How Many More Public Charging Stations Do We Need? A Data-Driven Approach Considering Charging Station Overflow Dynamics

The development of public charging infrastructure is crucial to support mass EV adoption. Although many cities worldwide already installed an initial network of public chargers, it is often unclear whether the current supply of infrastructure is in line with demand, and how many more charging stations are required to cope with future EV growth. In this sense, transactional charging data on the existing network can help answer these questions. We present a novel method that uses historical charging data as input to determine (1) how many more chargers are required to meet future demand, and (2) where to install these new chargers. By mining the individual charging behavior of EV drivers, we show that overflow dynamics can be found between charging stations. That is, when a preferred charging station is fully occupied, EV drivers are found to divert to other nearby charging stations. Identifying these dynamics allows us to simulate the impact of a demand increase on the charging infrastructure network more accurately. We found the required number of new chargers to be significantly lower when considering overflow dynamics. Our simulations indicate that for a doubling of the demand, 30-50% fewer charging points are needed compared to when overflow dynamics are neglected while maintaining the same failure rate (i.e., percentage of failed charging sessions in the network). Determining the exact number of chargers will depend on the failure rate policymakers are willing to accept, reflecting the trade-off between charging convenience and utilization.