As electric vehicles (EVs) become more common around the world, provision of public charging infrastructure will become a more pressing issues for localities. However, since widespread adoption of electric vehicles is still relatively new, researchers have conducted comparatively little research on real-world performance of charging infrastructure.
A research team based at the Institute of Transport Research in Berlin, Germany studied the real-world performance of public electric vehicle charging infrastructure. To do this, the team first collected data about charging stations in the greater Berlin area. Specifically, the team collected location and “charging event” information between December 2016 and March 2018 for EV charging stations newly installed by two operators. The team analyzed charging behavior and other relevant information to understand the real-world performance and utilization of public charging infrastructure in Berlin.
Analysis of the data yield several insights about real-world use of charging infrastructure. These insights include:
• Fully charged vehicles frequently block public charging infrastructure. During an observation period, the average blocked time (time that an EV was connected while already fully charged) for a charging station was 595 hours, almost as much as the charging time of 651 hours.
• Faster charging systems (e.g., high power DC fast charging) can discourage blocking of chargers
• Carsharing vehicles block chargers at much higher rates than privately owned vehicles
To improve turnover at charging stations, operators should consider using a time-based tariff system as opposed to a session fee. The average blocking rate (proportion of time at the charger while already fully charged) under a time-based system was 0.12 vs. 0.2 when a session-based fee was used.