Why we won't see KERS at Le Mans this weekend

It had been widely anticipated that with the introduction of hybrid / Kinetic Energy Recovery System (KERS) regulations by the Automobile Club de l'Ouest (ACO) for this years Le Mans 24 hour race that we would at least see a Peugeot 908 turbo diesel hybrid running as a 00 car, but apparently not.

Peugeot have been carting a hybrid version of their 908 HDi FAP called the 'hy' around the show circuit over the last 12 months. The HY had a customer spec Magneti Marelli KERS system based on the same KERS system currently supplied to the Ferrari and Renault Formula One teams. It featured a 60 kilowatt (80 horsepower) gear-driven electric motor in place of a conventional starter motor, 600 lithium-ion battery cells and a power inverter behind the front left wing to control the flow of energy between the batteries and the electric motor.

Unfortunately while the ACO hybrid rules were announced last year the actual details of the rules were left blank 'pending consultation' with the teams. The resulting ACO regulations for KERS at Le Mans are nothing like the F1 KERS rules and the systems are technically not even similar, so the Peugeot with it's adapted F1 KERS system technically does not qualify to run at Le Mans.

Any LMP1 car contesting the Le Mans 24 Hours with KERS has to comply with the following specifications.

− Recovery of energy from the brakes on the 4 wheels or from the heat of the exhaust fumes.
− Only the rear wheels can be used to propel the car.
− Regarding energy recovery from the brakes, only electric systems are allowed.
− Only the storage of electric energy is permitted.
− The combustion engine and the electric motor must be controlled by the driver using the accelerator pedal (push to pass buttons forbidden).
− The quantity of usable energy stocked on board the vehicle must not exceed 1 MJ.
- The use of such a system must not be aimed at obtaining additional power but at reducing fuel consumption.

Where F1 KERS input / output is limited to the rear wheels only, the ACO allows input from all 4 wheels (70% of braking effort is on the front wheels so there is greater potential for energy regeneration / recovery) and the battery for storing the energy has a maximum of 1 MJ compared to just 400kJ (111 watt hour) of energy per lap in F1.

The ACO also allow recovery from the exhaust which can be either thermocouple, organic Rankine cycle (ORC) or even perhaps simply an electric generator run off an exhaust gas driven turbo expander very similar to a regular turbocharger.

A study by Cranfield University found that in 2009 KERS would be no advantage anyways due to the rule limiting hybrid vehicles to 80 liter fuel cells while non-hybrid vehicles are allowed 90 liters. In 2010 all cars will have the 90 litre tanks which will mean KERS equipped cars will have a significant advantage at Le Mans.

There is some speculation that these more advanced KERS regulations may prove too tempting for Toyota to over-look as they have already won a 24 hour race with hybrid electric motors on all four wheels, using wheel motors on the front, and they have stated repeadly in public they think the Formula One version of KERS is 'primative'. Either way, we won't be seeing Hybrids at Le Mans until 2010 at the earliest.