Volvo has been working since 2011 to implement this technology in street-legal cars, and it has now been confirmed that the KERS system they will use in future alternative hybrid cars (these have come to have alternatives, too) will provide fuel savings of about 25 percent to owners, while decreasing emissions.
High performance motoring like Formula 1 has been an important source of inspiration since the invention of cars. Usually, it took years for technologies applied there to enter the mainstream automobile industry, and green inventions were usually not included. Kinetic Energy Recovery systems (KERS), however, succeeded.
Nowadays, every hybrid (an electric) car stores the braking energy in a battery and then propels an electric motor to help the internal combustion engine (ICE) get going. KERS, on the other hand, uses a slightly different approach: it halts the car by storing its potential energy into a flywheel that keeps spinning until you reengage the accelerator, when it transfers the momentum back to the rear wheels, thus saving fuel and the need for an expensive battery.
Volvo tested the system on an S60 sedan, which normally has a four-cylinder turbocharged engine. The extra 80 horsepower stored in the KERS were able to propel the car to 60 mph in just 5.5 seconds, which is nice for a heavy sedan with 250 to 325 horsepower (the 2013 version).