Interactions between groundwater and the cavity of an old slate mine used as lower reservoir of an UPSH (Underground Pumped Storage Hydroelectricity): A modelling approach

摘要: Abstract In the actual evolving energy context, characterized by an increasing part of intermittent renewable sources, development storage technologies are required, such as pumped hydroelectricity (PSH). While new sites for conventional PSH plants getting scarce, it is proposed to use abandoned underground mines lower reservoirs Underground Pumped Storage Hydroelectricity (UPSH). However, hydrogeological consequences produced cyclic solicitations (continuous pumpings and injections) have been poorly investigated. Therefore, in this work, groundwater interactions with cyclically fill empty cavity were numerically studied considering a simplified description slate mine. Two pumping/injection scenarios considered, both reference rock case sensitivity analysis variations aquifer hydraulic conductivity value. Groundwater impacts assessed terms oscillations piezometric heads mean drawdown around cavity. The value clearly influences magnitude response. Studying highlighted that seepage into occurs over time. volume seeped water varies depending on could become non-negligible UPSH operations. These preliminary results allow finally first geological feasibility aspects, which vary conversely according considered impacts.