Despite obstacles and global setbacks, the aviation industry is still forging ahead with its plans and renewed commitments to reach net-zero by 2050 and reduce its climate impact.
In environmental terms, 26 years is the blink of an eye, but with rapid technological advancements and strong government support, there is optimism about reaching these targets.
Yet it is understandable to have some reservations about our collective success, given that the industry’s current CO2 emissions stand at a significant 2.5% of the global total and we suspect this could increase as demand for aviation travel rises.
Recent research from Cambridge University and Aviation Impact Accelerator sets out a five-year roadmap that, if adhered to, should stand the industry in good stead in 2030 to continue its quest to reach net-zero. But solutions like reducing aircraft speed and switching to sustainable aviation fuels (SAF) might not be enough.
With large-scale, collective investment and support for emerging technologies – such as hydrogen fuel cell propulsion – from industry bodies, politicians, and global players, we can stay on track. However, if these key groups do not act, we may miss these targets entirely.
Currently, there is great emphasis being placed on SAF as a solution to reducing carbon emissions, with plans for this to account for 83% of total aviation fuel consumption by 2050.
The secondary effects of this, however, are not being accounted for. Scaling up production of SAF is an energy-intensive process, requiring large amounts of renewable energy. By comparison, using green hydrogen directly as a fuel offers a potentially more sustainable and less costly solution.
HARD CELL
Firstly, using hydrogen fuel cells to generate electricity to power an aircraft means no CO2 or nitrogen oxide emissions – two of the most significant greenhouse gases.
Hydrogen has other benefits beyond CO2, however. Contrails pose a significant environmental challenge to the aviation industry and are formed when hot, moist air from engine exhaust mixes with the colder atmosphere at high altitudes. This mixing creates ice crystals that can persist as clouds, contributing to warming effects.
One of the principal findings from the Cambridge report shows that optimising flight routes can reduce contrail formation. Cutting contrail formation would cut the aviation industry’s carbon impact by 40%.
A hydrogen-electric propulsion system generates electricity through an electrochemical reaction between hydrogen and oxygen in the fuel cells, producing only water as a by-product. This process emits approximately 90% of its water in liquid form and the remaining 10% as cooler water vapour. In other words, vastly different from contrail-forming, gas turbine engines.
While still in development, hydrogen propulsion is a viable solution for the aviation industry. Its sustainability hinges on its extraction, processing and storage. The most environmentally-friendly method for producing hydrogen is through electrolysis, which can be done through renewable sources such as solar, wind, or hydroelectric power. This ensures the process has a minimal carbon footprint.
The key to success in hydrogen is investing early and winning the backing of politicians and industry leaders. When viewing the technology in the long-term, its viability as a serious solution is obvious.
By creating space for the emerging technology now, we will have time to transform the industry before we miss the boat on net-zero.
Dr Josef Kallo is a co-founder and chief technology officer of Stuttgart-based hydrogen fuel cell pioneer H2Fly
