Network Rail and partners have begun work to create a battery-powered train, as part of an industry study into the feasibility of using electric trains on parts of the network which have not yet been electrified.
The project could see trains running on battery power over non-electrified lines, before charging at terminal stations, or using their batteries to run over diesel lines in otherwise electrified parts of the railway.
Electric trains are quicker, quieter, and more efficient - making them better for passengers and the environment. The potential to spread those benefits while not having to put up miles of wiring would be cost effective and sustainable, Network Rail says.
Richard Eccles, the company's director of network strategy and planning, commented: "We see this project as an important element of our strategy of increasing the electrification of the rail network, delivering improved sustainability whilst reducing the burden on the taxpayer.
"If we can create an energy storage capability for trains, electric traction can be introduced to more parts of the network without the need to necessarily extend the electrification infrastructure."
Working closely with Derby-based train manufacturer Bombardier and operator Greater Anglia, Network Rail will plans to adapt a Class 379 and fit it with two different forms of batteries: lithium (iron magnesium) phosphate and hot sodium nickel salt.
The modified 379 will then undergo a variety of tests before it can be run on an electrified branch line.
Bombardier said in a statement: "This project is an innovative development to provide an integrated battery system as a power source for the well proven Electrostar train. Bombardier recognises the potential benefits that this technology could bring to the rail industry and the travelling public."