On the way to climate-friendly flight – today, the German Aerospace Center (DLR) and Hamburg Airport presented a roadmap that sets out the steps required to develop a hydrogen infrastructure at medium-sized airports. The roadmap uses Hamburg Airport as an example to outline the growing demand for H2, the development of storage capacities and delivery routes. At the same time, it also highlights the requirements for setting the political course for an energy transition in aviation.

Innovative propulsion concepts and sustainable fuels are essential in order to achieve the EU target of climate neutrality in aviation by 2050. Hydrogen will play a key role as an energy carrier in the future, particularly for short-haul and regional aircraft through to medium-haul flights. In addition to the technological development of aircraft, the provision of the necessary infrastructure, the adaptation of airport processes and ensuring the availability of hydrogen are important prerequisites for success. Against this backdrop, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and Hamburg Airport have joined forces in the Networked Mobility for Liveable Places (Vernetzte Mobilität für lebenswerte Orte; VMo4Orte) project to create a roadmap for the use of hydrogen at airports. A strategy was developed that uses Hamburg Airport as an example for other medium-sized German and European airports to outline how such an introduction could be operationally feasible and economically viable.

Saving approximately 60 million tonnes of CO2 by setting the correct course

A binding planning and funding framework for air transport created by policymakers will be just as important as pilot projects and investments by the aviation industry. A current forecast by the DLR Institute of Air Transport on hydrogen demand at German airports shows that, assuming that the correct course is set by policymakers and airlines, approximately 19 million tonnes of kerosene used by air transport from Germany could be replaced by 6.6 million tonnes of green hydrogen by 2050, which corresponds to a saving of almost 60 million tonnes of CO2. The difference in the comparison is due to the higher energy density of hydrogen compared to kerosene.

Hamburg Airport could play a pioneering role among German airports in the future. It benefits from its connections to the North Sea, Baltic Sea, and the port of Hamburg. In addition, its route network focussed on short and medium-haul flights are favourable factors for the introduction of hydrogen Also, the airport is already focusing on transitioning ground services and flight operations to hydrogen. 

The topics covered by the roadmap that has been presented range from the expected demand for hydrogen, the design of the hydrogen supply system and the costs that can be expected from today’s perspective to practical aspects such as the adaptation of the airport infrastructure and operational changes to airport processes.

First hydrogen flights expected before 2040

Hydrogen combusted directly in highly efficient engines or used in combination with fuel cells and electric powertrains will play a decisive role in driving forward the energy transition in aviation. The first short-haul flights using hydrogen propulsion will be possible as early as the next decade, and the industry is planning to introduce hydrogen aircraft for medium-haul flights before 2040. By 2050, the proportion of departures with hydrogen aircraft in Hamburg could rise to 60 percent. This corresponds to an annual hydrogen requirement at Hamburg Airport of 60,000 tonnes, with a correspondingly significant reduction in CO2. According to the model calculations performed as part of the VMo4Orte project, up to 80 percent of current flight movements at Hamburg Airport could be carried out with hydrogen-powered aircraft beyond 2050.

Established delivery methods and storage capacity as a prerequisite for H2 air transport

In the first few years up to around 2040, it can be assumed that hydrogen will still be supplied in small quantities using special tanker trucks. As demand increases in the 2040s, an additional supply via a pipeline connection will become necessary. Without a pipeline, an annual average of approximately 40 tankers per day would otherwise have to supply the airport with hydrogen in 2050. On peak days, this number could be significantly higher. The delivery of hydrogen via pipeline must be in gaseous form due to the design of the system. As aircraft will primarily require hydrogen in liquid form for refuelling in the long term, a liquefaction plant will also be required at the airport. In addition to the additional space required, such a plant requires a substantial investment and very large amounts of electricity generated from renewable sources during operation.

In addition, storage tanks for the liquid hydrogen at the airport will be necessary to provide a fuel buffer for approximately three days – as is the case with conventional kerosene today. Such cryogenic tanks are still quite rare worldwide and have so far mainly been used by the space industry at rocket launch sites. The largest tanks to date are located at NASA’s Kennedy Space Center. For physics reasons, storage in a spherical tank is the most efficient solution. One such tank, for example, has a diameter of 34 metres with a capacity of around 400 tonnes and therefore requires a footprint of about 900 square metres. Such a large tank could be needed at an airport like Hamburg as early as 2040, and two such tanks could be required by 2050.

The future supply of green hydrogen – that is, hydrogen produced using energy from renewable sources – is heavily dependent on the global production potential for renewable energies and the resulting production and transport costs. The cost of hydrogen has a direct influence on demand, with aviation likely to compete with other sectors – particularly energy-intensive industries.