Impact of different EV charging strategies in the Spanish and Greek power systems

Abstract

Electric vehicles (EVs) can help decarbonise the transportation sector, which is responsible for a great share of greenhouse gas (GHG) emissions. However, electric companies are concerned about the effects of introducing EVs into the grid, especially for a large amount. The charging pattern of Evs is the main factor that determines these effects. Unregulated charging would have undesirable consequences for the system, it is therefore necessary to develop an intelligent charging strategy. However, different objectives may be considered for the design of an optimal charging strategy, such as for instance cost or emission minimisation or demand valley-filling. Furthermore, power systems have different characteristics and there are different agents involved. Therefore, different smart charging profiles may be defined. This paper analyses different possible strategies for charging EVs and compares their consequences in the power system. The impact on costs, CO2 emissions and RES integration is assessed. In addition, the use of pre-set profiles is evaluated in comparison to real-time management systems. The analysis focuses on the Spanish and Greek power systems for 2020 under different EV penetration levels and charging strategies (unregulated and smart). The results obtained show the benefits of using smart charging profiles, obtaining large cost reductions and maintaining system reliability levels. The differences observed between the two countries imply that smart strategies should be adapted to the singularities of each power system