Trains pollute and can give off greenhouse gases. The UK has many miles of unelectrified railway lines. Up until now, the solution has been to use diesel electric trains for most services; some minor lines use pure diesel in what are effectively buses or rail tracks. Next Monday, Parliament is due to legislate a target of net zero greenhouse gas emissions by 2050. The rail companies have already been told to eliminate the use of diesel traction by 2040.
Retrofitting overhead electricity cabling is prohibitively expensive; the cost of converting the Great Western Main Line will be £2.8 billion. The works can also be very distruptive and take many years. The only solution is for the trains to carry their own electricity. In most cases, the length of lines they serve and their frequency mean that pure battery power is impossible.
The solution being proposed is to use hydrogen cell generation. The German Railways already run hydrogen powered trains built by the French company Alstom, but are unsuitable for British tracks.
The current two car configuration is much too small for most services although that no doubt could be solved. The main problem is the location of the generating and associated equipment on the roof. With many over-bridges and tunnels built in the 19th century, there is not enough clearance on many parts of the British network.
Today the rolling stock company Porterbrook unveiled the prototype of the hydrogen powered train they jointly developed with the University of Birmingham’s Centre for Railway Research.
The UK prototype uses an existing Class 319 fitted with a hydrogen powerpack.
The hydrogen is stored on-board in high pressure tanks and is piped from these into a fuel cell where is mixes with oxygen from the air to generate electricity.
The electricity generated can be stored in a huge on-board battery, meaning that the train can continue to run on electricity on railway lines where there are no electrified overhead cables.
Currently only 42 per cent of the UK's entire rail network is electrified. In Scotland it is less than 30%.
Currently the different elements in the “powerpack” are located in one of the four cars set up as a lab to prove and monitor the technology. The next step is to relocate the equipment underneath the carriages in advance of main line testing later this year, permission was given today. Conversions could be running full passenger services in two or three years.
This is a very clever solution. You may have noticed that the design is far from a “bullet train”. This is because the idea is to convert existing rolling stock. The Class 319 trains were built between 1987 — 1990 and are being replaced by their initial users. Some have been refurbished and used in other areas but there are a number that will be available for conversion to hydrogen, including those already refurbished. The maximum speed is 75 mph but this is more than adequate on rural services.
Of course the lessons learned in the exercise will inform and improve new rolling stock they develop in future. The need to build for the existing network and its limitations mean that there will be a continued demand for “British” trains with underslung generating equipment.,
Refurbishing and retrofitting hydrogen-powered traction is an ideal green solution. For a start, upcycling saves huge amounts of resources and CO2 emissions compared to building new. It will mean fairly quick roll out which in turn will mean the rail companies will invest in hydrogen storage facilities.
The ulitmate aim should be to generate enough renewable electricity to provide at least base load and use the excess in high generation conditions to produce hydrogen. As well as for transport, hydrogen is likely to replace natural gas in other areas. Hydrogen production this way is already being done on an island scale in Scotland, it now needs to be the UK target. Net zero emissions by 2050 required by law will be pioneering but many feel it is not ambitious enough.