An integrated framework for the economic and environmental assessment of retrofitted hydrogen-powered aircraft

Achieving net-zero carbon emissions in aviation by 2050 requires a shift toward alternative energy sources. While hydrogen is emerging as a potential option for the transition, it is necessary to develop a comprehensive platform to evaluate the environmental and economic (2E) impacts of retrofitting existing aircraft for hydrogen use. This study introduces the Hydrogen-powered Aircraft Evaluation Tool (HyAET), a framework designed to assesses the 2E performance of retrofitted hydrogen-powered aircraft. HyAET incorporates six hydrogen production pathways, nine representative aircraft classes, and seven global regions, offering a robust foundation for strategic decision-making in the aviation sector. Results show that the use of green hydrogen (e.g., from electrolysis using renewable energy—ERE) can reduce CO₂-equivalent emissions by up to 45% in small regional jets, it also increases direct operating costs by around 65%. Medium-sized aircraft, particularly narrow-body types, demonstrate the most balanced performance and can achieve economic-environmental index (EEI) values near or below 1 when powered by low-carbon hydrogen (e.g., ERE or renewable thermal splitting). In contrast, very large or very small aircraft often face economic or environmental penalties regardless of flight region or fuel source. Sensitivity analyses reveal that reductions in NO_x emissions—especially for large aircraft—are essential to achieving environmental parity with kerosene, with a 30% cut required to break even. Finally, improving tank gravimetric efficiency from 0.2 to 0.8 reduces both emissions and DOC across all classes, reinforcing the importance of lightweight tank technologies.