Daimler Trucks has presented its technology strategy for the electrification of its vehicles, and revealed its technology for hydrogen-based fuel cell trucks for long-haul transport. The Mercedes-Benz GenH2 Truck, which has premiered as a concept vehicle, marks the beginning of the company‘s use of fuel cell technology. 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. Daimler claims operating ranges of 1000km on a single tank of hydrogen.

Daimler Trucks also presented a preview of a purely battery-powered long-haul truck, the Mercedes-Benz eActros LongHaul, which is designed to cover regular journeys on plannable routes in an energy-efficient manner. Daimler Trucks plans to have the eActros LongHaul ready for series production in 2024. Its range on one battery charge will be approximately 500km.

Also displayed was the Mercedes-Benz eActros for distribution transport, originally presented in 2018, which has been tested intensively by customers in everyday transport operations. Daimler Trucks will start series production of a purely battery-powered heavy-duty truck next year. The range of the series-produced eActros on one battery charge will significantly exceed that of the prototype‘s approximately 200km.

“We are consistently pursuing our vision of CO2-neutral transport with a focus on the genuine locally CO2-neutral technologies battery power and hydrogen-based fuel cells, which have the potential to succeed in the market in the long term. This combination enables us to offer our customers the best vehicle options, depending on application. Battery power will be used for lower cargo weights and shorter distances. Fuel cell power will be the preferred option for heavier loads and longer distances,” said Martin Daum, chairman of the board of management of Daimler Truck AG.

“Our customers make rational purchasing decisions and are unwilling to compromise on their trucks‘ suitability for everyday use, tonnage and range. With our alternative drive concepts from Mercedes-Benz – the GenH2 Truck, the eActros LongHaul and the eActros – and our electric trucks of the Freightliner and FUSO brands, we have a clear focus on customer requirements and are creating genuine locally CO2-neutral alternatives for them.”

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 tonnes and a payload of 25 tonnes. Two special liquid hydrogen tanks and a particularly powerful fuel cell system will make this high payload and long range possible, and therefore form the core of the GenH2 Truck concept.

Liquid hydrogen enables applications with high energy throughput

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. 

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 combined storage capacity of 80kg. 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 2x150kW and the battery is to provide an additional 400kW temporarily. At 70kWh, 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. At the same time, the relatively light battery allows a higher payload. It is to be recharged 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, ensuring maximum durability. In a pre-series version, the two electric motors are designed for a total of 2x230kW continuous power and 2x330kW maximum power. Torque is 2x1577Nm and 2x2071Nm respectively.

Mercedes-Benz eActros LongHaul offers advantages depending on use case

The Mercedes-Benz eActros LongHaul battery-powered long-haul truck will be in the same vehicle class as the GenH2 truck. Its features will be largely identical to those of the series-produced GenH2 Truck or a conventional diesel truck. Daimler Trucks says the comparatively short range of the eActros LongHaul on one battery charge is offset by its high energy efficiency, as battery electric drive has the highest efficiency among alternative drive systems, offering transport companies significant advantages in the application scenarios envisaged for the eActros LongHaul due to its low energy costs. 

Daimler says many of the long-haul applications in the practical operations of transport companies do not require a range greater than the approximately 500km that the eActros LongHaul will be able to cover on one charge. In addition, legal requirements regarding truck drivers‘ driving times limit the need for longer ranges, and during their rest breaks, the battery can be charged with a large proportion of the energy needed for the ongoing journey. 

Charging infrastructure for eActros LongHaul can be available relatively soon

With its market launch in the middle of the decade, the eActros LongHaul will be available some time before the GenH2 Truck. The required infrastructure can also be set up sooner – and at comparatively low cost – by the transport companies themselves for charging at their depots. This depot charging is the most important step for the use of the eActros LongHaul, and means that the first areas of application can already be covered. 

Another key component is opportunity charging for range extension, for example, while unloading or loading when the electric truck is stationary. In the future, public charging at stations along main transport routes will also become increasingly important – a nationwide charging infrastructure will maximise the operating range of battery-electric trucks. New, more durable batteries will also contribute to the competitiveness of battery-electric trucks, reducing total cost of ownership over a vehicle‘s lifecycle. 

Modular ePowertrain for various markets and segments

Within the context of its global platform strategy, Daimler Trucks is also using a globally uniform basic architecture for all-electric trucks, the ePowertrain. The technological heart of the ePowertrain is, as a first step, the integrated electric drive, the eDrive. This is used in the form of an e-carrier concept – an e-axle with one or two integrated e-motors including transmission. 

The eDrive is an in-house development by Daimler and offers numerous advantages over concepts with one central motor. For example, the more compact design allows a larger space to install a larger battery with a higher capacity, which has a positive effect on range. The high battery capacity also ensures high power transmission to the e-axle, allowing continuous power delivery. The recuperation potential also increases due to the combination of a large battery with very powerful e-motors. 

The eDrive is to be applied in various vehicles at Daimler Trucks in the medium- and heavy-duty segment worldwide – whether with purely battery-electric or hydrogen-based fuel cell drive. The eDrive is designed as a drive family consisting of different variants, the first of which will have its premiere in the series-produced version of the Mercedes-Benz eActros. Within a modular system, the eDrive can be tailored to suit the market, segment and vehicle type. 

By the year 2022, Daimler Trucks‘ portfolio in its main sales regions – Europe, the USA and Japan – is to include series-produced vehicles with battery-electric drive. The company also has the ambition to offer only new vehicles that are CO2-neutral in driving operation (‘from tank to wheel‘) in Europe, North America and Japan by 2039.