Fuel Cell Driven Cars
At present the fuel needs of humanity is met mainly by the fossil fuel. Automobiles are run by petroleum products. 
Most of the electric power generation is done by petroleum derivatives. Everyday the demand on petroleum products is going up. One day the petroleum reserve will dry up. Moreover, the gases coming from burning them cause health hazards to mankind. An alternative is hydro-electric power generation. Even though this power is harmless and has renewable source, there is not sufficient water with required pressure head available. Wind energy is another source with no harmful side effects. But that too is limited.
Another source of energy experimented for sometime is burning of hydrogen. It produces only water and hydrogen can be regenerated from water. On the other hand the fossil fuel produces very harmful gases like carbon monoxide and carbon dioxide. If this trial is successful we can have a never ending source of energy.
