As the world looks to curb carbon emissions, rail operators’ continued focus on diesel has put a spotlight on the industry. Rail electrification projects have been ongoing, while industry players have been looking for green fuel alternatives that will allow trains to continue running autonomously. Nevertheless, a huge number of noisy, CO2-emitting diesel multiple units (DMU) are still on the tracks – Germany, for example, has more than 4,000 still in operation.

However, French rail vehicle manufacturer Alstom believes this could all change with the launch of Coradia iLint, the world’s first zero-carbon train using hydrogen as its energy source. The train is based on the company’s Coradia Lint DMU and has been developed in partnership with German and Canadian companies. Powered by hydrogen fuel cells, the vehicle’s only emissions are steam and condensed water, and it is capable of operating in near-silence.

Alstom’s so-called ‘train of the future’ was first introduced to the world at industry trade fair Innotrans in 2016, and it is set to begin its first passenger trials in Germany from early this year. The company hopes the train could be highly marketable to rail operators looking to replace their DMUs on non-electrified lines.

During a press event at Alstom’s test facility in November 2017, company representatives said Coradia iLint could highlight the start of an industry-wide shift towards hydrogen as a sustainable fuel.

“We think it’s really a breakthrough in the technology,” said Alstom’s regional vice-president of products and innovation Wolfram Schwab at the event. “Fuel cells have been developed for other applications, but now is the time to get this done in the railway sector. Now we are just at the starting point of the migration phase to zero-emission trains.”

Zero-emission trains

At the core of the iLint system is a fuel cell situated on top of the train. Hydrogen is supplied to the cell and then combined with oxygen taken from the ambient air inside it. The two products of this chemical reaction are electricity, which is used to power an electrical traction drive controlling the train’s movements, and water, which is emitted as steam.

Any electrical energy that’s not immediately used for traction can be stored in lithium-ion batteries on the train’s underside. An auxiliary converter will also be used to adapt the energy for various on-board applications, including air conditioning, door systems and passenger information displays.

“Now we are just at the starting point of the migration phase to zero-emission trains.”

Aside from its clean output, iLint’s key advantages are its smart power management and flexible energy storage. Electrical energy is supplied on demand, meaning the fuel cell is only required to work in full operation when the train is accelerating over sustained periods. When the train brakes, the fuel cells are almost completely powered down, saving on hydrogen consumption.

Alstom claims that because energy being produced or recovered from braking is intelligently managed, iLint will be able to match the top speed of its latest generation of Coradia Lint DMUs at 140km/h, while being more energy-efficient. The company also says the train will be able to travel up to 800km on a single tank of hydrogen and be capable of holding up to 300 passengers.

Hydrogen generation and infrastructure

The first test run of an iLint prototype took place at Alstom’s Salzgitter facility in March 2017, and trials have been ongoing since. During the test phase, hydrogen has been sourced from industrial emissions.

Nevertheless, there’s still the question of how trains will be refuelled and where the hydrogen will come from in the long term. Alstom has pledged that it will make things easier for operators by providing maintenance services and hydrogen infrastructure – in particular, filling stations – alongside its partners.

The company is currently looking to green methods to produce fuel for iLint. One existing example is electrolysis, which involves splitting water into hydrogen and oxygen i.e. the iLint formula in reverse. Another is natural gas reformation, which involves combining methane contained in natural gases with high-temperature steam. Regardless, the company aims to mitigate CO2 emissions from hydrogen production through the use of wind energy.

Germany’s recent investment in Energiepark Mainz, a plant designed to generate hydrogen from wind power, makes it a suitable location for the launch of iLint. The country has also committed to reducing its CO2 emissions by 40% by 2020 compared with 1990 levels and to using 80% renewable energy in power supplies by 2050. It’s therefore unsurprising that Alstom signed letters of intent with four German states in 2014, under which it committed to provide 60 trains in total.

Getting passengers and operators onboard

Alstom’s first big test began in November 2017, when the company signed a deal to build 14 iLint trains for the Local Transport Authority of Lower Saxony (LNVG). After the new vehicles have been built in Salzgitter, LNVG will lease them to a contracted train operator for use on the region’s Buxtehude-Cuxhaven route from December 2021. However, the French rail giant has claimed that the first iLint could be tested on the network as soon as the first quarter of 2018.

As part of the deal, Alstom will provide maintenance for the trains over a 30-year period. Meanwhile, leading gas company Linde will supply hydrogen for the new trains and erect the first-ever hydrogen filling station for trains in Bremervörde. The plan is that hydrogen will be produced onsite via electrolysis and wind energy at a later stage of the project.

“The company is currently looking to green methods to produce fuel for iLint.”

“The use of hydrogen for rail vehicles is a milestone in the application of fuel cells for emission-free transport,” said Linde executive board member Bernd Eulitz in a press release. “This development will push the establishment of a hydrogen society and will create new solutions for the storage and transport of energy.”

Ambitious climate protection goals and the expense of electrification could help bring the iLint to other European countries in the future. In July 2017, the UK’s Department for Transport cancelled a number of electrification schemes in Wales and England, which is expected to increase demand for non-electric trains. Following this, Alstom has been in talks to run trials in Liverpool, UK, as well as establish a source of hydrogen from refineries in the region.

“There has been dialogue with [the] Liverpool city region and various rolling stock operating companies about how we can develop a demonstrator,” said Alstom UK managing director for trains and modernisation Mike Hulme in an interview with The Engineer magazine. “It is an option which we’re pushing quite heavily, and we seem to be getting some traction.”

Depending on the success of its implementation in Germany, iLint could prove to be an important proof case for the use of hydrogen fuel cells on trains. Until then, Alstom is on the charm offensive to attract further European partners.