Abstract
The increasing deployment of variable renewable energy (VRE) is essential for achieving a sustainable society; however, its inherent variability poses challenges for maintaining a stable electricity supply. Vehicle-to-grid (V2G) technology enables bidirectional electricity exchange between electric vehicles (EVs) and the power grid and can enhance the utilization of renewable electricity by charging EVs during periods of VRE output curtailment. This study developed a regional V2G system model and evaluated its potential through energy flow simulations and life cycle assessment (LCA). The model explicitly considered hourly operation schedules of individual EVs, the spatial distribution of V2G infrastructure, and minimum output constraints of thermal power generation. The number of EVs is assumed to increase to up to 10, 000 units. In the energy flow simulations, EV charging and discharging were calculated on an hourly basis over one year. LCA was conducted to assess greenhouse gas (GHG) emissions of regional V2G system. Fuel consumption, VRE utilization, and GHG emissions were quantitatively evaluated. The results demonstrated that regional V2G systems could reduce VRE output curtailment and GHG emissions and, under certain conditions, could also reduce thermal power generation. The developed model enabled a quantitative evaluation of the potential of regional V2G systems. For practical deployment, integrated regional platforms would be required to coordinate electricity flows and to manage financial transactions. By assessing the potential of regional V2G systems, this study would provide valuable insights to support the design and implementation of environmentally sustainable V2G systems.