“Not only electric on the track,” is the new rnv slogan. The way there was not without diversions. “The experience that we have gained with diesel buses over decades is only of partial use to us. We have to plan completely afresh in many areas.” But Stefan Prüfer is confident: “Electromobility using buses is one of the future topics in public transport – also in the Rhine-Neckar metropolitan region. … We would like to be a pioneer in this field.” The switch from diesel to electric buses throws up many questions about for example, range, charging strategy, the number of buses and depot requirements. “The conversion to electric buses changes the procedures in all areas,” stresses Sebastian Menges, who as Assistant to the Management, but now in Proposal Preparation and Product Development, is working on the electric bus project at rnv. That is why rnv appointed a project engineer for alternative drives, Yunus Keskin, who supported the steps for the introduction of the eCitaro.

At the same time, rnv worked closely with the Mercedes-Benz electromobility experts. Dr Robert Schimke from Development at the Mannheim site has helped rnv with requirement calculations, planning tools and technical expertise. “Without the sound advice of the experts and the back-up in our own ranks, six months would have been far from adequate for the preparations,” says Stefan Prüfer with conviction. In addition, rnv and EvoBus have agreed to share their findings from operations at an intensive level. “The issue of electromobility is new to us all, so we can learn a lot from each other,” says Stefan Prüfer. He recommends that all transport operators both keep an adequate number of their own personnel available and take advantage of the advice offered by Mercedes-Benz eMobility Consulting.

Last but not least, Prüfer values the benefit that Daimler Buses supplies the vehicles and charging infrastructure from a single source. One of the most difficult issues was the charging strategy. Charge at the depot or on the road? “There is no patent remedy for this … every operation is different,” explains Stefan Prüfer. For instance, in Mannheim and Heidelberg, it turned out that the planned terminal stations would not be accessible for months due to pending roadworks; hence, installing charging stations was out of the question. “That was one of the reasons why we decided to charge in the depot.” With around 200–300 kilometres being covered every day and a range of 120 kilometres for the eCitaro under the rnv operating conditions, the electric buses must be fully charged during the day, during which a third bus is put into service. Sebastian Menges explains: “Our charging stations have a maximum charging capacity of 150 kilowatts and need around 100 minutes to fully charge the batteries.” After that, the eCitaro goes back on route with full power. “The quick charging comes at a cost to the battery service life, however,” Menges explains. The charging stations therefore supply the power with a reduced and hence gentler capacity during the six-hour charging phase at night.

The project start in January was a good choice, Sebastian Menges believes: “With winter on our doorstep, we had the harshest test conditions right at the beginning.” After the successful start phase, Stefan Prüfer is already looking forward: “The two lines are just the beginning. We want to develop electromobility further.”