IMPACT OF DIFFERENT CHARGING STRATEGIES OF ELECTRIC VEHICLES ON THE GERMAN GRID

In this paper the impact of different utilization scenarios of electric vehicles on the German grid is analyzed. Two different charging strategies arc tested. Firstly the impact of unmanaged charging of electric vehicles on the national grid is simulated Secondly charging and usage of the mobile storage in off-peak times is simulated. An important part of the simulation is to analyse the availability of electric vehicles. This part determines the percentage of vehicles, which can be plugged into the grid on hourly basis for all days of a typical week The analysis of the availability of vehicles shows an overall high availability of plug-in electric passenger cars in Germany. A significant difference in the characteristics between weekdays, Saturdays and Sundays is evident A high potential to use electric passenger cars for balancing the fluctuating renewable energy can be presumed, on the one hand due to the high availability of electric vehicles and on the other hand due to the large number of vehicles being plugged into the grid in the evening hours for which charging could be delayed into the night In conclusion the simulation shows that with an unmanaged charging strategy the fluctuations of the demand increase above average assuming a rising number of electric vehicles introduced in Germany. If the whole vehicle fleet is substituted by electric vehicles, the national electricity consumption would increase only by about 18 % Concurrently the fluctuations of the national demand in Germany would almost double. However with an optimized charging strategy, a positive impact of the usage of the mobile storage on the national grid (reduction of fluctuations) can be recognized. Thereby the electric vehicles can be charged completely during the night, when the electricity consumption is low.