The 'Master plan for fast charging infrastructure in the Stuttgart region' clarifies how high the demand for fast charging stations is for how many electric cars. How many locations are needed if they are to be accessible from any point in the region within a certain travel time? How many charging processes per day can be expected for what number of electric vehicles, and how much energy is delivered per charging process? For example, 58 charging stations are required if they are to be accessible within ten minutes by car, and 218 if they are to be accessible within five minutes.

Fast charging stations with a charging capacity of around 50 kW make it possible to charge the vehicle battery within just under 20 minutes so that the electric car can cover a distance of around 100 kilometers. The charging process takes longer at the 22 kW charging stations that have been commonly used in public spaces to date. "However, there are hardly any fast-charging stations outside of freeways," says Dr. Martin Kagerbauer from the Institute of Transportation at the Karlsruhe Institute of Technology (KIT).

The planning tool developed by the scientists supports local authorities and potential investors in finding suitable locations for the expansion of the fast-charging infrastructure in the Stuttgart region. Among other things, the master plan for fast-charging infrastructure takes into account the number of charging points already available in the region, high-traffic locations such as museums, shopping centers and restaurants, as well as the connection to the power grid and the expected cost-effectiveness. Dr. Patrick Plötz from Fraunhofer ISI emphasizes: "In the case of well-utilized locations, economic operation is possible within a few years. However, the necessary connection of the charging points to the medium-voltage grid is very complex and depends on many local factors, and specific solutions need to be found."

To create the master plan, KIT researchers used data from the microscopic multi-agent-based transport demand model 'mobiTopp' that they had developed. In a simulation period of one week, the model depicts the mobility of all inhabitants of the Stuttgart region with all routes, destinations and means of transport, for example the regular use of certain means of transport or routine visits to certain destinations. The transport demand simulation, which was commissioned by the Verband Region Stuttgart, includes around 50 million journeys made per week using all modes of transport and reflects the complete mobility profile of the Stuttgart Region.

In addition to bicycles, cars and public transport, electric mobility was integrated into the model in the 'LivingLab BWe mobil' showcase project. Other pilot and research projects from the federal government and the state of Baden-Württemberg were also included in the calculations. "The master plan is specifically tailored to the Stuttgart region due to the underlying data, but the methodology is transferable to other regions," emphasizes Kagerbauer.