A hybrid car is a vehicle that uses two or even more distinct sources of power in order to get propelled. Among the power sources for a hybrid car there are gasoline or diesel fuel, on-board or out-board rechargeable energy storage systems (RESS), hydrogen, wind, compressed or liquid natural gas, solar, coal, wood or other solid combustibles, etc. The term hybrid car/vehicle is used most frequently to refer to hybrid electric vehicles (HEVs) in which an internal combustion engine is combined with one or more electric motors.

As mentioned above, there are other hybrid vehicles beside the hybrid car we will mainly deal with here. Just think of mopeds and electric bicycles. These are the simplest forms of hybrid vehicles. They combine the power from an internal combustion engine or electric motor with the power of the rider