Before the pandemic, the airline industry accounted for roughly 2.4% of global carbon dioxide emissions. This figure is predicted to rise to about 5% by the year 2050. When we all weren't roaming around with masks, long-distance travel was a huge part of the lives of many. However, all this comes at a cost. It’s clear that the consequences of air travel on the environment are substantial. Thus, it's only logical that a solution is proposed, and in three different new aircraft plans, Airbus says they have one.
In a move to revolutionise flying, Airbus unveiled three major concepts in late 2020 under the ZEROe branding, targeting an entry into service by 2035. This is part of the French company's plan to decarbonise the aviation industry. This begs the question, how exactly does Airbus intend to make these concepts into zero-emission aircraft? The answer lies in the use of hydrogen; an already somewhat established and proven power source in the automotive and aerospace industries, ranging from the Toyota Mirai to the Apollo 11.
"This is a historic moment for the commercial aviation sector as a whole and we intend to play a leading role in the most important transition this industry has ever seen. The concepts we unveil today offer the world a glimpse of our ambition to drive a bold vision for the future of zero-emission flight......These concepts will help us explore and mature the design and layout of the world’s first climate-neutral, zero-emission commercial aircraft, which we aim to put into service by 2035" - Guillaume Faury, CEO of Airbus
The first concept is the Turbofan. It features 2 hydrogen hybrid turbofans, with an estimated range of 2000+ nautical miles, seating for just under 200 passengers, and an average cruising speed of about 828 kph (511 mph). I would imagine that this concept would be the most popular choice for airlines if and when these planes take to the skies.
The second concept is the Turboprop. It's powered by 2 hydrogen hybrid turboprops, with an estimated range of 1000+ nautical miles, seating for just under 100 passengers, and an average cruising speed of about 612kph (380 mph). Unlike the first concept, which looks suited to travel all over the world, this concept looks like it's best for regional travel, like the current turboprops we have today (such as the Q400, or the ATR72). Like the first concept, this plane doesn't bring anything radically new in terms of its design. It looks very similar to the planes we already have today.
Rounding off the trio is the Blended-wing Body. In stark contrast to the first 2 concepts, this plane is a radical departure from the aircraft flying today. In terms of specifications, it's identical to the first concept. I personally think this concept is by far the most interesting. It will carry passengers and cargo in a completely different way than current aircraft. The most notable detail is that the aircraft as a whole acts as the wings, which makes it look like it's straight out of an Avenger's movie. This should allow for more space (for passengers, cargo, and fuel) and efficiency from a drag coefficient standpoint.
Although 3 concepts were unveiled, the company is not just talking about a few aircraft, but a redefining of the industry, including later additions to their lineup at the heart of it.
“We won’t be satisfied with simply putting a hydrogen-powered aircraft into the air: we’re targeting wide-scale adoption, and that starts with putting in place hydrogen infrastructure worldwide” - Glenn Llewellyn, Vice President of Zero-Emission Aircraft at Airbus
The plan is essentially to bring about a complete change in the way aircraft function from the mid-2030s onwards, as these aircraft come into commercial use.
This is a big move for a more sustainable aviation industry, but it begs the question of why electric power wouldn't be sufficient. I believe it's down to a few things. The batteries require a lot of resources to produce, and since planes cover huge distances, we're going to need a lot of them. This has a big impact on the environment and it also adds a lot of weight, something that we all know airlines are ever cautious about. I'd also imagine going electric would mean completely rethinking the design and layout of the plane. So, hydrogen-based fuel is probably the most viable choice. Apparently, hydrogen fuel can work with the current aircraft technology we have, and that it's simply a matter of modifying the engines to work with different fuels.
Although, don't rule out battery power entirely just yet, as Airbus emphasized that it may look to utilise both battery power and hydrogen fuels in some of their aircraft as an effective compromise solution, similar to a hybrid car.
But how does hydrogen power actually work? Well, hydrogen fuel cells work through the quick release of energy stored in hydrogen molecules, which generates electrical power through an electrochemical process that uses just hydrogen and oxygen. Firstly, hydrogen enters a fuel cell on the anode side, where a catalyst splits it into negatively charged and positively charged particles. Simultaneously, oxygen from the air around the plane enters the cathode side of the cell. The positively charged particles pass through a porous membrane to the opposite side of the cell, as they are attracted to the cathode, where they combine with oxygen to produce water as a byproduct. The electrons flowing in the opposite direction generate an electric current, which provides power to the aircraft.
This kind of fuel system is good for the environment compared to conventional systems, not only because of its relatively safe byproducts (water) but also because of how the hydrogen is produced in the first place. As we all know, fossil fuels are not environmentally friendly on either end: they require energy to produce and create harmful byproducts when they’re burnt. Hydrogen, on the other hand, can be produced from seawater, with the help of carbon-neutral sources of energy (wind or wave energy for example), which makes both ends of the supply green compared to the product they’re meant to replace.
