Mercedes' 2016-spec MGU-K | © F1i
SHORTER BRAKING DISTANCES = LESS ENERGY RECOVERED
As Zander alluded to, F1 batteries can receive up to 2MJ per lap from the MGU-K. The latter recovers that energy under braking. Like a bicycle dynamo, the generator slows down the vehicle – either instead of the brakes or in conjunction with them – by acting on the drive shaft.
With the maximum output of the energy recovery systems (ERS) still limited at 120kW, the amount of energy recovered depends on the time spent under braking. In other words, shorter braking distances will equate to a smaller energy harvest.
In 2016, drivers were braking for 1.1s (according to figures released by brake supplier Brembo) to decelerate from 330kph to 120kph on the approach to Turn 1 at Circuit de Barcelona-Catalunya. Overall, pilots spent 18 percent of the lap on the brakes. That figure is bound to decrease this year, with cars travelling faster through curves but slower on a straight line.
According to some reports, the braking time for Turn 1 in Barcelona could go from 1.1s down to 0.8s, which would affect the other seven braking areas at the Spanish Grand Prix venue. Some existing corners are even expected to become straights (i.e. be taken flat-out) in 2017, meaning even fewer opportunities to recover energy under braking.
Meanwhile, cars will spend more time on straights due to the increase in drag, so energy demands on these portions will be potentially higher. That said, the MGU-K energy is primarily needed “at the start of the acceleration phase so you can reach the highest speed as fast as possible”, Renault engine boss Rémi Taffin told F1i last year.
