In June 2023, Rowan Atkinson – the versatile English actor, comedian and writer – authored an opinion piece for the Guardian casting doubt on the environmental benefits of electric vehicles (EVs) powered by lithium-ion batteries.

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While the arguments and studies he based his arguments on have been debunked, he rightly argued for more focus on hydrogen-powered vehicles.

It, however, is too early for hydrogen vehicles since there currently are just 72,000 hydrogen-fueled vehicles on the planet. In comparison to the 14 million EVs sold the previous year alone, the hydrogen-vehicle numbers pale. It, however, is indisputable that hydrogen-fuelled vehicles will be one of the major players in the times to come.

Intelligent Energy, a start-up in Leicestershire, U.K., has started to roll off the hydrogen fuel cell units capable of powering cars, trucks and buses. BMW is heavily invested in hydrogen-powered vehicles and has started delivering its iX5 hydrogen vehicles to select partners in Europe, the U.S. and Asia. While the hydrogen-vehicle future is already here, there has been a keen interest in hydrogen as a fuel for the aviation industry.

The aviation industry is a vital part of global transportation and economic growth but its heavy dependence on fossil fuels and thereby greenhouse gas emissions is a severe problem.

Mudasir A. Yatoo, Ph.D.

—Research associate in the Materials Department at Imperial College London and freelance consultant at Outsmart Insight.

In order to tackle these challenges, hydrogen as a fuel is emerging as a promising solution.

One of the primary motivations for exploring hydrogen as an aviation fuel is its potential to reduce carbon emissions. When combusted, hydrogen produces only water vapor as a by-product, presenting a pathway to mitigate the aviation industry’s carbon footprint.

Hydrogen for aviation comes with benefits including environmental sustainability; energy efficiency; versatility in terms of production and scalability; and synergy with other renewable energy sources such as wind and solar energy.

Fuel cells and hydrogen storage systems are two such technologies that have the potential to provide the necessary energy density and power output for commercial aviation.

The ability to store significant energy in a small space is vital for long-range flights and heavy payloads. The energy content per unit mass of hydrogen is 120 MJ/kg, the highest, but its volumetric energy density is very low because of its exceptionally low density at ordinary temperature and pressure conditions.

Although hydrogen’s energy density per unit volume is lower than traditional jet fuels, advancements in fuel cell and storage technologies are making it increasingly feasible for commercial aviation.

However, major challenges in infrastructure, technological advancement and safety remain. Establishing a strong hydrogen infrastructure including the availability of hydrogen at airports worldwide is one such key challenge.

Developing and integrating hydrogen storage, transportation and refueling infrastructure into existing airports are crucial.

Hydrogen is highly flammable and requires careful handling to ensure safety. Adequate safety measures and regulations and learning lessons from existing hydrogen applications, such as fuel cell vehicles appear to be the way forward.

Therefore addressing safety concerns and public perception surrounding hydrogen in aviation should be prioritized.

Furthermore, a concerted effort is required: Collaboration among government bodies, industry stakeholders and research institutions is necessary.

The road to the hydrogen-based aviation industry is long, but world governments’ policy support and funding with a clear focus on emissions-reduction targets could very well catalyze the transition sooner than later.

Mudasir A. Yatoo, Ph.D., is a research associate in the Materials Department at Imperial College London and freelance consultant at Outsmart Insight.