A regenerative braking system is a system in which the power is generated through friction energy while applying brakes which otherwise would be lost to the environment. In this system, an electric motor that normally drives a hybrid or pure electric vehicle is essentially operated in reverse (electrically) during braking or coasting. Instead of consuming energy to propel a vehicle, the motor acts as a generator that charges the on-board batteries with electric energy that would normally be lost as heat through traditional mechanical friction brakes.
In this system the heat and kinetic energy is being converted into electrical energy with the help of generator. The amount of energy which is been produced with the help of generator thus stored into a battery. The stored energy can be further used for the better performance and efficiency of the vehicle. Thus accompanying friction arms to the normal brake pads in overcoming inertia and help in slow down the vehicle.
Practical investigation of a regenerative braking system shows about 35% saving in fuel consumption. It lowers operating and environment costs of a vehicle and should make it more efficient.