Energy tunnels for a sustainable future in rock engineering

The use of geothermal energy for heating and cooling purposes is an environmentally friendly and cost-effective alternative with the potential to replace fossil fuels and help mitigate global warming as well. In the boost of innovation of the tunnelling industry, to face the challenges posed by climate change and the need for sustainable growth of cities and territories, it is of interest to embody the innovative use of the tunnel linings to also produce thermal energy for conditioning of buildings, cooling of tunnel air or de-icing of infrastructures. Relevant examples from the Author’s recent experience, related to deep and shallow thermally activated underground excavations, will be revealed to highlight the methodological steps to be adopted for the geothermal potential evaluation and achieve a successful design of the integrated technology. These include specific rock mass thermal and hydraulic characterisation, GIS procedures and coupled numerical modelling. Applications under the Alps will show how energy tunnels may help unlock new opportunities for sustainability in rock engineering.