Optimizing the charging behaviors of private BEVs to enhance coordinated charging and V2G in Beijing

Abstract

Deep electrification of China's transport sector offers CO₂ emission reduction potential but poses reliability challenges to the urban power system. Smart charging strategies for battery electric vehicles (BEVs), including coordinated charging and vehicle-to-grid (V2G), are one of the most promising approaches to realizing the trade-off between decarbonization and stability of the electricity grid. In this study, an integrated model coupling load prediction and unit dispatching was developed to evaluate the multiple impacts of smart charging strategies considering the heterogeneity of individual driving and charging behaviors expected in Beijing in 2030. Compared with previous work, we have further revealed the different impacts of changing drivers' charging preference under uncoordinated charging, coordinated charging and V2G. The lowest operating cost and CO₂ emissions occur in the workplace charging preference (WCP) scenario with uncoordinated charging, but occur in the daily charging (DC) scenario when V2G is applied. It is indicated that smart charging strategies could simultaneously reduce grid operating costs and CO₂ emissions by decreasing the net load (thermal unit power outputs) on the electricity grid. Compared with the uncoordinated charging, using coordinated charging could reduce daily operating cost by 2.67 million RMB and daily CO₂ emissions by 10.23 kt on average, and the adoption of V2G could further increase the reductions to 8.74 million RMB and 24.25 kt CO₂. Annual CO₂ emission reductions enabled by coordinated charging and V2G are estimated to be 3700 kt and 8850 kt, respectively, which are equivalent to 1.2 × and 2.9 × the projected total emissions of the Beijing private BEV fleet. Increases in V2G participation can also smooth the net load profile and improve grid stability. In the DC scenario, the application of V2G reduced the peak net load by almost 30 % compared to the uncoordinated charging. Furthermore, there is a synergy between V2G participation and renewable energy (RE) development. Improving the electricity system and charging technology during future fleet electrification may be facilitated by coordinated charging and V2G opportunities.