The shipping and aviation industries are energy intensive, so they have a limited pool of options to choose from when it comes to decarbonisation. However, green hydrogen and carbon dioxide derived from direct air capture (DAC) will both be integral in their efforts to reach net-zero.

We established the Skies and Seas Hydrogen-fuels Accelerator Coalition (SASHA Coalition for short) to highlight the vital role of green hydrogen and DAC in decarbonising these sectors – here are our top five reasons why they are crucial for net-zero aircraft and marine vessels.

1. Shipping and aviation emissions will only increase if action isn’t taken

To put it (not very) lightly, the situation is dire. The most obvious reason is that, if we are to reach net-zero by 2050, these sectors cannot continue how they are operating today.

The International Maritime Organization (IMO) found that in 2018, the shipping industry emitted around 3% of global greenhouse gases. In the same year, the International Council on Clean Transportation (ICCT) found that the aviation industry emitted 2.4% of global CO2 emissions – a figure that doesn’t even account for the non-CO2 effects of aviation.

These figures are set to increase significantly if decisive action to decarbonise the sectors isn’t taken. And a key element of these decarbonisation measures will be rolling out green hydrogen and DAC derived fuels. And fast.

2. Oil is out

Engineers have come up with promising solutions such as efficiency improvements, direct electrification where possible and disruptive propulsion technologies. These options can do a lot, but they can also only do so much. Rather than tinkering to make the use of oil more efficient, we need to focus all our efforts on deploying zero-emission technologies. Ultimately, the shipping and aviation sectors needs to address the issue at the source – and this means changing fuels.

Implementing sustainable fuels for aircraft and vessels will be instrumental in delivering these industries to net zero by 2050 (at the very latest!). Our launch report with Arup, to be released in September, addresses this exact issue. We found that for shipping, hydrogen, ammonia and methanol are the most promising sustainable fuel options, and for aviation, it’s synthetic kerosene.

In a recent Lloyd’s List decarbonisation survey, 18% of shipowners responded that direct hydrogen would be the most viable fuel option after 2030, with 13% opting for ammonia and 10% methanol (both of which require green hydrogen to be produced in their most sustainable forms).

This is already being seen in practice. In the Netherlands, the MS Antoine has been given the go-ahead. She is the first inland ship in the country to run on green hydrogen. In the skies, ZeroAvia are working to put hydrogen-electric engines in every aircraft, with a test flight being successful last month.

So it’s clear people agree with us that sustainable fuel is key. Green hydrogen (and its derivative fuels) will play a crucial role in decarbonisation of these industries.

3. Green hydrogen is in all future fuel pathways

Green hydrogen – produced using renewable electricity – will be included in ALL pathways for sustainable fuel. Our snazzy infographic demonstrates this:

*Radial diagram of green hydrogen as a universal feedstock.*

We need to take into account the full lifecycle of emissions, and green hydrogen is the only route that can produce zero or near-zero carbon fuels. In considering the full lifecycle impacts, it is also clear that only green hydrogen will produce truly sustainable fuels for these sectors, whether that be hydrogen, ammonia or methanol for shipping, or synthetic kerosene for aviation.

Industry agrees with us that green hydrogen is key, and investment in electrolysers (the technology used to separate hydrogen atoms) is booming. Green hydrogen production capacity is set to see a 50-fold increase in the next five years. Airbus expects green hydrogen to power its future zero-emission aircraft when it reaches the market by 2035, and Maersk is set to become a major green hydrogen consumer as it embraces methanol to fuel vessels.

Yet while it might look at first glance like we’re on track to have enough hydrogen projects to meet demand, the reality is that we’re still falling short. That’s why we need first movers like Airbus and Maersk from industry to send clear demand signals and ramp up the supply of hydrogen-derived fuels.

4. There are limited non-fossil fuel sources of CO2

Ah carbon. This notorious element is the climate world’s ex-partner – can’t live with it, can’t live without it. CO2 is still needed for synthetic kerosene and methanol. Notably, there are very limited sources of CO2 which are not reliant on fossil fuel. CO2 derived from DAC is one of those limited sources.

There are several methods of capturing CO2, and you might be wondering what the difference is between DAC and CCUS (carbon capture, utilisation and storage). The Congressional Research Service explains it well:

CCUS only works during the release of carbon during any process. A chemical that can “grab” CO2 is placed at the source of CO2. The captured CO2 is then released and compressed to be transferred by pipeline.
DAC does not need a simultaneous process. DAC removes CO2 which already exists in the atmosphere, no matter when the CO2 was released. Air is forced over a chemical than can “grab the CO2”.

In the spirit of reducing carbon emissions, we are pushing for a preference for DAC rather than the other method of CCUS. This will result in a more circular process without the need for more production of carbon. In shipping, aviation and other hard-to-abate sectors, carbon cannot be captured at the source – therefore, DAC is the preference.

5. Green hydrogen and DAC are clear solutions for regulators and policymakers

The final reason why shipping and aviation need green hydrogen and DAC is because regulations are already beginning to mandate the use of hydrogen derived fuels from as early as 2030. At the EU and UK level, regulations and policy commitments have already begun sending a message that these fuels will play a key role in decarbonising shipping and aviation:

Shipping

The FuelEU Maritime regulation aims to increase the demand for and consistent use of renewable and low-carbon fuels – and reduce the greenhouse gas emissions from – the shipping sector.
However, the regulation only includes a 2% renewable fuels usage target by 2034 if renewable fuels of non-biological origin amount to less than 1% in the fuel mix in 2031.
The UK’s 2019 Clean Maritime Plan also states that the vast majority of emission reductions will be achieved through a switch to low or zero-emission fuels, with “two low carbon hydrogen-derived fuels (ammonia and methanol), meeting the vast majority of energy demand by 2050”.
But, the UK government currently has no hard targets at all for shipping decarbonisation and is only looking to regulate for the domestic shipping sector.

Aviation

The FuelEU Aviation regulation mandates fuel suppliers to supply a minimum share of SAF at EU airports. This starts at 2% of overall fuel supplied by 2025, reaching 70% by 2050 – of which 35% must be synthetic fuels.
The UK committed to introduce a SAF mandate in 2025 requiring at least 10% of jet fuel to be made from sustainable feedstocks by 2030 released in 2022. While there’s currently no sub-mandate for the use of hydrogen-derived fuels, the UK government has recently consulted on introducing a PtL mandate.

While it is encouraging to see regulations mandating the use of hydrogen-derived fuels, stronger regulations are still needed to drive uptake of these fuels. They can and must go further if both industries are to achieve net zero by 2050.

It will of course be a challenge to scale up production of these alternative fuels. And, policymakers and regulators must recognise that green hydrogen and carbon dioxide from DAC will continue to be in limited supply in the coming decades and should therefore be targeted towards sectors such as shipping and aviation that have no more efficient routes to decarbonisation.

Hydrogen is marked to play a critical role in decarbonising a wide range of sectors. Because of these wide-ranging possibilities, there could be heavy competition for the green hydrogen as the industry develops. This is the likely global usage of hydrogen presented in a hierarchy according to other viable alternative decarbonisation pathways.

The SASHA Coalition is facilitated by Opportunity Green and aims to create clear and strong messaging around the vital role of green hydrogen and DAC in the decarbonisation of the aviation and shipping sectors. Find out more about the SASHA Coalition here.