Long-distance road haulage is a significant cause of the continued increase of CO2 emissions in the transport sector. “If we were able to begin by electrifying just a few vehicles, the high mileage of these vehicles alone would create a significant absolute impact,” says Professor Dr. Stefanie Marker, head of the Chair of Naturalistic Driving Observation for Energetic Optimisation and Accident Avoidance at TU Berlin.
Together with other research institutions as well as partners from logistics, systems technology, software, automotive engineering, and the energy sector, Professor Marker has now successfully acquired approximately 6.5 million euros for the eHaul project. The funding comes from the Federal Ministry for Economic Affairs and Energy with further financial input provided by partner organizations. The goal is to develop an automated battery exchange station for electric heavy goods vehicles.
Professor Stefanie Marker’s research focuses on the energy optimization of electric vehicles. In her latest project, she turns her attention to very large heavy goods vehicles: juggernauts weighing up to 40 tons. “Unfortunately, there are currently still not so many electric vehicles in this category as they are generally only built to order. However, it makes particular sense to test out the possibility of electrifying fleets of such vehicles,” says Marker. There is, however, a problem: The majority of these heavy goods vehicles are used for journeys of distances which cannot be covered by a single battery charge. “Haulage companies also can’t afford to lose hours waiting for a battery to charge,” Marker adds. However, she does have a solution for this problem: a network of battery exchange stations for heavy goods vehicles. They would just have to drive in, exchange the battery and continue on their way. At first glance a seductively simple solution. “In reality, what we are missing is a feasibility study”, says Jens-Olav Jerratsch, team leader in Professor Marker’s research group and project leader for the joint project.
As part of the new project, which will run for three years until the end of September 2023, the consortium is now commissioning two electrified trucks for subsequent regular use by two logistics companies. Additionally, a battery exchange station is being developed in south Berlin to be used by haulers as part of their regular delivery operations. The goal is to provide a fully automated battery exchange. Upon arrival at the station, the spent battery is removed from the vehicle by a specially developed robot and exchanged for a fully charged battery. This can all be done in a matter of minutes with no need for time-consuming interruptions to charge batteries. “Both vehicles are fitted with a number of sensors to record data affecting energy consumption during regular operations: the energy consumption of the engine, the load, the weather, the altitude profile of the route, secondary energy consumption such as air conditioning in the driver's cabin as well as the energy required to maintain cargo hold temperatures,” says Marker.
“In a real-life test, we then want to determine whether 40-ton electric trucks with exchangeable batteries are actually a viable alternative, including when daily trips of more than 300 kilometers are involved.
“In the passenger car sector, battery electric powertrains are currently gaining ground. This is not yet the case to the same extent for trucks. Many trucks drive distances of several hundred kilometers every day, so we need a solution which still makes this possible. Battery electric solutions have to compete with other approaches, such as hydrogen technology. “We are examining the option of battery exchange as it is not possible to keep making bigger batteries without negatively affecting other consumption factors. Other options include fast charging, which is already used for passenger cars. For trucks, however, this would require a very high charging capacity - in effect you would need to build a power station next to the charging station - particularly as regular operations would require several trucks to be charged simultaneously,” Jerratsch explains.
Another problem is that fast charging has a negative impact on battery durability. “Developing a network of exchange stations could provide a viable alternative. However, there are a number of challenges involved here, too. We will be examining how to mount and bond batteries to trucks to enable a fast and easy exchange,” says Jerratsch. In the long term, another challenge lies in standardizing exchangeable batteries so as to enable cost-effective, modular battery exchange on a larger scale. However, given the limited number of truck models, this represents less of a problem than for passenger cars.
“Our work in the project also focuses on economic aspects as well as technical and energy consumption data: How to develop a system that makes it possible to provide a cost-effective and real alternative for the logistics branch,” concludes Marker.