The role of remaining charging energy as an additional EV flexibility indicator

Due to the deficiency in flexibility evaluation from charging power and maximum deferrable time, this paper introduces remaining charging energy as an additional flexibility indicator of electric vehicles (EVs) in data-driven analysis. It is defined as the part of EV battery capacity that needs to be recharged from the observed time step to the end of charging. As a joint indicator of charging power ratings, initial and final state of charge (SoC) values and EV battery capacities, it illustrates for how long EVs would have been charged if demand response (DR) had not been activated at a particular time, and for how long EVs would have to be recharged after DR activation. The remaining charging energy is assessed in the paper in terms of the potential for rescheduling aggregated EV charging demand to the off-peak hours in residential areas. The obtained results specify lower and upper boundaries of aggregated remaining charging energy, and how often during the year it was higher than a certain value at a given time.