Formula One’s first attempt at producing a hybrid engine was the Kinetic Energy Recovery System (KERS), introduced in 2009. The system functioned as an add on to the existing V8 engines, allowing for a boost of 60kW (around 80bhp) for almost 6.7s a lap. Such numbers are small by today’s standards, but could still be significant.

The boost in power obviously helped with lap times, and was also perceived as an aid to overtaking. This is particularly at the race start (more on that later). The KERS regulations were flexible about how the energy could be stored, with capacitors, batteries and flywheels all legal. However, every KERS system had similar downsides. Firstly, they were heavy, weighing up to 30kg, which negatively affected the cars weight distribution. In addition, concerns around reliability, tyre wear and cooling (not to mention its high cost and safety concerns) meant that there were significant downsides to the system.

Many teams opted not to run KERS in 2009, including championship winners Brawn GP. Here, I take an in depth look at what opinions of KERS were at the time, which teams ran the system, and whether the benefits outweighed the costs.

Early Opinions

As far back as June 2008, Ross Brawn was doubting whether teams would actually run KERS in 2009. His predictions came true, with every manufacturer (and the independent Williams too) developing a system whilst simultaneously being unsure of if they would actually use it.

2008 also saw a couple of high profile incidents which highlighted the potential dangers of the system. Firstly, a KERS failure caused a fire at Red Bull’s factory. Shortly afterwards, a BMW mechanic electrocuted himself touching a KERS enabled car. These two incidents likely did little to influence teams on whether to use the syste. However, it may have contributed to the general lack of enthusiasm by key players and was certainly not good optics.

Pioneer or Primitive?

Perceptions of the technology were quite mixed. President of the FIA, Max Mosley, claimed that KERS was “set to revolutionise F1” and make the sport “environmentally friendly, road relevant, and at the cutting edge of future automotive technology.” However, objections came from a variety of sources for differing reasons. There were regular claims that the system was too expensive, unsafe and not road relevant. Perhaps the most damning response came from Toyota, who were world leaders in hybrid technology at the time. They complained that the system was primitive. Flywheel engineer John Hilton made similar comments, suggesting that their flywheel system used elsewhere was too good for the F1.

Given the costs involved, and the understanding that the benefits of the system may be minimal, there was even a late attempt to block the introduction of KERS until 2010. A unanimous vote was required, and every team agreed except BMW. Renault team principle Flavio Briatore called the decision a “terrible mistake”, despite Renault eventually running the system.

Uncertainty of Benefits Within Team

Toyota were the first to confirm they wouldn’t use the system in Australia. They also suggested that this would give them competitive advantage, but were still open to using it later in the season. However, at the start of 2009, most teams had yet to make their mind up about KERS. Red Bull, Ferrari, Williams and BMW all agreed that they didn’t know if the system was even worthwhile. This was despite BMW’s insistence that it should be legal.

Although the system could be added and removed from cars relatively easily, the lack of commitment either way from most teams is perhaps surprising. A generous interpretation is that teams didn’t want to give too much away. The reality appeared to be that no-one had figured out if it provided a net benefit or not.

Use of KERS in 2009

It seems clear that the pros and cons of using KERS were finely balanced in 2009. In some ways that was a good thing, as teams that didn’t want the cost of the system didn’t have to run it (although this was somewhat undermined by the fact that several teams developed a system they didn’t use). However, the use of KERS and how teams spoke of it varied hugely.

Brawn and Red Bull: Championship challengers

Red Bull surged up the order in 2009. As a customer team, they worked closely with Renault, and like other teams ran tests. However they never ran the system in 2009.

Brawn GP also never ran the system, as their modest staff numbers and budget made it an impractical option. However, they were born out of Honda, who had previously a KERS system that they planned to run. Honda’s analysis from the time concluded that it was worth at least two tenths per lap at most circuits. This was presumably before the negative impact on weight distribution is considered.

