Selzam, PatrickPatrickSelzamBecker, SarahSarahBeckerDörre, EliasEliasDörreMetzler, KatjaKatjaMetzlerLauven, Lars PeterLars PeterLauvenHirschmann, FlorianFlorianHirschmann2026-02-142026-02-1420239783800761098https://publica.fraunhofer.de/handle/publica/5072222-s2.0-105027595634The increasing number of electric vehicles and heat pumps, which is explicitly desired for the German energy transition, will foreseeably lead to considerable additional loads in the low-voltage grid. Variable electricity tariffs based on hourly varying spot market prices can also lead to enormous simultaneity in the future if, in extreme cases, all customers nationwide want to charge their cars at the lowest price. Variable grid fees could be an instrument for grid operators to shift electricity consumption to non-grid-critical times and to better exploit the feed-in of temporally fluctuating renewable energies, thus reducing any necessary curtailment. The main results of this paper are the evaluation of the impact of consumer protection requirements on the effectiveness of variable grid fees in terms of grid efficiency and integration of fluctuating renewables. It also analyses the extent to which variable versus fixed grid fees can reduce curtailment if all electricity customers in a grid area receive the spot market price as their energy delivery price.defalseconference paper