Gravitricity, a Scottish firm specializing in energy storage, has revealed that an operational coal mine in Slovenia is considering underground gravity energy storage. The Velenje mine, located in northeastern Slovenia, is currently a fully operational lignite mine with over 1,600 employees.
The mine operators have commissioned a feasibility study to explore how underground gravity energy storage provided by Gravitricity could contribute to a low-carbon future as the mine prepares to wind down operations in the 2030s. Gravitricity’s energy storage system, known as GraviStore, raises and lowers heavy weights in underground shafts, offering characteristics similar to lithium-ion batteries and pumped hydro storage.
Velenje joins a growing list of mine sites in Europe, including those in Finland, Germany, and the Czech Republic, that are exploring gravity storage solutions. The mine’s parent company, HSE Group, is already Slovenia’s largest producer of renewable electricity, suggesting that any future storage scheme could complement on-site solar generation to support the country’s transition to net zero.
Gravitricity engineers have assessed the technical feasibility of installing systems in two specific shafts at the Velenje mine, one of which is a ventilation shaft that may be available for a potential pilot project starting as early as next year.
Nigel Voaden, Gravitricity’s engineering project manager, commented on the potential of the Velenje mine, stating, “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.”
The feasibility study includes an assessment of energy demand, production, and storage, an initial calculation of potential energy storage capacity for each of the six shafts on site, and a technical feasibility assessment for the installation of two GraviStore systems. Following the submission of Gravitricity’s findings, the mine operators will have the opportunity to consider a second phase of the feasibility study before making any final decision on a pilot scheme.
Gravitricity is currently fundraising on the Crowdcube platform and has surpassed its £500,000 funding target.
