The fuel cell was used to power the laser lights, which projected environmental messages onto the famous landmark as part of a drive to encourage the adoption of green technologies.

"I strongly support the development of these technologies in London as a viable alternative to noisy, dirty petrol and diesel generators," said the deputy major and chair of the London Hydrogen partnership, Nicky Gavron.

"It is high time that this clean, green and efficient technology was used more widely," she added.

The hydrogen fuel cell in question was used last year to power the Trafalgar Square Christmas tree's lights and other fuel cells can be seen in use on three of London's buses.

The London Hydrogen Partnership and the London mayor are now working together to establish a hydrogen fuel cell economy in the capital.