This means there was a real possibility of a KERS car winning both championships had Honda continued in the sport. However, both Toyota and Williams planned to use a KERS system that they never actually ran, so there is no guarantee that Honda would have actually implemented the system either. Ross Brawn (head of Honda/Brawn GP) suggested that the team planned on an optional system that could be added/removed for different Grand Prix, depending on the benefits offered for each circuit. Regardless, the 2009 world championship was ultimately contested between two teams that never ran the system.

Dedicated KERS users: Ferrari and McLaren

The two teams that ran the system for most of the year were McLaren and Ferrari. Ferrari suffered a KERS failure at Malaysia, which was significant enough for Ferrari mechanics to wear gas masks as a precaution as they handled the car. (Kimi’s eventful weekend race also featured Ferrari fitting him with full wet tyres on a bone dry track. Somehow, his most memorable moment of the weekend was eating an ice-cream.) Due to the KERS failure, Ferrari ran without it at the next race in China before putting the system back on for the rest of the season. Ferrari driver Massa suggested that the lack of KERS in China was a “step-back”. This was the first clear indication from a driver that KERS was a net benefit.

The McLaren KERS was considered the lightest system on the grid, due to improvements made in power densities and experimenting with electrical circuit setups. Even then it was not utilised in every race, with the team opting against use at Silverstone, presumably due to the lack of braking opportunities.

McLaren and Ferrari finished the season 3rd and 4th in the constructors, with the two teams winning 3 races between them. Whilst this suggests that a KERS car could be competitive, the fact that they fell back from 1st and 2nd is a clear sign that their general direction for the season was misguided. That doesn’t necessarily mean that KERS was the issue though. One simple explanation for this fall from grace is that both teams had focused on their 2008 championship challenges whilst others turned their attention to 2009 early on.

BMW and Renault: Uncommitted KERS users

Countering this argument is the fortunes of BMW and Renault during 2009. Robert Kubica was famously unhappy at the team stopping development of their 2008 car to focus on 2009. Renault meanwhile had no championship to consider in 2008 and unlike other teams were able to significantly improve their engine over the winter. Despite this, both teams had hugely disappointing campaigns, slipping to the back of the midfield.

We can’t say that KERS was responsible for these failures. However, it’s unlikely to be a coincidence that every team that ran KERS during 2009 finished lower in the championship than it had the previous year. All 4 teams also started the seasons with an identical driver lineup to 2008.

Removing KERS

Renault and BMW also both ditched KERS after just a few races. By June, head of BMW Mario Thieson suggested that no-one would run KERS unless it became mandatory. This was quite a climb down for the only team that insisted KERS should be used in 2009. However, he somewhat bafflingly called the BMW KERS system a “huge success“. The announcement came a couple of months after BMW stopped using KERS, with suggestions inbetween these dates that the team was intending to run the system again ultimately coming to nothing. This paints a rather messy picture of BMW’s KERS policy. To muddy the water further, the team also had different KERS policies for their two drivers. Whilst Nick Heidfeld used it at 4 races, teammate Kubica used it just once, in Bahrain. This was due to Kubica being a heavier driver, which already negatively affected mass distribution.

This fact highlights how finely balanced the line was between KERS being an asset and a liability. Overall it felt like BMW were in denial of how ineffective their KERS system was, having supported the concept so obviously before the start of the season. Perhaps there were also political pressures at hand, particularly with the parent company suddenly turning their back on the sport.

Uncertain Conclusions

Having one driver with KERS and another without does allow a direct comparison between the two. Unfortunately we only have three races where they had distinct cars, which makes any conclusions tentative. However, the data seems to indicate that KERS was not providing a noticeable benefit to Heidfeld. His average deficit to Kubica was larger when he had the (supposed) benefit of KERS!

Ultimately they decided that a more tightly packaged aero system outweighed any benefits of KERS. A case could be made that their results began to improve after this point. However, the evidence does not directly support this. Firstly there several races between BMW ditching KERS and the team becoming regular points scorers. Secondly their rise up the grid was far less impressive than McLaren’s, who maintained KERS until the season’s end.

