Hydrogen could be a very environmentally friendly source of energy in the future. In the long-term, hydrogen is likely to reduce dependence on conventional sources of energy such as petrol, diesel and coal. In addition to it, the use of hydrogen as source of energy will help in reducing the emission of greenhouse gases and other pollutants.
When hydrogen is burned, the only emission it makes is water vapour, so a key advantage of hydrogen is that when burned, carbon dioxide (CO2) is not produced. Thus, hydrogen does not pollute the air. Hydrogen has the potential to run a fuel-cell engine with greater efficiency over an internal combustion engine. The same amount of hydrogen will take a fuel-cell car at least twice as far as a car running on gasoline.
Though, the hydrogen fuel cell has proved to be a viable source of energy for vehicles, but there are serious questions on its production, storage and distribution. There are also questions on its efficiency, in so far as it takes more energy to manufacture it than what it produces. Besides, it costs a considerable amount of money to run a hydrogen vehicle because it takes a large amount of energy to liquefy the fuel.
Hydrogen is one of the most abundant elements in the universe. It is the lightest element, and it is a gas at normal temperature and pressure. Hydrogen as a gas is not found naturally on Earth, because hydrogen gas is lighter than air and rises into the atmosphere. Natural hydrogen is always associated with other elements in compound form such as water, coal and petroleum.