An approach to determine charging infrastructure for one million electric vehicles in Germany

Germany has set a goal of having one million electric vehicles in use by 2020. This is a crucial part of the national program Energy Transition, which aims to reduced greenhouse gas emissions and transition the economy to renewable energy sources. Achieving this goal requires adequate charging infrastructure, while also remaining economically efficient. Furthermore, infrastructure must be sufficiently robust to accommodate diverse future scenarios. These include variations in the electric vehicle fleet make-up (battery electric vehicles versus plug-in hybrid electric vehicles), range of vehicles, access to charging stations, charging locations, and charging speeds. This paper presents an approach to determine charging infrastructure using the German case study. We present a demand-oriented methodology to determine charging infrastructure requirements. Utilizing actual travel survey data from a national travel survey, charging demand for user-profiles are determined. Relating charging demand with infrastructure supply (based on the average distance to the next available charging point), we find the required number of charging points. The robustness of the methodology is verified through scenario analyses. The work presents four main findings. First, offering on-street charging in residential areas dramatically increases charging infrastructure. Second, a high percentage of electric vehicles with a private home parking spot notably decreases the total number of charging points. Third, PHEVs slightly increase charging infrastructure demand. Forth, demand for charging infrastructure does not increase linearly with charging demand. Applying the approach to the German case study, between 14,700 and 29,500 charging points are required for one million electric vehicles