Accessing flexibility of electric vehicles for smart grid integration

The rising awareness of the limitation of resources and the environmental impact of CO₂ emissions in combination with the technological progress in the last decades brought electric vehicles back on the market. Contrary to the still mainstreaming passenger cars with internal combustion engine, electric cars do not necessarily depend on a CO₂-emmitting process as power source if they are equipped with a charging interface for the internal battery. The fact that an infrastructure for electricity already exists is beneficial in terms of power availability and the possibility to use renewable energy sources for charging. But the challenging aspect is that the capacity of the electrical grid was originally neither designed for the additional load by electric vehicles nor for the simultaneously ongoing energy transition from conventional to renewable energy generation. However, the fact that an average vehicle is most of the time parking and potentially connected to the grid makes an electric vehicle flexible regarding the charging time schedule. This flexibility can be utilized in a smart grid context. Researchers are involved with this topic for several years now and many findings have already been published. The objective of this paper is to give an overview over already investigated problems and developed solutions. Therefore a general map of aspects which outline the problem of grid integration and the utilization of the electric vehicles flexibility is presented. The report on the review of papers shows which topics have been investigated and what methods have been used.