Grid Integrated Vehicles: business models and technical constraints for car manufacturers

In order to cope with the emerging climate change challenges, the electricity sector is undergoing profound mutations. More and more Renewable Energy Sources (RES) are introduced to reduce CO₂ emissions. However, such RES are unpredictable and intermittent by nature. In order to address this issue, the concept of integrated grids was developed. According to this approach, all units (including distributed energy resources) should be considered in the planning and in the operation of electric grids. The automotive industry has to face similar challenges, and therefore car manufacturers offer plug-in hybrid (PHEV) and full electric (EV) vehicles in their product line to cap their overall CO₂ emissions. However, the increase in PHEV and EV penetration may trigger additional stress on the electrical grids, which already have to face an increase in RES penetration. Indeed such vehicles require high charging power and are likely to charge during peak periods. Several surveys show that PHEVs and EVs could severely overload electric grids, in particular at the local scale. On the other hand, if their charging pattern is managed properly, EVs could be used as distributed storage units and turn into valuable assets for the electrical grids. In this thesis, Grid Integrated Vehicles (GIVs) are studied from technical, regulatory, and economics perspectives. First, the general framework for a smart grid integration of EVs is reviewed: application areas and benchmark scenarios are described, the main actors are listed, and the most important challenges are analyzed. Then, the emphasis is put on system wide services, and more particularly on frequency control mechanisms. The regulatory conditions enabling the participation of GIV fleets to this service are studied based on an intensive survey of existing transmission system operator rules. Several economics and technical simulations are performed for various market designs. Then, local grid services are investigated. A representative eco-district is modeled, considering various consumption units and distributed generation. A local energy management system is proposed; it is responsible for controlling the charging / discharging patterns of the GIVs which are located in the district in order to mitigate the overloading conditions of the eco-district transformer. Economic consequences are derived from this technical analysis. At last, some real life experiments are carried out within the Danish Nikola demonstration project. The experimental proof of concepts confirms the theoretical abilities of GIVs: they are very fast responding units (even considering the complete required IT framework) and are able to follow grid signals very accurately. (author)