In a similar vein to BMW, Renault also seemed reluctant to formally reject KERS after they stopped using it. They even reintroduced it after several months for the long straights at Monza. Despite this Alonso suggested that the system provided no lap time benefit and was exclusively used as a strategic device for the start.

Toyota and Williams: Non-KERS users

In the late 2000s, Toyota were strongly associated with hybrid technology, both commercially and within other forms of motorsport. As such, they were an ideal candidate to prosper with KERS. Whilst they did begin development of a system, they never appeared to seriously consider using it at any event. It’s been suggested that their experience with hybrid cars actually hurt them! This is because they refused to push the boundaries of the technology for fear of missteping, which could negatively affect their commercial sales. (As a side note, this kind of conservative attitude is a major reason why they never succeeded in F1.)

Williams were the only team to fully develop a flywheel system as opposed to an electrical battery. They were also the only non customer engine to develop their own system. Similar to Toyota, Williams confirmed they wouldn’t use KERS at the season opener, and talk of a potential midseason introduction came to nothing. Unfortunately this denied us the opportunity to see the a flywheel design in F1.

Toro Rosso and Force India: Non-KERS developers

The other teams on the grid were Toro Rosso and Force India. Like team Red Bull, these two teams had the option of running a manufacturer’s KERS system, but never did so in anger. These 3 teams would all have ran different KERS systems (Red Bull, Toro Rosso and Force India used Renault, Ferrari and Mercedes engines respectively). This suggests their choice was dictated by general principles, rather than the limitations of a specific KERS system.

It’s possible that these three customer teams wished to maintain a more simple but focused program. Alternatively, perhaps the benefits of full integration between the engine, KERS and chassis afforded by manufacturers meant that it was less worthwhile for the customer teams. One final point to note, is that the results of these 3 teams over the season showed no pattern. Toro Rosso had a disastrous campaign. Force India were genuinely competitive on some circuits. Red Bull were championship contenders. This contrast further underlines that KERS was not the most important factor in a team’s success over the season.

KERS Use vs Success

As seen in the table below, the biggest indicator of KERS use in 2009 was a team’s finishing position in 2008. Whilst it’s tempting to consider this to be incredibly revealing, it is actually just highlighting what we’ve already established: In general manufacturers used KERS, whereas customer teams did not. The only exception to this rule was Toyota.

Team	2008 Constructors POSITIon	USED KERS in 2009?	ENGINE MANURFACTURER?
Ferrari	1	YES	YES
McLaren	2	YES	YES
BMW	3	Sometimes	YES
Renault	4	Sometimes	YES
Toyota	5	NO	YES
Toro Rosso	6	NO	NO
Red Bull	7	NO	NO
Williams	8	NO	NO
Honda/Brawn	9	NO	NO
Force India	10	NO	NO

We can also compare how teams improve/declined from 2008 to 2009, and whether they ran KERS or not:

The chart above looks pretty damning for KERS, but should be interpreted within context. Firstly, the significant rule changes mixed up the grid in general. The fact that the previous championship competitors fell to the upper midfield is actually pretty standard after a major rule change, even if their early season slump was more extreme than usual.

We can also see that the teams that partly used KERS (Renault and BMW) fell back more than those that kept with it. Overall there was no general consensus across the 2009 season as to whether KERS was worthwhile. The indecisiveness of BMW and Renault is only one example of this. Hamilton suggested it was worth four tenths at Monza, but this was refuted by Alonso, who suggested the time gained on the straights would be lost elsewhere. Alonso’s comments on KERS echoed those made by Christian Horner earlier in the year: KERS was “more of a strategic tool than a performance tool”. So what exactly was this strategic gain?

