Large Scale energy storage for a 100% renewable electricity system in Germany

This paper presents results of a study commissioned by the German Federal Environment Agency on possible ways to realise a 100% renewable electricity supply of Germany by 2050 [1]. In the scenario presented here, 94% of the electricity demand are met by national renewable energy sources, about two thirds being provided by wind energy and about 19% by PV. Heat demand is covered mainly by electric heat pumps with the option of demand side management. Half of the energy demand for road transport is supplied by electricity (for electric and hybrid-electric vehicles) with the possibility of load management. Large momentary deviations between supply and demand remain and the available pump hydro storage power plants in Germany are not sufficient to balance supply and demand. About 43 TWhe of storage capacity and considerable storage power is needed. This could be supplied by underground storage of hydrogen or so-called ""renewable power methane"" in northern Germany.