Comparative environmental impact assessment of ICT for smart charging of electric vehicles in Germany

Abstract

This study examines the environmental first-order effects of information and communication technologies (ICT) required for private smart charging of electric vehicles (EV) in Germany. With the focus on CO2-optimized charging, the environmental assessment compares bidirectional (V2G) and unidirectional (V1G) smart charging infrastructure to direct (uncontrolled) charging on a household level. Specifically, the applied life cycle assessment (LCA) investigates the production, transportation, operation and end-of-life phases of intelligent metering systems (iMSys) as well as private wallboxes operating with direct current (DC) and alternating current (AC). First, the technical prerequisites for smart and direct charging are outlined, with differences for direct charging depending on the household’s total electricity consumption. Secondly, the LCA shows an impact of 145.4 kg CO2-eq. per vehicle and year for V2G infrastructure by 2020, being 84 % higher than V1G (79 kg). The impact of direct charging infrastructure is significantly lower with 45.2 – 57.5 kg CO2-eq. per year. Due to the power consumption during the operation phase, the AC and DC wallboxes contribute most with 77% (V2G) and 57% (V1G) of the impact, respectively. Assuming ongoing decarbonization of the annual average German emission factor of electricity, the total impact of private charging infrastructure can be reduced by up to 56 % (V2G) and 67 % (V1G) by 2040. Next to the high energy efficiency of components, manufacturers should focus on a sustainable design of components including longevity. Overall, the environmental impact of the ICT infrastructure for smart charging is highly dependent on the charging strategy as it determines the annual duration of charging and discharging. Suggested further research involves investigations on first-order effects associated with other smart charging strategies (e.g. peak shaving), suitable allocation methods for multifunctional ICT components (e.g. iMSys), along with an assessment of higher-order effects such as energy system-wide environmental consequences.