How does KERS kinetic energy recovery system in Formula 1 work?

Answer 1

There are two basic types of KERS systems being developed for F1 - mechanical and electrical: both store energy that would otherwise be lost when braking, and allow that energy to be re-used when accelerating. In the mechanical systems, the energy is stored in a flywheel. When the driver brakes, the flywheel is driven from the car's transmission system to spin it up: when the driver needs the stored energy to add to the engine output under acceleration, the flywheel is re-connected to the transmission system and drives it. The direction of transfer of power (i.e. transmission to flywheel or flywheel to transmission) depends on the gearbox that lies between the two (a special continuously-variable-transmission gearbox is usually used). In the electrical version, under braking the transmission drives a generator that charges a battery: under acceleration, the battery drives an electric motor that drives the transmission. (The generator and motor can be the same device). More details can be seen on http://www.f1fanatic.co.uk/2007/09/26/kers-technology-revealed/ (mechanical version) and http://www.f1network.net/main/s491/st130882.htm (electrical version).