ZeroAvia is building an accessible, sustainable aviation industry
Listen to this article
reading time: 6 protocol
We’re standing at the other end of Hall One on the second day of the Farnborough International Air Show. The temperatures outside the hall reach around 38 degrees Celsius – inside it gets even hotter.
“Customers say they see how we’re pushing the technology,” says James Peck, vice president of business development at ZeroAvia, a company working on hydrogen-powered aviation.
“But you take it [Boeing] If the 777-9 is out there flying, there’s still a long way to go.”
However, ZeroAvia believes its retrofit, production-ready and forthcoming purpose-built hydrogen-powered aircraft will prove an enticing and enduring solution for airlines around the world. We spoke to Peck and his colleague Rudolf Coertze, CTO Hydrogen, to find out why ZeroAvia is taking the lead.
hydrogen and batteries
“At ZeroAvia, we are focused on developing what we call a zero-emission hydrogen-electric aircraft engine,” says Coertze.
“It is therefore very important for us to reduce emissions from aviation or the contribution of aviation to CO2 and greenhouse gas emissions. So we decided to focus on hydrogen, but not hydrogen combustion, specifically hydrogen that’s produced electrochemically by using hydrogen and oxygen from the air in fuel cells, and then powering electric propulsion systems to actually power the aircraft .”
ZeroAvia’s fuel cell-based approach is far from new, but, as Coertze explains, its application in the aviation industry is.
“Fuel Cells and Hydrogen Fuel Cells per se, are of course not entirely new. There is already a large body of knowledge and also a large industry that is already active in the automotive and truck sectors as well as in the bus sector in relation to fuel cells and hydrogen.
“What we are doing at ZeroAvia is we are taking fuel cell technology to the next level to actually use it in aviation. However, we also understand that there is already a considerable degree of technological maturity in fuel cell technology, which we can already bring to certifiable products and market maturity relatively quickly with the existing state-of-the-art fuel cell technology.”
ZeroAvia wasn’t the only company to demonstrate its alternative propulsion systems at Farnborough last week. Lilium, for example, had a huge booth with a scale model of their four or six seater eVTOL battery-powered aircraft.
For Coertze and Peck, however, batteries simply don’t offer the range, flexibility, or scalability needed for the larger 10-19 and 70-80 seat aircraft that ZeroAvia is targeting.
“Batteries have limitations because their energy density is much lower than that of hydrogen,” Peck explained.
“So you have a big battery that is very heavy, and the batteries also have a cyclic life. So if you drove an electric car, the batteries need to be replaced after 100,000 kilometers, for example.
“If you equate that on an airplane with flights and cycles in terms of charge, discharge, charge, discharge, replace the batteries on the plane, in less than a year in some cases. This is a major maintenance event and very expensive. So you have this problem, and then you have the fact that you have to charge them.
Hydrogen propulsion thus eliminates most of the problems associated with battery-powered flying in one fell swoop. However, hydrogen propulsion is not quite perfect.
“Fuel cells are already very mature, but what you’re finding is that we need to increase the power density of fuel cells for airplanes because in many automotive applications, cost, not weight, has been the biggest driver. The automotive industry is very cost-sensitive, but in aerospace, weight is an extremely big driver,” Coertze explained.
“Similarly, there are technological challenges for hydrogen storage and hydrogen storage technologies in both gaseous and cryogenic liquid hydrogen forms.”
Storing hydrogen for use in aircraft is far from easy and poses different challenges for battery- and kerosene-powered flights.
“Hydrogen has a much higher energy density than typical kerosene,” Coertze continues, “usually three times the energy density.”
“However, you can’t store that much in gaseous form, you really have to compress it to high pressure. So there is always a challenge with gas storage that tank weight is a significant factor in the amount of hydrogen you can store.”
ZeroAvia is investigating the storage of gaseous hydrogen for its 10- to 19-seat aircraft. However, the company uses cold storage techniques for its 70-80 seat aircraft.
“We’re definitely looking at cryogenic liquid hydrogen storage, which of course has its own specific benefits, but also challenges,” said Coertze.
“So first of all, it’s the cryogenic temperatures. Hydrogen is liquid at around -250 degrees Celsius. These technologies exist and have been used in space and other industrial applications. But they must get to the point where all the necessary storage, refueling and distribution systems onboard the aircraft are designed and certified to operate effectively and safely for a reasonably cost-effective lifetime.”
Unsurprisingly, hydrogen needs to be kept so cold on an airplane that it requires some space-age solutions.
“You can keep it cool with insulation,” Coertze said.
“So you have to use vacuum insulation with advanced thermal insulation materials, a large number of which have been developed since the early days of the space shuttle, and they were typical foams. However, today you have much more advanced installation materials available to you such as aerogels and all sorts of different materials that are already in use, as well as vacuum and double wall tank installations.”
Build the future
For many sustainable transport companies, the switch to alternative drives is an excuse to tear up the rules when designing their vehicles.
However, ZeroAvia takes a different path – at least initially.
“We are currently concentrating on fixed-wing aircraft and are also aiming for retrofits,” explains Coertze.
“Then we also aim for what we call Line Fit. Line modifications are also existing aircraft, but if they are newly manufactured, they will get our hydrogen-electric engine and hydrogen storage when they come off the assembly line instead of a traditional engine and fuel storage.”
This may seem like a relatively unexotic business plan – take existing planes and swap out the engines. But according to Peck, ZeroAvia is successful precisely because the model is well known.
“It’s less about the opportunity and more about the speed to market, the evolution of the technology, the maturity of the engine.
“Retrofitting,” Peck continued, “will allow us to build a decent fleet more quickly, reach that maturity, and begin development, while also generating revenue that will help fund development.”
“So the retrofit is strategically the best way to do it. Line Fit is very attractive because when someone takes a new plane, they will usually operate it for a long time. So if you’re someone who’s going to be flying an airplane for 20 years, our chances of generating revenue over the life of the product are very good.”
ZeroAvia also has a unique ability to provide continuous service to its customers. Rather than just making the engines, retrofitting them to existing planes, and then performing routine and emergency maintenance, the company also supplies the hydrogen needed to fly the planes.
“So we have a very separate department that focuses on infrastructure,” Peck continued.
“We have infrastructure partners like Shell who have invested in us to work with the infrastructure. So from a B2B perspective, we sit down with an operator, we lay out their entire route network, we calculate how much fuel they would use, how much hydrogen they would need for each route network, and we put together a complete plan for delivery and infrastructure.
“We take responsibility for fuel delivery and offer a price of $1 per flight hour, which has never been done before. Normally that only covers maintenance, but for us it is maintenance and fuel.”
ZeroAvia’s approach may not be particularly headline-grabbing, but with its reliance on existing technology, affordable fares, and customers like United Airlines, there’s a good chance you’ll see a hydrogen airplane overhead