Mercedes GenH2 Fuel Cell Truck Prototypes Pass Summer Alpine Testing

Gerane

Daimler Truck has taken its GenH2 fuel cell truck prototypes into the Alps for high summer temperature trials. The company tested performance under steep gradients, heat stress, and altitude. Results show progress. Challenges remain. Here’s what the tests reveal—and what lies ahead for hydrogen heavy-duty trucking.

What Daimler Tested: Conditions and Objectives

The summer trials build on earlier winter tests. The goal was to evaluate how fuel cell systems, batteries, cooling, tank design, and controls work under hot Alpine conditions.

Key test conditions:

Location: Valais region, Swiss Alps, with passes between 600 and 2,478 meters elevation.
Prototypes: Four advanced development stage trucks of the next-generation GenH2 model.
Test duration: Several weeks during summer, following winter trials.
Focus areas: Thermal management, engine and fuel cell interaction, battery support, and vehicle controls.

Key Findings: What Worked

The Alpine trials highlighted several positive outcomes:

Thermal systems held up. Cooling and heating for fuel cell, battery, and e-axle managed ambient heat effectively. Software-controlled cruise systems optimized energy use on climbs and descents.
Fuel cell and battery collaboration proved reliable. The battery handled peak loads, while the fuel cell delivered sustained power. Energy recuperation during downhill driving and braking reduced waste.
Reliable performance under load. Trucks carried gross vehicle weight up to 40 tons, tackling climbs of 10-12% grade with thousands of meters of elevation.
Refuelling logistics viable for testing. Daimler used mobile hydrogen stations and liquid hydrogen tanks, allowing consistent refuelling for prototypes.

Remaining Challenges

While the tests confirmed many strengths, several areas still require more evidence before commercial rollout.

Extreme Heat Performance
Alpine summers reach high temperatures, but sustained desert-like heat at 40-45°C still presents risks. Cooling, hydrogen tank insulation, and electronics must be tested under harsher climates.
Range in Hot Conditions
Extra cooling demands reduce range. Daimler has yet to publish hydrogen consumption data per 100 km under heavy load and high heat.
Hydrogen Supply and Refuelling Infrastructure
Mobile refuelling works for trials but not fleets. Permanent liquid hydrogen stations, large-scale distribution, and reliable storage remain unresolved.
Cost and Durability
Long-term maintenance costs and durability under thermal cycling remain open questions. Hydrogen production, storage, and delivery costs will directly affect fleet adoption.

Broader Context: GenH2 Trials and Policy Support

The Alpine program is part of Daimler’s larger hydrogen push.

Over 225,000 km in customer trials already logged by GenH2 trucks in Europe.
Range over 1,000 km and refuelling times of 10–15 minutes demonstrated in earlier testing.
Public funding of $245–260 million USD secured from German federal and regional governments to develop, produce, and deploy 100 hydrogen trucks.
Small series production of GenH2 trucks planned for late 2026 at Daimler’s Wörth plant.

Implications for Operators and Supply Chains

If Mercedes GenH2 scale-up succeeds, it could shift logistics and emissions strategies for global freight operators.

Long-haul fleets stand to benefit the most, particularly those running routes with heavy loads and limited charging infrastructure.
Governments and regulators will need to support refuelling infrastructure, safety standards for liquid hydrogen, and green hydrogen production.
Suppliers of fuel cells, hydrogen tanks, and thermal systems will become essential. Their ability to guarantee durability under heat will influence adoption.
Total cost of ownership will determine success. Even if purchase costs are high, savings in fuel, emissions compliance, and maintenance must balance the equation.

What to Watch Next

The transition from trial to market hinges on several critical areas:

Data from extreme heat trials in desert and coastal regions at 45–50°C.
Published figures for hydrogen consumption per 100 km under varied loads and climates.
Expansion of liquid hydrogen refuelling stations across key freight corridors.
Long-term degradation data for fuel cells, tanks, and power electronics under thermal stress.
Cost comparisons with battery-electric trucks and efficient diesel models when factoring in hydrogen production and operating costs.

Verdict

The summer Alpine program shows that Daimler’s GenH2 fuel cell trucks can deliver consistent performance in hot, high-altitude environments. Trucks handled heavy loads, steep climbs, and complex energy management without major issues.

The technology appears ready for pilot deployment. But large-scale adoption depends on hydrogen availability, cost competitiveness, and durability under extreme heat. If infrastructure and economics align, hydrogen fuel cell trucks could become viable zero-emission options for long-haul freight in the late 2020s and early 2030s.

Fleet managers should monitor results closely, update procurement models to include hydrogen options, and engage with infrastructure initiatives now.