Energy from geo-structures: a topic of growing interest

Underground geotechnical structures (piles, diaphragm walls, tunnel linings, anchors etc.) can be instrumented to become energy geo-structures. This short paper focuses on the use of energy tunnels, which are shown to have a number of advantages. An example of a possible application to the Turin Metro Line 1 south extension is discussed. Preliminary results of numerical analyses, performed to study the hydro-thermal interaction and the influence of the energy tunnel on the surroundings, show that the energy stored in the ground can be exploited without generating relevant effects on the aquifer. This highlights the importance of additional research to improve the understanding of the geothermal process and exploit the potential of energy tunnels allowing for great economic and environmental benefit.