Hydrogen and Our Development Route to Zero Emissions

September 02, 2024

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Last year our CTO, Mike Durham, explored the four reasons why we are choosing hydrogen as a future fuel for Airlander, in this blog we further explore the potential uses, logistics, and operations concerning the use of hydrogen in aviation and on Airlander.

The first Airlander 10 aircraft in the markets will be fitted with internal combustion engines. That will deliver up to 90% fewer harmful emissions than other aircraft in service. However, over time we want to deliver zero-emission aviation and for that purpose we expect to use hydrogen, fuel cells and electric motors in future Airlander variants.

So, it is important that our technical team also keep an eye on Airlander’s future development, from technological advancements in avionics and materials, to exploring the pathway to electrification. In order to deliver a zero-emissions Airlander by 2030, the team have a research and development stream that explores all things hydrogen, including green hydrogen production, infrastructure requirements, and the required aircraft technology.

Where will aviation get hydrogen? What is green hydrogen and why is it better than other colours?
Hydrogen for aviation will come from specialised providers, but the UK currently lacks the infrastructure for large-scale hydrogen delivery. For regular use of hydrogen a more mature supply pipeline and infrastructure is required and this is currently under development. The aviation industry is exploring the establishment of hydrogen refuelling hubs at airports, though this is still in the planning stages.

Among various sources of hydrogen from, blue to brown to green, Airlander will use green hydrogen. Green hydrogen is produced through the electrolysis of water powered by renewable energy sources like wind or solar. Electrolysis uses an electrical current to break down water molecules into their constituent elements: hydrogen and oxygen. This method is sustainable from production through to use and is the only hydrogen type that enables zero-carbon flight.

How safe is hydrogen for use on board aircraft?
The shift from kerosene to hydrogen fuel brings new safety and regulatory considerations. Hydrogen's lighter-than-air properties mean that conventional aircraft must adjust design elements, such as fuel storage and excess gas offload systems. Additionally, aircraft hydrogen storage can present a challenge due to its greater volume demands than kerosene. For fixed wing aircraft this is likely to mean utilising cabin space to accommodate the vacuum storage vessels, however with Airlander we have ample space within the hull ensuring that there is no compromise in cost to go green. Additionally, Airlander’s design features hydrogen storage within the hull keeping it away from passenger areas, increasing aircraft safety and supporting the early adoption of hydrogen technology with fewer risks.

Will it cost more to fly on hydrogen?
In the short term, yes—hydrogen will be more expensive as industry builds the demand and infrastructure required. However, as production scales up and becomes more efficient, costs are expected to decrease. At the same time, kerosene prices are likely to rise due to potential government taxes aimed at promoting cleaner energy sources. Airlander uses only about one-third to one-half the amount of kerosene compared to fixed-wing aircraft per passenger kilometre. This lower fuel consumption means that, even with the higher cost of hydrogen, Airlander can remain cost-effective using hydrogen fuel compared to fixed-wing aeroplanes utilising kerosene over the same distance, allowing us to afford to adopt hydrogen fuel sooner than traditional aircraft.

Where would it be stored? How would it be stored?
Airlander will operate with liquid hydrogen, which will be stored in high-technology vacuum flasks. To keep the hydrogen liquified it must be stored at close to absolute zero (-273.1°C). The system architecture includes a vaporiser which converts the liquid to gas before passing the gas through a fuel cell and converting it to electrical energy and onto the electric motor.

Onboard Airlander our vacuum storage will be mounted up inside the hull and will be able to carry enough fuel for a day’s worth of flying. Unlike traditional aircraft, our hydrogen storage will be laid out in the same way we will have our existing kerosene tanks, allowing us to easily transition an aircraft from kerosene to hydrogen. When looking at traditional aircraft, current kerosene storage systems are within the wing of the aircraft, however this will need to change when they adopt hydrogen, presenting a far harder challenge. Hydrogen storage onboard Airlander has zero detrimental effect on the passenger cabin volume of the aircraft and hence minimises any additional cost for airlines and passengers.

What will hydrogen infrastructure look like? Has work started in the industry to work this out?
The precise details of hydrogen infrastructure are still in development. Regulators and infrastructure designers, such as our partners at AECOM, are currently in the planning phase, consolidating industry requirements and feeding into policy. We have been working alongside them to help better understand what the future looks like, including considerations for liquid vs. gas hydrogen, tank sizes, and their placement relative to existing infrastructure. Hydrogen adoption is also advancing in automotive, trucking, maritime, and rail industries, highlighting the need for cross-industry collaboration to create a comprehensive infrastructure. As these developments progress, industry-wide cooperation will be crucial for overcoming challenges and establishing effective hydrogen solutions.

Source : Hybrid Air Vehicles (HAV)

Hydrogen and Our Development Route to Zero Emissions