Assessing the Potential of Vehicle-to-Grid Technology for London Bus Fleets

Abstract

Growing concerns over climate change have accelerated transport electrification. Transport for London (TfL) commits to fully electrifying its bus fleet by 2034. While this transition brings challenges to grid infrastructures, simultaneously, it provides opportunities to integrate Vehicle-to-Grid (V2G) to reduce operational costs and enhance grid stability. This study develops a modelling framework using London bus open data to assess the potential of V2G under different charging and discharging cycles, state-of-charge (SoC) range, battery degradation, passenger load, and tariffs. Results show that maintaining SoC between 40–88% provides a balance between cost savings and V2G capacity. Wider SoC ranges reduce costs but accelerate battery ageing, limiting long-term benefits. Passenger load had little effect on V2G capacity (<5%) but significantly influenced operating costs. Fluctuating tariffs predictably affected costs but not V2G potential. Overall, transitioning from petrol to electric buses with V2G integration could deliver up to 98% cost savings over 14 years.