Analysis of vehicle-integrated photovoltaics and vehicle-to-grid on electric vehicle battery life

Abstract

Electric vehicles (EVs) with vehicle-integrated photovoltaics (VIPV) and vehicle-to-grid (V2G) technology can help address power grid challenges arising from the energy transition. While VIPV and V2G offer widespread benefits, their impact on EV battery life affects their economic viability. Many existing studies examining the impact of VIPV and V2G on EV battery life do not fully capture the complexity of real-world battery usage, often relying on less detailed battery data. This work models and combines detailed and validated EV battery data with validated battery ageing models to determine the impact of VIPV and V2G on EV battery life. First, a validated EV battery simulation model is used to generate realistic, per-second battery data for an EV operating in The Netherlands and Spain. Following this, VIPV power profiles, V2G day-ahead energy trading power profiles, and V2G automatic frequency restoration reserve power profiles are integrated with the battery data. Subsequently, battery datasets for different scenarios are implemented in both NMC and LFP-based semi-empirical ageing models to quantify calendar and cycling ageing capacity loss. The results show that gradual VIPV charging decreases the required annual grid charging frequency by 23% in The Netherlands and 44% in Spain, leading to lower SoC ranges, which can reduce NMC and LFP calendar ageing capacity loss by 9% in both countries. Additional cycling due to V2G day-ahead energy trading can shorten battery life by up to 12.5 years for NMC and up to 3.9 years for LFP. Moreover, the research indicates that ageing models based on tests with regular power profiles may not accurately estimate cycling ageing in power profiles with increased irregularity caused by VIPV and V2G.