Bonn Politicians are postponing the decision as to whether all vehicles that Stadtwerke Bonn wants to buy should be air-conditioned. The purchase would cost a total of 65 million Euro.
Before the summer break, the city council decided on financing details for the purchase of 26 new trams (lines 61, 62, 65) for around 65 million Euro. Companies can still submit bids until the end of this month, and the contract is to be awarded at the latest at the beginning of October. However, it is not yet clear whether the vehicles will be air-conditioned. The Stadtwerke Bus und Bahn (SWB) have considered this aspect as an option in their tender, but no fundamental political decision has yet been taken.
Operating an air conditioning system consumes twice as much electricity
The SPD has submitted a motion to the Council which aims to only consider air-conditioned low-floor trams. However, it was postponed and referred to the next Transport Committee on September 11 for a joint discussion. According to the Social Democrats, SWB should in future only use air-conditioned vehicles and "climate-friendly refrigerants" for all new purchases of trains and buses. The refrigerant R134a - a greenhouse gas - is currently being used. According to the Federal Environment Agency, a number of research projects are currently being carried out into alternative systems.
Even more than the SPD is the Bonn Federal Government (BBB), which, due to climate change and the expected rise in summer temperatures, even insists on full air conditioning in new buses and trains. In contrast to electrical air-conditioning systems, which according to the city are able to cool the room temperature by about four degrees compared to the outside temperature, full air-conditioning systems can lower the inside temperature to 20 degrees. BBB faction leader Marcel Schmitt justifies the initiative with the words: "A trip with buses and trains during hot days in Bonn is more like going to the sauna".
The factions of the Jamaica coalition consider air-conditioning systems to be „desirable". However, they also emphasize the economic and ecological proportionality of the equipment. "It should be installed wherever it is technically possible and economical or justifiable in terms of electricity consumption," said Henriette Reinsberg (CDU) on request. Rolf Beu von den Grünen emphasises that "air conditioning of buses and trains serves to increase the attractiveness of public transport". However, "overmodulation" is not only harmful to health, but also "undesirable" for ecological reasons. FDP parliamentary party leader Werner Hümmrich does not consider it necessary to equip buses with full air-conditioning systems, as for example buses with diesel engines "consume more fuel and thus emissions rise sharply".
However, such an undertaking has its price from several points of view: "The costs for the procurement of air conditioning systems vary depending on the type and size of the vehicle and the results of the tender, but cannot be neglected", writes the Bonn city administration in a statement. The SWB refer to the current call for tenders when asked about the exact price differences in relation to the GA.
At least some examples show the financial impact of air conditioning systems. SWB currently has 15 light rail vehicles (lines 16, 18, 63, 66, 67, 68) with electric air-conditioning systems. According to their information, maintenance per tram costs 3200 euros a year. When the air conditioning system is in operation, it needs twice the traction current. In the case of buses, maintenance and repair costs per vehicle are 250 euros per year for electrical air-conditioning systems and 1500 euros per year for full air-conditioning systems.
In addition, a bus in operation consumes half a litre more diesel in the case of simpler air-conditioning systems and four litres more in the case of technically advanced systems. However, the announcement by Anja Wenmakers, head of the SWB subsidiary, that she wants to switch to electric buses by 2030 is still valid. Nevertheless, the additional energy will also have to come from somewhere for electric buses. From the administration's point of view, there is no serious answer to the question of "at what level additional passengers and fare income can be generated through greater travel comfort".
How efficient are the air conditioning systems?
The SWB have always asked whether it makes sense to invest in vehicles with expensive air conditioning systems. Trams and buses in particular have many stops and open the doors accordingly frequently. "In addition, temperatures are perceived very differently by passengers," said SWB spokesman Werner Schui. This raises the question of efficiency. The Bürger Bund countered by saying that air-conditioned buses and trains were standard in many southern European cities.
With an amendment to the SPD's proposal, the left-wing parliamentary group is advocating that SWB should pay particular attention in future to purchasing models with larger windows when purchasing articulated buses. This would at least ensure that fresh air would enter the vehicle from the outside if air conditioning systems were to fail. There would have to be locking options for the windows so that they would not be open when the air-conditioning systems were in operation.
For ten years now, SWB has been relying on vehicles with electric air-conditioning systems for its public buses. Currently, 162 standard and articulated buses are equipped with them. According to Schui, the municipal utilities are setting up new vehicles to create more pleasant working conditions.
Original text: Philipp Königs
Translation: Mareike Graepel