Underground Pumped Hydro Storage - A versatile forever asset for a sustainable energy future

Pumped-storage hydropower is undoubtedly the most sophisticated and environmentally friendly energy storage for balanced and stable electrical energy systems compared to other energy storage facilities. Underground pumped hydro is becoming a promising concept to address various challenges and enabling completely new, multifunctional and synergetic plant concepts regardless topography. The substitution of surface reservoirs by storage caverns not only has economic and technical advantages, but also enables flexible and long-lasting power schemes in the vicinity to consumers.
The upgrade of existing hydro reservoirs by deep underground caverns significantly increase the energy content by high heads, utilizing available resources for an even more economical realization of pumped hydro. Underground seawater pumped storage hydropower with the ocean as an infinite upper reservoir can be combined with a desalination plant. Thermal pumped-storage power schemes as electrically and thermally combined energy storage are the innovative technological evolution for a holistic and resource-efficient, renewable energy supply.