Aviation is cited as one of the hard-to-abate sectors, where options for reducing emissions with current technology are limited. Jan Toschka, president of Shell Aviation, shares his view on the most viable opportunities for decarbonising aviation in the near-term and how hydrogen may play a role in the future.

What are some of the key challenges to developing ‘zero carbon’ aviation technology? Are certain technologies more suited for domestic versus long-haul flights?

Toschka: To meet net-zero emissions in aviation, we need to explore every avenue available to us. At Shell, this involves supporting innovative R&D that helps develop new aviation solutions.

“It is important to develop multiple production pathways and technologies”

In the future, new technologies such as electric-powered and hydrogen-fuelled aircraft have the potential for certain applications and uses, particularly for smaller aircraft over short-to-medium-haul flights.

While both these technologies offer exciting potential, they are in their infancy and will probably only materially affect sector emissions after 2040, at the earliest. Certification may take years and, unlike sustainable aviation fuel (SAF)—another decarbonisation lever available—which is a drop-in solution, these technologies will require new aircraft design and infrastructure investment, from supply chains to airports.

This means that SAF, as the only potentially scalable alternative to conventional fuel currently available, will play a vital role in the years ahead and will be a primary driver for energy decarbonisation in aviation, especially for long-haul travel.

A number of different routes have been proposed for decarbonising aviation, from offsets to electrification to SAF from a variety of sources. Can you outline which routes Shell Aviation is currently investing in, or investigating for future investment?

Toschka: We cannot afford to neglect any of these elements. Scaling up SAF, ensuring the uptake of high-quality offsets and investing in future technologies are all important to reaching net zero.

Shell sees SAF as the most viable solution for decarbonising aviation in the short-to-medium term, but it is important to develop multiple production pathways and technologies, as all will be needed to meet the sector’s goals. The key question is not whether one technology will be better than another, but how quickly can we develop, scale, and commercialise multiple pathways to decarbonise the sector?

As mentioned, Shell is already taking steps, and will continue to do so, when it comes to scaling up our production of SAF. The focus is on making investments for the long term, from world-scale production facilities through to emerging technologies. We are transforming our refinery facility in Rotterdam and have completed the upgrading of our facility in Singapore to enable SAF blending in the burgeoning Asia-Pacific region.

High-quality carbon credits must be used now as we fully develop the other solutions needed to reduce emissions from aviation. We are investing in nature-based solutions that protect and enhance natural ecosystems that capture CO₂ emissions, offering our customers carbon credits to help compensate for the carbon emissions produced during flight.

And in the future, new technologies such as electric aircraft and hydrogen-fuelled aircraft have the potential for certain applications and uses, particularly for smaller aircraft over short-to-medium-haul flights. For example, our investment in [hydrogen-electric engine developer] Zeroavia aims to accelerate hydrogen as a viable solution for larger aircraft.

What are the current costs of biofuel-based and synthetic (hydrogen, captured carbon) SAF versus conventional aviation fuel?

Toschka: SAF is between two and eight times more expensive than traditional jet fuel, depending on the mix of feedstock, technology and manufacturing processes. With airlines operating on tight margins in a highly competitive industry, this cost is likely more than can currently be absorbed. Producing SAF at scale could lead to costs falling, but improvements in cost and technology efficiencies for SAF production could take time to deliver, as many production pathways are still developing to their full potential.

Shell aims to produce SAF from multiple sources: from biomass, such as used vegetable oils or agricultural waste today, through to via the conversion of non-recyclable waste or synthetically produced alcohol in the future.

“The industry needs a wide range of feedstocks that meet an agreed sustainability and greenhouse gas reduction criteria”

Another long-term SAF solution for aviation may be power-to-liquids, using initially industrial point source emission, and moving towards direct air capture coupled with renewable power and hydrogen sources to produce synthetic fuels.

There are multiple SAF technologies at various stages of maturity, and it is critical that we progress as many pathways as quickly as possible to meet the growing demand. The industry needs a wide range of feedstocks that meet an agreed sustainability and greenhouse gas reduction criteria. This would allow the industry to accelerate the growth of a range of more established and promising SAF production technologies—hydroprocessed esters and fatty acids, alcohol-to-jet and recycled carbon fuels—as well as de-risk investment in synthetic fuels such as power-to-liquids.

Our industry study shows that investing in both bio- and synthetic SAF will make it possible to scale up production and bring down costs to the levels required for large‐scale adoption, which can already happen within 15 years.

How have these costs changed over the past few years? What kind of policy will need to be in place to bring these costs down to parity?

Toschka: With the stage of commercialisation that SAF is at, costs will continue to fluctuate in the near term as the industry works together to ramp up its supply and use. But what the last few years have shown clearly is that, in order to achieve the SAF uptake required, you need long term, consistent policies. These start with setting clear targets to achieve net-zero emissions with suitable interim targets and providing the necessary levers that both stimulate demand for SAF as well as incentivise production.

For example, policy measures such as mandates can help in creating the commercial market, yet on their own they are not effective to drive investments. So you need a sectoral approach that looks to synchronise supply and demand, develop the appropriate infrastructure, put a price on carbon and share the cost burden across all parts of the value chain and governments.

A full version of this interview was originally published in Transition Economist.

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Author: Polly Martin