Transport Minister Michalis Liapis handed over a 40-seater bus to the scientists from the National Technical University of Athens yesterday so they can outfit the vehicle to run on hydrogen fuel cells.

The project is expected to take about a year. The bus will then be tested for 12 months in Athens to check for kinks. If all goes well in the test period, the Transport Ministry is expected to urge the production of more of the buses.

Several European cities are already using hydrogen-powered buses, which are more expensive to run than diesel-powered ones but far cleaner, as they emit only water vapor, not harmful emissions