FlyZero, the UK-based study into zero-carbon commercial air travel, has released its vision for a new generation of liquid hydrogen-powered aircraft.

The report “Our Vision for Zero-Carbon Air Travel” concludes a 12-month study that examined the feasibility of zero-carbon aircraft. Aviation can achieve net zero emissions by 2050, the project concludes, through the development of both sustainable aviation fuel (SAF) and green liquid hydrogen technologies.

To maintain a competitive edge in the market for new hydrogen-powered aircraft, UK firms must be prepared to demonstrate technologies by 2025. This timeframe is critical for new zero-carbon aircraft to enter service by 2035 and for achieving the net-zero emissions target of 2050.

FlyZero, led by the Aerospace Technology Institute (ATI) and backed by the UK government, has determined that green liquid hydrogen is the optimal fuel for zero-carbon flight, capable of powering a midsize aircraft carrying 280 passengers directly from London to San Francisco or from London to Auckland with only one stop.

By introducing a midsize hydrogen-powered aircraft by 2035 and a narrowbody hydrogen-powered aircraft by 2037, the greatest opportunity for carbon reduction and market impact will be realized. Aviation’s carbon emissions would decrease by four gigatonnes (Gt) by 2050, or four years’ worth of total global aviation carbon emissions, if half of the commercial fleet was hydrogen-powered by then, and by 14 Gt by 2060.

The UK can leverage decades of aerospace innovation expertise to usher in a new generation of liquid hydrogen-powered aircraft by collaborating with global OEMs, governments, and regulatory bodies. With targeted technology investment, the UK could increase its market share in civil aerospace from 12% to 19% by 2050, boosting the sector’s gross value added to the economy from £11 billion to £36 billion and the number of aerospace jobs from 116,000 to 154,000.

The report details how aviation can connect businesses, cultures, families, and nations while minimizing carbon emissions. Accomplishing this presents challenges for every aspect of our aerospace and aviation industries, as well as for broader industries and energy infrastructure. To protect our planet, maintain the benefits of aviation, and ensure economic growth, an integrated, collaborative, international approach to these challenges is required.

Simultaneously, the UK must advance technologies for sustainable aviation fuels (SAF), as both SAF and liquid hydrogen are required to achieve the net zero emissions by 2050 target.

Chris Gear, project director said: “Zero-carbon emission flight can be a reality. Tackling the challenge of our generation requires accelerated technology development and urgent investment in green energy together with regulatory and infrastructure changes.

“The next three years are crucial to develop the technologies, build our skills in liquid hydrogen and demonstrate capability here in the UK to enable our aerospace sector and supply chain to secure its role in a new era for aviation.

“Realising hydrogen powered flight by 2035 is a huge challenge but is essential if we are to maintain the social and economic benefits of air travel while protecting our planet and meeting our commitments to fight climate change.”

Industry Minister Lee Rowley said: “Realising zero carbon flight is one of the most ambitious challenges we can contemplate. However, it could also be one of the biggest economic opportunities for the UK’s world leading aerospace sector.

“It’s great to see FlyZero’s final outputs following a year of intense research, successfully bringing UK industry together to think through how to reduce aviation’s impact on our Earth and sky while ensuring and celebrating the immense benefits of air travel and connecting the world”.

The report summarizes FlyZero’s findings in a number of critical areas:

To achieve zero-carbon flight, six technological breakthroughs are required: hydrogen fuel systems and tanks, hydrogen gas turbines, hydrogen fuel cells, electrical propulsion systems, aerodynamic structures, and thermal management. Today, the UK possesses expertise and capability in these areas, but not in liquid hydrogen fuels.
Carbon emissions – By 2050, aviation’s cumulative CO2 emissions could be reduced by 4 gigatonnes (Gt) and 14 Gt by 2060. This requires that 50% of the commercial fleet be hydrogen-powered by 2050, with midsize hydrogen-powered aircraft entering service by 2035 and narrowbody hydrogen-powered aircraft entering service by 2037.
Non-CO2 emissions – while hydrogen combustion in a gas turbine produces no CO2 or SOx, it produces more than 2.5 times the amount of water emitted by fossil fuel-powered aircraft. Particulate matter will be largely eliminated, and NOx emissions will be reduced by 50% to 70%.
Sustainability – Developing a new generation of aircraft provides an opportunity to incorporate sustainability principles into the design and manufacturing processes, as well as to further improve material reuse.
Economically, liquid hydrogen will be more affordable than the most widely available sustainable aviation fuel (SAF), power-to-liquid, by the mid-2030s.
Market impact – the most efficient way to decarbonize aviation is to accelerate the introduction of a large commercial aircraft similar to FlyZero’s midsize concept, which is capable of connecting to any destination in the world with a single stop. Less risky commercially than developing a narrow body first, this approach would also allow infrastructure development to concentrate on fewer but larger international hub airports.
Infrastructure and operations – To generate the amount of hydrogen required for aviation, unprecedented renewable energy capacity will be required. To transport hydrogen to airports, gaseous pipelines or liquid hydrogen tanker deliveries will be required, while refueling aircraft will require larger diameter hoses and increased automation to ensure that it can be done safely and efficiently alongside other aircraft.
The UK requires a hydrogen research and development facility that is open to academia and a diverse range of industries, including aerospace, automotive, marine, space, and energy.
Climate science – alongside technology development, research into the climate impact of hydrogen gas turbine emissions, including through modeling and testing, is critical.