In 2018, Swiss rail vehicle manufacturer Stadler began a research project to develop a battery-powered train designed to operate on non-electrified or semi-electrified lines.
Now the Flirt Akku (akku is the German term for a battery), which carries its batteries on the roof, has covered some 15,000 km in pure battery operation, and has demonstrated a range of 185 km, better than the 150 km that the Stadler team was expecting to see. Stadler and its battery partner, the German firm Intilion, say they gained valuable experience for the design of future vehicles from the pilot.
“We are proud to have developed an environmentally friendly, flexible vehicle to market with the Flirt Akku and not only proved our assumptions, but also exceeded our assumptions,” says Steffen Obst, Head of Sales at Stadler Germany.
Stadler received a first order for the Flirt Akku before the completion of the research project—the Schleswig-Holstein public transport network ordered 55 units in 2019. Stadler will deliver a preliminary set of 5 vehicles in November 2022, and the remaining units will be put into operation by mid-2024.
The project team placed particular emphasis on testing the batteries in extreme weather conditions. “In the summer of 2019, we tested the Flirt battery during a heat wave at 40 degrees (104 Fahrenheit) outside temperature and full use of the air conditioning system, as well as in winter 2021 during double-digit minus degrees. The use in pure battery operation was possible at any time without pushing the lower limit of capacity,” says Evelyn Thiel, Technical Director of the research project at Stadler.
Emission-free rail vehicles represent “a fundamental building block for achieving the EU’s climate targets,” Stadler said. Only 54 percent of the European rail network is equipped with overhead electrical lines. Recently, Germany’s Federal Ministry of Transport announced plans to expand that to 70 percent of the country’s rail network, while also supporting the development of alternative drives for trains. Stadler also offers a fuel cell-powered rail vehicle, the Flirt H2.