Bjorn’s Corner: The challenges of hydrogen. Part 28. Airbus priorities

March 12, 2021, ©. Leeham News: I had the chance to talk about Sustainable Air Transport with Airbus VP Zero Emission Aircraft, Glenn Llewellyn, in the week.

The discussion centered around Airbus’ overall direction and the targets with their ZEROe project.

Figure 1. Airbus ZEROe airliner concepts. Source: Airbus.

Airbus direction for Sustainable Air Transport

Llewellyn started by stressing that Airbus’s ideas around hydrogen airliners are not new. Already in 2016, hydrogen was a clear alternative when Airbus looked at sustainable aviation.

As the Electric and Hybrid-Electric alternatives became less attractive, the hydrogen-fueled track strengthened. The French state’s investment in hydrogen aeronautics announced in June 2020 supported Airbus’ direction, but it did not change it.

Another point Llewellyn stressed was Airbus’ equal support for Sustainable Aviation Fuel, SAF. “SAF is very important for us as a complement to hydrogen. It’s the only alternative for the existing fleet and a future long-range aircraft. Our SAF support has drowned in the interest in our hydrogen work. But hydrogen is one part of the solution, SAF is the other. Hydrogen is the solution for regional and intra-continental traffic as it has better operating economics. For long-range aircraft, the volume demands of hydrogen make SAF the only carbon-free alternative.”

The third point for Llewellyn was the importance of a broad hydrogen eco-system. Air transport is only a smaller part of a hydrogen economy. Airbus, therefore, actively engages with ground transport (trucks, busses, cars, trains), energy and space industries to create a rational and effective production and distribution system for hydrogen. Regarding distribution, he mentioned the low weight of hydrogen makes tankering possible, which means not all airports in a future network need LH2 installations.

“Right now, for the next years, we are developing and testing technologies and engaging in infrastructure discussions. It’s still too early to talk about demonstration aircraft, and decisions around an aircraft for introduction 2035 can only be made after we have evaluated the result of the present work packages,” said Llewellyn.

He gave examples of how the ground transport industry has developed the fuel cell, focusing on a low cost of manufacture. For airliner applications, the balance skews towards performance, which is the focus for Aerostack Gmbh, its joint venture with ElrinKlinger AG around advanced fuel cells.

Propulsion and APU technology

We then discussed the results of my calculations around propulsion and auxiliary power to the aircraft. Llewellyn stressed Airbus’s goal is zero emissions, thus the name ZEROe for the presented concepts.

The fuel cell has the advantage here (no NOx and Soot emissions, H2O is not emitted as ice crystals). Depending on the performance it can achieve, it will set the balance between fuel cell and gas turbine propulsion for future hydrogen aircraft. For auxiliary power, the fuel cell has many advantages.

22 Comments on “Bjorn’s Corner: The challenges of hydrogen. Part 28. Airbus priorities

  1. Sounds logical, but can be hard to implement. In the EU with small countries intermixed with larger ones they need to implement rules and fee’s coordinated otherwise traffic will cross the border to the cheapest Airport to fill’er up and fly long range. The UK will be special as they have the possibility to introduce Alcohol and Tobacco Tax Free sales and cheap JET-A1 while connecting the channel trains directly to Heathrow T5.

  2. As the Electric and Hybrid-Electric alternatives became less attractive, the hydrogen-fueled track strengthened. The French state’s investment in hydrogen aeronautics announced in June 2020 supported Airbus’ direction, but it did not change it.

    Why did Electric and Hybrid-Electric alternatives become less attractive?

    • You have a good rundown on why if you go to our search box and enter ePlane. There is a series of Corners detailing why. But essentially; Electric and Electric-hybrids are based on storing energy in batteries and these are too heavy for airliner use, today, tomorrow and for the foreseeable future (right now they are 80 times heavier than Jet fuel and 240 times heavier than hydrogen for the same energy content. This huge difference kills all concepts that use batteries as an energy store). Batteries work for cars as our normal car sucks energy efficiency-wise (5-7% efficiency in day-to-day driving, today’s airliners are almost 10 times more efficient) and is insensitive to weight.At this efficiency level for the replacement technology the battery/hybrid car works. For airliners, the level of technology is a magnitude higher and then batteries doesn’t cut it.

      • Plus, for land vehicles, regenerative braking leads to massive increases in efficiency. Airplanes already have this, as they coast down from altitude.

      • Interesting that Boeing uses batteries in their 787 for aux power then. Might still be an option at least for aux power.

