For decades, the aviation industry has been under pressure to reduce its carbon footprint. The perils of air travel and climate change have been well documented. Overall, air travel accounts for 2.5% of all greenhouse gas emissions in the world. And while other industries have seen declines in their greenhouse gas figures, aviation has not. Up until the pandemic, increases in air travel were resulting in a steady rise. This is a major reason why alternative fuel options are being explored, including hydrogen fuel cells.
Within the aviation sector, exploring new fuel alternatives has tremendous potential. Several companies are exploring how lithium batteries might advance an eco-friendly aviation industry. However, lithium batteries have their own set of problems, of which limited distance travel is currently a major one. But this is not the only solution as several startups are exploring hydrogen fuel cells as more viable options. Given that the technology already exists in cars, boats, and buses, this makes perfect sense.
“This will probably be the most disruptive technology in aviation since the founding of the industry. People are talking about the third revolution in aviation. The first was the invention of heavier-than-air flight. The second was transatlantic flight. The third will be electric.” – Julian Renz, Business Development, ZeroAvia
Air Travel and Climate Change Options
The use of combustible fuel is not an ideal solution for air travel and climate change improvements. Some have suggested that biofuels may be an immediate alternative. However, these fuels also release hydrocarbons and emit soot and aerosols into the atmosphere. Therefore, any alternative fuels would preferably non-combustible, which is why electricity is so attractive. The obvious choice has been to investigate lithium ion batteries. However, their weight-to-energy ratio is far from ideal. Likewise, lithium batteries need frequent replacement and are expensive to make. These factors have limited advancement of this technology in the aviation sector to date.
This is where hydrogen fuel cells come into play. Unlike lithium batteries, hydrogen fuel cells weigh much less and can generate a significant amount of electrical energy. Hydrogen fuel cells are also non-combustible in nature, generating electricity by combining hydrogen and oxygen from the air. The key issue has been safely storing and transporting hydrogen for use as an alternative energy source. The use of hydrogen as fuel for planes naturally triggers images of the Hindenburg catastrophe. But that was in 1937, and this is now. And a few innovative companies are showing just how much progress has been made since then.
“There is fundamentally an incrementalist mindset in the incumbents. Hydrogen is a fairly drastic step for the industry. I think it’s a necessary step, given the industry has no other way to meet the goals of the Paris agreement.” – Paul Eremenko, Chief Technology Officer and Senior Vice President of United Technologies Corporation
Companies Leading the Way in Hydrogen Fuel Cells
Understanding that air travel and climate change improvements are needed, a few bold businesses are emerging in the field. ZeroAvia, previously based in California, is now experimenting with hydrogen fuel cells in the UK. In September, they will plan their first small aircraft flight using hydrogen fuel cells. The company also expects flights under 500 miles that use hydrogen fuel will be ready by 2023. And by the mid-2030s, ZeroAvia anticipates larger, trans-Atlantic flights will similarly be operating.
Universal Hydrogen Company represents another emerging startup in this field as well. Committed to air travel and climate change progress, UHC is also investing efforts in hydrogen fuel cells. Specifically, UHC has designed Kevlar-coated storage pods for hydrogen that can be stacked and transported safely. In fact, these pods can be used for airplane fuel without the need to pipelines, hoses and other infrastructures. UHC also expects to be retrofitting small aircraft with hydrogen fuel cells by 2024. And it hopes to attract the attention of larger airplane designers in the process. This would then accelerate the use of hydrogen fuel in larger planes perhaps by the mid-2030s as well.
“We think a demonstrated flight in a large aircraft is definitely possible by 2035. Up to 2023 we will be retrofitting existing planes, but in the future planes will be built from scratch to run on hydrogen fuel cells, especially as we move to 200-seat and longer-range aircraft.” –Julian Renz
Is Safety a Big Concern for Hydrogen Fuel Cells?
In terms of safety concerns, hydrogen fuel is certainly flammable. The potential for it resulting in a hazardous event is always possible. But in reality, it is no different than other fuels used in aircraft in this regard. Yet, it is more eco-friendly for air travel and climate change, and its safety has improved greatly. This is evident by the fact that hybrid cars, buses and other transportation vehicles utilize hydrogen fuel cells today. Thus, while safety is always important, today’s hydrogen fuel cells have been proven to be as safe as other fuels in the industry.
It is also important to note that hydrogen fuel cells are better for air travel and climate change in other ways. For one, the carbon footprint that results from hydrogen fuel cells being manufactured is much less than even lithium batteries. Likewise, their ability to generate electricity only requires hydrogen, oxygen from the air, and a chemical catalyst. This makes their structure simpler while only releasing water as their only byproduct. In addition to the advances in the safety of newer hydrogen fuel cells, these benefits highlight their potential. It therefore seems like hydrogen fuel cells should be a no-brainer for the future of the airline industry.
Convincing the Industry’s Major Players
While implementing hydrogen fuel cells in smaller aircraft will be easier, the larger planes may take some time. Companies like Boeing and Airbus design such models in advance. Therefore, they would need to consider hydrogen fuel in their design process if such changes were to become reality. But this is not too far-fetched. Boeing has already tested a manned flight using a hybrid model of hydrogen fuel and lithium batteries. Thus, this is clearly on the company’s radar. Both ZeroAvia and UHC both hope to further persuade these companies with their upcoming developments. If successful, then we may all be flying planes with hydrogen fuel cells by 2040.