Gravitricity weighs up one of Europe’s deepest mines

Scotland’s Gravitricity is set to deploy its underground energy storage technology at Pyhäsalmi Mine in central Finland, Europe’s deepest zinc and copper mine.

The Pyhäsalmi mine tower in winter
The Pyhäsalmi mine tower in winter - Gravitricity

Located about 450km north of the Finnish capital Helsinki, the Pyhäsalmi Mine extends 1,444m below the Earth. With mine operations at Pyhäsalmi winding down, the local community set up a development company to explore redevelopment projects around the mine’s infrastructure, including energy storage.

Gravitricity is set to deploy its GraviStore energy storage technology in a 530m deep auxiliary shaft. GraviStore can utilise off-peak electricity by raising heavy weights in the mine shaft, releasing the energy back on to the grid during high demand by lowering the weights. It’s claimed the 2MW scheme at Pyhäsalmi will provide grid balancing services to the Finnish network.

“This project will demonstrate at full scale how our technology can offer reliable long life energy storage that can capture and store energy during periods of low demand and release it rapidly when required,” said Martin Wright, Gravitricity executive chairman.

“This full-scale project will provide a pathway to other commercial projects and allow our solution to be embedded into mine decommissioning activities, offering a potential future for mines approaching the end of their original service life.

“It will also provide vital new low carbon jobs in an area which has suffered significantly from the end of traditional mining operations.”  

Mining ended at Pyhäsalmi in August 2022. The mine was the area’s biggest employer and its closure led to a loss of over 600 direct and indirect jobs. Alongside the GraviStore project, the local development company - Callio Pyhäjärvi - is also exploring several other initiatives at the mine, including solar farms, technology startups, mining technology testing facilities and an underground 5G network.

“We can take advantage of the best of the region’s electricity grid and transformation of the energy market,” said Callio Pyhäjärvi’s CEO, Henrik Kiviniemi. “It is also very attractive to take advantage of these opportunities for energy-intensive industry to be located here utilising also the good logistical location of Pyhäjärvi.

“Our industrial park can provide an excellent framework for electricity-intensive operators in the future, like Gravitricity, who can utilise the infrastructure and local know-how coming vacant from mining operations.”