Vehicle-to-grid impact on battery degradation and estimation of V2G economic compensation

This study investigates the Lithium-ion battery degradation of battery electric vehicles (BEVs) and calculates the compensation cost when BEVs are used as primary energy storage systems using vehicle-to-grid (V2G) technology. We introduce a novel co-simulation interface in MATLAB Simulink, which includes a V2G model, a BEV mobility model, and a battery degradation model to estimate the BEV battery degradation. This study considers three V2G operational scenarios from the fleet perspective and three individual user profiles to examine different battery degradation levels under different scenarios. Unlike studies that analyse battery degradation for a shorter period (1 day to 1 year), with standard drive cycles under a constant C rate, the co-simulation model calculates the battery degradation with a variable C rate energy flow under multiple real-world drive cycles, variable V2G operational and participation scenarios until the end of the life of the battery, followed by the estimation of V2G economic compensation. The results show that V2G increases the battery degradation rate by 9 % - 14 % over 10 years. Unlike the calender degradation process which contributes 85 % to 90 % of total degradation over 10 years without V2G, the cyclic degradation process contributes only 10 % to 15 %, which increases to 20 % - 25 % with V2G for different sub-scenarios. As V2G only contributes to cyclic degradation, the results show an average of 0.31 % increase in total degradation per year due to V2G for 33 charging/discharging cycles. To break even the degradation rate and infrastructure cost, the comprehensive economic analysis estimates the V2G compensation as €132/MWh of V2G energy flow in the 2030 scenario and €70/MWh of V2G energy flow in the 2050 scenario. • The battery degradation in BEVs caused by V2G is analysed over 10 years • Cyclic degradation contributes 15 % of total degradation for normal EV operation • Cyclic degradation contributes 25 % of total degradation with V2G service • Constant and varying C rates have less impact on the degradation rate • The compensation rate averages €132/MWh for 2030 and €70/MWh for 2050 scenarios.