Air transport, encompassing both passenger and cargo airplanes, is the second-largest energy consumer in the transportation sector, following road vehicles. The passenger sector has seen rapid expansion in recent years, with demand expected to double by 2040. Air cargo, which surged during the pandemic, is also experiencing increasing growth due to e-commerce and express logistics. Although frequent flying significantly boosts global connectivity and economic development, it also results in increasing carbon emissions.
Despite technological improvements making current aircraft 80% more fuel-efficient than those from the 1960s, aviation remains a significant environmental concern, responsible for around 4% of global CO2 emissions. The industry’s reliance on fossil-based jet fuel poses challenges for decarbonization, especially as carbon emissions at high altitudes have a substantial atmospheric impact.
Nevertheless, pressure to mitigate climate change is rising. The European Green Deal aims for climate neutrality by 2050, pushing the aviation industry towards net-zero carbon emissions.
Given that the current kerosene-based propulsion system is the primary source for carbon emissions, a radical change in propulsion technologies is urgently needed to achieve zero-carbon-emission flying by 2050. Among the technologies being explored, hydrogen propulsion is identified as a promising alternative for medium-range flights, making it particularly suitable for European air transport. Therefore, this master thesis focuses on the transition to hydrogen propulsion as a solution to significantly reduce aviation’s carbon footprint.
This study aims to understand how hydrogen propulsion can aid in decarbonizing air transport by identifying key factors influencing its adoption and exploring a strategic pathway for implementation.
The Multi-Level Perspective (MLP) framework served as the theoretical foundation for analyzing the transition, focusing on a technological niche, the socio-technical regime, and landscape pressures. This framework aids in the understanding that energy transitions often start in niches, highlighting hydrogen propulsion as a potential technological niche to significantly reduce carbon emissions in aviation.
Moreover, this study intended to investigate the idea of introducing hydrogen-powered technology in a specific aviation market niche to accelerate the transition. The air freight sector was examined for its potential to be perceived as a safer market for the implementation of a new technology compared to a direct application in passenger aviation. Additionally, the air cargo sector was found to be an underexplored market in the development of sustainable aviation technological solutions, resulting in a
significant knowledge gap in both scientific literature and industry applications. Following a qualitative approach, an extensive literature review and eleven interviews were conducted with aviation experts from academia, industry, and government. The interviews aimed to gather
insights on the drivers and barriers for hydrogen adoption in aviation, as well as on the potential of air cargo. The questions for the experts were formulated according to different levels of the MLP framework to drive the discussions. Firstly, at the niche level, technical aspects on hydrogen technology and air cargo were addressed. Secondly, the necessary conditions for hydrogen-regime transition were discussed across five different dimensions. Thirdly, global events in the aviation landscape that influence the adoption of hydrogen were specified. The wide variety of insights provided by the experts led to the classification of drivers and barriers into four main areas: technological, political, economic, and societal. Since hydrogen technology is still in the early experimental phase, a greater number of
technological challenges were identified compared to the other areas. Results showed diverse technological drivers including hydrogen’s clean production using renewable sources, its high gravimetric energy density, and its zero-carbon emissions during flight. However, technical barriers such as low volumetric energy density, the need for a complete overhaul of the existing aviation ecosystem, and challenges in hydrogen logistics and storage were noted. Politically, support for hydrogen adoption is driven by climate commitments and the potential for energy independence, but kerosene taxation and new regulations are needed. Economically, fluctuating fossil fuel prices and job creation are positive factors, but high initial R&D and infrastructure costs pose substantial challenges. Moreover, societal perception plays a crucial
role in the adoption of hydrogen technology. Public support is influenced by the environmental benefits of hydrogen-powered aviation, but safety concerns and a lack of understanding about hydrogen technology necessitate extensive public education and transparent communication efforts. Although the potential of hydrogen in aviation still needs to be proven, targeting the cargo sector is viewed as a smart move to demonstrate feasibility and build acceptance. Advantages of implementing hydrogen in air cargo include greater flexibility in technology integration due to simpler cabin systems and expertise in handling hazardous materials. Cargo aircraft can optimize tank placement without passenger accommodation constraints and benefit from centralized operations at key hubs, requiring less extensive infrastructure. Socially, it offers a low-exposure environment for technology testing, and economically, centralized hubs reduce costs, with potential market opportunities for ”green” military freighters. Nonetheless, the air freight sector may encounter difficulties in adopting hydrogen technology due to less public pressure for sustainable solutions, weaker economic incentives, and the challenge of justifying infrastructure costs, given the lower flight frequency and smaller market size compared to passenger aviation. This thesis is the first to explore the intersection of hydrogen-powered technology, socio-technical transitions, and the air cargo sector. It provides a comprehensive analysis by integrating technical, political, societal, and economic perspectives, highlighting the air cargo sector as a promising niche for early adoption. The theoretical framework offers insights into the challenges and opportunities in transitioning to hydrogen propulsion, with broader implications for other high-emission sectors seeking sustainable innovations. Based on the findings of this research, several recommendations were made to facilitate the transition to hydrogen-powered aircraft. Firstly, governments should implement policies and regulations that incentivize the adoption of hydrogen technology, such as kerosene taxation and CO2 restrictions on flights. Secondly, public education campaigns are necessary to improve societal perception and knowledge on hydrogen-powered aviation. Thirdly, collaboration with other industries working on hydrogen is essential to create a supportive ecosystem for hydrogen technology. Finally, focusing on the
air freight sector as a testing ground for hydrogen technology will help build acceptance and pave the way for its introduction into passenger aviation. Future research should focus on several key areas such as incorporating quantitative analyses to assess the economic viability and environmental impact of hydrogen-powered aircraft, expanding the scope of interviews to include diverse geographical regions, and integrating other research methods like case studies and surveys. Additionally, developing policy frameworks to support large-scale adoption and exploring other market niches, such as military and unmanned aircraft systems, are crucial for scaling hydrogen technology in aviation.