Integrating Guarantees and Veto-Buttons into the Charging of Electric Vehicles at Office Buildings

The electricity demand by electric vehicles (EVs) is rapidly increasing and will lead to violations of grid capacity constraints if supplied in an uncontrolled manner. However, introducing controlled charging often makes EV users feel anxious. To increase the transparency of coordinated charging, we propose a framework of charging guarantees and veto-buttons that provides users with a sense of control. Here, veto-buttons allow users to opt for fast charging instead of controlled charging. We demonstrate the effectiveness of the features for an office parking lot use case, modelled based on a large real-world EV charging parking lot in Utrecht, the Netherlands. Using data from real charging sessions and the work-home commute distance surveyed among EV-driving employees frequenting that parking lot, we demonstrate the effect of the features on the aggregated power profile and its compliance with local grid capacity constraints. In particular, we show that when simulating 400 EVs behind a 1.3 MW power connection, controlling around 60% of the EV population based on their commute-distance information suffices to operate within power limits, even if the remaining 40% of the EVs opt for fast charging of their full electricity requirement using veto-buttons.