Does BEV always help to reduce CO2 emission? impact of charging strategy
研究了不同充电策略（无序充电、有序充电、车网互动）对电动汽车二氧化碳排放的影响，发现无序充电会增加排放，而有序充电和车网互动能减少排放，且影响随碳价非单调变化，对政策制定者有参考价值。
The environmental impact of battery electric vehicles (BEVs), which are an integral part of climate change mitigation measures, depends on charging strategies, such as uncontrolled charging, controlled charging (V1G), and discharging (V2G). However, the impact is unclear because power system operation involves the cost of carbon dioxide (CO2) emissions and flexibility requirements for imbalances caused by renewable energies. To clarify the robustness of the environmental impact of BEVs, we assessed the interactions between CO2 prices and flexibility requirements in Japan in 2030 using a production cost model. The results showed that uncontrolled charging increases CO2 emissions, whereas V1G or V2G reduces them. Further, the impact of BEVs was non-monotonic with respect to CO2 prices, implying that policymakers should carefully evaluate CO2 prices to achieve decarbonization as BEVs do not always reduce CO2 emissions. This study provides useful insights for policymakers in countries with low-cost, inflexible, and high-emission power plants.