Prospects of electric vehicle V2G multi-use: Profitability and GHG emissions for use case combinations of smart and bidirectional charging today and 2030
Patrick Vollmuth, Daniela Wohlschlager, Louisa Wasmeier, Timo Kern
Abstract
Smart charging (ability to manage charging processes by time shifting and power control) and bidirectional charging (additional discharging of electric vehicles (EVs)) are essential to decarbonize the power sector. To accelerate EV adoption, use cases should provide a financial benefit for private EV users. We thus evaluate the use cases spot market trading, PV self-consumption optimization, and the combination of both (multi-use) for smart and bidirectional charging for German households using the eFlame model. Our approach involves sequential spot trading on the day ahead, the intraday, and the continuous intraday market. For multi-use, both use cases are applied simultaneously. Key features of this paper are realistic scenarios for today (2021,2022) and 2030, incorporating additional costs, and assessing operational greenhouse gas (GHG) emissions expressed in kgCO2-equivalents. Our results reveal that smart charging is profitable in most cases today and in all cases in 2030, yielding annual electricity cost savings of up to 530 €/EVa compared to direct charging. Bidirectional charging, today profitable only for the combined PV self-consumption and spot market trading use case, becomes universally profitable in 2030, with electricity cost savings ranging from 310 €/EVa to 2780 €/EVa. Influential factors include year-specific price characteristics, user behavior, charging restrictions, and regulations for discharged electricity. Concerning emissions today, some charging strategies reduce operational GHG emissions while others increase emissions. Applying smart and bidirectional charging today is consequently not always beneficial in terms of emissions. In 2030, emissions decrease across all cases, positively influenced by a lower GHG intensity of the German electricity mix and less restrictive constraints on charging and discharging processes. • A novel modeling approach for sequential market trading and combining market trading and PV self-consumption is presented. • Results show that the use case combination yields significantly more electricity cost savings than single use cases. • In 2030, cost savings for smart charging range from 280 –530 €/EVa and for bidirectional charging from 310 –2,780 €/EVa. • Key influences on cost savings are price characteristics, charging hour restrictions, charging power, and user behavior. • Operational emissions today are only reduced in some cases depending on emission intensity and charging losses.