Yes, it is 'Kinetic Energy RECOVERY systems'. When a car uses its brakes the kinetic energy is normally converted to heat. In F1 now when they brake they convert some kinetic energy into electricity instead of heat (in the brakes) and store it in a battery. Or in one team they convert it into momentum of a spinning flywheel. An electric motor than assist the engine during the 6s, yes they are hybrids!
There is no magic, its simple physics. You can do this in an internal combustion car by disconnecting the battery for long periods and charging during braking. As a result you brake less hard and convert some energy to stored electricity, but I suspect the result wil be less than impressive. I did see one performance device that disconnected the battery during acceleration, not huge benefits but perfectly valid. Increasing the alternator output may help with this, but I doubt a simple regulator change would be enough and it requires another device to control when to charge (ie during braking or if voltage too low).
-- Tony