Definition of a Stochastic Charging model of EV Aggregation and Estimation of its Flexibility Amount

The massive diffusion of Electric Vehicles in the next years is one of the expected outcomes of the Energy Transition. However, this scenario will impact on Medium and Low Voltage electric distribution systems, due to the installation of a multitude of charging infrastructures. Coupled with the accommodation of a plethora of small generation plants (largely photovoltaics), it may cause huge network investments. On the other hand, if smartly managed, they can become a valuable resource of flexibility for the correct electric system operation. Indeed, Electric Vehicles can be considered as mobile storage units that, coordinated by an Aggregator, provide network support by modulating their slow charging at home or workplace. The knowledge beforehand of this resource behavior (expected combined charging profile, available flexibility to adapt this profile and related uncertainties) is essential for Distribution System Operators to be confident in its use and tailor a sustainable network development plan. In the paper, such models have been obtained on the base of Monte Carlo simulations, for different habits of Electric Vehicles drivers.