Estimating the geothermal potential of heat-exchanger anchors on a cut-and-cover tunnel

This study addresses the geothermal potential of using the anchors of a cut-and-cover tunnel as heat exchangers with the ground for seasonal heat storage. The influence of the soil properties and water table level were investigated. Various service conditions were examined, optimised and compared using finite-element analyses. The extractable heat from the ground through the anchors, per year and per kilometre of tunnel, ranges from 0.4 to 0.8 GWh. The seasonal heat storage is shown to be an important factor for the efficiency and sustainability of the heat source.