The world's big car companies are out in force in Geneva for the city's annual motor show this week.

It is a chance to show off fanciful concept designs as well as the models destined for the road.

Luxury car maker Rolls-Royce is displaying a one-off battery powered electric vehicle - it is dubbed the Phantom Experimental Electric.

The chief executive Torsten Muller-Otvos spoke to the BBC about the new car.