Citaro Fuel Cell Hybrid

The hybrid drive system in buses is a logical interim step on the path from the combustion engine to the fuel cell drive with hydrogen. Eleven years ago, Mercedes-Benz presented the “Nebus” (New Electric Bus), the first bus in the world featuring a fuel cell drive system.

In 2003, the company introduced the first Citaro bus with fuel cells. In the largest worldwide test in daily service, 30 vehicles of this kind were used successfully by transportation companies for two years in widely varying conditions throughout Europe. Three further buses were in service in Australia for two years, whilst another three vehicles are in use in the capital of China, Beijing. The European test was even extended by two years in some cities: nine of the alternative Citaros are currently in service in Hamburg, with another three in use in Amsterdam.

In total, the vehicles have covered a combined distance of more than two million kilometers and have been in operation for 125,000 hours. The buses have impressively proven their suitability for everyday use with availability of between 90 and 95 percent.

In the next step, Daimler will further develop the recently-presented Citaro G BlueTec Hybrid into a Citaro fuel cell hybrid. The electrical wheel-hub drive can be retained, while the diesel engine and generator will be replaced with fuel cell stacks. Instead of the tanks for diesel and Ad-Blue, hydrogen tanks are on the roof of the vehicle. These comparatively minor changes enable creation of a low-noise, zero-emission vehicle for the city. The vision is becoming reality.