        • ‘nofly’:
          batteries in regular airplanes like the 787 are _backup_ power not _auxiliary_ power.

          Those fairly small batteries are usually recharged by engines, either propulsion engines or the small non-propulsion engine called ‘auxiliary power unit”.

          The APU provides compressed air to start propulsion engines, and for cabin climate on the ground, and electrical power on the ground plus in the air on modern airliners as another generator.)

          The batteries provide power to start the APU, and power essential systems such as navigation instruments in the case of loss of all engine driven generators.

          (On airplanes without manual control reversion a very small windmill called a ram air turbine pops out to provide hydraulic power and electrical power (directly or indirectly via a hydraulically driven generator). It has saved a few airplanes including a B767 that ran out of fuel north of Winnipeg.)

          Small airplanes may start engines with battery power, a tough assignment. (The R-R Dart turboprops on the CV640s used batteries, whereas the Allison turboprops on the CV580s, L188 Electras, and C-130s used bleed air from an APU. An even tougher starting assignment for batteries is to turn the honking wide blades on a Bell 214B helicopter that are directly coupled to its single-shaft engine, everything has to turn.))

          Such batteries are in the ballpark of 40ah capacity, two of them on B214B and CV640, one on B737, IIRC one on the B787, roughly speaking about the size of the starting battery on a full-size automobile like a V-8 pickemup truck.

  3. Bjorn is quite correct: Battery power, hydrogen power and so-called ‘bi-mode’ power are very effective in transport media where wheels are planted firmly on the ground. Indeed battery power trumps hydrogen in cases like heavy rail simply because weight is not an issue. In the UK for example as governments quail at the cost of electrification a bi-mode (an electric train that carries a pair of diesel engines) is perfect as a way of avoiding the need to fill in gaps in electrified networks. Of course outside the UK and the Americas rail networks are already massively electrified, giving them a profound edge over aviation in terms of political support for carbon-reduction.

    • Airbus’ equal support for SAF is something new for me. I thought there is more bias towards H2.
      Here in South Africa we might be on the way to pipeline green H2–methanol -SAF with estimates production cost of €300-350/t, but still in very early stage for certainty. It seems to me SAFs as a better option, not to mention earlier deployment possibilities.
      In “The challenges of Hydrogen. Part 15. Hydrogen cost” I posted very late comment, which I doubt anyone has read, so I would reposted it with very small re-edit.
      Repost:>>
      About Figure1:
      1. Truck transportation: I’ll ignore that option, because it will be irrelevant, might be, but for some small airports.
      2. On-site production: It will very unlikely to happen, I would rather say it will never happen, because it will be too expensive; the long story short: only the cost of power transmission, distribution and administration will be $40-$85/MWh (very much dependent on the transmission distance to the nearest power station). Let’s assume it 5c/kWh in average, even if the electricity production cost is for free.
      3. H2 Pipeline: One of the most typical feature of the hydrogen economy will be developing and after that established hydrogen grids with industrial, commercial and even residential connections and so airports definitely connected to it. In short- the corporate price of the hydrogen will be based mainly on LCOH (production cost), hydrogen purchase agreement (HPA) cost and pipeline transportation cost. It finally will end-up at about $2/kg at the main input pipeline valves of the airport. (Forget about all other predictions!)
      – The price of the liquefaction is not fixed in dollar terms ($0.8), it is mainly a function of the electricity price and the energy consumption is currently about 10.25kWh/kg of H2, which may decrease slightly when technology improves. Airports are industrial consumers, they are getting cheap electricity, but it is unlikely to be less than 9-10c/kWh ever. So another option would be producing electricity from the available pipeline H2 by Fuel Cell Power Station (FCPS). Each 1kg of H2 can easily produce about 25kWh electricity plus heat to supply some airports needs. That makes 8c/kWh autonomous production. So, for 10.25kWh/kg for liquefaction, it will result in $0.82 additional cost so far for OPEX : $2 + $0.82 = $2.82/kg. Add some CAPEX induced costs and one can easily end up to $3.5/kg. This is not bad at all and will get even cheaper!
      It must be mentioned that the jet fuel prices could be $0.5/l now, but that does not include the environmental costs (CO2 etc). By the way the same applies to the ship fuels. That privilege will disappear the moment the first ePlanes emerge, so the fuel cost can easily go up to $1.5 – $1.6/l, which will make it much more expensive than H2. All prices are normalized for 2030.

