Techno-economic evaluation of EV battery degradation with and without V2H

Abstract

This thesis presents a techno-economic evaluation of a Lithium-Ion electric vehicle battery with LFP chemistry under different Vehicle-to-Home (V2H) scenarios and introduces Vehicle-To-Grid (V2G) for a cost-effective implementation. The study introduces realistic state-of-charge (SOC) profiles based on daily driving behavior, considering commuting to work between 8:00 and 17:00 with a 30-minute travel time and with an 80 kWh battery electric vehicle (BEV). For V2H operation, the electric vehicle is used to provide residential peak shaving in a raw house in Gothenburg, and the economic savings are evaluated based on the tariff structure of Göteborg Energi. For V2G operation, the vehicle provides Frequency Containment Reserve for Disturbances for up regulation (FCR-D up) during office hours and at night, based on market prices from Svenska kraftnät. Moreover, the ageing evaluation is based on the newly developed semi-empirical model proposed by Ahouad M. [1], where parameters are extracted from experimental analysis. Results show that the ageing model is very sensitive to calendar ageing across all investigated scenarios, while cycling ageing is consistently smaller by two orders of magnitude. Simulations performed over 1 year and 10 years period indicate that 25- 30% of the total degradation happens during the first year while the overall capacity loss remains at around 15% at the end of the simulation. The average SOC has the highest impact on ageing, so this study confirms that maintaining the battery between 15% and 50% as [2] mentioned and charging the car twice a week reduces the total degradation to 9% after 10 years. From an economical perspective, V2H with peak shaving alone provides limited profitability, with savings around 3000 SEK in 10 years in the specific scenario considered. In contrast, combining V2H with V2G for FCR-Dup offers substantially greater economic potential without significant changes in battery degradation.