Formula E, the numbers of the technological leap: from the beginning to Gen4 | FP

By Carlo Platella
The Mexico City E-Prix inaugurated the tenth historic season of Formula E. In the same weekend, the multiple Olympic champion Usain Bolt was the protagonist of a performance with the GENBETA, a modified version of the Gen3 which offers a glimpse into the future of category. Long gone are the days of the first generation, a seemingly prehistoric car compared to the current ones, a sensation which itself is an indication of the speed with which technology evolved in the first decade of the championship.

Gen1 (2014-2018)

In 2014 the first E-Prix in the history of the category was held. The Gen1s take to the track in Beijing, single-seater with Dallara chassis capable of releasing up to 200 kW of power, limited to 150 kW in race configuration. The battery is the main limiting element, with just 28 kWh of energy available, forcing drivers to make the iconic mid-race car change. The accumulator is made by Williams Advanced Engineering, while in the first year McLaren Electronic Systems supplies the powertrain to all participants.

Starting from the second season, the electric motor, inverter, gearbox and suspensions are designed directly by the manufacturers. Remember Lucas di Grassi: “As soon as the constraints were opened, there were immediate improvements in performance and efficiency. A five-year real-world development program, with the goal of improve engine efficiency by 10%was completed in just one year of racing in Formula E.” In a short time the efficiency exceeded 95%, thus allowing the number of gears to be reduced, which dropped from 5 to 3, and then reduced to a single ratio.

For the second season the power in the competition was increased to 170 kW, rising to 180 kW in 2016. In the same year, the third since the birth of the category, the debut took place the Gen1 EVO. What has changed above all is the front wing, which changes to a particular biplane configuration. In three years of free technological development, the team title was awarded to as many manufacturers, Renault, Audi and DS, a sign of extremely dynamic competition on a technical level.

Usable energy: 28 kWh
Maximum power: 200 kW
Maximum race power: 150 kW (2014-2015), 170 kW (2015-2016), 180 kW (2016-2018)
Maximum regeneration power: 200 kW
Voltage: 1000V
Battery weight: 230 kg
Minimum weight: 888 kg (pilot included)
Number of reports: 5 (2014-2015), 3 (Audi, 2015-2018)
Power-weight: 0.23 kW/kg
Battery energy-weight: 0.12 kWh/kg
Battery power-weight: 0.87 kW/kg
Pit-stop: car change
Energy regenerated during the race: 15%
Rear-wheel Drive
Chassis: Dallara
Battery: Williams Advanced Engineering
Powertrain: McLaren Electronic Systems (2014-2015), manufacturers (2015-2018)
Estimated maximum speed: 225 km/h

Gen2 (2018-2022)

In 2018 the Gen1s retired after four years, making way for the futuristic Gen2s. The new battery from McLaren Applied Technologies represents a clear step forward, going from 28 to 52 kWh of energy, improving the energy-to-weight ratio from 0.12 to 0.19 kWh. Considerable work was then carried out to improve aerodynamic efficiency, reducing the rear wing to two small side flaps and fairing the front wheels. Drivers are thus able to complete the entire race distance without changing cars.

The maximum power in qualifying goes from 200 kW of the Gen1 to 250 kW of the Gen2. The regeneration power during braking has also increased, which means that during the race the cars recover around 25% of the overall energy, compared to 15% of the previous generation. Mid-cycle was also expected the introduction of the Gen2 Evo, characterized by a more aggressive aerodynamic look with open wheels and a stabilizing fin at the rear, but the complications of Covid forced its debut to be cancelled. On the other hand, it was decided to increase the race power for the 2021-2022 season, bringing it from 200 to 220 kW.