Clear Benefits of KERS

Crucial Overtakes

There are a couple of examples of KERS enabled cars making overtakes at crucial points. The most obvious is Räikkönen’s overtake of Fisichella on route to victory in the 2009 Belgian Grand Prix. Whilst overtakes half way down a straight are not rare occurrences with DRS, such an easy pass was unprecedented at the time. The fact that Fisichella seemed to be faster over the race only emphasised the importance of KERS more. Räikkönen used the system defensively on the straights when necessary.

It is also sometimes forgotten that Räikkönen started the race down in 6th. The only reason he was in contention at all was due to a brilliant KERS assisted start, combined with some canny car placement at La Source.

Another example was Hamilton’s win in Hungary, where he had to overtake the Red Bull of Mark Webber twice on route to victory. Hamilton specifically referred to KERS allowing him to make the overtake work. KERS therefore had a significant role to play in 2 out of the 3 races won by KERS cars in 2009.

Race Starts

As alluded to with Räikkönen in Belgium, KERS seemed designed to thrive at race starts (and to a lesser extent, safety car restarts). To test how significant this effect was, I studied how likely cars were to gain/lose positions on the first lap.

(Non-KERS cars did not include Red Bull and Brawn, as I wanted a roughly fair comparison of average grid positions).

Whilst a non-KERS car was roughly as likely to gain places as to lose them, a KERS car was more than twice as likely to gain places than lose them. The difference is made even starker if you look at the exact number of places gained/lost.

A non-KERS car chances in the first lap are probably not a great surprise. The results resemble a Normal distribution, with the most common result being the driver staying put. Perhaps more surprising is that the KERS cars do not follow this trend, with a roughly flat line for anything between gaining 4 places and losing 1. The small increase in probability for a driver losing 5 or more places is typically due to an accident or technical issue.

2009 was before DRS and Perelli tyres were introduced, meaning that overtakes were generally rare in this era after races starts. This is despite the new rules for 2009. Attempting to overtake a driver that was strategically deploying KERS could be especially difficult, as referenced by Ross Brawn, although the era did at least offer ways past via different fuel strategies.

No Gains From Pole

One thing to remember with places gained/lost is that the potential change depends on the initial grid position. Some of biggest gains were made by Fisichella and Badoer, who gained an average of 3 places on lap 1 due to their lowly grid positions. This may suggest that the data is overemphasising the potential gains of KERS, but it also looked at data from non-KERS drivers who generally qualified poorly for comparison.

In contrast, Hamilton secured 4 poles (equal to that of champion Button), and maintained the lead every single time with a KERS enabled McLaren. These perfect starts are recorded as “maintaining position” above, meaning if anything KERS’ prowess in starts is slightly underrated. (For comparison, non-KERS pole sitters maintained the lead 8 times out of 13, a little over 60% of the time.

Regardless, the general trend is clear: KERS was a genuine benefit at the start of a race. The trend is also consistent and significant enough that other possibilities (such as McLaren and Ferrari’s launch systems or driver launch abilities were simply better, independent of KERS) can realistically be dismissed as the main differentiater. Despite this, KERS cars did not always get good starts. A good example was Räikkönen’s 2nd on the grid at Monaco. Much was made of his potential to take the lead, only to see him lose a place instead.

Other Uses

KERS could be a useful asset in qualifying, with drivers able to use a full laps worth just before starting their lap, then getting another 6.7s boost on the lap itself. When combined with their aforementioned strong starts, this meant that KERS cars could potential be in artificially strong positions early in races.

Would KERS teams adjust their strategy due to this? Remember that cars in 2009 qualified (in Q3) with the fuel they started the race on, meaning a team could theoretically run heavier in qualifying knowing that their KERS use in qualifying and race starts could theoretically make up the difference. However, when I looked into this, I saw no significant difference in starting fuel loads of strategies employed. This may be due to the competitive nature of the 2009 season: with differences of a few tenths often putting drivers several places behind rivals.

So, Was KERS Worth It In 2009?

The use of KERS by some teams and not others created a fascinating dynamic. It’s clear that every team was at least considering running KERS at some point, but most were unconvinced of its benefits over the season.

