David Shires has written an article in the July issue of Modern Railways, in which the main theme is the electrification of the railway system. Electrification to him, means electric trains, per se, or trains running on renewable hydrogen, and battery trains.
So far, around 5300 km of routes have been electrified. He has carefully gone over the system, and concluded that out of the 9120 Km remaining, 4327 is definitely worth electrifying. This includes commuter routes, intercity core and intercity extensions. Modern Railways shows a map of his proposals.
There is another “possible” 1963 km, which is harder to justify, and 1036 of “unlikely” These two could be targets for the hydrogen train. Shires does not see battery trains as amounting to much, and puts these lines into a special category. But there are only 393 Km of such routes. This is where passenger numbers are quite low, but the routes are short.
Hydrogen trains could also be used on some of the “Electrification Possible” routes, so the use of hydrogen trains could vary widely, depending on political and economic decisions.
As well as the problem in storing hydrogen, on trains, which is more difficult in this country than on the Continent, because of the early nineteenth century loading, gauge, hydrogen trains are a rather poor use of electricity. Shires states a straight electric train requires 1.2 KW of electricity to put 1.0 KW onto the rails. For hydrogen it is 3.4 KW.
So, the crunch is, according to the Committee on Climate Change, hydrogen trains will not count for much in the great scheme of things. They think that by 2050, hydrogen trains will need 0.3 TWh a year. This compares with 22TWh for HGVs and 3 TWh for buses. This might be an underestimate as Shires thinks that, although his low estimate, in terms of passenger miles, is just 5%, hydrogen trains could account for up 18%. There would be no hydrogen freight trains
Even so, 0.3TWh equates to an average power 34 MW, although it is not clear to me whether the figures refer to “hydrogen energy” or “raw electricity”. Even if it is the latter, on Shires figures it means that only 100 MW would be needed to generate the required hydrogen.
30th June 2020
Dr Fred Starr FIMMM, FIE, MIMechE, C.Eng