Leinfelden-Echterdingen, Germany – Following successful winter testing, Daimler Truck has returned to the Swiss Alps for summer testing with four advanced prototypes of the next generation of its Mercedes-Benz GenH2 Truck. The region of Valais, with its demanding mountain passes ranging from 600 to 2,478 meters in elevation – some only accessible in summer – offered ideal test conditions. The combination of high summer temperatures of more than 35 degrees Celsius and the thin mountain air on these particularly demanding route profiles pushes vehicles to their limits in terms of cooling performance and thermal management. The objective was to validate reliable operation under these extreme conditions and to gain valuable insights for the ongoing development and future deployment of these vehicles in everyday operations.

Specifically, the development team tested driving behaviour and dynamics, the performance of the electric drivetrain, thermal management and the interaction between the fuel cell, battery and tank system under real load peaks. Moreover, further development of the digital assistance system Predictive Powertrain Control (PPC) for fuel cell trucks was another focus area. Geobased route data helps the system recognize upcoming inclines several kilometers ahead. This enables the vehicles to tackle gradients proactively and optimize power delivery accordingly. The fuel cell then increases its performance in time, charges the high-voltage battery as needed and ensures that sufficient power is available for ascents at the best possible efficiency – even on the demanding mountain passes of the Alps. The fuel cell trucks were refueled with liquid hydrogen using a mobile hydrogen refuelling station from Air Products (sLH2 standard), which was set up at the test base in Vailais during the trials.

Over the course of several weeks, the test vehicles covered more than 10,000 kilometers and climbed a total of 146,000 meters in elevation, confirming the advanced maturity and performance capabilities of the next generation fuel cell trucks. After the extreme testing, the systems also demonstrated stable and reliable performance even under the challenging conditions of the Alps. The data obtained flows directly into further development and brings the vehicles one step closer to series production maturity.

The next step will be to build a small series of 100 of these advanced semitrailer tractors at the Mercedes-Benz plant in Woerth (Germany), with real-world operation at various customers scheduled to start end of 2026. Large-scale industrialisation of fuel cell technology and series production of hydrogen-powered trucks with a focus on Europe are planned for the early 2030s.