Additional emissions of vehicle-to-grid technology considering China’s geographical heterogeneity

Vehicle-to-Grid (V2G) technology is regarded as a promising distributed energy storage solution that can help address grid challenges arising from the integration of renewable energy and the large-scale uncoordinated charging of electric vehicles. However, issues such as additional battery degradation and energy efficiency losses induced by V2G may lead to increased greenhouse gas (GHG) emissions in providing energy storage services, thereby reducing its overall potential to contribute to power system decarbonization. Existing studies on the additional GHG emissions of energy storage technologies have largely overlooked V2G technology. To fill this research gap, this study develops a comprehensive life cycle assessment model for V2G technology in China. The model first simulates the charging and discharging processes of EV batteries in V2G applications, as well as the additional battery degradation caused by V2G participation. Building on this technical modeling and incorporating multidimensional geographic heterogeneity data, a high-resolution assessment of V2G’s lifecycle additional GHG emissions is conducted across 337 cities in China. The results reveal that V2G’s additional GHG emissions for frequency regulation (FR) and peak shaving and valley filling (PSVF) services range from 0.046-0.152 and 0.036-0.148 kgCO2-eq/kWh, respectively. Energy-related GHG emissions constitute the largest proportion, accounting for 59.0% and 66.8% of total emissions for FR and PSVF services, respectively. From a geographic perspective, the additional GHG emissions of V2G are lowest in southwestern China and highest in the northeast. The findings of this study highlight significant regional variations in the environmental impacts of V2G technology in China and underscore the importance of region-specific strategies for the effective and sustainable deployment of V2G technology.