For many people, announcements regarding another brand-new innovative project funded by the European Union seem nothing new under the sun, at a first glance. Moreover, news about green innovations promising great advances in almost every domain are being spread almost on a daily basis. Nevertheless, some initiatives require some attention, in particular. Especially the ones which mention the lightest element in the world – hydrogen (H₂), and even more so these days.
OLGA, also known as Holistic Green Airports, is a new response of the European Commission under the European Green Deal. It started in October 2021 and will last until the end of 2026. Its primary goal is to improve the environmental impact of aviation. How? Inter alia, via creating a Hydrogen Hub for ground operations and aircraft.
The significant budget of 34 million euro (including 25 million euro from the European Commission) and 57 entities involved in the project show the scale of the initiative. The diversified consortium of partners and third parties, ranging from large and small airports, airlines and the aviation industry to public authorities, researchers and innovative start-ups, ensures that the issue will be approached from different angles. Among the parties are Paris-Charles de Gaulle in France as a leader and coordinator, Zagreb Airport in Croatia, Cluj in Romania and Milan-Malpensa. They will provide scalability and EU-wide applicability.
This multinational partnership will conduct a pre-feasibility study of a hydrogen hub. So what is this hydrogen all about? And why do so many want to invest in it so much?
Liquid hydrogen (LH₂) – The advantages
Some see hydrogen as “one of the most promising technology vectors to allow mobility to continue fulfilling the basic human need for mobility in better harmony with our environment" (words of Grazia Vittadini, chief technology officer at Airbus). Some are more careful while discussing this new “miracle’ solution in the aviation sector. As always, the truth lies somewhere in the middle.
Hydrogen can be used in several ways as fuel onboard aircraft. It can be a source of power for battery-like fuel cells (e.g. power all the flight and communication systems in the cockpit), in hybrid aircraft, or as combustible fuel.
The advantages of LH₂ are numerous. What makes it so appealing for the EU’s officials is, undoubtedly, its potential to completely eliminate combustion emissions. When burning in a jet engine, it produces only water vapour as a by-product. As a result, up to 90% fewer nitrogen oxides are released into the atmosphere than in the case of kerosene fuel. From the green perspective, therefore, hydrogen has abundant potential. It is estimated that it could significantly contribute to a CO₂ emissions cut by 50% by 2050.
On a safety note, even though hydrogen is flammable, many studies have shown that it is safer than kerosene. Since H₂ is a gas already present in the atmosphere, a spillage would not represent an environmental hazard to the same extent as a hypothetical fossil fuel spill.
Not surprisingly, just like any novel solution, hydrogen doesn’t come without controversy.
As hydrogen (H₂) is naturally found as a gas rather than a liquid, it needs to be manufactured. This means that the gas must be compressed or turned into a liquid (LH₂) by cooling it to extremely low temperatures (-253 °C). This, obviously, requires energy. As for now, only 4% of the global hydrogen supply is produced via electrolysis, the rest being fossil fuel-based. Therefore, the truly “green” hydrogen is a minuscule part of all hydrogen produced (the rest is referred to as “grey hydrogen”).
What is more, LH₂ has a lower volumetric density than kerosene. It is only about a quarter of that of traditional jet fuel, which means it needs a heavy storage tank four times the size – for the same amount of energy. As a consequence, in order to accommodate the storage tanks, aircraft may either have to carry fewer passengers or become significantly larger. It poses a serious challenge for the engineers since a significant redesign of conventional airframes would be necessary.
Yet, the very last argument against hydrogen does not pertain to ecology or technical adjustments, but its cost. As things stand, liquid hydrogen is more than four times as expensive as conventional jet fuel. Naturally, the price is expected to drop as infrastructure scales up and becomes more efficient. Still, according to the British Royal Society and the management consulting group McKinsey, it is likely to remain at least twice as expensive as fossil fuels for the next decades to come.
Aware of all the pros and cons, numerous big companies and small start-ups have taken up the hydrogen challenge and, independently from the EU’s plans, heavily invested in this innovation.
Pioneers around the world
Airbus & CFM International have already made a few steps in the direction of commercializing the hydrogen innovation.
In September 2020, Airbus brought to life its ZEROe project. Its main premise is that hydrogen-fuelled propulsion systems would be at the heart of a new generation of zero-emissions commercial aircraft. Airbus has announced that it will produce a small "ZEROe" passenger aircraft powered by hydrogen to enter service in 2035.
In February 2022 Airbus declared that it would build a demonstrator to test propulsion technology for future hydrogen airplanes. It is being developed in cooperation with French-U.S. engine maker CFM International.
CFM, jointly owned by General Electric and Safran, is the world's largest jet engine maker (by the number of units sold). The new engine demonstrator will burn hydrogen fuel in the combustion chamber in place of jet fuel. The companies refused to disclose to Infra Journal the cost of the research project.
Air Liquide, a French multinational company, is present across the entire hydrogen value chain. Low-carbon hydrogen is already produced in gaseous form on the company’s site in Bécancour (Quebec) by using renewable energies for water electrolysis.
At Seoul-Incheon International Airport (South Korea), Air Liquide provides recharging stations for airport vehicle fleets. It wouldn’t be anything exceptional, apart from the fact that all vehicles are powered with hydrogen. It is noteworthy that it takes less than five minutes to fill up one vehicle.
In June 2021, Air Liquide partnered with Airbus and the ADP Group (Paris airports) in order to better prepare for the arrival of the above-mentioned hydrogen-powered commercial aircraft planned to be constructed by the European multinational aerospace corporation by 2035.
In the last few years, the California- and UK-based start-up ZeroAvia has become one of the leaders in zero-emission aviation. Its partners range from the UK government, Amazon’s Climate Pledge fund, to Shell Ventures and United Airlines.
As for today, the company has completed test flights with a converted six-seat Piper M, both battery and hydrogen-electric powered. It is currently working on an H₂ version of another 19-seat aircraft.
ZeroAvia's CEO, Val Miftakhov, says the company expects to offer commercial flights using such a plane as early as 2024, and that by 2026 it will be able to realise flights over almost 1.000 kilometers in aircraft with up to 80 seats.
The European Commission is not the only one that has noticed potential in hydrogen. Given its budget, OLGA may be one of the most successful projects in fledging hydrogen aviation innovation. Yet, all this seen, the capabilities of other private and public leaders of the sector should not be underestimated. Neither, the liquid hydrogen itself. The element, omnipresent in the world, has a lot to offer.