Finite element modelling of an energy-geomembrane underground pumped hydroelectric energy storage systemHans Henning Stutz, Peter Norlyk, Kenneth Sørensen, Lars Vabbersgaard Andersen, Kenny Kataoka Sørensen and Johan ClausenE3S Web Conf., 205 (2020) 07001DOI: https://doi.org/10.1051/e3sconf/202020507001