In contrast to road transport, large parts of rail transport are nowadays already based on drive technologies that can easily be operated in a greenhouse gas-neutral manner. In Germany, for example, around 60% of the entire rail network is electrified, which means that overhead lines are present that can be used to supply trains with electrical energy. For electrified lines, it is therefore sufficient to ensure that the electricity comes from renewable sources to enable climate-neutral train services. Although both, the German government and the rail industry, are striving to continuously increase the share of electrified lines in the coming years, there will still be lines in the future whose electrification does not make sense for technical and, above all, economic reasons. 

 

On such non-electrified lines, trains powered by diesel engines are usually used today. As in road transportation, in rail transportation hydrogen-powered vehicles are one way to replace diesel vehicles with greenhouse gas-neutral alternatives. At the end of 2018, the world's first train powered exclusively by hydrogen was tested in Germany as part of a pilot project. Just three years later, at the end of 2021, hydrogen trains for local passenger transport are already in series production. The pioneer is the french manufacturer Alstom. Local transport operators in several German states (Lower Saxony, Hessen) are currently in the process of creating the necessary conditions for the use of hydrogen-powered train fleets. By the end of 2022, around 40 fuel cell trains are expected to be in regular service.

 

In terms of the technological design of the powertrain, the hydrogen trains available to date are comparable to the FC vehicles for road transportation. A FC supplied with gaseous hydrogen generates electricity, which in turn drives an electric motor. To compensate peak loads, part of the electrical energy generated by the FC is temporarily stored in a battery. The battery can also be used to store energy that is recovered during braking (recuperation). In Alstom's hydrogen train, the hydrogen tanks and the FC are located on the roof of the train. The batteries, electric motor and required current converters are located on the train's underside.