Efficiency wins the miles – hydrogen’s role in heavy-duty transport

There’s an appealing logic to the idea that putting hydrogen into an internal combustion engine (ICE) could be a quick way to get cleaner trucks on the road - it reuses familiar manufacturing, service, and vehicle architectures, and it creates immediate hydrogen demand to grow refuelling networks. It points to the urgency everyone shares to scale hydrogen supply and get emissions down.

But if the objective is sustainable decarbonization at the lowest lifetime cost, the physics and economics pull in a different direction. The distinction that matters isn’t familiar or new technology; it’s how many kilograms of hydrogen are consumed to move a ton of freight per kilometer, what that means for operating cost and logistics, and how resilient the solution is to tightening emissions legislation and rising utilization expectations.

Fuel cell systems convert chemical energy to electrical power with far higher conversion efficiency than combustion engines. Typical proton-exchange membrane (PEM) fuel cell stack systems operate with stack efficiencies in the high forties to mid-fifties, and – when integrated into an electric drivetrain – they benefit from regenerative braking and far fewer mechanical losses than ICE architecture. This results in materially lower hydrogen consumption for the same duty cycle.

Transitional — or a distraction?

It’s common to frame hydrogen combustion as a pragmatic bridge: something to pull hydrogen demand forward while fuel cell manufacturing and infrastructure scale. However, it can obscure a critical risk - transitional choices that look economical in the short term can become a false economy and a distraction if they delay the investments that serve to make the more efficient solution mainstream.

In practice, early hydrogen demand absorbed by higher-consuming combustion vehicles can distort market signals and slow fuel cell scale-up. Infrastructure optimized for those vehicles reinforces the imbalance, favoring volume over efficiency, while capital sunk into retooled combustion lines and service networks becomes hard to repurpose.

"Lower hydrogen consumption is not a trivial matter - it’s the single largest lever available to a fleet operator already working with thin margins. Every percent of fuel saved reduces the volume of hydrogen to procure, store and distribute; it reduces refuelling throughput constraints at stations; and it reduces exposure to volatile commodity prices. In Ballard’s modelling, the differential is meaningful: hydrogen consumed by combustion systems is typically 20–30% higher than by fuel cell electric drivetrains across comparable heavy-duty cycles."

Nicolas Pocard Vice President, Marketing & Strategic Partnerships, Ballard

Complexity is cost

Complexity and durability are the next pair of pragmatic considerations. A combustion power plant, even one designed for hydrogen, inherits the drivetrain architecture of a legacy ICE: lubrication systems, high-temperature components, precision machining, and after-treatment hardware. This adds complexity – bringing more moving parts, more attention to materials compatibility with hydrogen (embrittlement and oxidation) – and opens questions around component lifetimes that matter for fleet uptime (for example, current injector lifetimes in H2ICE are short relative to the expectations of a long-haul operator).

Simplicity scales – fewer parts, fewer problems

By contrast, fuel cell engines are inherently simpler as a subsystem: fewer moving parts,lower operating temperatures, no lubrication circuit, and an exhaust stream that is essentially water vapors. Their simpler subsystems scale into automated manufacturing more readily; they produce fewer failure modes in the field and, therefore, present a clearer pathway to lower maintenance and higher availability as volumes increase. Put simply: complexity is cost.

Cost trajectories also matter. Today, fuel cell systems carry a capital expenditure (CAPEX) premium versus mature diesel powertrains. But that premium is a function of scale, not physics - and scale economics are real. Ballard’s fleet modelling indicates that, with reasonable assumptions on manufacturing scale and fuel cell cost decline, fuel cell solutions can reach parity with H2ICE alternatives within a few years in long-haul applications. This crossover is driven by continuing reductions in fuel cell engine cost and the persistent sensitivity of total cost of ownership (TCO) to fuel consumption.

There are also regulatory realities to consider. Combustion, even of pure hydrogen, produces species and particulates that require after-treatment and may face tightening urban and corridor emissions rules. The certainty of “true zero-tailpipe” that comes with a fuel cell electric driveline simplifies long-term compliance planning and reduces the risk of stranded or redundant assets as local and national policies evolve.

Practical steps for a pragmatic solution

So where does this leave practical action? A few clear, non-ideological takeaways:

The transition to sustainable freight: Align physics, economics, and policy

The transition to sustainable freight is complex and multidimensional: technology choice, hydrogen supply, station economics and fleet operations all interact. My experience is that the best decisions come from aligning the physics (efficiency), the economics (fuel and service cost), and the regulatory horizon (future proofing). For the majority of on-road heavy-duty applications that must optimize fuel use, uptime and regulatory certainty, the balance of advantages – fewer parts, higher efficiency, a clearer path to manufacturing scale and lower lifecycle emissions – point to fuel cell electric drivetrains as the most practical way to deliver zero-emission trucking at scale.

We should use every early adopter and pilot to learn faster about hydrogen supply logistics, station economics, and real-world duty cycles, but not lose sight of the metric that ultimately matters: how many kilograms of low-carbon hydrogen do we need to keep the freight lanes moving, and which architecture uses those kilograms most effectively? The cleaner, simpler, more efficient path wins the miles.