To a fairly significant extent, all electric trains in the UK are running on steam power... Just with the steam being generated and used to produce electricity in large power stations which, even with transmission losses, are much more efficient than any self-powered train ever has been. That's the future of steam power.
This was the case until recently, but not these days.
For two weeks, no coal whatsoever has been burnt to produce electricity for the UK grid, the first time that this has been achieved since the very beginning of the electric age well over a century ago.
Our electric power has come largely from wind, solar, imports, hydroelectric plant, nuclear and gas.
Nuclear plants use steam, and natural gas power stations also use some steam. Wind and solar involve no steam.