Why is a new energy source needed for rail transportation?

Christian Pieper: Deutsche Bahn has set ambitious climate protection goals. By 2040, we want to achieve CO2-free rail transport. To do this, we naturally need to move forward with the electrification of the rail network so that we can use electricity from renewable energy sources directly. However, not all routes can be electrified with overhead wires. And on these routes, we also want to make green hydrogen available as a power source for trains in the future.

And why is hydrogen a suitable energy source for CO2-free rail transport? Aren’t the conversion losses comparatively high here?

At DB Energie, we rely exclusively on green hydrogen as an energy source for rail transportation. Green hydrogen is produced through electrolysis using renewable electricity. As part of the H2goesRail project, we will both procure green hydrogen and produce it directly at the refueling station site. In my view, green hydrogen is an ideal complement to the success of the energy transition. Electricity from wind farms and solar power is dependent on natural supply and is volatile. Electrolysis offers a way to make the energy system more controllable, since hydrogen can be stored. This means hydrogen can be produced at locations with high availability of green electricity—and during periods of high availability—and then used as needed.

What do you hope to learn from this joint project? What further research is needed to move into full-scale operation?

A key factor in making hydrogen technology competitive with the diesel fuel used to date in day-to-day operations is an efficient and rapid refueling process. DB has therefore developed an innovative process that allows a hydrogen-powered train to be refueled just as quickly as a diesel unit. This is an important consideration given the tightly scheduled train intervals in DB’s regional service. Even in the future, we do not intend to employ a “refueling attendant.” Instead, refueling on-site will continue to be handled on a self-service basis by the locomotive engineer. All vehicle and refueling data will be automatically read and transmitted to DB Energie. Each rail carrier will then receive a bill from our colleagues that reflects its exact consumption. The entire hydrogen infrastructure—from rapid refueling to billing for green hydrogen—must run smoothly; we aim to gain valuable experience in this area through the project.

What is your timeline? When will passengers be able to use the train? And what will passengers notice about the train?

First, we’ll refuel the Mireo Plus H with commercially available hydrogen. Starting in 2024, the approach will change: DB Energie will produce our own green hydrogen directly on-site, right next to the refueling station, through electrolysis. This combination will allow us to manage the market ramp-up quickly and flexibly.

What about the cost-effectiveness of the hydrogen system in rail transport? Will trains and energy become significantly more expensive than before?

The cost-effectiveness of the service also depends on efficient, digital processes. In the project, for example, we’re using the DB EcoRail Simulator to analyze hydrogen demand. The system takes into account route characteristics, environmental factors, and vehicle behavior, thereby providing an important foundation for an efficient overall design. We have also developed wireless communication between the vehicle and the refueling infrastructure. This allows important vehicle parameters, such as tank pressure and temperature, to be transmitted from the vehicle to the infrastructure, ensuring efficient and rapid refueling.

However, the right political framework is also needed to make hydrogen trains economically attractive. For hydrogen trains—as well as battery-powered trains—to become essential building blocks of climate-friendly rail transport, a mix of various policy instruments is required. This includes energy taxation. The Minister of Finance should not burden the innovative use of hydrogen in transportation with high taxes. Rail transportation should also be granted equal access to greenhouse gas emissions trading. The expansion of e-mobility and the use of renewable energy should by no means be promoted exclusively in road transportation. This is also in line with the EU’s Renewable Energy Directive. And if the framework conditions are right, we want to present options for green hydrogen that are not too far removed from the current diesel supply.

In my view, green hydrogen is not only an attractive option for regional transportation. Rather, the hydrogen infrastructure can also help provide CO2-free rail freight and shunting services.

What market do you foresee over the next 10 years for hydrogen trains and refueling systems in Germany and Europe?

Various providers will bring hydrogen trains to the European market. At the same time, the core sales market could also emerge in regions outside of Europe. Due to the patchy infrastructure in terms of electric rail network, there is significant interest in hydrogen trains within the railway sector. In addition, the production costs will decrease as green hydrogen is produced on an industrial scale. In my view, these developments will also have a significant impact on the ramp-up of hydrogen in rail transport.