Optimal energy management of small electric energy systems including V2G facilities and renewable energy sources

The emerging of plug-in hybrid vehicles results not only in the increase of electric vehicles as means of transportation, but also in the utilization of vehicle batteries for grid support, which is referred to as vehicle-to-grid (V2G). However, V2G is still at a conceptual stage, and the lack of practical and realistic frameworks to help moving from concept to implementation causes serious challenges to its adoption. In this context, this paper proposes a practical model for the assessment of the contribution of V2G systems as a support to energy management within realistic configurations of small electric energy systems (SEESs) including renewable sources, such as Microgrids. Considering the uncertainty factors related to renewable power sources and gridable vehicles, the model materializes into a robust linear optimization problem suited to be easily integrated in the Energy Management System of SEESs, to support – in operation or operation planning – SEESs’ participation in the electricity market. The paper also presents a practical methodology to model the aggregation of gridable vehicles, contributing to the literature in the field and helping towards the actual implementation of V2G. The efficiency and usefulness of the developed aggregation and optimization models are shown using a realistic SEES case study.

► We develop an optimization tool for energy management in operation within small electric energy systems including vehicle-to-grid facilities. ► We provide a model for electric vehicles aggregation. ► Uncertainty related to vehicle-to-grid is accounted for via robust optimization. ► The aggregation model results to give realistic representation of vehicles behaviour. ► Robust optimization represents the best solution when the level of uncertainty materializes into small variations.