, enough to meet global electricity needs. .

Mine reuse can also bring economic benefits to communities that have traditionally relied on mines for their livelihoods.

IIASA analysts noted that the mine already has the basic infrastructure for such an endeavor and is also connected to the electricity grid.

“This will significantly reduce the cost and equipment required to deploy underground gravitational energy storage (UGES) plants,” the study said.

The Pihasalmi mine will be decommissioned in 2022 and Gravity City claimed that 600 direct and indirect jobs were affected. Other initiatives being considered for the site include a solar farm.

Gravitricity’s website states, “As the world generates more electricity from intermittent renewable energy sources, we are developing technologies that can capture and store energy during periods of low demand and quickly release it when needed. The need is growing.”

“We are developing innovative, long-life underground technologies that safely store energy and deliver it on demand at lower lifetime costs than current alternatives.”