Hydrogen fuel cells convert hydrogen and oxygen into water by reverse electrolysis. They rely on a store of hydrogen but take oxygen from the air. The reaction creates electricity and heat.

Interesting Facts

• Fuel cells were first invented in 1839, but until recently they have been difficult and expensive to build.
• Today the technology can power buses and cars, heat water and provide electricity.
• Since 2004, London has been involved in a pioneering project to reduce air pollution and noise by testing the first generation of zero emission fuel cell buses.
• Honda Motors launched a new hydrogen powered fuel-cell vehicle in Japan and the United States in 2008.

Benefits

• Fuel Cell Vehicles are very quiet.
• The only waste products are water and heat.
• Fuel cells have a higher efficiency than diesel or gas engines.
• Most fuel cells operate silently.

Downsides

• Production, transportation, distribution and storage of hydrogen can be difficult.
• Producing hydrogen currently uses a lot of non-renewable energy.
• Some fuel cells use expensive materials.
• The technology is not yet fully developed and few products are available – it will be some time before hydrogen is as freely available as petrol is now.
• Hydrogen is flammable.