      • “SAF” is a new buzzword that I confess I first discovered in this article. As many corporations, airlines, IATA, ICAO, BP are now using it it must have a future. It seems to be a term covering use of waste oil, biogas converted to fischer-tropsch jet fuel and I think eventually PtL (Power to Liquids). Hard to tell if it covers offsets. Either way it has to be ‘saleable’ to both the rational and irrational public.

        The future of PtL “Power to Liquids” seems bright. The German firm Sunfire will do well in any cryogenic hydrogen economy but has also long demonstrated medium and high temperature steam electrolysers that can take in CO2 and Water to directly produce syngas for immediate conversion to jet fuel or methanol via fischer-tropsch catalysts. The efficiency is 70% given a reasonably concentrated source of CO2 so more efficient than cryogenic hydrogen. Fortunately there are many of these concentrated sources. The CO2 by-product of biogas production is ideal. It will even integrate into existing oil refineries and Gas to Liquids plants exploiting their CO2.

        Sunfire’s technology combines well with the swiss firm Climeworks technology for extraction CO2 from air where CO2 is absorbed on amine impregnated ceramics where it is released and the amine regenerated with low grade waste heat, in this case from the exothermic fischer tropsch reaction. This reduces efficiency to around 50%.

        There are many firms with similar technology eg in Sth Africa. Some targeting direct atmospheric carbon capture and others focusing on capture near Co2 emissions.

        Apart from solar thermal and photo electric in remote locations Variants of these will use thermochemical water splitting (solar and perhaps nuclear). The Saud’s may yet produce cheap thermochemically produced SAF and PtL though neighbouring Ethiopia has better sun.

        It’s worth checking out Norsk e-fuel which will use this technology to make 10 millions tons of eFuel/year (about 330 tons per day) in Herøya, Norway building up from 2023.
        https://www.norsk-e-fuel.com/en/
        https://www.climeworks.com/news/making-unlimited-renewable-fuel-a-reality
        https://climeworks.com/news/christoph-gebald-co-ceo-and-co-founder-of-climeworks

      • Fully compatible SAF stuff is low hanging fruit for the airframer. ( probably why Boeing prefers it. looks good, lots of PR opportunities to look good and other have to do the heavy lifting.)
        Production and engine adaptions ( if needed at all ) is away from their core activities.

        • If the airline blends in 5% SAF/e-fuel/PtL as standard the passenger can be offered the option of purchasing the upgrade costs of their mineral based fuel to SAF or e-fuel for their entire flight. Fuel burn is about 2L/100km/seat so at slightly optimistic mature production the costs would be maybe $30/1000km or $50/1000 miles per seat. Business class and pop stars would be 50% offset inclusive to maintain social credibility.

        • One statement by Llewellyn is very noteworthy: “For long-range aircraft, the volume demands of hydrogen make SAF the only carbon-free alternative.”

          • SAF is not carbon free. I guess CO2 neutral would be more appropriate.

          • What is tagged “carbon neutral” today isn’t environmentally neutral at all.
            more like the “Teufel and Belzebub” interchange 🙂

      • Hybrid aircraft for the main propulsion is out of the question as has been covered before , maybe for APU.
        Anyway far more interesting from your link was other non rail profiles, hybrid fishing boat ( Norwegian of course) and ‘electric’ gold mine in Ontario

        • Apparently 40% of the Philipines foreign exchange is used for marine diesel to power the fishing fleet. PtL, SAF, hydrogen will hopefully bring about a “democratization” of energy. Hybrid trains or battery trains make sense for low traffic spur lines not economic to electrify but I can’t see the rational for heavy freight.

          Tom Enders, ex CEO of Airbus, has joined the board of Lilium https://lilium.com/ so some extremely heavy hitters getting in on EVTOL with connections to banks, Governmnt with deep pockets.

          With the EU pushing car makers to abandon ICE airlines would be well advised to get a small amount of SAFE PtL involved ASAP or they may find high speed rail subsidized even more.

      • A small battery is present in nearly any fuel cell solution, for peak usage, onboard systems and store the brake energy.

        But I would hardly call it “hybrid” when you can only use it for a few minutes.
        From the link: “at peak times the train even needs 450 kilowatts for a maximum of 40 seconds”

        • It still is a series hybrid design.

          fuel cells just aren’t responsive enough and would need to be (over)dimensioned for peak supply anyway.
          ( IMU fuel cells are not really overloadable.)

          know of any fuel cell application that does not show intermediate storage?

          • ( IMU fuel cells are not really overloadable.)
            PEM fuel cells (and electrolyzers) withstand overload, but efficiency suffers.

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