An operational coal mine in Slovenia has become the latest in mainland Europe to consider underground gravity energy storage, Scottish firm Gravitricity has revealed.
The Velenje mine in the northeastern part of Slovenia is currently a fully operational lignite mine, with six working shafts and more than 1,600 mine employees.
The mine operators have now commissioned a feasibility study to examine how underground gravity energy storage provided by Gravitricity could offer a low carbon future as the mine winds down operations in the 2030s.
Gravitricity has developed a energy storage system, known as GraviStore, which raises and lowers heavy weights in underground shafts – to offer some of the best characteristics of lithium-ion batteries and pumped hydro storage.
Velenje is the latest mine to look to gravity storage, following mine sites in Finland, Germany, and the Czech Republic.
The mine’s parent company HSE Group is already Slovenia’s largest producer of renewable electricity, and any future storage scheme could potentially be combined with on-site solar generation to support the country’s transition to net zero.
Gravitricity engineers have already visited the site to assess the technical feasibility of installing systems in two specific shafts one of which is a ventilation shaft which may become available for a potential pilot project, which could start as early as next year.
Gravitricity engineering project manager Nigel Voaden said: “The Velenje mine could be very well suited to future energy storage schemes as the operational shafts are both deep and in excellent condition and we are grateful to the mine’s operators for commissioning this study.
“Any future project could offer a new future to many of the hundreds of people who work at the mine today.
“The survey includes an all-site assessment looking at energy demand, production, and storage, provides an initial calculation of the potential energy storage capacity for each of the six shafts on site, and completes a technical feasibility assessment for the installation of two GraviStore systems.”
Following submission of Gravitricity’s findings, the Velenje mine operators will have the opportunity to consider a second phase of the feasibility study prior to any final decision on a pilot scheme.
Gravitricity is currently fundraising on the Crowdcube platform and has already passed its £500,000 funding target.