Why trucks are the hard end of decarbonisation

Most of the easy wins in transport decarbonisation are already being taken. Vans, buses and company cars are moving to battery electric at pace, because they mostly return to a depot each night and cover modest daily distances. Heavy goods vehicles are a different problem entirely. A 44-tonne articulated lorry running from a distribution centre in the Midlands to a depot in central Scotland may cover 400 miles in a shift, sometimes more, and it needs to be back on the road in the morning.

Battery electric trucks can do that work, but not without trade-offs. A long-haul tractor unit needs a battery pack in the region of 500 to 700 kWh to manage a realistic motorway range, and that pack weighs several tonnes. Every tonne of battery is a tonne of payload the operator cannot sell. Charging is the second issue: to turn a truck around in a reasonable break, you need megawatt-class charging, which means serious grid connections at depots and, eventually, at motorway service areas. Those connections take years and considerable capital to deliver.

Hydrogen fuel cells offer a different answer to the same question. In a fuel cell electric truck, electricity is generated on board from hydrogen stored in tanks, and the only tailpipe emission is water vapour.

How a fuel cell truck actually works

A fuel cell stack sits where a diesel engine would, producing electricity by combining hydrogen from the tanks with oxygen from the air. That electricity drives an electric motor, with a modest buffer battery to capture regenerative braking and smooth peak demand. Because the energy is carried as compressed gas rather than stored in a heavy pack, the powertrain is comparatively light.

The practical consequences matter more than the physics:

• Refuelling takes around 15 to 20 minutes, comparable to a diesel fill and far quicker than even the fastest battery charge.
• Range of 400 to 600 miles is achievable with 40 to 80 kg of hydrogen at 350 bar, depending on duty cycle, terrain and load.
• Payload is preserved, because the tanks and stack together weigh considerably less than an equivalent long-range battery.
• Depot disruption is limited, since no megawatt grid upgrade is required for the vehicles themselves, only for the hydrogen supply.

Fuel cells are less efficient than batteries well-to-wheel. A battery truck converts renewable electricity to motion at perhaps 70 to 80 per cent overall; a fuel cell truck manages roughly 45 to 55 per cent once electrolysis, compression and conversion losses are counted. That inefficiency is real, but it may be a price worth paying for vehicles that cannot practically be tethered to a charger for hours at a time.

The infrastructure gap is the binding constraint

Here is the honest position: the UK does not yet have a hydrogen refuelling network suitable for heavy goods vehicles. There are a small number of stations serving cars, buses and light fleets, but high-flow 350 bar dispensers capable of filling a truck quickly are rare. An operator cannot commit a fleet to a fuel that is only reliably available on one corridor.

This is a classic chicken-and-egg problem, and it is being addressed through clusters rather than a nationwide roll-out. The sensible approach is to build demand in concentrated pockets: a port, a logistics park, a major distribution corridor, an industrial cluster where hydrogen is already produced. Prove the model on a defined route, then extend it. Hydrogen hubs along the M6, around Teesside, in South Wales and near the major ports are the natural starting points, because that is where both the vehicles and the refuelling demand will sit first.

Green hydrogen is the other half of the problem

A fuel cell truck is only as clean as the hydrogen in its tanks. Most hydrogen produced today is derived from natural gas without carbon capture, and running a truck on it delivers limited climate benefit. Genuine decarbonisation requires green hydrogen, made by electrolysing water with renewable electricity, or blue hydrogen from gas with carbon capture and storage where the lifecycle emissions genuinely stack up.

Cost is the sticking point. Green hydrogen at the pump currently sits somewhere in the region of £6 to £9 per kilogram, and a truck will use roughly 7 to 9 kg per 100 miles loaded. That compares poorly with diesel on a pence-per-mile basis, even after accounting for fuel duty treatment and the fuel efficiency penalty of the alternative. Electrolyser costs, renewable power prices and utilisation rates all need to improve before the numbers work without subsidy.

Encouragingly, the direction of travel is clear. Government support for low-carbon hydrogen production capacity, allocation rounds for producers, and the zero emission vehicle mandate for new trucks give manufacturers and operators a reason to invest. The mandate phases in gradually, with smaller rigid trucks expected to lead and long-haul articulated units following later, which mirrors how the technology is likely to be deployed.

Where fuel cells make sense, and where they don't

Hydrogen is not a universal answer, and treating it as one would waste money. It suits vehicles that need long range, fast turnaround and maximum payload. It makes least sense for short-haul, back-to-base operations, where battery electric is simpler, cheaper to run and already viable.

So the practical split looks something like this:

• Long-haul articulated trucks on fixed trunking routes — strong fuel cell candidates.
• Regional distribution and urban delivery — battery electric, almost always.
• Construction, quarrying and agricultural haulage — promising for fuel cells, given high energy demands and remote sites.
• Refuse collection and municipal fleets — battery electric, with depot charging overnight.

What operators can do now

If you run a heavy fleet, the useful steps are modest but concrete. Map your routes and identify which could be served by a defined hydrogen corridor. Talk to your energy supplier and your local authority about hydrogen plans in your area, and ask whether your depot sits within a potential cluster. Trial one or two vehicles on a fixed duty cycle rather than committing a fleet, and measure real fuel consumption and uptime rather than relying on brochure figures.

Above all, keep the decision grounded in the route, not the technology. Hydrogen fuel cells will not decarbonise every lorry on British roads, but for the heaviest, longest-distance work, they remain one of the few credible options — fast to refuel, light enough to earn a living, and genuinely zero-emission at the point of use once the green fuel arrives in volume.