Responsible Aviation: Focus on SAF, Not Hydrogen

09.24.21 | Blog | By:

Aviation is a global activity and as such is represented at world level for regulatory matters by the United Nations agency International Civil Aviation Authority (ICAO) and by the International Air Transport Association (IATA) for commercial matters. More than ten years ago, these two powerful bodies recognized air transport had to become more responsible and sustainable. Eventually, an ambitious environmental target was agreed upon to reduce greenhouse gas (GHG) emissions by 50% in 2050 compared to 2005 though (pre-Covid 19) it was projected that passengers would double every 20 years. The vast majority of scientific and technical stakeholders agreed sustainable aviation fuels (SAF), renewable liquid fuels with a lower fossil carbon intensity than crude oil-based jet-fuel, would be the major contributor to that thirty-year project.

SAF production pathways have been developed and certified for worldwide use, and SAF is now waiting for the proper regulations to be implemented and enforced to become commercial. This could not happen in the previous decade as this renewable fuel is much more expensive than conventional fossil jet-fuel, in the context of a highly competitive commercial air transport sector. But now, regulations are on the way in Europe and in the U.S. which will no doubt kick-off this new market this decade, deemed so important in the fight against climate change.

So why are the media only talking about hydrogen?

Is hydrogen a response to the ICAO/IATA 2050 challenge? The answer is a clear and loud NO.

There are two reasons for that.

First, hydrogen powering requires a brand-new design for airplanes and engineering studies are nascent. Airbus, pioneering this technology, only announced earlier this year a full-scale prototype for 2035, thus there is no chance to see a fast turnover of the 20,000-ish commercial plane fleet in less than 15 years for hydrogen lower carbon footprint to make an impact.

Second, hydrogen will likely replace liquid fuel on short-haul planes, at least in the first phase of development (before 2060?). This part of air transport only contributes one-third of GHG emissions. The remaining two-thirds comes from mid- to long-haul flights, driven by international tourism from Eastern emerging middle classes towards the Western world, which are not yet targeted for hydrogen powering. With a 30% carbon footprint reduction expected for hydrogen-powered planes versus 2020 state-of-the-art models, and an extremely ambitious 75% turnover of the short-haul fleet by 2050, GHG emissions abatement looks modest at well below 10%. Especially when compared to SAF, today certified for a 50% incorporation rate on any airplane and generating specific GHG emission reduction beyond 70%.*

So, why the hype? There are many possible answers.

SAF can significantly reduce the carbon footprint of commercial aviation, as from now. But SAF are mostly biofuels, which have a bad image in the EU. Environmental NGOs never miss an opportunity to criticize this readily available sustainable solution. This is not a rational position in the EU where the sustainability criteria in regulation are quite exhaustive, unless you are a “flight-shamer” looking for any possibility to ground air transport. There are alternatives to biofuels such as e-fuels, but the technology is not mature and competition for renewable electricity can only increase in the future, making the economics of this pathway unsecure.

SAF being readily available, and already produced by big actors, like Neste and TotalEnergies in the EU, the price to fly more responsibly could be felt now. But increasing the price of plane tickets is not welcome in the post-Covid 19 environment, is it? Whereas postponing the solution to 2035 and beyond costs nothing. Hydrogen is the perfect candidate for such an approach. Water and green electricity from solar and wind, are potentially plentiful, although with a lot of competition for end-use, technology to manufacture hydrogen exists, if not at scale and economically competitive. This is a perfect solution for regulators and airlines, and passengers.

It is also an opportunity for entrepreneurs to capture public money, especially in the EU, for Research & Development or Innovation (RDI). Public money is plentiful and the EU would love to score a competitive technological advantage, having so far lost the battle on electric vehicles.

So, let us hope regulators will follow the sensible approach to support existing, proven, mature solutions to reduce the carbon footprint on a commercial scale, as from now, which is not exclusive of funding RDI for future solutions, if we manage the critical decades ahead so that aviation remains what it has brought since 2050, a wonderful link for people and businesses that are far apart.


* Note: Based on the key messages from the May 6, 2021 workshop “Hydrogen-Powered Aviation Research & Innovation,” aimed at providing the EU with a roadmap to deploy this technology in aviation as part of the European Green Deal of climate-neutrality by 2050.

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