Report: Hydrogen Internal Combustion Engines in Europe’s Road Mobility Decarbonisation

Executive Summary

Hydrogen internal combustion engine vehicles (H₂-ICEVs) have recently seen increased interest, culminating in their classification as zero-emission vehicles (ZEVs) under the updated Heavy-Duty Vehicles CO₂ standards in May 2024 (1). 

H₂-ICEVs present opportunities to accelerate European zero-emission vehicle deployment and support the roll-out of hydrogen-refuelling infrastructure to meet the 2030 Alternative Fuels Infrastructure Regulation (AFIR) targets, by building on the existing experience of the automotive sector with ICE vehicles.

H₂-ICEVs are similar to their diesel equivalents, enabling OEMs to repurpose existing manufacturing infrastructure, supply chains, and engineering knowledge. As a result, H₂-ICEVs are projected to be the least capital-intensive zero-emission technology until BEV and FCEV markets reach higher maturity. The similarity between hydrogen and diesel combustion engines may also normalize the use of hydrogen fuel, supporting the roll-out of FCEVs among end users in the future.

While some in the automotive sector see the role of H₂-ICEVs as a transition technology towards FCEVs, H₂-ICEVs are now also being considered as one of the zero-emission technologies of choice for certain, particularly high-load applications over a range of distances. For specific heavy-load road and non-road mobile machinery (NRMM) applications, H₂-ICEVs offer high efficiency and robustness compared with alternative zero-emission technologies.

While H₂-ICEVs can offer higher fuel efficiency in certain heavy-load on-road and off-road applications, fuel cell electric vehicles (FCEVs) remain the more fuel-efficient solution under typical road conditions and at lower loads. H₂-ICEVs are nonetheless expected to play an important role in the heavy-duty road transport sector. Building on the existing fossil-fuel ICE manufacturing base, H₂-ICEVs are expected to be manufactured at scale before the end of the decade.

As such, H₂-ICEVs will be important offtakers from Europe’s first HRS networks and may present fuel suppliers with an opportunity to accelerate the roll-out of a broader HRS network. H₂-ICEVs and components can be locally produced, bolstering Europe's industry, supply chains, and skilled employment while also enhancing its regional autonomy.

Despite the opportunities presented by H₂-ICEVs and their classification as ZEVs, H₂-ICEVs are not yet classified equally with other zero-emission truck technologies. H₂-ICEVs have been excluded from incentivising mechanisms and, in some EU Member States, remain unable to refuel from existing HRS infrastructure due to existing energy taxation legislation (Regulation (EU) 2024/1610).

To support H₂-ICEV deployment and accelerate decarbonisation, European policymakers must:

• Ensure that hydrogen ICEVs are classified as zero-emission vehicles across all EU Member States.

• Ensure equal treatment of zero-emission vehicle technologies. Hydrogen ICEs should be subject to the same incentives as other zero-emission technologies and must not be excluded from funding schemes for research or deployment of vehicles.

  • Ensure that hydrogen used in an H₂-ICEV is subject to the same taxation and exemptions as hydrogen used in a FCEV, allowing both vehicles to refuel from the same HRS infrastructure.

  • Ensure that hydrogen trucks are included as eligible technologies for national and European zero-emission vehicle deployment projects.

  • Ensure Member States treat H₂-ICEVs and FCEVs equally when implementing RED II / RED III certificates.

  • Research projects into hydrogen combustion engines should continue to be funded by European funding schemes such as Horizon Europe.

H₂-ICEVs present a significant opportunity for Europe to deploy a zero-emission technology at scale before the end of the decade, building on existing expertise and maintenance base for fuel trucks. To pursue this opportunity, European policymakers must ensure that H₂-ICEVs receive equivalent subsidies and support as alternative zero-emission vehicles, namely fuel cell and battery electric vehicles.

(1) Regulation (EU) 2024/1610