What will it take to support zero-carbon emission flights?

A narrowbody hydrogen-powered aircraft concept developed by the ATI’s FlyZero project. (Image courtesy of UK Aerospace Technology Institute).

Jacobs’ Chris Pickard looks at how airports can prepare now if they are to be ready to fuel hydrogen-powered aircraft and become catalysts to support wider decarbonisation initiatives. 

Airports worldwide continue to make significant progress in reducing their carbon emissions, but without decarbonising aircraft, overall reductions from the aviation sector will be limited. 

Meanwhile, the aerospace industry is working hard to decarbonise aircraft through the design and development of new methods of propulsion. While rapid progress continues in the development of sustainable aviation fuel (SAF) and battery-electric propulsion, hydrogen is being explored as a potential zero-carbon emission fuel.

Research into the use of hydrogen continues to gain pace, with projects such as the UK Aerospace Technology Institute’s (ATI) FlyZero programme demonstrating its feasibility. As such, commercial aircraft powered by liquid hydrogen are anticipated to be in operation by the mid-2030s, with smaller gaseous hydrogen fuel cell aircraft potentially in operation within this decade. 

To achieve rapid decarbonisation of aviation and net zero by 2050, multiple approaches will be needed. SAF, more efficient engine technology, operational processes improvement, and hydrogen all have a potential role to play. 

Of these, the infrastructure required for hydrogen aircraft is perhaps the biggest challenge, from the need to generate and supply vast quantities of green hydrogen, to the ability of airports worldwide to provide standardised equipment and processes needed to safely operate these aircraft. 

Studies such as FlyZero suggest that most commercial flights will require the use of liquid hydrogen, due to the low volumetric density of gaseous hydrogen. To be stored and used as a liquid, hydrogen needs to be cooled to -253°C, presenting unique challenges for an airport environment. 

Recognising the scale of the infrastructure challenge, FlyZero – working with Jacobs – investigated the feasibility of providing the required infrastructure at airports

Three major pathways:

The project identified three major pathways and the associated infrastructure for hydrogen supply and operation at an airport, depending on the airport’s size, location and demand for fuel. 

The first pathway is likely to initially apply at all airports, with hydrogen generated off-site and transported to the airport by tanker. For many smaller airports this may be all that is needed on an ongoing basis, operating in a similar way to their current supply of traditional fuel. 

However, for larger airports, as demand increases, the logistics of supplying hydrogen by road or rail may become infeasible with hundreds of tanker deliveries being required each day. 

Therefore, the second pathway considered the supply of hydrogen through a gaseous hydrogen pipeline, requiring on-airport liquefaction and storage capability. 

While it may be possible for airports to generate hydrogen on-site, the high energy requirement for electrolysis of green hydrogen is likely to make this unattractive, especially for larger airports where demand for hydrogen is high. As a result, the supply of hydrogen through a gaseous pipeline may become the preferred solution for large hub airports. 

Despite the high on-airport energy requirement, the third supply pathway investigated the infrastructure required to provide electrolysis, liquefaction and storage at an airport. 

Although unlikely to be used for large airports with high demand, this remains a potential option for smaller airports, particularly where plentiful renewable energy is available. 

In the future, multiple complementary technologies and fuels will likely be operated in parallel at most airports. However, without knowing if or when new aircraft will be introduced, airport owners face the challenge of preparing for multiple and uncertain future scenarios. 

Infrastructure and investment planning:

Airports may feel there is little they can do to plan for future fuels like hydrogen, with no choice but to act reactively as aircraft technology develops. 

However, infrastructure and investment planning are needed today to enable the effective use of hydrogen in the future. 

Early planning and implementation of compatible infrastructure offers airports sustainability and resilience, positioning them to capture new carriers and route connections as airlines move towards the use of new technology. 

Airports can begin preparing by considering early adoption for their own and other stakeholders’ use, such as by handling agents, transport providers, local industry and freight distributors. 

With early adoption that stimulates an integrated hydrogen ecosystem, airports not only prepare for the eventual use of hydrogen as an aircraft fuel but also become catalysts to support wider decarbonisation initiatives. 

The certainty of demand that this ecosystem provides also allows longer-term investment in infrastructure, knowing that there will be a positive return on investment. 

Providing the infrastructure needed for hydrogen aircraft presents a challenge to industry, requiring deep collaboration and innovative thinking. Encouragingly, momentum continues to build with many new collaborative projects and initiatives underway, giving hope that the required infrastructure will be ready to support the introduction of the future generation of aircraft.   

Click here to access Jacobs’ full report.

Chris Pickard is transportation sustainability specialist at Jacobs.

This feature first appeared in the digital edition of Infrastructure Intelligence.

If you would like to contact Rob O’Connor about this, or any other story, please email roconnor@infrastructure-intelligence.com.