Comment: Why hydrogen will fuel a more sustainable aviation future

The aviation industry, a cornerstone of global connectivity, grapples with a critical challenge: achieving sustainability. With the globe’s ambitious net-zero goals - the race is on, and with the industry accounting for about two per cent of global carbon dioxide emissions and three per cent of all human-caused global warming, innovative change must be implemented.

In this quest, Sustainable Aviation Fuel (SAF) has emerged as a promising alternative to current fuels, but its limitations necessitate a more comprehensive approach than is being advertised. Hydrogen, with its zero-carbon emissions and immense potential, offers a compelling path towards a truly sustainable aviation future. 

Despite SAF deserving credit for demonstrably reducing lifecycle emissions compared to conventional jet fuel, its potential is constrained by inherent limitations. 

SAFs’ Achilles' heel

While boasting lower emissions, SAF's Achilles' heel lies in its energy-intensive production process. According to research, it suggests a 1.8-2.3 times greater energy demand compared to solely producing and liquefying hydrogen. This translates to a significant financial burden –  the need for vastly increased installed renewable power capacity, with potentially detrimental environmental and financial consequences.   

Essentially, we might be mitigating carbon emissions by placing a heavier strain on our already stretched renewable energy resources. Additionally, a significant amount of energy is required for large-scale CO2 capture, a crucial step in SAF production. 

SAF storage, though less demanding than hydrogen, suffers from the fuel's fundamental energy intensity. Hydrogen, while requiring dedicated upgraded infrastructure development, presents a long-term solution. The choice boils down to readily available yet less sustainable fuel versus investing in building a cleaner, future-proof infrastructure. 

The cost equation: SAF vs hydrogen 

Investing in SAF for flights under 2,000km in Europe alone could incur a staggering €750bn for energy needs and €80bn for production. Globally, this figure balloons to a colossal €3.5tn. While seemingly a step forward, is it the most optimal path? 

Transitioning to hydrogen necessitates an initial European investment of €300bn for renewable energy infrastructure and storage, alongside €50bn for technological advancements. This translates to approximately €1.5-1.7tn globally, boasting significantly lower long-term energy demands. 

Moreover, companies in Europe and beyond are making important headway in proving the durability and reliability of hydrogen. Last September, the world’s first piloted flight of a liquid hydrogen-powered electric aircraft, built by H2FLY, took to the skies - showing the world the capabilities of liquid hydrogen.  

However, while the initial investment in hydrogen appears substantial, a broader perspective is crucial. WEF estimates $1.7tn is required globally to support alternative propulsion systems for 38 per cent of flights by 2050. Investing in a temporary solution like SAF, with its innate limitations, becomes an extravagance in the face of a future-proof alternative like hydrogen. 

The Future is Now: Hydrogen takes flight 

Transitioning to hydrogen-powered aviation is not without its challenges. Technological advancements in areas like fuel cell efficiency and infrastructure development for large-scale hydrogen production and distribution are crucial. However, the long-term benefits are undeniable: 

Significant reduction in greenhouse gas emissions: Hydrogen combustion or utilisation in fuel cells produces zero CO2 emissions, directly addressing the industry's environmental impact.

Sustainable and secure energy source: Green hydrogen, produced from renewable sources like solar and wind power, offers a future-proof solution that mitigates dependence on fossil fuels.

Potential for performance improvements: Studies suggest hydrogen-powered aircraft could see range improvements compared to current jetliners due to the fuel's lighter weight and new, highly-efficient aircraft designs

Investing in hydrogen signifies a commitment to a demonstrably cleaner future for aviation. While the initial costs may seem substantial, they pale in comparison to the long-term environmental and economic benefits.  The time for band-aid solutions has passed.  Embracing hydrogen is not just an option, it's an imperative for ensuring a sustainable future for the aviation industry and the planet. 

Prof Dr Josef Kallo, CEO and founder of H2FLY