This paper presents the main results of a fleet-level assessment of H2-powered aircraft defined within the H2Avia research project, focusing on their energy performance and climate impact. The assessment is based on a global, long-term fleet evolution framework using scenario-based inputs for an in-house model which applies linear optimization to minimize the energy component of direct operating costs and the climate impact of a global fleet. Different transition scenarios from fossil-based aviation toward an H2-powered aviation system are evaluated. The main findings show that H2-based scenarios result in up to 15% higher block energy consumption at the fleet level compared with an SAF-based baseline in 2050, while providing the highest potential for a climate impact reduction of up to 60% relative to the same baseline. However, this benefit depends strongly on the inclusion and modeling of non-CO2 effects for hydrogen, as well as on the weighting between energy cost and climate impact-driven objectives. The findings demonstrate the added value of an integrated assessment framework for capturing long-term fleet evolution and enabling rapid evaluation of emerging aircraft technologies in support of climate-neutral aviation strategies.
Muslić et al. (Sun,) studied this question.