Assessment of Carbon Emission Reduction Potential of V2G in Public Charging and Discharging Stations for Green Power Accommodation

With the advancement of “dual carbon” goals and rapid growth of the new energy vehicle industry, large-scale EV charging loads increasingly challenge power grid operations, while high-proportion renewable energy integration exacerbates the urgency of green power accommodation. Vehicle-to-grid (V2G) technology, enabling bidirectional energy flow between EVs and the grid, offers an effective path to enhance power system flexibility, promote green power accommodation, and reduce carbon emissions. This paper focuses on public charging and discharging stations for green power accommodation, constructing a framework to assess carbon emission reduction potential under V2G mode. First, using the carbon emission factor method, an EV charging carbon emission accounting model is built, integrating energy conversion losses in charging and carbon emission characteristics of various power generation modes. Second, based on the “electricity substitution” principle, V2G discharging is treated as equivalent substitution for incremental power from peak-shaving units, with a discharging-side carbon reduction model constructed to evaluate system-level benefits. Finally, these models are integrated into the assessment framework, validated via a typical urban public station case. Simulation results show optimized green power-V2G scheduling enables the station to reduce 7006 kgCO2 on a typical day, yielding about 500 CNY daily from carbon trading, verifying V2G’s significant environmental and economic value in advancing low-carbon transition of transportation and energy sectors.