Potential of bidirectional charging from the customer's perspective considering metering concepts, § 14a ENWG modules 1-3, and grid fee exemptions on temporarily stored energy

Achieving climate targets requires not only expanding renewable energy but also electrifying the transport and the heat sector. As a result, increasingly high-power consumers such as electric vehicles and heat pumps are being increasingly connected to the grid. This is posing substantial challenges, particularly for distribution grids. Ideally, these loads should operate when renewable generation is abundant. Dynamic tariffs generally support adjusting load to generation, but they can also increase the local grid load and provide no incentives for grid-friendly behaviour. To enable intervention, § 14a EnWG allows grid operators to control or reduce flexible loads in the event of potential overload. In return, customers are compensated through reduced grid fees for the energy consumption of the controllable load. This paper investigates the economic potential of Vehicle-to-Grid (V2G) charging from the customer perspective, focusing on § 14a EnWG Modules 1-3 and a hypothetical full grid fee exemption (Module 4). A new metering concept developed in the “BDL Next” project enables accurate separation of bidirectional charging energy flows for regulatory purposes and is incorporated into the model. Simulation results using the EBZ OptiTwin optimization model show that the choice of the § 14a Module has a significant impact on the economic efficiency of V2G applications, especially when no grid fee exemption is granted. In addition, there is a particular focus on regional differences in the savings potential. Due to the heterogeneous grid fees charged by the more than 700 grid operators in Germany, the potential varies significantly from region to region. For that we present the “Germany Atlas”, a map of Germany with locally mapped potentials, which shows that the potential for V2G energy trading varies from minus 10 % to plus 40% relative to a BDEW average grid fee, depending on the region in Germany.