It sounds like the plot of a Liam Neeson film – a train full of explosive hydrogen, picking up speed and barrelling towards an uncertain fate. But this particular journey ended not with a trail of destruction, but a rather dull round of polite applause.
On Wednesday, the UK’s first hydrogen powered train made its public debut, running a successful test at a rail industry event in the Midlands. The HydroFLEX concept consists of three parts. Large hydrogen tanks inside the train store the element at high pressure, before it’s fed through a regulator into a fuel cell that uses a catalyst to combine it with oxygen, in a reaction that produces electricity and water.
The third component is a battery, used to store the electricity and power the train. The fuel is created by using electrolysis to split water into hydrogen and oxygen, and the technology on the train simply reverses that process.
The UK’s first hydrogen trains come several years after the first tests of the fuel in other countries. That’s partly a legacy of the UK’s early adoption of railways which left engineers with a much tougher job. The Coradia iLint, which has been carrying passengers in northern Germany since September, has much of the hydrogen equipment on the roof, which is not an option with our Victorian infrastructure and tunnel heights.
HydroFLEX is, however, the first project in the world to retrofit hydrogen technology onto an existing carriage. “Our prototype shows how hydrogen powered technology can be incorporated within existing trains, without needing to modify the drivers’ controls,” says Stuart Hillmansen, a lecturer at the University of Birmingham, which helped develop the train along with rail company Porterbrook. “It’s an exciting advance because it shows how this technology could be adopted into the mainline system to deliver emission-free public transport.”
It’s hoped that hydrogen trains could help decarbonise the railway system, which still relies on diesel trains to a much greater extent than other countries. But hydrogen won’t be a panacea in the effort to make train travel more climate friendly.
Converting more of the UK’s railways to supply electricity to trains directly would be a much bigger win – particularly for mainline services, high-speed trains and inter-city journeys, according to a report published earlier this year by the Institution of Mechanical Engineers.
“Storing hydrogen requires significantly more space than diesel fuel,” says David Shirres, one of the authors of the report. “For this reason, hydrogen is not suitable for high-powered rail traction and so should not be considered as an alternative to electrification.”
Hydrogen can be part of the solution, but it can’t replace electrification, which has stalled. Only 42 per cent of the UK rail network is electrified, and in 2016 the government indefinitely delayed upgrades to the Great Western Mainline between London and Bristol.
Where hydrogen could be a boon, however, is for more rural areas such as Scotland, Wales and the South-west of England, where electrification is impractical, and where two carriage diesel trains are still the norm. Hydrogen trains could also be a viable option in places where it’s already being produced as a byproduct of industry. “Trains and buses which operate near industries where hydrogen is produced could use hydrogen as a fuel, as production, storage and refuelling would be nearby, thereby reducing fuel distribution and transport costs,” says Jen Baxter, head of engineering at the Institution of Mechanical Engineers.
Helen Simpson of rail company Porterbrook agrees. Hydrogen won’t be the right answer for all trains, but she says one of the system’s great strengths is its flexibility. A train could start its journey powered by overhead cables, and then switch to hydrogen if it passes through an area where electrification is not in place. She also argues that you could theoretically include hydrogen under the umbrella of electrification too – “a philosophical debate” – but an important one.
At the moment, electrification means that trains draw their power from the grid at the point of use, so if a train is travelling at a time of peak electricity demand or during the night it may be being fuelled by coal or gas-fired power stations rather than renewables. Hydrogen has the advantage of being able to balance the grid – excess solar or wind energy can be used to create hydrogen, which can then be deployed at times of higher demand.
It will be two or three years at least before hydrogen trains are carrying passengers on the UK rail network, as Porterbook and their partners work to prove they’re safe, and show them to potential customers. But building trains is only part of the challenge. “The infrastructure is not there at the moment,” admits Simpson. “But until we create a demand it won’t be.”
This article was originally published by WIRED UK
