The verdict on KERS

Before the 2009 F1 season began, there was much talk about the introduction of regenerative braking devices, known as KERS (Kinetic Energy Recovery Systems), designed to make racing more road-relevant and to facilitate overtaking. However, with the announcement that Williams will now be subscribing to FOTA's "gentlemen's agreement" and dropping its plans to run the technology in 2010, it seems that the concept has been consigned - for the moment at least - to the scrap pile.

That teams have struggled to make KERS work effectively is shown by the fact that by Abu Dhabi, only two - Ferrari and McLaren - were still racing using the devices, of the four who began the season with them. For Renault and BMW, which both ran it up to and including Bahrain, KERS appears to have been an expensive distraction, at a time when they could least afford it. Both manufacturers struggled for pace in 2009, and they may come to regret having invested so heavily in technology that gave them little on-track advantage. Already BMW has been forced to pull out of F1, leaving the future of the Hinwil-based squad uncertain, and Renault may yet follow in the next few weeks.

In BMW's case it seems that the F1.09 may even have been quicker without KERS from the start. At both Melbourne and Sepang Robert Kubica elected to remove it from his car; in both qualifying sessions he outpaced team-mate Heidfeld, who kept it, by almost 0.7s. Perhaps influenced by other teams' struggles with the technology, Force India, Red Bull and Toyota all put on permanent hold their plans to introduce their own devices, despite in the latter's case having developed the technology to an advanced stage. Likewise the unique flywheel system favoured by Williams never made it to the racetrack, though the team had been hoping to race it in 2010, before it rejoined FOTA and subscribed to the mutually-agreed ban.

Indeed it is questionable how much KERS has improved racing in 2009. Certainly it has been easier for cars equipped with it to pass those without it. And there is a considerable advantage in using it off the starting line, as Kimi Räikkönen proved at Spa, rising from sixth to second within the first few corners. Nonetheless, its benefits over the course of the season have been variable: fast circuits have tended to be better suited to it than tight, twisty ones; hence Renault dusted off their device at Monza despite having abandoned the experiment at most other venues.

Perhaps counter-intuitively, KERS has been less potent as a means for overtaking than as a defence against following cars. Again this was most apparent at Spa, where Giancarlo Fisichella was unable to take the lead from the Ferrari of Räikkönen, despite having visibly the quicker car for much of the Grand Prix. Although slower through the twisty second sector, the Finn was able to stay ahead by using his KERS to accelerate harder along the main straights up to Les Combes and the Bus Stop, thus denying Fisichella a slipstream into the key passing places.

By and large the advantage in lap time gained by using the technology seems to have been negligible, since it is offset by the penalty of having less movable ballast to help balance the car. More efficient systems, with a better power-to-weight ratio, would go some way to solving this problem, but that would require even more development, and consequently more investment. In the current economic climate that is an unrealistic expectation, especially when gains can be made elsewhere more cheaply - in aerodynamics, for example. The fact that the four constructors which had a race-ready KERS this season were all backed by major manufacturers is a clear demonstration of how expensive the technology has been to develop.

Another reason why KERS has not improved the spectacle of the sport is because at the moment there is no tactical dimension to using it. One solution would be to combine the system with the PowerBoost (or 'push-to-pass') concept currently employed in A1 GP, in which the extra horsepower can be activated on only a limited number of occasions per race, rather than on every single lap. This would mean drivers would have to choose their moments and make instant judgement calls on whether to use it. If employed judiciously, it could help them rise through the field. Otherwise, if they use up their allocated number of charges too quickly, they may be left vulnerable later in the race.

For such a KERS/PowerBoost system to work, it would have to be made compulsory throughout the field, or else cars running it would be at a distinct disadvantage to those without. A good case might be made, then, for a standard system to be developed and made available - for a price - to all teams. Until recently the FIA has been reluctant to put out an invitation to tender, in the interests of promoting competition between the teams, though it is rumoured that Ferrari's suppliers MTS and Saft have been approached to supply a standard system in time for 2011.

Yet it is doubtful whether a standard system on its own will help increase overtaking, unless its use is restricted to a PowerBoost function, for the simple reason that all drivers are likely to be utilising their extra horsepower at the same points on each circuit. The effect will be to increase their straightline speed, but otherwise the cars will perform relative to each other exactly as if they each had no KERS at all.

Although the regenerative braking concept is far from being a failure, it is fair to say that so far it has not revolutionised F1 racing in the way that many might have hoped. And while the FIA is to be applauded for its vision of making the sport more road-relevant and perhaps in the longer term even greener, if KERS is to fulfill its potential in improving the spectacle of racing, there is still a lot of work to be done.