AUTONEWS

Tracking a flight path to a green aviation future

An Adelaide University-led study has mapped out a route to advance the commercial aviation industry towards a net-zero emissions future, powered by green hydrogen.

Aviation is one of the fastest growing producers of greenhouse gas emissions,  generating around 14% of transport emissions – second to road transport. It is also one of the world's hardest-to-decarbonise industries. Unlike conventional jet fuel, hydrogen produces no direct carbon dioxide emissions during operation and, when generated from renewable energy sources, has the potential to transform the sector.

The comprehensive research, undertaken in collaboration with Hong Kong Polytechnic University, analysed 138 international studies published between 2015 and 2025 to consolidate how far the production of green hydrogen has progressed, and understand what’s needed to see it become commercially viable as a jet fuel solution.

Adelaide University PhD candidate Zahra Jaffary, lead author of the study, said green hydrogen is a viable technology but there are significant uncertainties around its feasibility, deployment and broader sector implications.

“Our research identified the current research trends and the immediate priorities that are needed to fill the gaps in understanding,” Jaffary said.

“There is a need for airport-specific case studies to assess hydrogen infrastructure needs, comparing onsite, offsite and hybrid supply chain models.

“We also need to urgently understand the future demand for fuel at airports, including spatial constraints and what refuelling systems could look like.

“And we need to identify the policy frameworks and regulatory measures needed to enable a successful transition to hydrogen power at the airport level.

"Additionally, hydrogen introduces safety considerations. Its wide flammability range, low ignition energy and need for careful handling require revised systems including design standards, leak detection and operational procedures for both aircraft and airport environments." 

With airport operators set to play a pivotal role in a hydrogen transition, detailed knowledge is essential to inform the significant decisions and investments required, and long-term planning should start soon.

“Much effort is focused on improving the cost and efficiencies of hydrogen production,” Jaffary said.

“Our research has identified what else we need to know, implement and cost in order to make hydrogen jet fuel a reality, particularly given the long lead times for investment and infrastructure development.”  

Co-researcher, Adelaide University’s Professor Shane Zhang, said the report’s findings highlight the need for government intervention and incentives to reduce the growing environmental impact of the sector.

“Without clear signals from airlines and governments, airports have little commercial incentive to invest in costly hydrogen infrastructure,” Professor Zhang said.

“Targeted policies, incentives and regulatory frameworks will be essential to provide certainty for investment and accelerate the adoption of clean hydrogen fuel.

“Australia has an incredible opportunity to become a leader in a future hydrogen aviation economy given its abundant renewable energy resources and green hydrogen ambitions, and we need to start getting the ducks in a row.”

Green flight paths could unlock sustainable aviation...‘Green flight paths’ between key global locations could help to fast-track fully decarbonised aviation, according to research funded by IDRIC and led by an international team based at Heriot-Watt University and the American University of Sharjah in the United Arab Emirates.

The research, published in the Royal Society of Chemistry’s top international journal, Energy and Environmental Science, recommends that a small number of long-haul flights with high passenger volumes, such as London to Dubai, could be used to establish these green flight paths by demonstrating and reporting on sustainable aviation fuels (SAF).

SAF are non-petroleum-based fuels that emit significantly fewer greenhouse gas emissions than traditional fossil-based jet fuels.

Dubai and London Heathrow airports are two of the busiest airports in the world and the first and second highest ranked in the world terms of CO₂ emissions from international flights, as well as total international passengers. London Heathrow is already a world leader in SAF ambition and is working towards a target of incorporating 11% of SAF into its overall fuel usage by 2030.

SAF is compatible with existing aviation fuel systems and can be used in current aircraft engines and infrastructure without requiring any modifications. This makes SAF easier to implement since airlines can use it with their current fleets, the study noted.

The green flight paths would encourage the “dedicated large-scale investment” needed to encourage the worldwide adoption of SAF.

Professor Steve Griffiths, Vice Chancellor for Research at the American University of Sharjah, is a sustainable energy expert and lead author of the paper. He said: “The UAE and UK are both highly dependent on long-haul flights, so have a compelling opportunity to lead the establishment of green flight paths, to demonstrate and deploy sustainable aviation fuels. Establishing green flight paths has the potential to not only drive decarbonisation of the aviation sector, but also lead to international cooperation for the development of SAF, and the related clean technologies needed to achieve net-zero by 2050 on a global scale.”

Professor John Andresen, Associate Director of the Research Centre for Carbon Solutions (RCCS) at our University, co-authored the paper and is a chemical engineer with an expertise in fuel processing technology. He said: “The concept of green flight paths is inspired by green shipping corridors, which are paving the way for net-zero shipping. A similar framework for prioritising long-haul flight segments is becoming increasingly urgent, to drive the global production and use of net-zero SAF technologies.”

Currently, widely available sustainable flights are a long way from being a reality. SAF provide a potential route to changing this. Since the chemical and physical characteristics of SAF are almost identical to conventional fuels, they can be safely mixed. However, figures from 2022 show SAF production is way off track, currently sitting at 0.1% of the 2050 net zero goal that has been set by the international community.

There are a number of reasons for this lack of progress, many of which are economic, the researchers explain. SAF production is costly and in its infancy, so significant investment is needed to de-risk and reduce the costs of production. Unlocking investment is key to developing the scalable solutions that will lead to much wider uptake of SAFs.

Targeting a small number of high-volume, long-haul routes would demonstrate the economic viability of the green flight path model because it would speed up the development of commercially viable SAF supply chains, the researchers say. These targeted global locations often lie geographically close to industry clusters already working towards decarbonisation.

Coupling plans for green flight paths with the growing agenda for decarbonising whole clusters of the economy – for example, industry or transport – offers the opportunity to tackle challenges in a coordinated, holistic way, the researchers add.

The research paper also makes a strong case for the ‘climate justice’ of green flight paths. This is because only about 10% of the world’s population currently take flights, so green flight paths rightly place the onus on countries benefiting the most from aviation to develop solutions to make it sustainable. Solutions that can be scaled will also become increasingly important as worldwide incomes rise, along with a likely increase in demand for flights.

Adelaide University