| Abstract |
Nowadays, many countries are making significant progress towards an energy model based mostly on renewable energies. To ensure this transition, it is crucial to develop new methods for storing and distributing energy reliably and flexibly. Flooded abandoned mines offer high potential for hosting local energy communities, serving as large-scale thermal storage systems and supporting grid stability. This study, conducted within the framework of the European WeForming project, explores the use of a flooded mine in southern Belgium as a multi-service demonstrator for heating, cooling, and electricity dispatch. The mine infrastructure enables daily, weekly and seasonal thermal storage by using different distinct water-flooded caverns: 600 m³ at 50–60°C, 6,000 m³ at 25–45°C, and 20,000 m³ at 5–20°C. Additionally, a large volume of 475,000 m³ at 8–10°C is available as a cold sink. A dynamic simulation model developed in Dymola is presented alongside the construction progress of the demonstrator, which is expected to be fully operational by the end of 2026. Key system components include a chiller, heat pumps, a Carnot battery (power-to-heat and heat-to-power), district heating infrastructure, thermal tanks in apartment buildings, and electrical batteries. Preliminary results highlight the system's great potential for seasonal heating applications and its attractiveness for warehouse operations (cooling), offering a stable COP of around 3.5 throughout the year, while other heat pumps can vary between 2.2 and 5, depending on boundary conditions. The paper also includes an analysis of the Levelized Cost of Storage (LCOS) and capital expenditures (CAPEX) for this integrated community-scale solution. |