The future promise of vehicle-to-grid integration: a sociotechnical review and research agenda

Vehicle-grid-integration (VGI) describes various approaches to link the electric power system and the transportation system in ways that may provide benefits to both. VGI includes systems that treat plug-in electric vehicles (PEVs) as controllable load with a unidirectional flow of electricity, such as “smart” or “controlled” charging or time-of-use pricing. VGI typically encompasses vehicle-to-grid (V2G), a more technically advanced vision with bidirectional flow of electricity between the vehicle and grid, in effect treating the PEV as storage device. Such VGI systems have the potential to help decarbonize transportation, support load balancing, integrate intermittent sources of renewable energy into the grid, increase revenues for electricity companies and create new revenue streams for automobile owners. This review introduces various aspects and visions of VGI based on a comprehensive review. In doing so, it identifies the possible benefits, opportunities and barriers relating to V2G, according to technical, financial, socioenvironmental, and behavioral components. After summarizing our sociotechnical approach and the various opportunities and barriers indicated by existing literature, we construct a proposed research agenda to provide insights into previously understudied and unstudied research objectives, and to provide additional rigor for continued technology-focused research. We find that the majority of VGI studies to date focus on technical aspects of VGI, notably on the potential of V2G systems to facilitate load balancing or to minimize electricity costs, in some cases including environmental goals as constraints. Only a few studies directly investigate the role of consumer acceptance and driver behavior within such systems, and almost zero studies address the need for institutional capacity and cross-sectoral policy coordination. This creates promising opportunities for future research.