Local commuter trains powered by hydrogen could replace the need for electrification on smaller routes, an industry expert has suggested.

Speaking at the New Civil Engineer Future of Rail conference last week, Railway Industrial Association decarbonisation task force technical director David Clarke said the fledgling technology could provide an alternative to electrification of smaller local rail lines.

“Hydrogen will definitely play a role [in the future of rail] especially in the more remote parts of the network where there isn't a case for electrification,” Clarke said.

Clarke said that under incoming net-zero carbon rules, around 3,400 locomotives would need to be retrofitted to run on a different energy source, or have their emissions offset.

He added: “70% of the UK rail fleet is already fully electric, so we are looking at the remaining 30%, that’s about 3,400 passenger locomotives [not including 1,000 bi-mode diesel and electric hybrid trains] and a further 850 freight locomotives. We will need to deal with these under net zero.

"However, we need to think about where our hydrogen comes from, it currently takes 3kw of energy to produce 1kw of hydrogen, so until we are making that with entirely renewable energy it's not completely green." Clarke added.

Another issue is the energy density of hydrogen, Clarke explained, which is much lower than diesel. This means the fuel will only be suitable on shorter journeys or services that can regularly refuel, but could be used to cover "the last mile"

In January this year, an Alstom and Eversholt Rail joint venture revealed concept designs and plans to convert Class 321 rolling stock into hydrogen powered trains of the future, which could operational as a soon as 2021.

Transport for the North has also included plans to use hydrogen powered locomotives in its Northern Powerhouse Rail scheme.

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