The Mercedes-Benz GenH2 Truck, with hydrogen-powered fuel-cells, was put through some rigorous testing in the third week of May. With the GenH2 Truck, which has been designed from the ground up, Mercedes-Benz aims to achieve a range of up to 1,000 kilometres without stopping to refuel.
The truck features new components, which the developers are focusing on during the tests. These components include the fuel-cell system, the all-electric powertrain, and other associated systems such as the special cooling unit.
As a new worldwide modular platform architecture, the ePowertrain will be the technological basis of all medium- and heavy-duty CO2-neutral, all-electric series-produced trucks from Daimler Trucks – whether powered purely by batteries or by hydrogen-based fuel cells. It will feature high levels of performance, efficiency and durability. With the ePowertrain, Daimler Trucks plans to achieve synergies and economies of scale for all relevant vehicles and markets.
Martin Daum, CEO of Daimler Truck AG, said, “We are consistently pursuing our technology strategy for the electrification of our trucks. We’re right on schedule, and I’m delighted that the rigorous testing of the GenH2 Truck has started successfully.”
GenH2 Truck was unveiled as a concept vehicle in September 2020. The GenH2 Truck revealed which specific technologies Daimler Trucks is driving forward so that heavy-duty fuel-cell trucks can perform flexible and demanding long-distance haulage operations with a range of up to 1,000 kilometres, and more, on a single tank of hydrogen.
Daimler Trucks plans to begin customer trials of the GenH2 Truck in 2023; series production is to start in the second half of the decade. Thanks to the use of liquid instead of gaseous hydrogen with its higher energy density, the vehicle’s performance is planned to equal that of a comparable conventional diesel truck.
GenH2 Truck vis-a-vis conventional long-haul truck
The development engineers at Daimler Trucks have based the GenH2 Truck on the capabilities of the conventional Mercedes-Benz Actros long-haul truck with regard to tractive power, range, and performance. For example, the series-production version of the GenH2 Truck is to have a gross vehicle weight of 40 tons and a payload of 25 tons. Two special liquid-hydrogen tanks and a particularly powerful fuel-cell system will make this high payload and long range possible.
Daimler experts can draw on existing expertise for the development of liquid-hydrogen tanks, and they are also cooperating closely with a partner. With regard to fuel cells, the manufacturer benefits from its experts’ decades of experience, in terms of technology as well as production methods and processes.
In April this year, Daimler Truck AG concluded a preliminary, non-binding agreement with the Volvo Group to establish a new joint venture for the development to series maturity, production and commercialisation of fuel-cell systems for use in heavy-duty commercial vehicles and other applications. Joining forces will decrease development costs for both companies and accelerate the market introduction of fuel cell systems.
Use of liquid hydrogen
Daimler Trucks prefers to use liquid hydrogen (LH2), because in this state, the energy carrier has a far higher energy density in relation to volume than gaseous hydrogen. As a result, the tanks of a fuel-cell truck using liquid hydrogen are much smaller and, due to the lower pressure, significantly lighter. This gives the trucks a larger cargo space and higher payload weight.
At the same time, more hydrogen can be carried, which significantly increases the trucks’ range.
This makes the series GenH2 Truck, like conventional diesel trucks, suitable for multi-day, difficult to plan long-haul transport and where the daily energy throughput is high.
Daimler Trucks is currently pressing ahead with the development of the necessary tank-system technologies to make liquid hydrogen usable also in mobile applications as an energy source for series-produced fuel-cell trucks. The storage of cryogenic liquid hydrogen at -253 degrees Celsius is already common practice in stationary applications, for example in industry or at hydrogen filling stations. This also applies to the transport of liquid hydrogen as cargo.
Interaction between battery and fuel-cell systems
The two stainless-steel liquid-hydrogen tanks intended for the series version of the GenH2 Truck will have a particularly high storage capacity of 80 kilograms (40 kg each) for covering long distances. The stainless-steel tank system consists of two tubes, one within the other, that are connected to each other and vacuum-insulated.
In the series version of the GenH2 Truck, the fuel-cell system is to supply 2 x 150 kilowatts and the battery is to provide an additional 400 kW temporarily. At 70 kWh, the storage capacity of the battery is relatively low, as it is not intended to meet energy needs, but mainly to be switched on to provide situational power support for the fuel cell, for example during peak loads while accelerating or while driving uphill fully loaded.
At the same time, the relatively light battery allows a higher payload. It is to be recharged in series-production vehicles with braking energy and excess fuel-cell energy. A core element of the sophisticated operating strategy of the fuel-cell and battery system is a cooling and heating system that keeps all components at the ideal operating temperature, thus ensuring maximum durability.
In a pre-series version, the two electric motors are designed for a total of 2 x 230 kW continuous power and 2 x 330 kW maximum power. Torque is 2 x 1577 Nm and 2 x 2071 Nm respectively.
Daimler Trucks presents technology strategy for electrification – world premiere of Mercedes-Benz fuel-cell concept truck.