Articulated buses

July 20, 2023

Alpine Challenge: Mercedes-Benz eCitaro fuel cell defies extreme cold and steep passes.

At the beginning of June, Mercedes-Benz showcased the new eCitaro fuel cell for the very first time, the first regular-service bus with a fuel cell to extend the range. Before the start of series production, the eCitaro fuel cell had to pass numerous functional and safety tests. This also included a winter alpine crossing – a test run with many challenges.

The cold alpine air envelops the yellow, low-floor articulated bus, making it seem like a foreign object in the extensive car park on the Plan de Gralba at an altitude of 1795 metres above sea level in the South Tyrolean Alps.

While driver Andreas Hoffmann is eagerly scraping ice off the windows, a small white cloud of steam curls upwards from the roof structures of the bus – an unmistakable sign that the fuel cell on the roof of the bus has begun its work and is now generating electricity from hydrogen and oxygen in the air – emitting only steam. This articulated bus is a test vehicle, one of four prototypes of the Mercedes-Benz eCitaro fuel cell.

The first electric bus in which a fuel cell system extends the range has just undergone one of a range of tests and passed with flying colours: after a night at temperatures far below freezing, the electric drive system and fuel cell started up smoothly.

At the beginning of 2023, a team of Mercedes-Benz test engineers went to the Alps with the eCitaro fuel cell in order to test its cold-starting behaviour in winter temperatures and to try out the newly developed thermal management system.

At the same time, the runs at elevations of more than 1700 metres above sea level were intended to provide insights into the function of the fuel cell system at extreme altitudes. The new drive system also had to prove its performance on demanding mountain pass runs with uphill and downhill gradients of as much as 15 percent. Last but not least, the energy consumption was of great interest in these challenging conditions.

The test run that lasted several days, started with crossing the Alps from Neu-Ulm via Füssen, the Fern pass and the Reschen pass to Bolzano. The combination of battery and hydrogen was designed to be able to cover the 360-kilometre route.

On the way across the Fern pass, it soon became clear that the eCitaro fuel cell was capable of dealing with the demanding route even better than expected.

Bolzano turned out to be the ideal destination for the winter test run. With a public hydrogen filling station directly next to the Bolzano South motorway junction and another H2 filling station at the depot of the Bolzano-based Sasa transport company, it has one of the best H2 infrastructures in Europe. Added to this, the hydrogen available here comes exclusively from renewable sources – primarily electrolysis using hydroelectric power.

Moreover, the surrounding Dolomites with their steep mountain passes and high elevations offer ideal conditions for altitude testing of the fuel cell system and further tests across challenging topography and at low temperatures.

https://hydrogen-central.com/alpine-challenge-mercedes-benz-ecitaro-fuel-cell-defies-extreme-cold-steep-passes/