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Page 2 of 15 Geng et al. Carbon Footprints 2025, 4, 8 https://dx.doi.org/10.20517/cf.2025.02

INTRODUCTION
The development of electric vehicles (EVs) is widely recognized as one of the effective strategies for
achieving decarbonization and sustainable development in the transportation sector, as it eliminates the
sector’s fundamental dependence on petroleum resources and mitigates the distributed nature of carbon
[1-3]
emissions generated from the use of petroleum-based fuels . According to the China Automotive Industry
Yearbook, annual EV production in China has increased from approximately 0.2 million units in 2013 to
[4]
9.5 million units in 2023 . The future development of EVs is expected to accelerate.

The rapid growth of EVs is expected to drive an increase in electricity demand and grid load. Such a surge
in demand will have considerable long-term implications for the infrastructure construction and
development of electricity generation, transmission, and distribution. Furthermore, the widespread
uncoordinated charging of EVs contributes to a substantial rise in grid load during peak periods, posing
challenges to the stability and reliability of the grid . In scenarios with high EV penetration, uncoordinated
[5]
charging is projected to increase peak load by over 10%, which will not only place great demands on
generation capacity and the transmission network but also threaten the safe operation of local distribution
grids .
[6]

Vehicle-to-Grid (V2G) technology offers a promising solution to the challenges arising from the large-scale
deployment of EVs. V2G enables bidirectional electricity flow between EVs and the grid through
bidirectional charging equipment, effectively transforming EVs into distributed energy storage systems that
[7]
provide storage services . When participating in V2G, EVs can both charge from the grid and return stored
energy to the grid, generating revenue in the process. V2G technology can support services such as peak
[8]
shaving and valley filling, as well as frequency regulation . Currently, the development of V2G technology
has entered the demonstration stage, with hundreds of demonstration projects underway globally [9,10] . As an
emerging low-carbon technology, it is crucial to assess the carbon emission impacts of V2G technology.

For the power system, V2G technology can optimize EV charging and discharging strategies, shifting
charging to low-carbon periods when renewable energy generation is higher. It can also feed energy back
into the grid during periods of low renewable energy availability, which provides flexibility to the power
system, promotes the integration of renewable energy, and subsequently reduces greenhouse gas (GHG)
emissions from the power system. Current research on the emission reduction potential of V2G technology
primarily focuses on its impact on the overall carbon emissions of the power system. Yao et al. analyzed the
role of V2G technology in promoting the low-carbon transformation of the power system at different V2G
penetration levels, assessing GHG emissions under various scenarios . The results showed that as the
[11]
proportion of V2G participation increases, GHG emissions in the power system continue to decrease.
Wohlschlager et al. analyzed the environmental benefits of EVs as distributed storage resources in
Germany's power system . The research demonstrated that V2G technology helps accelerate renewable
[12]
energy integration, thereby reducing overall GHG emissions in the power system; however, as the power
system gradually achieves deeper decarbonization, the environmental benefits of V2G technology will
weaken. Sioshansi et al. analyzed the role of V2G in improving energy efficiency and GHG emission
reduction in the electricity sector . The results showed that V2G technology can effectively reduce
[13]
emissions, including CO and SO , from electricity generation. Liang et al. explored the impacts of V2G on
2
2
the environmental benefits of the power system, using both GHG emissions and costs as objectives . The
[14]
results indicated that, under the peak shaving and valley filling service scenario, V2G technology could
significantly reduce GHG emissions in the power system. Ali et al. examined the emission reduction
benefits of V2G under both non-intermittent and intermittent grid scenarios, finding that integrating V2G