Ten hydrogen buses belong to the vehicle fleet of the Wiesbaden mobility operator Eswe Verkehr - and the operation of the environmentally friendly buses is increasingly under an unfavorable star.
The buses have been standing still for a few weeks because they can no longer be refueled.
Wiesbaden's head of traffic, Andreas Kowol (Die Grünen), confirmed this when asked at the weekend and described it as "very annoying".
The reason for the forced break is therefore a certain spare part, without which the hydrogen filling station on the Eswe site would not work.
At the moment, Kowol continues, it is not foreseeable when this spare part, which is said to be a special compressor part, will be delivered.
It is hoped that this absolutely necessary part will be available in the next few weeks, but there is still no promised delivery date.
According to the head of the transport department, it is also not possible to refuel the buses at another hydrogen filling station, for example in the district of Nordenstadt.
"That's not possible because vehicles are refueled there with a pressure of 700 bar, but our buses are only allowed to be filled with a pressure of 350 bar," explained Kowol.
According to this, cars are refueled with a pressure of up to 700 bar, while most buses and trucks, which have larger tanks and therefore more space, are only refueled with the 350 bar mentioned.
So the ten buses, each of which cost around 600,000 euros, will remain in the depot for the time being.
Eswe is currently discussing whether and how the hydrogen fleet will be used in the future.
The company is considering selling the buses again, but a decision has not yet been made, a spokesman for Eswe Verkehr said: "We are testing our hydrogen buses for operational readiness and cost-effectiveness."
The purchase of the buses, which are supposed to be part of Wiesbaden's traffic turnaround, has always been the subject of heated debate.
The hydrogen filling station had already been set up on the Eswe company premises in February 2020, but at that time the company did not yet own a single one of the fuel cell buses that are operated with hydrogen.
This led to Eswe being accused of wasting tax money, because the construction of the gas station had cost more than two million euros.
Own hydrogen buses only drove in Wiesbaden from December last year.
The previous management had originally even announced that the entire fleet would be operated with e-buses and hydrogen buses.
This goal could not be realized.