A taxi firm in Utrecht is conducting a major trial of electric taxis. Just for a change these are not converted London cabs or homemade jalopies, it's a fleet of 40 brand new Renaults, Nissans and Mercedes.

The company chose cars straight from the factory, just like their existing diesel models. And that is a global first. The director of the Utrecht business has total confidence in the electric taxis.

But are they really all that green? Do they use green electricity, for instance, and what about the need to charge them for eight hours a day?

On the other hand, the environmental advantages for the centre of Utrecht are quite obvious. The electric taxis are incredibly quiet and complete odourless.