From the racing driver’s perspective the vehicles will be similar to a traditional car, but with an extra aspect of drivetrain control that can be tweaked – regenerative braking. Formula 1 cars already use a system called KERS (Kinetic Energy Recovery Systems) which has a small generator to capture some of the energy lost during braking. That powers an electric motor for an acceleration boost when needed. Formula E will be able to do that to a much larger extent, using the electric motor as a generator with more power stored in the larger battery packs. The amount of regeneration could even be adjustable on the fly by the driver. Increasing the regeneration would be similar to increasing engine braking in a conventional engine, perhaps comparable to downshifting a gear.
But, as with many electric cars, the batteries are the crux. Although the cars will use high performance lithium batteries, they will not be able to hold enough charge for an entire 60-minute race. “With batteries the things you are playing with are the amount of torque that you generate, versus the range that you have, versus the weight of the battery,” says Peter Van Manen.
To increase the performance of the battery and to keep the weight down, the engineers had to compromise on range. And, as recharging during a pit-stop is currently impractical, races will feature what some consider a radical – even controversial – move: swapping cars mid-race. Formula E made the decision to introduce this rule after it was deemed impractical to swap the batteries during a pit stop. It also could not be done in a way that met safety requirements.
As a result, Formula E will feature pit-stops, where, instead of mechanics racing to get everything done, the driver will have to race from one car to another. “It will be kind of fun actually,” says Peter Van Manen.
But Formula E officials believe that future developments in battery and charging technology will eventually cut out the need for car swaps. For example, cars could be recharged as they race with variations on an inductive charge system or charging coils buried directly in the road.
In the short term, however, it is unlikely that any solution that requires major changes to infrastructure or special roads will be possible because of Formula E’s plans to host the races in major city centres. Already Rio de Janeiro and Rome have announced their intentions to host a race, and plans for London are in discussion. In all of these cities, sections of the city’s roads would be closed and converted into a temporary track, in a similar way to the Formula 1 race in Monte Carlo.
But, even without wireless roads, this new silent frontier in motor racing could eventually impact us all, says Peter Van Manen. “You’ll benefit early on from good racing, and then benefit again down the line with better electric vehicles and hybrids on the road.”