Battery electric bus transit system optimization with battery degradation and energy consumption uncertainty

Implementing battery electric buses (BEBs) in transit systems offers a sustainable mobility solution. However, BEB systems present challenges related to battery degradation, fluctuating energy consumption, and limited charging resources. This study develops an optimal lifecycle model for BEB system configuration, addressing charging schedules, component sizing, and resource allocation. The model incorporates battery degradation and uncertainties in energy consumption through a deterministic multi-stage optimization approach, followed by a stochastic model to account for energy consumption uncertainty. The application of a real-world transit network highlights that neglecting battery degradation and energy consumption uncertainty could lead to substantial operational disruptions. Furthermore, decisions regarding battery replacement throughout the BEB system usage lifecycle do not adhere to a standard pattern and are influenced by charging decisions. Sensitivity analysis highlights that doubling the battery degradation rate raises system costs by 20.7%, while a 30% fluctuation in battery costs substantially increases costs by up to 52.4%.