How Formula E built the world’s most efficient electric vehicle

Just over eight months ago, the FIA ​​proudly announced the new beast in Formula E’s arsenal: the third generation of all-electric championship racing cars, the gigantic leap forward that would be a milestone in the series’ progress towards being a top-level sport.

That Gen3 EV is now three races and lots of tests, into its lifespan – one meant to run for four years all told. It’s not just about making cars smaller and lighter (both achieved) or even faster (somewhat under discussion), but also about increasing their efficiency.

Indeed, the FIA ​​proclaimed the Gen3 both the world’s first zero-carbon racing car and “the most powerful and efficient electric racing car ever built”.

Given the championship’s already established track record of transferring race week data into real-world enhancements for EVs sold by manufacturers involved in the series, it was quite a statement in both a sporting and wider commercial sense. But now it is also being shown more and more that it is not just a statement, but a result.

“We are only three races away and it depends on the efficiency of the teams storing it, but it varies from 40 to 50 percent of the energy used during the race coming from the regenerative part – it’s huge.” Such was the candid assessment of how successful Gen3 has been from an efficiency perspective, coming from one of the most informed sources available: Alessandra Ciliberti, the FIA ​​technical director responsible for carrying out the Gen3 plans.

Ciliberti, a mechanical and automotive engineer who previously worked in BMW’s electric vehicle department, played a key role in transitioning new race cars from a list of requirements and a technical brief to a track-worthy vehicle.

His current role at the helm of Formula E from a technical perspective means that the most critical part of the job was two years developing the Gen3 cars. “It was a great project, which allowed me to get close to cutting-edge technology,” he said the independent. “It’s basically an electric motor and you run it in the opposite direction. You use it to propel the car, but in regeneration it works the other way around, to get energy from the wheels, back into the motor and back to the battery. It’s the opposite use of the same hardware.”

All explained very offhandedly, of course, to someone to whom such feats of engineering are no doubt second nature.

For those less inclined or less adept at solving electrical and mechanical intricacies on the fly, a little more detail is needed as to where precisely the additional efficiencies were sought.

A coherent explanation is coming fast, as the masterplan of Formula E vehicles becomes clearer, as does the technology that will spill into commercial cars. “It comes from the fact that we are regenerating energy during braking. You are not wasting energy with conventional hydraulic brake systems. And it’s even more so because in the Gen3 we have added the front power unit. It is the first single-seater to have one.

“Both the front and rear axles regenerate under braking, up to 600kW in total. Much of the energy you use during the race is not stored in the battery from the start, otherwise the battery would be too big.

“So we harness the efficiency of braking technology that allows cars to go faster and further without needing extra cells in a battery – the more cells you have, the bigger the volume. It’s not feasible for a motorsport car.”

Again that’s a mission already accomplished in that regard, with the leaner Gen3 looking impressive so far in Mexico City and Diriyah.

But while size and speed matter visually to the distant viewer, there’s a race and a championship to be won.

For teams, and increasingly in the Gen3 era, race strategy plays a huge role this year in regards to using attack mode (increasing power for short periods of time) and energy management it is central to everything in Formula E.

While the car body itself is standardised, the open technology aspect means that the rear powertrain is up to the manufacturers to develop alongside the software they use. The ability to regenerate maximum energy during the race is – together with driving talent and decision-making, clearly – what can give the advantage and make the difference, turning missed shots into points and points into podiums.

And there’s more to come. Ciliberti notes that while the powertrains have been massively upgraded, the performance of the cars will continue to increase as more data is collected and more teams are grappled with the combination of new cars, tyres, equipment and even new race venues.

“Gen2 had only the rear thruster and regenerated 250kw. We increased rear horsepower to 350kw and then added 250kw up front, taking us from 25-30% regeneration efficiency in Gen2 to nearly 50% in Gen3.

“What we are seeing is that we still have a lot to leverage on the performance of the cars. It’s normal because we introduced it in record time, so the manufacturers have this new tooling and they put their own parts in it – you have to give it some time for the performance to reach a limit. We are going in the right direction, but there is still a lot to do.”

There’s always more to do—that’s the nature of competitive sport, not to mention technology. Ciliberti is working at the intersection of both, and as a self-confessed motorsport fan there is surely satisfaction to be had from seeing the finished article on the track?

Apparently, the answer is yes, albeit with initial trepidation and an acceptance that the wheels of progress keep turning.

“It was exciting, the moment when I drove the cars through the grid gear before the race, it was quite an emotional moment!” she said.

“After the first event we were happy; We still have challenges as we progress, but every race is a little more happiness for the work we’ve done.”

Except, as she points out, the job is never really done. Gen3 is in a delivery phase and Gen4 discussions are already active.

By its very nature, cutting-edge technology does not reach an end point. And given the obvious enthusiasm and insight into what has been learned and applied, you suspect the FIA’s chief technical officer would not think otherwise.

—

:: Buy tickets for the Hankook London E-Prix 2023 on Saturday 29th and Sunday 30th July by visiting the Formula E website.