This is not necessarily a dig at the general concept, but the reality of the specifics of the technology and regulations during 2009. After all, KERS later became a staple part of all competitive teams from 2011-13, despite the basic set up being the same as 2009.

A Beneficial Concept, in Theory

McLaren finished the season with a genuinely competitive car, and the KERS cars of Hamilton and Räikkönen were the top scorers in the last 8 races of the season. Whilst McLaren’s turnaround was primarily due to aerodynamic improvements, KERS was an integral part of their package for most of the year.

This, combined with the clear benefits of KERS at vital points in the race, perhaps suggest that in a world where a team had infinite time and resources to perfect their car, they would run KERS in 2009. That doesn’t mean that developing and running KERS in 2009 was a good idea in reality though. There was much to focus on before and during the season, with the reintroduction of slick tyres being combined with fundamentally different aero regulations. It is perhaps telling that none of the 3 teams that found the double diffuser loophole (Brawn, Williams and Toyota) ever ran KERS. Neither did Red Bull, who nailed the new regulations.

Based on this, I would tentatively conclude that KERS was beneficial in 2009 if implemented well. However, it was typically a distraction that took attention and money away from areas that had much larger lap time gains. The comments and attitudes from Renault and BMW also suggest that it may have been a hard system to integrate.

KERS beyond 2009

Rejection in 2010

The cost consideration of KERS became more acute as 2009 progressed. As the global financial crisis hit in 2008, the FIA responded with proposals to slash costs and impose a severe budget cap for 2010. This lead to every team threatening to quit F1 altogether at one point. Whilst KERS mainly took a backseat in these negotiations, the fact that the FIA was demanding teams to dramatically slash their spending for 2010 despite introducing a new technology cost tens of millions in dollars in 2009 demonstrated the rapid shift in priorities.

This ultimately lead to a gentleman’s agreement between teams for KERS to not be used during 2010, despite it still being in the regulations. This was remarkably similar to the delay for the technology that was proposed for 2009, but this time there were no objections.

Return in 2011

When KERS returned for 2011 (with a raised upper mass limit for the cars), all teams that could afford to run it did so. However, Red Bull we’re still somewhat skeptical of the system, and won the first race of the year despite not having the system on their car. By this point KERS was generally thought of an asset, but weight and reliability concerns still persisted.

After being used for a few more years, KERS became fully integrated into the design of the hybrid engines that debuted in 2014. However, the full scope of the current engines is significantly more advanced than the original KERS system, which only focused on kinetic (not thermal) recovery.

Road Relevant Applications?

One of the main reasons KERS was introduces was to push F1 in a direction that was more relevant to road technology. So, did it actually make any difference?

As previously mentioned, it had been suggested even before the season that the 2009 regulations were too primitive to have any real applications. Heck, Mercedes developed a somewhat comparable system for F1 in the 1990s. However, Williams’ system eventually made its way onto buses, although it was considered too cumbersome for many road cars.

Perhaps the biggest achievement of 2009 KERS is showing that F1 could become hybrid. It ultimately paved the way for KERS to become standard in F1, and for the modern hybrid engines. These engines had similar criticisms to KERS on the cost front, but have definitely helped to push boundaries of what is possible in terms of engine efficiency.

Conclusions

• KERS was right on the cusp of being beneficial across the 2009 season.
• The system was clearly beneficial during race starts, making it significantly more likely for drivers to gain places on the opening lap.
• However, it was expensive, and it was questionable whether there were consistent lap time gains given it’s significant downsides.
• All the teams that used KERS fell backwards relative to the 2008 standings, and none of them discovered the Double Diffuser loophole. KERS may acted as an expensive distraction relative to other much more significant aero gains despite its advantages.

Further Reading

Technical information on KERS in 2009

Different energy storage options explored by teams

June 2008 interview with Pat Simonds and Geof WIllis on KERS development

Autosport have many illustrations of KERS in 2009

Williams’ flywheel KERS system and its uses outside of F1