The impact of variable grid fee tariffs on the electricity costs of EV users in Germany

This paper investigates the impact of the 2023 framework of rules to § 14a of the Energiewirtschaftsgesetz - German Energy Industry Act, EnWG - (§ 14a framework) on electric vehicle (EV) users. The § 14a framework requires distribution grid operators (DSOs) to connect new heat pumps (HPs) and EV charging infrastructure (EVSE) while allowing them to reduce power drawn from HPs and EVSEs in case of grid overload. The DSOs are mandated to provide remuneration for these components. The study develops remuneration mechanisms in the form of variable grid fee tariffs together with DSOs, which are then implemented into an optimization model for the flexible marketing of EVs to analyse their effect on the EV charging behaviour and the total costs. The analysis reveals that the § 14a framework gives high flexibility in designing variable grid fee tariffs to meet the needs of the different distribution grids. These different tariffs enable flexible EV users to achieve substantial cost savings, thereby providing a strong incentive for the load shifting required by DSOs. This research fills a gap in understanding how the incentives outlined in the § 14a framework affect EV users.