Is hydrogen the future of motoring?
The UK's first commercial hydrogen filling station has opened in Swindon.
The opening of the UK's first public refuelling station for hydrogen vehicles in Swindon is part of efforts to create a "hydrogen highway" along the M4 motorway.
It is also seen as an important step in a UK-wide scheme to make hydrogen vehicles a viable alternative to petrol-driven cars.
"A hydrogen car is much cleaner than a conventional car," says Professor Kevin Kendall, a hydrogen and fuel cell expert from Birmingham University.
"This will clean up our cities enormously," he says in an interview with BBC News. "No emissions whatsoever."