Impact of Plug-in Hybrid Electric Vehicles in the Portuguese electric utility system

This research paper analyzes the potential impacts of the plug-in hybrid electric vehicles (PHEV) on the Portuguese electric consumption profile. The plug-in vehicles will affect utility operations by adding additional electricity demand. There has generally been the expectation that the grid will not be greatly affected by the use of these vehicles, because the recharging would only occur during off-peak hours. Several scenarios of PHEVs´ penetration are studied considering the grid-for-vehicle (G4V) energy transferring as a primary approach. Depending on the power level, timing, and duration of the PHEV connection to the grid, there could be a wide variety of impacts on grid constraints, capacity needs and emissions generated. In a strong penetration scenario, if many households charge their PHEVs over the same time period, especially if it is when the owners first return home and the domestic consumption is increased, then the peak may be higher than the utility expects. Evaluating the potential impacts that different charging scenarios can have in the demand profile is important so that the distribution utility and regulator understand the problems involved and anticipate ideas that will better optimize the whole system in the future.