Mercedes: H2-ICE Is Ready for Primetime in Commercial Trucks

Mercedes-Benz and Mörtlbauer collaborate on a demonstration project to show that hydrogen combustion is a viable path to commercial truck decarbonization.

August 21, 2024

Matt Wolfe

The prototype vehicles are both being tested to verify driving and refueling operations at the Mörtlbauer factory in Fürstenzell, Bavaria. (Mercedes-Benz)

Mercedes-Benz has unveiled a pair of prototypes powered by hydrogen combustion engines that were created in collaboration with Mörtlbauer Baumaschinen Vertriebs. The prototypes are part of the “WaVe” development project to research hydrogen combustion engines for special-purpose vehicles.

The Mercedes H2 prototype vehicles were created in collaboration with Mörtlbauer Baumaschinen Vertriebs. (Mercedes-Benz)

The WaVe project is a publicly funded program by Germany’s Federal Ministry for Economic Affairs and Climate Action. It consists of 18 partners ranging from industry and science experts and began in July 2021. Development work on the prototypes began in mid-2022. The main objective of the WaVe project was to develop a hydrogen-based drive system for working machines that demonstrated the practicality of replacing diesel-fueled trucks.

Currently they are both being tested in the field to verify driving and refueling operations. The Unimog test vehicle and crawler were tested at the Mörtlbauer factory in Fürstenzell, Bavaria. The dump truck crawler was put into operation in spring 2024.

“After numerous test deployments, emission measurements and technical fine-tuning, we are convinced that hydrogen combustion for work machines with high power requirements, both for driving and for powering auxiliary drives, is worthwhile, practical and very low in emissions,” said Franziska Cusumano, head of Mercedes-Benz Special Trucks.

Armin Mörtlbauer, managing director of Mörtlbauer, said in a statement: “The fact that our crawler and the Mercedes-Benz Special Trucks Unimog can be easily refueled with gaseous hydrogen and that these vehicles also work reliably when using implements is the result of the outstanding cooperation in this research partnership…However, to apply these in series production, we have to go even further on this path. If the government and society choose to follow the path toward hydrogen combustion engines, we are ready to go.”

The Unimog and crawler were equipped with medium-duty engines that were converted for hydrogen propulsion. (Mercedes-Benz)

The converted Unimog U 430 implement carrier transported the crawler on a low loader to the Mörtlbauer factory. Developers reportedly demonstrated the refueling process at a mobile hydrogen refueling station as well as implement operation with a front-mounted sweeper from Schmidt.

Tests were also conducted to ensure the viability of the PTO system while driving. These systems require sustained high-power output, which Mercedes states the hydrogen combustion engine is well-suited for. The Unimog and crawler were equipped with medium-duty engines that were converted for hydrogen propulsion. This conversion included specialized pistons, a hydrogen-compatible intake system and an optimized ignition system.

The Unimog was equipped with four TÜV-certified, 700-bar (10,152-psi) high-pressure tanks that hold roughly 13 kg (28.6 lb.) of gaseous hydrogen in total. The engine delivers around 290 hp (216 kW) and was operated with several different attachments to demonstrate all potential use cases. The crawler dumper’s engine had a similar output and a slightly higher H2 capacity.