Decarbonizing STIB Bus Fleet: A Multi-Criteria Comparison of Battery Electric and Hydrogen Fuel Cell Buses[Décarboner la flotte de bus de la STIB : une comparaison multi-critères des bus électriques à batterie et à hydrogène]

This study evaluates the optimal technological pathway for the Brussels Intercommunal Transport Company (STIB) to progressively decarbonize its urban surface transit fleet. A comprehensive, region-specific evaluation framework is developed, comparing Battery Electric Buses (BEBs) and Fuel Cell Electric Buses (FCEBs) across three key pillars: environmental performance, economic feasibility, and operational practicality. The methodology integrates a cradle-to-grave Life Cycle Assessment (LCA), a discounted Net Present Value Total Cost of Ownership (TCO) model, semi-structured interviews with transit engineering experts, and a final Multi-Criteria Decision-Making (MCDM) matrix. The LCA results demonstrate that environmental benefits are highly contingent upon upstream energy pathways; under an optimized low-carbon Belgian electricity mix and green hydrogen, FCEBs achieve lower lifetime emissions than BEBs (0.21 versus 0.30kgCO2e/km), though this advantage is entirely neutralized if fossil-derived grey hydrogen is used. Conversely, the TCO analysis outlines a severe economic penalty for hydrogen fleets; over a 15-year design lifespan and 675,000 km of operation, BEBs achieve a standardized unit TCO including infrastructure amortization of 1.19€/km compared to 1.84€/km for FCEBs, a gap driven by current green hydrogen market price premiums relative to grid electricity. Empirical interview results confirm that BEBs exhibit superior localized practicality due to established infrastructure compatibility, mature depot electrification roadmaps, and high power supply reliability, which offset the FCEB's theoretical advantages in range and refueling logistics. Finally, the multi-criteria analysis confirms that BEBs represent the optimal near-to-mid-term transition pathway for STIB, securing a global suitability score of 0.94 compared to 0.76 for FCEBs.