ERS stand for Energy Recovery Systems. There are two basic types of ERS systems - mechanical and electrical and both recover energy without using fuel and damaging the environment. The rule to use KERS was introduced by the FIA in 2009. It works by storing energy in a flywheel or battery (like the one on the right) that would be lost when braking, and allow that energy to be re-used when accelerating. ERS was introduced in 2014 to activate wherever a driver chose permanently throughout a race weekend