London, UK: Hydrogen fuel cells powering electric motors have been touted as the environmental solution for heavy trucks. Fuel cells tick all the boxes: they reduce weight and extend the range of trucks. But making the change from diesel to fuel cell is expensive requiring new truck systems.
Electric batteries are a non starter for heavy trucks and especially for long haul operations so some intermediate technology is need and many, including Volvo, Iveco, Daf, and MAN, see reworking existing diesel engines to run on low-emission hydrogen instead of polluting diesel, as quicker low-cost fix to the energy transition challenge.
In its first pilot project, MAN will deliver some 200 trucks with engines that run on hydrogen to European customers next year to test prior to mass production.
MAN has had a truck prototype powered by a hydrogen combustion engine since 2021. The core element is a 16.8 litre hydrogen engine with a power of over 50 hp and 2,500Nm of torque based on the modular diesel engine system. The expected service life is comparable to that of conventional diesel engines – even when using low-grade hydrogen. The integration of hydrogen pressure tanks into existing vehicle concepts enables a range comparable to that of a conventional vehicle with the same payload, Man says.
Hydrogen fuel cells remain a longer term goal for truck makers but both technologies an exist side by side for different vehicle types and uses, Volvo says. It will have hydrogen fuel cell trucks “commercially available in the second half of this decade,” but is also is planning customer tests of hydrogen combustion engine models in 2026.
Hydrogen combustion engines “will not be the majority” of Volvo’s sales, said chief technology officer Lars Stenqvist. “But it will be a substantial volume.”
Anders Johansson, vice president for heavy-duty vehicles at Vancouver-based Westport Fuel Systems, said his company has already provided fuelling systems for 6,000 combustion engine trucks in Europe that run on natural gas or biogas and can easily be adapted to hydrogen. There are still challenges to overcome despite the relative maturity of the technology.
Burning hydrogen in an engine can produce some harmful emissions that Michael Krueger, senior vice president for engineering at Bosch says will require a filter. Westport’s engine system currently uses 1% diesel to ignite hydrogen, which Johansson said will be reduced and eventually be replaced with a carbon-free fuel.
Hydrogen needs to be pressurised so fuel tanks need to be larger and far stronger than the typical diesel fuel tank. There is also the safety issue: hydrogen is immensely more flammable than diesel.
But, as with fuel cells ,the current stumbling block remans green hydrogen availability. The European Union and the United States government, as well as Daimler are funding green hydrogen projects but it will take years to build up sufficient large fuelling infrastructure.
What is stacked in favour of hydrogen fuelled engines is that truck makers already have factories and supply chains dedicated to the technology. And there is the advantage for operators, since unlike fuel cells, it’s a technology they are familiar with.
