Fuel cells (FCs) are critical for decarbonizing the transport industry, with Life Cycle Assessment (LCA) serving as the standard evaluation framework. However, existing literature exhibits severe methodological heterogeneities and divergent system boundaries that introduce deep epistemic uncertainties. This review conducts a systematic analysis to critically harmonize FC environmental performance across the road, aviation, and maritime sectors. Quantitative synthesis reveals global warming potential (GWP) as the dominant metric. For light-duty vehicles, GWP drops to around 30 gCO₂eq/km, matching battery-electric configurations exclusively under deeply decarbonized grids. Manufacturing FC stacks and advanced storage imposes a severe upfront carbon debt, particularly prominent in heavy-duty freight (60–130 tCO₂eq). In aviation, 80–90% in-flight GWP reductions trigger massive burden-shifting, transferring 60–70% of lifecycle damages to ground-based infrastructure. Maritime FCs shrink GWP to 0.06–0.60 kgCO₂eq/kWh, strictly contingent on upstream hydrogen production. Crucially, despite long-term GWP advantages, FC pathways face systematic penalties in acidification, eutrophication, and ecotoxicity, heavily driven by platinum-group catalysts and fluoropolymer membranes. By isolating software-driven biases and database discrepancies, this work delivers an actionable methodological roadmap, establishing a policy-aligned baseline for future FC transportation sustainability frameworks.

For commercial electric vehicles tasked with heavy-duty freight, fuel cell hybridization is considered as a potential solution for maintaining the driving range and refuelling times of diesel engines. However, with fuel cells and hybridization in general comes a number of technological challenges, of which durability and fuel efficiency—factors depending on a well-performing control strategy—are regarded as critical. Therefore, to facilitate research in fuel cell hybrid vehicle controls, a comprehensive benchmark problem was formulated for a fuel cell electric truck, and was used in a competition at the 2023 IFAC World Congress. Six solutions from universities all over the world were submitted and compared for a number of driving missions. While all solutions were unique, some similarities were found in the various approaches: multi-layered control structures, multi-objective cost functions, and spatial domain formulations. The competition also highlighted the difficulty of the challenge:no solution considered all aspects of the benchmark problem, and most were vulnerable to disturbances. The simulation platform used in the benchmark is available as open source. For researchers and industry professionals in the field of fuel cell vehicle controls, the provided solutions may serve as starting points and inspiration for new developments.

The aviation sector is a major contributor to global greenhouse gas emissions, highlighting the urgent need for sustainable alternatives to conventional propulsion systems. Hybrid-electric and fully electric powertrains represent promising solutions, with lithium-ion batteries playing a central role alongside emerging clean energy technologies such as fuel cells. This study introduces an electrical and thermal model of a lithium-ion battery tailored for application in hybrid-electric aviation. The model is designed to balance versatility with computational efficiency, ensuring its suitability for system-level analyses. The key contribution is the development of a simplified procedure for estimating the power demand of battery pack auxiliaries, particularly the thermal management system. To enhance general applicability, a normalization rule is proposed, enabling rapid adaptation of the method to different battery pack configurations with only a limited set of design parameters. Furthermore, a corrective factor is included to capture the dependence of cooling load on battery operating temperature. The proposed methodology exhibits scalability and reduced computational complexity compared to conventional approaches reported in the literature. The approach, validated using a representative flight mission, demonstrates accuracy in predicting voltage, state of charge, and heat generation. The case study analyzed reveals that in a fuel cell hybrid-electric powertrain, increasing battery operating temperature from 20 °C (i.e., benchmark case) to 30 °C reduces additional hydrogen consumption by 22.0%, with potential savings up to 58.1%. The work lays the foundation for future studies on control and energy management in hybrid electric powertrains to support the shift toward a more sustainable aviation.