Influence of plug-in hybrid electric vehicle charging strategies on charging and battery degradation costs

The profitability of plug-in hybrid electric vehicles (PHEVs) is significantly influenced by battery aging and electricity costs. Therefore a simulation model for PHEVs in the distribution grid is presented which allows to compare the influence of different charging strategies on these costs. The simulation is based on real-world driving behavior and European Energy Exchange (EEX) intraday prices for obtaining representative results. The analysis of comprehensive lithium-ion battery aging tests performed within this study shows that especially high battery states of charge (SOCs) decrease battery lifetime, whereas the cycling of batteries at medium SOCs only has a minor contribution to aging. Charging strategies that take into account the previously mentioned effects are introduced, and the SOC distributions and cycle loads of the vehicle battery are investigated. It can be shown that appropriate charging strategies significantly increase battery lifetime and reduce charging costs at the same time. Possible savings due to lifetime extension of the vehicle battery are approximately two times higher than revenues due to energy trading. The findings of this work indicate that car manufacturers and energy/mobility providers have to make efforts for developing intelligent charging strategies to reduce mobility costs and thus foster the introduction of electric mobility.