Battery chemistry, climate exposure, and V2G economics in electric bus fleets: A two-stage degradation-aware dispatch framework

Abstract

Electric buses are central to urban decarbonization, yet public transportation operators face uncertainty regarding battery degradation, climate sensitivity, and the economic value of vehicle-to-grid (V2G) services. This paper proposes a two-stage framework to address these challenges. First, degradation models are calibrated using accelerated aging tests on Lithium Iron Phosphate (LFP) and Nickel Manganese Cobalt (NMC) cells under bus-representative conditions. Second, these models are embedded in a fleet-level dispatch optimization that co-optimizes charging and V2G participation while internalizing battery wear. Monthly throughput-to-end-of-life anchors are derived from weather profiles and incorporated into an annual model. Results show that LFP sustains 2.3–2.4 times the throughput-to-end-of-life of NMC, more than doubling the expected battery lifetime. Degradation-aware dispatch reduces annual operating costs by 12.6% and shifts V2G activity away from wear-prone batteries. Sensitivity analyses confirm robustness to changes in energy prices and replacement costs, providing actionable guidance for climate-resilient fleet electrification. By translating laboratory battery evidence into procurement, scheduling, and market-design guidance for public transport operators, the study bridges battery science, operations-research modeling for decision support, and transport policy, informing the interdisciplinary debate on how cities can electrify public transport at the lowest long-term economic and environmental cost.