Electric commercial vehicles have long been more than just a topic for the future—they are currently becoming a critical competitive factor for logistics, municipalities, and industry. In this interview, Dr. Frank Steinert explains why the total cost of ownership is shifting in favor of electric trucks, what role the right charging infrastructure plays, and why the Underbody Charging System is key to cost-effective depot charging.
There are several reasons why the topic of electrification is currently so high on the agendas of fleet operators. For one thing, the regulatory framework for purchasing electric trucks is very favorable at the moment—consider, for example, the toll exemption in Germany. Second, fuel prices have risen so dramatically in recent months and years due to the global political situation that electric vehicles have now become very attractive to logistics companies in terms of total cost of ownership. In addition, there have been significant developments in the manufacturer market over the past two years. Vehicles produced today have significantly longer ranges, and maintenance requirements have also decreased. This finally makes electrification a realistic option for operators. Many freight carriers have already purchased electric trucks and are finding that the transition is going smoothly; beyond the initial trial phase, they can certainly envision continuing to opt for electric vehicles for their next fleet.
This brings us to the exact point where we need to give more thought to the charging infrastructure. Thanks to developments in the passenger car sector, the public infrastructure will soon be ready to enable practical charging of electric trucks on the road. From an economic perspective, however, depot charging is of central importance—and this is where the underbody charging system offers a decisive advantage: not only can it transfer very large amounts of energy, but, more importantly, it does not require any additional space at the depot, since it is recessed into the ground in such a way that vehicles can simply drive right over it. There is no need to purchase additional land, and from a structural standpoint, the depot can remain as it is.
The roof pantograph is a charging system that we develope about 15 years ago for electric city buses. The primary requirement was to fully recharge the vehicle at the end of the line as quickly as possible during the drivers’ breaks, in time for the next cycle.
City buses offer the advantage of them all having a very similar design, regardless of the manufacturer. The roof is the lowest common denominator here, so it was clear to us that our charging system would have to be mounted on the roof and operate automatically at the push of a button. Our solution: A canopy with a multipole contact system is suspended above the bus on the roadside; the bus drives underneath it, the pantograph extends, and establishes a connection with the infrastructure. Through this principle, we struck a chord with the bus industry just as the topic of electric mobility in public transportation was gaining momentum. We demonstrated the entire system with the EDDA-Bus prototype vehicle in Dresden, which was met with enormous interest from numerous transport agencies and subsequently implemented in practice.
Building on the expertise we had developed in the areas of contact technology and automation, we then turned our attention to other industries where electrification plays a role. Our vision: Making the charging of electric vehicles as quick and easy as filling up a conventional gas tank.
Ideally, this solution should work for both passenger cars and all other vehicle categories—especially in the commercial vehicle sector, which has historically been our focus. And since the lack of space for charging infrastructure is a major challenge here, we realized early on that a solution with a laterally mounted plug connection was out of the question. This left us with only one option: charging from below—and tackling all the challenges that entails: water, dust, leaves, as well as the weight and proper positioning of the vehicle. Our researchers have succeeded in finding a viable solution for all the constraints involved in underbody charging, so that the system has now reached the point where it is market-ready.
Energy costs are a key factor in cost-effective operations, and efficient charging at depots plays a crucial role in this regard. Here, operators can charge their vehicles much more affordably than on highways or at public charging stations. This makes a system that meets charging needs right on the company’s own premises particularly attractive for hub-to-hub transport. This is particularly interesting, for example, for use cases in which vehicles shuttle between a company’s various locations, or in distribution operations: In these cases, a vehicle completes a daily route with its cargo and returns to the depot at the end of the workday to recharge.
Our numerous discussions with users have also shown that the space required for the charging infrastructure plays a particularlym important role: Every charging station means fewer parking spaces for the fleet. Compared to purchasing new land—which can be extremely expensive, especially in urban areas—purchasing a solution for charging from below is the more cost-effective and therefore preferred option for operators.
The short charging times we have achieved are accompanied by very high system voltages of up to 1,250 volts and high charging currents of 2,000 amps and more. Therefore, safety played an essential role in the development of the contact system—whether in terms of protection against accidental contact, preventing unintended overheating, or safeguarding the overall charging process control.
Standardization is extremely important for resolving the so-called "chicken-and-egg problem." This means that vehicle manufacturers will only integrate a technology if compatible charging infrastructure also exists and for which there is demand. At the same time, a new charging technology will only be implemented if there are vehicles on the market that use it for charging. Our institute, therefore, supports the development of these systems through active participation in standardization committees and industry associations at both the national and international level.
One thing is certain: There will be a standard for underbody charging that both vehicle and charging infrastructure manufacturers can rely on. It should be defined so that even very high charging capacities will be covered in the future. With our system, which achieves charging capacities of up to 4.5 megawatts, we are well on our way to playing a decisive role in shaping the global standard. Our industry partners are already benefiting from this today, as they are testing the system with us at an early stage and, as early adopters, are able to experience the future of charging firsthand.
We were surprised by how enthusiastic the drivers were about the technology and how quickly they got the hang of using the system. We had planned a training session on proper vehicle positioning to ensure that the positioning tolerance of the charging interface would not be exceeded.
However, the drivers were almost offended that we wanted to practice positioning the truck with them—on the very first try, all the test drivers parked the truck in the correct spot. Of course, this was also impressive proof or us that our system works as seamlessly as planned and does not require any costly training.
It won‘t get any easier than this!
Fraunhofer Institute for Transportation and Infrastructure Systems IVI