Designed by Alstom teams in Salzgitter, Germany, and in Tarbes, France, hydrogen fuel-powered trains are gaining traction as an alternative to diesel propulsion, reducing greenhouse (GHG) gas emissions significantly and decarbonising mobility on the journey towards net zero.

In 2016, Alstom introduced the Coradia iLint train in Berlin at the IssoTrans show, calling it the world’s first train based on hydrogen technology. Within two years, the Coradia iLint had entered commercial service in Germany. On 15 September 2022, the train travelled 1,175 km without refuelling. It achieved a top speed of 140 km/h and acceleration and a braking performance comparable to a standard regional diesel train – but without the noise and emissions. To date, 59 hydrogen-powered train sets have been ordered by clients in Europe.

In 2023, the train carried passengers for the very first-time outside Europe, in Canada, where it transported over 10,000 passengers in a demonstration project in the Province of Quebec from mid-June to late September 2023 (see box).

Today, Alstom offers a range of zero direct-carbon emission rail technologies, including hydrogen and battery-electric solutions, both newbuild and retrofit, along with the infrastructure for sustainable power supply, including partial electrification and charging stations for batteries.

‘Emission free mobility is one of the most important goals for ensuring a sustainable future... The world’s first hydrogen train, the Coradia iLint, demonstrates our clear commitment to green mobility combined with state-of-the-art technology.’ – Henri Poupart-Lafarge, CEO and Chairman of the Board of Alstom

Hydrogen versus battery options  
Alstom says it supports ‘the complete ecosystem’ of hydrogen and green traction solutions. And it maintains that hydrogen and battery technologies both offer credible and complementary alternatives to diesel, depending on the operational context and technical requirements. In addition to functional requirements, a total cost of ownership approach now requires consideration of the environmental footprint impact when choosing between technologies, including infrastructure availability.

In general, the company recommends that battery trains are a more suitable solution for shorter lines, given that battery-electric trains require sufficient charging capacity via overhead lines or dedicated charging solutions located in stations and in depots. Hydrogen trains are more suitable for the operational autonomy required to cover longer, non-electrified lines, as hydrogen-powered mobility requires access to local hydrogen production and distribution logistics.

From a country perspective, the cost of operation of hydrogen trains depends on the evolution of an entire hydrogen ecosystem, with ease of accessibility for operators and other consumers. For battery train lines, the installation of new charging stations connected to the existing medium-or low-voltage grid adds to their cost-efficiency, as they can be more easily installed than catenary systems on low-density lines.

Alstom’s vision is to see green traction powered with green/renewable energy, further lowering wheel-to-wheel emissions, along with potential declining costs.

Optimising costs are key, with a view to achieving optimal fuel cell dimensioning and hydrogen storage, battery size, quick charging and power conversion – as the energy demands from different operating systems need to be taken into account. To gauge the right balance, the company has developed a proprietary digital energy calculation tool. In addition, smart energy management helps to control and assure optimal service.

For existing rolling stock, Alstom’s FlexCare Modernise portfolio offers replacement of diesel propulsion with hydrogen and battery solutions, with zero direct emissions. That enables train operators to capitalise on existing rolling stock while reducing costs and becoming more sustainable, and potentially adding about 20 years of useful life to an existing train.

How the hydrogen train works  
From a technology perspective, the primary source of energy for the hydrogen-powered train resides within the intermediate railcar known as the ‘power car’, where the energy is generated through a combination of hydrogen, stored in tanks, with oxygen from external air. The energy is stored in high performance lithium-ion batteries, which are utilised during acceleration to complement the hydrogen cells, optimising fuel usage.

Alstom has facilitated seamless transition from diesel to hydrogen refuelling worldwide, together with key partners in the hydrogen sector. The company has also worked closely with key sector players on refuelling protocols and communication technologies between the vehicle and the station to drive international standards.

Trains using hydrogen can cover longer distances than vehicles using battery traction. Alstom’s Coradia iLint train is designed for non- or partially-electrified lines up to 1,000 km. To date, its hydrogen trains have travelled more than 2 million km in passenger service in 10 countries.

The company has also invested in fuel-cell development for trains with the acquisition of HELION Hydrogen Power in 2021, a 100% subsidiary of AREVA Energies Renouvelables.

Alstom’s Coradia iLint in commercial service in Quebec, 2023

Photo: Alstom/C Fleury

A cluster of European deals  
Alstom currently has four contracts for hydrogen fuel cell powered regional trains. Two are in Germany – the first of 14 for Lower Saxony, and the second for 27 Coradia iLint trains in the Frankfurt metropolitan area, operated by RMV. The third contract is in Italy, where Alstom is building six Coradia Stream hydrogen trains, with the option of eight more. The fourth is in France for 12 Coradia Polyvalent, dual-mode hydrogen trains shared across four different French regions. Furthermore, the Coradia iLint has been tested successfully in Austria, the Netherlands, Poland, the Czech Republic, Slovakia, Sweden and Quebec, Canada.

In greater detail, Alstom signed a deal in December 2023 to supply the first hydrogen trains to the Italian region of Puglia to Ferrovie del Sud Est, with two Coradia Stream H hydrogen trains to replace current diesel trains. In addition, Lombardy transport operator Ferrovie Nord Milano ordered two more hydrogen trains within an existing framework agreement. The trains will be manufactured by Alstom in Italy – with an option for eight more.

In addition, a Coradia Stream H train is scheduled to enter commercial service in Val Camonica between 2024/2025, along the non-electrified Brescia-Iseo-Edolo line of Ferrovie Nord, as part of the H2iseO project, which aims to create Italy’s first Hydrogen Valley in Brescia, northern Italy.

After four years of trial operations with two pre-series trains, in August 2022 the first of 14 hydrogen fuel powered trains began operating in Lower Saxony, Germany – marking the world premiere of a 100% hydrogen train route for passenger operations. The fleet of hydrogen fuel cell powered trains will be operated by Landesnahverkehrsgesellschaft Niedersachsen (LNVG), gradually replacing 15 diesel trains. Project partners are the Elbe-Weser railways and transport company and gas provider Linde.

The Coradia iLint project benefits from the support of the German government and was funded as part of the National Innovation Programme for Hydrogen and Fuel Cell Technology (NIP).

At the German launch, Henri Poupart-Lafarge, CEO and Chairman of the Board of Alstom, expressed the Group’s ambition: ‘Emission-free mobility is one of the most important goals for ensuring a sustainable future. Alstom has a clear ambition to become the world leader in alternative propulsion systems for rail. The world’s first hydrogen train, the Coradia iLint, demonstrates our clear commitment to green mobility combined with state-of-the-art technology.’

Some of Alstom’s hydrogen-related programmes are funded as part of the European Union-led IPCEI Hy2Tech programme, which comes under the NextGenerationEU programme. Speaking at the first IPCEI Hydrogen conference in Berlin in December 2023, Stephane Kaba, H₂ IPCEI Director at Alstom, called for ‘standardisation and the development of common norms across various transportation sectors [namely rail, truck, buses and maritime], before technical specifications for interoperability are defined by 2030, as a prerequisite to ensure competitiveness of hydrogen rail solutions’. 

• Further reading: ‘US announces $7bn for clean hydrogen hubs’. Funded by President Biden’s Bipartisan Infrastructure Law, seven regional clean hydrogen hubs are expected to collectively produce 3mn t/y of hydrogen, reaching nearly a third of the 2030 US production target and lowering emissions from hard-to-abate industrial sectors that represent 30% of total US CO₂ emissions.
• Find out more about what a rival supplier of hydrogen trains, Siemens, is doing to reduce emissions from rail transport.