  Electrification of transport in RES-based power system will support the
decarbonisation of the transportsector. However, due to the increase in energy
demand and the large peak effects of charging, the passiveintegration of
electric cars is likely to undermine sustainability efforts. This study
investigates three differentcharging strategies for electric vehicle in Europe
offering various degrees of flexibility: passive charging,smart charging and
vehicle-to-grid, and puts this flexibility in perspective with the flexibility
offered byinterconnections. We use the Balmorel optimization tool to represent
the short-term dispatch and long-terminvestment in the energy system and we
contribute to the state-of-the-art in developing new methodologiesto represent
home charging and battery degradation. Our results show how each step of
increased chargingflexibility reduces system costs, affects energy mix, impacts
spot prices and reduces CO2 emissions untilthe horizon 2050. We quantify how
flexible charging and variable generation mutually support each other(¿100TWh
from wind and solar energy in 2050) and restrict the business case for
stationary batteries, whereaspassive charging results in a substitution of wind
by solar energy. The comparison of each charging schemewith and without
interconnection expansion highlights the interplay between European countries
in terms ofelectricity prices and CO2 emissions in the context of electrified
transport. Although the best outcome isreached under the most flexible scenario
at the EU level, the situation of the countries with the cheapest andmost
decarbonised electricity mix is damaged, which calls for adapted coordination
policy at the EU level.
