Batteries in grid assisting charging infrastructure for E-mobility

The collaborative project ""Cities in Charge"" aims at deploying charging infrastructure for electric vehicles throughout Germany taking into account the interaction with vehicle owners and the electricity grid. As part of this project, Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM is investigating the possible contribution of battery storage systems for grid assisting charging of electric vehicles. From more than 150 planned charging sites those are analyzed, where the excess capacity of the electricity grid is limited and the use of batteries is a possible alternative to grid reinforcement. The expected utilization of charging stations at different locations is determined on the basis of a probabilistic simulation model. This utilization is used to assess the resulting load flows with help of a second simulation model. The basic functionality of both simulation models is explained using an example of a fictitious location. In the course of the project this approach will be applied to the real locations. Based on these results, recommendations for the use and dimensioning of batteries for charging stations are derived. Additionally, economic analyses will be performed, assessing whether the deployment of batteries or grid reinforcement is the most economical solution. In the further course of the project, the results will be also included in the comprehensive analyses of the influence of charging infrastructure on the grid, performed by the Institute for High Voltage Technology of RWTH Aachen University.