Florida has become the world's first purchaser of hydrogen-powered buses for commercial purposes.

The state has bought eight new shuttle buses from Ford, planned for use by Orlando tourists next year.

The 12-passenger bus is propelled by an internal combustion engine that is supercharged and inter-cooled for maximum efficiency.

The vehicles are equipped with a 26-gallon equivalent hydrogen fuel tank with an expected range of about 150 miles. With near-zero emissions, including carbon dioxide, the engine is up to 25 per cent more fuel-efficient than a typical gasoline engine.

The move is part of Florida's initiative, announced by Governor Bush 18 months ago, to pursue sources of alternative energy.

"H2 Florida" aims to connect the state of Florida with industry, governments and academia to showcase hydrogen technologies and stimulate a consumer market for the newest hi-tech approach to cleaner, sustainable sources of energy.

The news comes as Iceland prepares to adopt a widespread hydrogen-powered bus network, with the country aiming to ramp up its clean transport capacity.

The Icelandic government has set the goal of making the country oil-free by transferring cars, buses, trucks and ships over to hydrogen by 2050.

The first step is the introduction of buses made by DaimlerChrysler. Each vehicle costs about 1.25 million euros each but the only emission is water.

Similar hydrogen bus projects are already being tested in Barcelona, Chicago, Hamburg, Madrid, Stockholm, and Beijing.