INDUSTRY FOCUS: Alternative Propulsion Systems
Bonn’s municipal transport operator SWB Bus und Bahn has started revenue service with its first three battery-electric articulated buses. The buses are the “Urbino 18 electric” of Polish manufacturer Solaris which belongs to the Spanish CAF Group.
The ebuses are the first Solaris in the history of the Bonn bus company (founded in August 1925), but they are not SWB’s first electric buses. At the beginning of 2016, there were already six 12-metre electric buses on the road, followed by a seventh one at the beginning of 2018. SWB argues they had one problem: they did not provide the range that the manufacturer had promised. That’s why they were returned to the manufacturer altogether, the last two at the beginning of 2019.
Now we see a “new start” with electric buses in Bonn. Anja Wenmakers, managing director of SWB Bus und Bahn, says: “The future is electric. We are sticking to the plan to gradually convert the bus fleet to emission-free and comfortable buses that are powered locally CO2-neutral and quiet.” And they will do so with “green energy”, i.e. electricity from renewable sources.
Solaris guarantees an autonomy of at least 200 kilometres without recharging during the expected minimum service life of 12 years. Solaris relies on a new generation of lithium-ion batteries, called “high-energy batteries”. Their capacity is more than 550 kWh. This should enable the required range under any circumstances, regardless of the road and weather conditions and regardless of whether heating or air conditioning is running and how busy the buses are.
The electric buses are driven on the third axle. This is the AVE 130 electric portal axle from ZF, in which two electric motors with an output of 125 kW each are integrated. In contrast to the earlier Bonn electric buses, the new Solaris vehicles are heated and air-conditioned exclusively electrically; the air-conditioning system uses a heat pump.
SWB has installed a new charging infrastructure at its Friesdorf depot in recent months. The cars are charged here overnight using CCS combo plugs (over-night charging). The system is designed in such a way that all electric buses, regardless of their respective manufacturers, can be charged here with direct current.
And one thing is particularly important to Bonn’s SWB: “Because we don’t have to recharge our electric buses en route during the day, each of our electric buses can also be used completely freely on any of our routes.”