RVBW’s line 5 runs between Baden Baldegg and Ennetbaden through dense residential areas en-route and the main hub for bus and rail services in the city center.
Clean and quiet journey through residential areas
This bus line serves mainly densely populated urban areas. «This is exactly the reason why we’re now fully electrifying this bus line,» explains Stefan Kalt, Director at RVBW. «Residents will benefit directly because electric buses don’t produce harmful emissions and emit significantly less noise compared with diesel fuel powered buses.» Furthermore, e-buses can recuperate braking energy on the two downhill segments, which recharges the energy storage system.
Gradual fleet electrification by 2030
In 2018, RVBW’s Board of Directors decided to gradually transition to a full electric bus fleet by 2030. «We will phase out existing diesel-powered buses which have reached the end of their service life and replace those with new electric buses. Urban routes are best suited for electrification and will therefore be prioritized.» However, with the acquisition of new buses and the installation and expansion of charging options, bus operation will become increasingly complex. This means infrastructure, IT, and working processes will need to be adapted to the new circumstances, and a local partner with industry expertise like ABB is needed.
Drivetrain solution provided by ABB
For line 5, RVBW acquired four electric buses from Swiss bus manufacturer HESS. These low-floor buses of the type «lighTram» measure 12 meters in length and feature ABB drive technology – specifically a permanent magnet motor that is powered by a traction inverter. The energy storage system mounted on the roof is also provided by ABB, manufactured in ABB’s production site in Baden that was opened at the end of 2019.
Increased passenger space
This roof installation creates additional space in the passenger compartment. One bus can now carry up to 100 passengers, meaning an increase in passenger capacity by 30% compared with the previously used conventional buses.
ABB charging stations installed at final stops
The energy storage systems of the buses are recharged with an ABB fast-charging station at the final stops of the bus line at «Baldegg» and «Äusserer Berg». The Pantograph Down system enables a quick and efficient charge of the electric bus by descending the pantograph from the charging station, controlled by a laser, and connecting to the energy storage system via rails on the roof of the bus. The energy storage is charged with 300 kilowatts for two to four minutes depending on the bus schedule without impacting the normal operation of the route.
Optimally dimensioned depot charging solution
The buses are fully charged overnight in the depot, for which ABB has provided two charging stations of type HVC 100 with two charge boxes each. They sequentially charge the buses with an output of 100 kilowatts. The bus drivers connect the four buses to the depot charge boxes during the night when the bus is not operating. One charging station first charges one bus, then automatically the second one. This means that each bus does not require its own charging station, and the grid connection can be optimized because the buses are not charged at the same time.
ABB chosen as partner for the overall project
«The electric buses are equipped with ABB drive technology, so we also chose ABB to supply the charging solutions and be our partner for the overall project», says Stefan Kalt. ABB entered the EV charging market in 2010 and is a leading supplier of charging stations. Products include alternating current wall boxes for home installation and direct current quick-charge stations for highway rest stops and charging solutions for e-trucks and electric buses.
400 tons of CO2 savings per year
«With the transition of line 5 to full electric operation, we will save 155,000 liters of diesel fuel and around 410 tons of CO2 every year», says Stefan Kalt, emphasizing the ecological benefits of the electrification. Regionalwerke AG Baden (RWB) is supplying power to this line sourced from regional hydropower.
Financial contribution by Canton of Aargau
The Canton of Aargau is contributing almost 1.5 million francs from the special financing of public transport infrastructure to the investment costs for the charging infrastructure of Baden Line 5.