Lewis Hamilton painted a glum picture in his post-race interview with BBC Sport after the Italian Grand Prix, describing his ninth-place finish as the result of “a disaster of a weekend.”
While Hamilton was clearly a disappointed man and also said he “drove like an idiot” in qualifying, his overtaking moves during the race were a delight to behold as he carved his way through the field after an early puncture forced an unscheduled stop.
Hamilton surged past Lotus’ Kimi Raikkonen and both McLarens in the final laps of Formula One’s fastest circuit, using his KERS power-boost system to good effect. But what is KERS exactly and how did it benefit the Mercedes man?
KERS stands for Kinetic Energy Recovery System and is a means of recovering a vehicle’s kinetic energy from the heat generated by the car braking. The energy is then stored in a battery or used to turn a flywheel for later use under acceleration, particularly useful for a Formula One car to gain extra speed on long straights such as those in Monza, particularly on the 650-metre stretch on the start/finish straight where Hamilton passed Sergio Perez and forced Raikkonen into an error before blasting past at Curva Grande.
System failures are not uncommon, however, and it was exactly why Raikkonen was unable to defend his position properly as he suffered with a KERS problem.
The system was introduced in the 2009 season but due to the expense of implementing the device, only four teams decided to employ it: Ferrari, Renault, BMW and McLaren. Now, it is used by all teams.
There are two principal KERS systems that teams can employ, electrical storage by use of a battery or mechanical using a flywheel. The electrical battery system is now the universally used method, utilising a motor generator incorporated in the car’s transmission that converts mechanical energy into electrical energy to be stored in the battery and released when required by the driver.
The mechanical system, pioneered by Williams back in 2011, captures braking energy and uses it to turn a small flywheel that can spin at up to 80,000 rpm, connected to the rear wheels, when more power is required.
When the driver needs an additional power boost, either to aid passing or to maintain a gap to a chasing car, the driver simply presses a boost button on his steering wheel to unleash an additional 80bhp. It can be worth as much as 0.3 seconds a lap—a lot in Formula One. It is also of vital importance at the start of the race when the device is already fully charged, allowing the driver an extra boost off the line.
But KERS is not merely important to help Formula One cars in a racing situation. Like so much other F1 tech, it is also used to promote the development of environmentally friendly and road-car-relevant technologies.
The flywheel device developed by Williams was fitted to Porsche's new 911 GT3 R Hybrid road car in 2011, and this year Ferrari unveiled a KERS system for a road car engine at last year’s Beijing Auto Show.
As of 2014, the capacity of the KERS units in F1 will increase from 60 kilowatts (80 bhp) to 120 kilowatts (160 bhp) to balance the sport's move from 2.4 litre V8 engines to 1.6 litre V6 engines.