Together with the Dresdner Verkehrsbetriebe (Dresden transport undertaking) and scientists of the TU Dresden, Spheros continues to promote hybrid bus technology. The goal is to propel buses over longer distances in purely electric mode and save fuel. The first results of the “Pilot route 64” were presented at the end of August.
How can the electric range of hybrid buses be extended? Two promising concepts are being pursued: on the one hand, better use must be made of the existing energy in the bus. On the other hand, the vehicle mass must be reduced.
For the first time in a bus: air heat pump
What is long since familiar to house owners is now also being used in a DVB MB-Citaro G BlueTec hybrid type public service bus: the principle of the eco-friendly air heat pump. Across Germany this state of automotive engineering is hitherto only to be found in Dresden. The new electrical system extracts heat from the outside air to warm up the passenger compartment. Auxiliary heating with heating oil or infrared lamps is then only necessary at low temperatures. In summer the heat pump serves as an air conditioner and cools the passenger compartment to a comfortable level. The scientists anticipate savings in heating oil of 10 to 20%.
Control software thinks in advance
The hybrid bus equipped with 117 additional sensors has been running on Route 64 since November 2014 and collecting data such as temperature, pressure, flow, current and brightness. In addition, the respective position of the bus is monitored by GPS system. On the basis of the acquired data the scientists have written a route-specific program that predictively controls, among other things, the internal heating.
The “Pilot line 64” project is one of a total of 40 projects of the “Showcase Bavaria-Saxony Electromobility Connects” to which the Free State of Saxony has pledged funds of 4.2 million euros.
Interview in video with Reiner Zieschank, DVB Director Technology and Finances