Hydrogen is the most abundant element on earth. Hydrogen can provide power to vehicles in either combustion engines or fuel cells. In a combustion engine, the compressed hydrogen is injected into the engine and "burned" in a similar way to other fuels. In a fuel cell vehicle, hydrogen reacts with oxygen which produces electricity to power an electric motor. The only by-product of using hydrogen is water.
British Columbia showcased the world’s largest demonstration fleet of hydrogen fuel cell buses (20 in all) at the 2010 Olympic and Paralympic Winter Games.