Racing goes electric: At the track with Formula E, the first e-racing series

MIAMI—The pit lane we're standing in is unusual, and not only because it's a temporary setup placed in the shadow of American Airlines Arena (home of the NBA's Miami Heat). Garages are set up on both sides rather than being limited to one. A few things also appear to be missing. To start, a familiar smell from the usual mix of burning hydrocarbons is absent. And it’s remarkably quiet. The occasional impact wrench bursts out in a mechanical staccato, generators drone here and there, but there are no V8s burbling, no V6s screaming.

But the biggest omission? Well, it's what powers the entire event—or, perhaps more notably, what doesn't.

Welcome to Formula E, the world’s first fully electric racing series. Miami is playing host to the first of two US rounds—the next being held in Long Beach, CA, on April 4—and it's the fifth race in this ePrix's inaugural season. Given we’ve got a bit of a thing about racing at Cars Technica, as well as an obvious interest in electric vehicles, we had to be on the ground in Miami to experience this for ourselves.

The series kicked off in Beijing in September 2014, and this inaugural 11-round season ends in London this June. Each race takes place in a city center on a temporary street circuit, and the events are condensed into a single day. This both maximizes the spectacle for the fans in attendance and minimizes the disruption to everyone else in the city (with the road closures and so on). It's one of many things we discovered Formula E does in contrast to the more traditional two- or three-day race meeting.

The Miami track has been built on the streets surrounding the city's NBA arena (and the small park that lies next to it). But our day begins in the media center, a gigantic room that usually plays host to the Miami Heat (the court side bathrooms are really nice). After signing the requisite waivers and grabbing a cup of coffee, we head out to the pit lane with an open mind and a sense of curiosity about a series that was—and continues to be—viewed by some with a healthy skepticism.

The cars

Largely, that skepticism is aimed at the cars Formula E is racing. For this first season, each of the ten teams is using identical Spark-Renault SRT_01Es, open wheel race cars that look somewhat similar to a Formula 1 or IndyCar. Unlike those series, the SRT_01Es are actually a mix of carbon fiber and aluminum (rather than just carbon fiber), but that may be the least significant difference. Behind the driver where you’d normally expect to find a fuel tank and internal combustion engine, there’s a 28 kWh lithium-ion battery supplied by the Williams F1 team. This sends up to 200 kW to the powertrain, an electric motor, and five-speed gearbox (supplied by McLaren, another F1 team).

Both companies are rather proud of their contributions to the SRT_01E. Williams was constrained by a rulebook that insisted the battery couldn’t weigh more than 441 lbs (200 kg), and the design of the chassis also dictated its dimensions. Despite this, the company built a battery that actually exceeds the allowed energy storage and meets all the crash safety requirements. What’s more, it did it in six months, drawing on its experience in F1 and with the stillborn Jaguar CX-75 hybrid hypercar. McLaren actually adapted the electric motor and gearbox from its P1 hypercar for the SRT_01E. The company claims that, at 8 kW/kg, the motor has three or four times the power density of typical series hybrid motors.

During practice and qualifying, the SRT_01E is set to maximum power—200 kW, which is equivalent to 270 horsepower. In the races, this is reduced to 150 kW, although in practice drivers will turn this down even further to maximize battery life.

Ah yes, battery life. This is Formula E’s elephant in the room. At 28 kWh, the SRT_01E’s batteries don’t store enough electricity to last a full race, and recharging takes almost an hour—far too long to be practical in a pit stop. What’s more, a decision was made to use the battery’s safety cell as part of the car’s structure, so they can’t just be swapped during a race (even though Williams had just such a system in development).

The solution? Each Formula E driver needs two cars for the race, jumping from one to the other during a pit stop. In the lead up to the season, this idea drew much derision, and we must confess it still doesn’t sit right. However, the alternative would be a battery that weighed twice as much. The current Formula E battery has roughly the same energy density as Tesla’s 85 kWh unit, which weighs more than twice as much. And at almost 2,000 lbs, the SRT_01E could ill afford to gain more weight.

The final big difference between a Formula E car and every other single-seater—or just about every other circuit racing car for that matter—is the fact that these cars don’t use slick tires. Instead, Michelin has created bespoke 18" treaded tires that look quite similar to the Pilot Sport Cup 2s that the French company makes for track-focused super and hypercars like the Ferrari 458 Speciale or Porsche 918 Spyder. Michelin told us that despite appearances, the Pilot Sport EVs are still purpose-built racing tires. The fact that they have treads means no need for pit stops in the event of rain (slick tires with no grooves or sipes to displace water mean instant aquaplaning when encountering puddles), and this versatility allows it to bring many fewer tires to each race (further cutting costs and the environmental impact). It might be subjective, but to us the SRT_01E’s 18" wheels look a lot better than the tiny 13" wheels that F1 continues to use.

The result of all of this is a car that has a lot of low down acceleration, but which tops out at around 140 mph. On a purpose-built racetrack, the SRT_01E’s limitations would be quite apparent, but the layouts of the street circuits that Formula E runs are designed to reward the car’s performance envelope; the straights are short enough that the cars don’t seem slow. This is probably the main reason why both the Long Beach and Monaco rounds of the series will use shorter versions than the IndyCar and Formula 1 events those cities hold. (We have a sneaking suspicion that preventing direct lap time comparisons may also factor in to things.)