Hydrogen could be used to power London Underground trains following a US-led project to develop a fuel cell locomotive.
An international consortium, led by Vehicle Projects LLC of Denver in the US, is developing the world’s largest fuel cell vehicle, a 1MW locomotive.
The $12m (£7.6m), five-year project, which is being funded primarily by the US Department of Defence, is aiming to design and fit a fuel cell stack to a US Army non-tactical, diesel-electric train.
The consortium hopes the project will act as a springboard, leading to the use of fuel cells in commercial trains, including high-speed, commuter, and underground lines.
Tube Lines, the infrastructure company responsible for the Jubilee, Northern and Piccadilly lines on the London Underground, is providing commercialisation guidance to the project team as a potential customer of fuel cell locomotives, said Arnold Miller, president of Vehicle Projects LLC.
‘The customers are providing us with guidance so that the technology evolves in the way the operating companies want. This will be the nucleus for spin-off projects (to find commercial applications), and one of these will be to utilise fuel cell locomotives on the Underground.’
Fuel cell trains are likely to be used initially to replace the 30 battery and 15 diesel-powered locomotives used for early morning maintenance work on the underground, when the electrified third rail is shut down. With fewer trains using the tunnels to push the air through and provide ventilation, the pollution created by the diesels cannot be cleared, while the battery-equipped locomotives are unable to store much power.
‘We believe the first step will be maintenance trains, but eventually we are looking at commuter underground trains. There are advantages to having a fuel cell-powered commuter train, such as eliminating the need for the third rail, and all the maintenance issues that go with it,’ said Miller.
Intelligent Energy, the UK-based proton exchange membrane (PEM) fuel cell specialist, is taking part in the project, and Miller is also in preliminary discussions with Rolls-Royce Fuel Cell Systems, which has considerable expertise in solid oxide fuel cells (SOFC).
The team will investigate the best fuel cell type for use in locomotives, including PEM, SOFC, and phosphoric acid fuel cells. The researchers will also study the best fuels, such as hydrogen stored within metal hydrides and liquid ammonia, as well as the most suitable fuel production methods.
Many have questioned whether cars powered by fuel cells will ever become a reality, partly as a result of the high costs and difficulties of establishing the infrastructure needed for drivers to fill up.
Powering trains with hydrogen, however, would be less complicated, while fitting fuel cells to locomotives is also much more straightforward as the devices do not need to be significantly reduced in size, as is the case if they are to be used in cars.
‘Automobiles are very challenging devices to build, because they have to be very fast, beautiful, roomy, luxurious and cheap at the same time. Trains don’t have those constraints, so they are easier to build.’
Fuel cells should also lead to a significant reduction in running costs, said Miller.
‘In locomotive applications, the cost of fuel is very important, and is one of the greatest costs, second to labour.’
Miller claimed fuel cell-powered locomotives will be about twice as efficient as diesel engines, so there should be enormous savings.