An optimization framework of hydrogen fuel cell buses in multi-depot urban transit networks

Hydrogen fuel cell buses offer a remarkable zero-emissions solution for public transit, attributed to their extended operational range and faster refueling. However, shortcomings remain in hydrogen supply, infrastructure allocation, and power management. Hence, this study proposes a multi-depot optimization model that minimizes annual system costs through optimal refueling infrastructure sizing, coordinated hydrogen supply strategies (on-site production, market imports, and inter-depot sharing), and optimized bus configuration. Five scenarios; centralized, semi-decentralized, renewable-based, grid-based, and capacity-constrained systems; are applied to a real-world transit network comprising 358 buses and two depots. Findings indicate that the unconstrained grid-based system (Scenario IV) is most cost-effective. However, a capacity-constrained flexible operation and fuel supply system (Scenario V), provides the most realistic configuration with a relatively higher cost by 1.9%. The sensitivity analysis of Scenario V indicates that the system relies predominantly on the external hydrogen market at prices below 9 $/kg.