Mercedes-Benz has delivered the first 3 of 48 fully electric eCitaro articulated buses with a 60 kW fuel cell as range extender to Rhein-Neckar-Verkehr GmbH (rnv). The buses offer a range of up to 400 kilometers and will be in use in urban traffic throughout the cities of Mannheim and Heidelberg.

In addition to the three eCitaro G fuel cell vehicles, a further 45 eCitaro articulated buses of identical design will be delivered successively by mid-2025. 40 of the total 48 vehicles will be destined for regular service in Mannheim and Heidelberg. The eight other buses will be used in Ludwigshafen am Rhein. I

n addition, rnv has an order option for an additional 27 eCitaro G fuel cell vehicles, with which rnv’s bus quota can be increased to a total of 75 fully electric fuel cell articulated buses provided by Daimler Buses by 2027 if required.

rnv has set itself the objective of converting its entire vehicle fleet in the Mannheim-Ludwigshafen-Heidelberg metropolitan area to locally emission-free drives by 2032. Since 2018, the transport company based in Mannheim has already received 36 eCitaro electric solo buses and integrated them into regular service. Another important part in this are the all-electric eCitaro G low-floor articulated buses with a fuel cell as range extender.

rnv is receiving support to achieve this objective through the H2Rhein-Neckar and H2Rivers funding projects, in which the everyday suitability of hydrogen and fuel cell technology in the mobility sector is examined and tested in day-to-day operation.

Before the new eCitaro G fuel cell electric articulated buses are used in regular service in the rnv operating area, they will first undergo test operation until the beginning of 2024. In addition to instructing and intensively training drivers, rnv will use this period of time for test refueling and range estimations, among other things, in order to be able to optimally design and shape operations on the routes in Mannheim, Heidelberg and Ludwigshafen.

The H2Rhein-Neckar project’s accompanying research will evaluate the data from day-to-day operation and provide further indications for optimizing processes in the depot, energy consumption and route planning.

The three-door electric articulated buses with fuel cell range extender each have four battery packs with the latest generation of lithium-ion batteries (NMC3) and a battery capacity of 392 kWh per vehicle. They form the basis of the power supply. The hydrogen supply of the 60 kW fuel cell is provided by six H₂ cylinders, each with a capacity of five kilograms, installed on the vehicle roof. The hydrogen tanks are refueled on the right above the second axle in the direction of travel.

Both the center and rear axles of the articulated buses are powered. The vehicle is driven by two low-floor portal axles with electric motors near the wheels, each with 250 kW of output. The electric motors produce 141 kW per wheel and generate a torque of 494 N·m. This results in an outstanding torque of 11,000 N·m per wheel due to a fixed ratio. This ensures high levels of grip and good performance even on demanding uphill gradients en route, and enables the eCitaro G fuel cell to achieve a range of around 400 kilometers.

30 charging stations supply rnv’s electric buses with electricity, supplemented by two recently completed hydrogen refueling stations. The batteries are charged with 150 kW charging capacity, and the hydrogen tanks are refueled at a refueling pressure of 350 bar at rnv depots in Heidelberg, Mannheim and Ludwigshafen or in their immediate vicinity.

The Mercedes‑Benz eCitaro low-floor electric bus has been in production at the Daimler Buses Mannheim plant since 2018. More than 1,000 eCitaro units have already rolled off the production line. With the eCitaro fuel cell, the first model with a hydrogen-based fuel cell as a range extender is now in series production in Mannheim.

The site has built up cross-departmental know-how in order to optimally prepare for the new technology. In addition, the plant has installed a hydrogen tank facility for commissioning the vehicles. This makes Mannheim the first Daimler Buses site to produce buses with a fuel cell.

The plant is the center of excellence for city buses of all drive types and is part of the Daimler Buses production network. In addition to city buses with alternative drives, the site currently also produces conventionally driven vehicles with maximum flexibility on a single assembly line. Preparations are currently underway at the plant for the production of exclusively electrically powered buses. The conversion is planned to take place in 2024.