Obtaining an order with such a highly innovative character with regard to improving fuel economy and reducing harmful emissions proves that VDL, with all its developments, leads the market," said Willem van der Leegte, Supervisor of VDL Bus & Coach Belgium. The delivery is scheduled for autumn 2014. The vehicles will be put in service in various cities in
Flanders.
VDL Citea SLF-120 Hybrid
The VDL Citea SLF-120 Hybrid is a next-generation serial hybrid bus. For this new generation we have improved available techniques and employed new technologies. The vehicles for De Lijn are equipped with a serial hybrid system from Siemens (ELFA) and a 4.5-litre Euro 6 diesel engine from Cummins. The rear axle is driven by an electric motor for which the electric current either comes from the battery pack, in which case it is purely electric-powered, or the diesel generator.
When the diesel engine is running, this charges the batteries too. In addition, recovered braking energy is also used to charge the batteries. The battery pack can supply 17 kWh, so the electricpowered action radius is quite large. That is to say it is possible to drive a fairly long distance on purely electric power. Moreover, there is still sufficient capacity to power all the auxiliary units (compressor, steering pump, doors, air conditioning, etc.) electrically.
Optimal hybrid city bus
The hybrid Citeas for De Lijn are equipped with a start-stop system. This system switches off the diesel engine at stops and whenever else the bus is at a standstill, and the bus drives off under purely electric power. This means 0% emissions. An additional, and certainly not unimportant, environmentally-responsible aspect is that much less noise is produced. In the zones where the diesel engine is running, the speed is kept as constant as possible to maintain the lowest possible
noise levels. Significant fuel savings are also achieved: around 30 to 35% better fuel economy than a traditional diesel bus. Because the battery pack is mounted on the roof of the bus, and because the weight increase has been kept to a minimum, there is hardly any impact on the capacity. The hybrid Citeas for De Lijn are fitted with 25 regular seats and 5 folding seats. The total capacity is 95 passengers. The low floor construction makes it exceptionally easy to enter the bus and offers optimal access, for travellers with a baby buggy or wheelchair for example.