"I strongly believe that the use of hydrogen, both in synthetic fuels and as a primary power source for commercial aircraft, has the potential to significantly reduce aviation's climate impact" - Guillaume Faury, CEO of Airbus
The fuel cell also has a benefit over conventional batteries, as it continues to supply energy provided hydrogen is supplied. This means that the limitation of hydrogen power, like with conventional jet fuel, is how much hydrogen can be carried onboard. As hydrogen is relatively light, there are plenty of possibilities.
Although, it's not all sunshine and rainbows. There are a few problems with the ZEROe concepts. First of all, hydrogen fuel is not currently produced on the scale required for airlines around the world because it's simply expensive. Even biofuels, which have seen a 7% increase in year-on-year production, are not even close to being produced on the scale needed to take over the aviation industry. To put things into perspective, KLM would use up the world's supply of biofuels in less than a day when it operates at its peak. Now think about hydrogen fuels, and it all seems quite silly.
Currently, hydrogen fuel is very expensive compared to conventional jet fuel due to its lack of availability and the high costs of producing it. We can expect its price to drop in the future, as it becomes more commonly used in sustainability initiatives that incentivise its production, but we don't have much of an idea of the time scale for that to happen.
Then there's a problem we've become all too familiar with alternative fuel vehicles: range. The range offered by hydrogen is much less than that of jet fuel. With our current technology, planes can fly up to 2000 nautical miles with hydrogen fuel, so it's unlikely that most airlines would make the switch. There's still going to be a need for long-haul aircraft powered by petroleum to link distant countries. Although, let's be optimistic that we can find a way to improve the efficiency of future aircraft to make this a possibility.
The problems don't end there as although hydrogen doesn't emit pollutants, we do have to keep in mind that it emits water, which is a greenhouse gas. This means that these aircraft could still contribute to the enhanced greenhouse effect and global warming. Scientists also believe that a minor byproduct of hydrogen fuels is nitrogen oxide, which is responsible for the production of tropospheric ozone. Although, we should also consider that while these impacts negatively affect the planet, the damage is much less than that of current aircraft.
That leaves us with two other problems. Airports will require significant overhauls to accommodate hydrogen transport and refueling infrastructure so that they meet the needs of daily airline operations. This means that governments will need to invest significantly to meet these ambitious objectives. There will also need to be factors that encourage the transition to sustainable fuels to persuade airlines to retire older, less environmentally friendly aircraft.
"The transition to hydrogen, as the primary power source for these concept planes, will require decisive action from the entire aviation ecosystem. Together with the support from government and industrial partners we can rise up to this challenge to scale-up renewable energy and hydrogen for the sustainable future of the aviation industry." - Guillaume Faury, CEO of Airbus
Lastly, the problem lies with Airbus themselves. You see, Airbus has a poor track record when it comes to environmentally friendly aircraft concepts. The company planned to fly an electric aircraft called the E-FANX, which had a single electric motor on its wings and 3 jet fuel engines, made in partnership with Rolls-Royce. They ended up cancelling the entire project in April 2020.
So, the question still remains. Will these hydrogen aircraft see the light of day? For now, all we can do is sit around and wait. There is definitely potential for the ZEROe concepts, as European low-cost carrier easyJet has shown interest in the project, which is part of their commitment to making flying more sustainable. Airbus seems enthusiastic about the whole premise of ZEROe, and the French government seems to agree, as they have dedicated 10% of their $17 billion COVID rescue package for the airline industry explicitly to be used on hydrogen-powered aircraft.
Despite Airbus’ efforts, there is still skepticism about the idea, particularly from those pointing to the aforementioned issue of insufficient supply of sustainable fuels. We know that it is something that is already in process, though on a very small scale, to potentially be a more straightforward route to a greener aviation industry. Alternative fuels are capable of a 70% reduction in emissions, provided enough of them can be produced to sustain the aviation industry. That said, 70% is nowhere near on par with the hydrogen-based system Airbus proposes. Although, I like the idea of having two alternative paths to reducing the impact on the planet.
Should Airbus’ concept come to fruition, it would certainly beat the industry’s measly efforts to go green. As you'd imagine, planting trees to offset the carbon footprint - as some airlines offer as part of the ticket cost - is better than nothing, but hardly a sustainable solution. The ZEROe concepts could very well lead to commercial flight without the guilt or the negative impacts on our planet.
So, how far would you be willing to go? Would zero-emission options make a change to how often you fly (assuming we're free of COVID troubles)? Would you be willing to pay extra to fly onboard a zero-emission aircraft? Leave a comment below to let us know!