Mobility in the Smart Grid: Roaming Protocols for EV Charging

While most smart grids approaches assume that the user consumes services in a fixed location, the case of charging Battery Electric Vehicles (BEVs) adds an interesting mobility dimension. Drivers increasingly need to rely on public charging facilities, and given local grid conditions, such facilities often cannot offer their services without smart charging and tight integration in the smart grid. In analogy with mobile telecommunications, stakeholders in the field of EV charging have developed EV roaming protocols to allow for a mobility dimension, and, for some, add smart grid integration. However, this development is still in its early phase, and in Europe, there are at least four different, mutually incompatible protocols in use. In this paper, we investigate the history of these protocols, their characteristics – especially in relation to the smart grid – and investigate their openness and neutrality. We then explore scenarios for future development towards a single standard, also taking the regulatory dimension into consideration. We end with a reflection on the development of standards for the smart grid.