Still, as diesel-powered trains continue to use up to 2 billion liters of fuel every year, the railway sector also faces an urgent call to transition to clean energy sources to help meet the targets of the Paris Climate Accord and a range of national and European Union net-zero pledges.
For rail to secure its future standing as the most sustainable transport option — for both passenger travel and freight — one energy vector in particular is quietly gaining momentum: hydrogen.
From France’s Alstom launching the world’s first hydrogen-powered train, to Japan testing its first hydrogen-powered train earlier this year, to Canadian Pacific developing a H2 locomotive, and to Germany’s Berlin region ordering several H2 trains from Siemens Mobility, the hydrogen rail movement is gathering speed around the world.
Electric and battery-powered solutions
Multiple solutions to decarbonize the rail industry have already been implemented in recent years, which all offer certain advantages, but also challenges. Electric trains running on overhead cables have proven to be highly efficient with quicker acceleration as they don’t carry heavy diesel engines. Their system of power lines transfers about 95% of the energy to the wheels, compared with 30 to 35% when the energy is generated by combustion.
However, at anywhere between 2 and 3 million euros per kilometer, electrifying train lines is costly and the grid needs to be strengthened to deliver the necessary amount of power. Hydrogen-powered trains don’t require the same massive track overhauls and can be created by retrofitting already existing diesel trains, making them more cost effective. The retrofit process is particularly well adapted to trains as compared with other types of vehicles, as trains have a longer lifespan (from 30 to 50+ years). Furthermore, electric trains are truly sustainable only if the power generation mix is not dependent on fuels with high carbon content, such as coal.
Average well-to-wheel (WTW) carbon intensities for diesel powertrains and electric powertrains using various primary sources, in grams of CO2e per megajoule. Source: IEA 2019
Another potential solution for sustainable railways relies on battery power, garnering attention and investment along the recent boom in consumer uptake of battery-powered electric vehicles. Battery-powered trains are potentially even more efficient than cars as they can charge on an electrified track. Yet challenges arise when it comes to autonomy — which is limited to a maximum of 100 km — and the usage of electric battery-operated trains, which, if done incorrectly, can cause lithium-ion batteries to overheat, making their usage challenging and expensive.
The many benefits of hydrogen
That leaves hydrogen, increasingly seen as a game-changing energy vector across the entire economy, and transportation in particular. Hydrogen trains are quicker to refuel, while also boasting a larger range than their battery electric counterparts. Refueling a hydrogen train can take no more than 20 minutes, and a hydrogen-powered, multiple unit passenger train can run for more than 18 hours with a range of more than 1,000 kilometers between refueling — 10 times farther than battery-powered electric trains.
The prospect of a hydrogen-power railway future requires taking on several key challenges. Advances are still needed in freight technology to meet the power demands of high-speed and freight trains, leaving electrification as the only widespread viable option for now. Replacing the existing infrastructure with charging ports, substations, and train feeders, while far cheaper than electrifying, will also require major investment to scale across national and international lines. A hydrogen-powered train’s fueling station could cost between 10 and 12 million euros to operate, with about 280kg of H2 needed for a train to travel for 1000 km. Still, overall, it appears to be the most cost-efficient route, with the total price of ownership (including building, maintenance, and energy costs) making hydrogen rail competitive with diesel within the next 10 years.
The push for H2 implementation throughout the EU
With 50% of its rail network still not electrified and in need of decarbonization, the European Union is currently pushing for new regulations and expectations to secure a cleaner, carbon-neutral territory thanks to hydrogen. From the European Commission’s Hydrogen Strategy for a Climate-Neutral continent adopted in July 2020 to the latest Fit-for-55 package, proposed on July 14, 2021, it will be rolled out in three stages:
- Phase One, from 2020 to 2024, will aim at decarbonizing all existing hydrogen production;
- Phase Two (2024-2030) will integrate green hydrogen into the energy system;
- Phase Three (2030 to 2050) will see a large-scale deployment of hydrogen in the decarbonization process.
With its REPowerEU plan to speed up the energy transition, the European bloc plans on producing as much as 10 million tons of renewable hydrogen, and importing the same amount, by 2030. But for this major H2 market to turn into a reality, public authorities need to dedicate significant investments to a massive overhaul of current infrastructure and to promote a more detailed and ambitious set of rules and standards aligned with sustainability goals.
Electric, battery, hydrogen-powered and hybrid options have the possibility to be complementary on the path to decarbonize rail transport. Yet the full potential of hydrogen as a key energy vector for sustainable transport, from trucks and cars to airplanes and railway, requires a commitment to building an entire H2 ecosystem to achieve cost competitiveness that will move us closer to carbon neutrality.
In the meantime, hydrogen trains have already become a reality. In Germany, after 530 days and more than 180,000 kilometers traveled, Alstom’s trial operation of two hydrogen trains in Lower Saxony was successfully completed on schedule earlier this year. With a fleet of 14 trains provided by Alstom, the 100-km railway line is now powered entirely by hydrogen — a world first. Additional 30 trains will soon be put into commercial service in two other landers.According to SNCF and FNM, France and Italy will also equip themselves with 12 hydrogen trains each by 2025 running in different key regions, while other manufacturers are aiming to roll out at least one commercial hydrogen train in their fleets within the next two years. The hydrogen train evolution is well on its way.