Comparing Options to Electrify Heavy-Duty Vehicles: Findings of German Pilot Projects

Abstract

While the electrification of passenger vehicles is in full swing, for the decarbonization of heavy-duty trucks still various challenges exist. Especially the high energy consumption in combination with high daily driving ranges makes battery electric operation much more difficult than for passenger cars. Accordingly, a broad set of different drivetrains is discussed, inter alia hydrogen trucks, catenary hybrid trucks and synthetic fuels. One main advantage of the direct use of electricity in trucks is the high energy efficiency. Still, for heavy duty trucks different concepts for electrification do exist. Here, we compare battery electric trucks with a fast charging option, full electric catenary trucks and battery swap trucks. For a broad perspective, we use seven different comparative dimensions ranging from total cost of ownership to more qualitative but not less important aspects such as necessity of standardization, which would reduce manufacturer’s decision-making freedom. We base our comparison on findings from German pilot projects. While battery electric trucks or battery swap are advantageous since they can be operated in niche operations and thus allow a demand driven rollout of charging infrastructure, catenary infrastructure needs high investments upfront which entails financial risks, but allows for lowest cost if utilized to capacity.

Review and Evaluation of Automated Charging Technologies for Heavy-Duty Vehicles

“…However, they must be compatible with different vehicle systems [19]. The standardization of the batteries limits the innovative power and the flexibility of both the vehicle and the battery manufacturer, and the uniqueness and the design of the products [19,97]. Besides being standardized, the batteries must be robust, as they have to withstand frequent removals and installations [19].…”

“…The overhead contact line of the eHighway in Schleswig-Holstein, Germany, is depicted in Figure 8. To charge a vehicle via an overhead contact line, a pantograph must be installed on the roof [97]. As soon as the vehicle is located below the contact line, the arm of the pantograph extends and connects four carbon contact strips to the two contact wires [111] (see Figure 8).…”

“…If the supplied energy exceeds the energy required to propel the vehicle, a battery can be charged. This battery can then power the vehicle on non-electrified road sections [97]. It is important to notice that the power supplied to the vehicle is used to propel the vehicle and to charge the battery [112].…”

“…Additionally, frequent shallow charging with dynamic charging technologies is better than sporadic deep charging with static charging technologies regarding battery lifetime [116]. Another possibility lies in exploiting synergies with the static charging technology using a pantograph regarding, e.g., standardization [9,97]. Standards for dynamic charging technology using an overhead contact line are under development [110].…”

“…To determine the TRL for the dynamic charging technology using an overhead contact line for electric HDTs, the comparatively high number of research and demonstration projects employing the same technology, the already elapsed parts of the project durations, the many involved transport companies, the use of the operational environments and the ongoing testing has to be taken into account [12,97]. This indicates a TRL 7.…”