• 3 August 2023
  • E-Mobility

Talking Transport Transformation: The future of trolley bus systems with Adrian Kobayashi

Public transport in the western German city of Solingen dates all the way back to 1897, when, like many European cities, there were electric tramways using raillines embedded in the streets. Though much of the rail infrastructure was destroyed during World War II, the electrical lines remained, providing the basis for an electrical infrastructure that gave way to a hybrid tramway/bus line. Like many cities in Germany during the reconstruction period, Solingen began operating a system of trolley buses that continues to be in use today. 

Although diesel buses grew popular in the 1970s and many cities moved away from trolley buses, which can only run on limited routes due to the overhead electrical wires, Solingen maintained its trolley bus system — and in so doing, paved the way for the bus electrification project that Adrian Kobayashi, director of planning at Solingen’s municipal transport operator, is overseeing today.  

That project will see Solingen switch out their bus fleet to an electrified trolley bus system; while battery-run buses may offer the same flexibility that diesel buses have done as they don’t need the buses to follow electric wires, Solingen already has the electrical infrastructure for a trolley system, which lowers the up-front investment costs. “The main objective of every bus operator is to electrify their fleet,” says Adrian, who says that the quickest and most efficient way to use renewable energy is through direct electrical consumption and that requires a bit of a mindset shift away from the fully flexible diesel route many have grown accustomed to.

“Unfortunately, we do not have the bus that completely replaces a diesel bus with as little impact as possible on operations.” 

Yet Solingen’s trolley bus system benefits from the existing network of chargers spread out throughout the city. With extended capacities and the ability to charge without returning to a depot, they’ll be looking at replacing diesel buses with electric on a scale of 1-1. While the electric trolley bus network is not for every city, there are nearly 300 cities around the world who have the infrastructure in place to make it possible. For those that don’t, a trolley bus system may be more expensive an investment up front, due to infrastructure costs. And one of the biggest challenges beyond the costs comes from the planning. That’s something Adrian has firsthand experience with. Listen to our podcast episode with Adrian Kobayashi here to find out more about how Solingen has made their trolley bus system fit for the future and to learn more about the planning challenges they’ve faced.