Vehicle-to-Grid (V2G) Optimization for Grid Peak Demand Reduction and Decarbonization: A State-of-the-Art Review

Electric vehicles (EVs), as a greener alternative to fossil-fuel-based internal combustion engine (ICE) vehicles, contribute significantly toward developing sustainable transportation systems with no or less planet-warming greenhouse gas (GHG) emissions. However, the recent widespread adoption and integration of plug-in electric vehicles (PEVs) into the electricity grid poses great challenges to the reliable, stable, and sustainable operation of utility smart grids due to their massive charging power demand. To make PEVs earth-friendly, their large charging power requirements must be met not by polluting fossil-fuel-based energy sources but by clean renewable energy sources (RESs) integrated into the smart utility grid. Utility grid operators can utilize vehicle-to-grid (V2G) technology, a new smart grid technology, to effectively reduce the grid peak demand and GHG emissions. PEVs with bidirectional V2G capability offer immense techno-economic-environmental benefits to utility grid operators in efficientlybalancing grid power generation and demand, providing grid-support services, reducing GHG emissions, producing economic benefits, and supporting critical energy needs during outages. Hence, the V2G optimization of PEVs has become essential in utility grid operation for lessening grid peak demand and environmental degradation. A state-of-the-art review of the latest research carried out on the V2G optimization of PEVs for grid peak demand reduction and decarbonization has been presented in this paper. The V2G concept, technologies, its positive & negative impacts, and V2G optimization of PEVs have been discussed. The research studies reveal that V2G technology has great potential to offer immensely effective solutions to remarkably reduce the huge peak demand and GHG emissions of the PEV-RES-integrated utility grid. Directions to conduct effective future research on V2G optimization are also provided.