New technology means that clean battery powered electric trains can run the length of the route without electrifying the entire line.
They can charge up while under the ‘wires’ and use their batteries in the gaps.
There are an increasing range of battery trains available, one example that is made in the Midlands are Vivarail class 230 trains. These are even greener by being rebuilt Tube trains with completely new interiors.
They have all the features you expect in a new train, from passenger information displays to WIFI & USB sockets.