In addition to a massive expansion of renewable energies, a successful change towards a decarbonized energy system requires the flexibilization of consumers and the integration of storage and sector coupling technologies. Bidirectionally chargeable electric vehicles (EVs) represent such a consumer flexibility. They are able to charge when there is an electricity generation surplus and to discharge when there is a shortage in electricity generation. Therefore, they can act as a storage from the perspective of the energy system.
This paper analyzes different modeling approaches of bidirectionally chargeable EVs in large-scale energy systems and evaluates the impact of bidirectionally chargeable EVs on the future European energy system design. We compare the modeling of discrete EV profiles, clustered EV profiles as well as an aggregated EV profile with simplified constraints. Aggregation of EV profiles per country leads to significantly lower computation times, while still achieving results close to the reference case. The number of bidirectionally chargeable EVs in a cost optimal future European energy system increases from 6 million EVs in 2025 to over 60 million EVs in 2050. We show that bidirectionally chargeable EVs lead to a better integration of PV generation, to lower installed capacities of gas- and hydrogen-fired power plants as well as stationary battery storages. They also lead to decreasing electricity prices and total European energy system costs.