Nimrod Golan-Yanay is the CEO of Urban Aviationthe company behind the first wingless, eco-friendly, compact eVTOL designed for cities.
I am not the first to say that hydrogen is the future of green energy, especially when it comes to aviation. The promise of hydrogen has been discussed in scientific and transportation circles for decades. This year, the Intergovernmental Panel on Climate Change released a report stating that greenhouse gas emissions should peak in 2025 to give the world a chance to avoid catastrophic consequences and accelerate the hydrogen conversation.
If the push for CO2 neutrality by 2050 has contracted, investment in hydrogen has seen a boom, including by governments around the world. Aviation is increasingly adopting technology, with even big companies such as Delta, Boeing and Airbus that are committed to green hydrogen power.
So with all these promises and increased focus, what challenges do we face before realizing hydrogen’s green potential?
Where are we?
Right now, hydrogen-as-green fuel means one of two things: using hydrogen as a combustible fuel or as the power behind battery-like cells. Each technology has its own advantages and challenges, but I believe that the hydrogen fuel cell is a favorable choice for aviation.
Where are we going?
The potential advantages of the hydrogen fuel cell model (HFC) are numerous. It is high in energy, which means that it contains a large amount of energy relative to its weight. (Traditional batteries are powered by lithium-ion, which is not only a burden on the environment, but is also heavy — far too heavy to power airplanes.) And because these cells are refueled rather than charged like traditional batteries, it is the downtime of a hydrogen fuel cell can be negligible – as short as four or five minutes.
However, the coolest advantage of hydrogen is that when consumed in a closed system, it is accompanied by oxygen, generating a constant electrical current and water as a by-product. And when the hydrogen comes from renewable energy such as sun or wind, the cycle is completely green.
Currently, long-haul flights are out of reach to support hydrogen fuel cells, but regional flights and smaller aircraft, like the ones my company designs, are much closer to realizing the green potential of these cells.
Is the switch to hydrogen something for your company?
Hydrogen as a fuel makes sense for a company with a high demand for electricity and a strong desire to reduce their carbon footprint. But industries that cannot connect power simply by plugging a cord into the power grid, e.g. transportation, are ideal users of HFC technology. That said, there are changes that are needed to prepare for a hydrogen future.
How can business leaders prepare for a hydrogen future?
Switching to HFCs will not be as simple as a one-to-one replacement of a power source, such as switching from alkaline batteries to lithium ions. In aviation, for example, it is important to see the HFC system as a full stack. In addition to simply including H2 tanks, engineers will need to consider structural changes throughout the vessel, in areas such as power profile, operating voltage, weight, volume, safety, etc. This is why business leaders looking to a greener future may want to consider to join forces with academics and government agencies to ensure this opportunity becomes a reality.
It’s understandable if this technology sounds like science fiction, but the switch to using hydrogen is actually not as out of reach as you might expect. Research on the use of hydrogen power has been held for decades, with substantial breakthroughs in recent years. Since HFCs already meet the criteria to integrated in carsHFC-powered aviation may not be far away.
Research and development: Weight is a concern engineers must address to introduce HFC technology into aerospace. Liquid hydrogen, or LH2, has the necessary energy density (how much energy you can put into a given weight of technology) and versatility to support short-haul flights in smaller aircraft. However, it poses the new challenge of temperature control. To implement liquid hydrogen, it must be stored in a cool, temperature-stable environment, such as a cryogenic tank, which adds weight when integrated into an aircraft. The greatest engineers in the field are working with new materials and designs to make this technology as light as possible.
Certification: A major hurdle for the aviation industry to adopt hydrogen technology is certification. When a company chooses to implement HFC technology in an aircraft, it means a complete overhaul of the propulsion system, fuselage, aerodynamics – it changes the core design of the aircraft and safety standards must be met every step of the way.
To meet the necessary standards to get a new aircraft certified, you must prove that all operations are safe, from labs to manufacturing, ground testing to extensive flight testing. This costs both time and money, and can leave companies with significantly less capital to scale operations after the aircraft has been certified. When planning to fly people and fly over people, certification is necessary for the entire development process and to ultimately gain public acceptance of the aircraft. This is where business leaders across industries can put pressure on agencies to prioritize certification requirements.
We are starting to see this pattern in hydrogen – the Biden administration has pushed aside $8 billion to build hydrogen production hubs. The UK has a step-by-step plan hydrogen investor. Like solar, hydrogen sees the kind of investment that will make it the most sustainable and the most affordable fuel source of the near future.
Greenhouse gas emissions from transport accounting for about 27% of total US greenhouse gas emissions, and 8% of that is directly attributed to aircraft – the transportation sector plays an important role in the fight against climate change. Green hydrogen fuel holds enormous promise in the development of sustainable fuel sources in the long term. If you ask me, the future of green hydrogen fuel is as clear as water.