Usable energy: 52 kWh
Maximum power: 250 kW
Maximum racing power: 200 kW (2018-2021), 220 kW (2021-2022)
Maximum regeneration power: 250 kW
Voltage: 1000V
Pit stops: no
Battery weight: 280 kg
Minimum weight: 903 kg (pilot included)
Number of reports: 1
Power-weight: 0.28 kW/kg
Battery energy-weight: 0.19 kWh/kg
Battery power-weight: 0.89 kW/kg
Energy regenerated during the race: 25%
Rear-wheel Drive
Frame: Spark
Battery: McLaren Applied Technologies
Estimated maximum speed: 280 km/h

Gen 3 (2022-2024)

After another four years, the Gen2s give way to the third generation of cars, bringing about a technological revolution with an even broader scope than the previous one. If with Gen2 the priority had been the specific energy of the battery, the Gen3 has the main objective of increasing maximum power, which in the traction phase goes from 250 to 350 kW. The biggest innovation, however, is the introduction of a second electric generator at the front, which can only be used when braking. The regeneration power thus rises to 600 kW, allowing for recover up to 40% of the total energy marching . It is no coincidence that the organizers limit the useful capacity of the battery in the race, bringing it to less than 40 kWh.

The 100 kW of power gained is accompanied by this a significant weight reduction, saving almost 50 kg compared to the Gen2, thus dropping to 854 kg in total, including the driver. In Formula E's plans, Gen3 will allow the return of pit stops in the category. Starting from the middle of Season 10, in some E-Prix the drivers will return to the pits to carry out the Attack Charge, a fast battery charging at 600 kW for 30 seconds, recovering approximately 10% of the initial energy.

Battery capacity: 51 kWh (<40 kWh usable in the race)
Maximum power: 350 kW
Maximum power in the race: 300 kW
Maximum regeneration power: 600 kW
Voltage: 1000V
Pit stop: fast charging (from 2024)
Battery weight: 284 kg
Minimum weight: 854 kg (pilot included)
Number of reports: 1
Power-weight: 0.41 kW/kg
Battery energy-weight: 0.18 kWh/kg
Battery power-weight: 1.23 kW/kg
Rear-wheel Drive
Frame: Spark
Battery: WAE
Estimated maximum speed: 320 km/h

The future

For the 2024-2025 championship, the debut of an evolved version of the Gen3 is expected, whose former project manager Alessandra Ciliberti has already provided some previews in recent months: “We are considering using the front powertrain also during the push phase, enabling all-wheel drive in specific scenarios”. The hypothesis is to allow the use of all-wheel drive in qualifying and during the Attack Mode regime in the race. Meanwhile, Formula E has begun to test its potential with the GENBETA, a performance car that embodies a modified version of the Gen3, whose thrust power reaches 400 kW.

Gen3 Evo (2024-2026)
Battery capacity: 51 kWh (<40 kWh usable in the race)
Maximum power: 400 kW (to be confirmed)
Maximum power in the race: 300 kW
Maximum regeneration power: 600 kW
Voltage: 1000V
Pit stop: fast charging
Battery weight: 284 kg
Minimum weight: 854 kg (pilot included)
Number of reports: 1
Power-weight: 0.47 kW/kg
Battery energy-weight: 0.18 kWh/kg
Battery power-weight: 1.41 kW/kg
Traction: all-wheel drive (qualification and Attack Mode only, to be confirmed)
Frame: Spark
Battery: WAE

The debut of the Gen4 is expected in 2026, for which supplies have already been assigned. Spark will continue to supply the chassis, while the battery will be from Italy's Podium Advanced Engineering. The front electric motor will be manufactured by Marelli and can also be used when pushing, fully embracing all-wheel drive. The maximum power will thus rise to 600 kWa notable leap compared to the 350 kW of the Gen3 and above all compared to the 200 kW of the first generation.

Gen4 (2026)
Battery capacity 55 kWh
Maximum power: 600 kW
Maximum power in the race: 600 kW
Maximum regeneration power: 700 kW
Voltage: 1000V
Pit stop: fast charging
Battery weight: 340 kg
Minimum weight: 930 kg (pilot included)
Number of reports: 1
Power-weight: 0.65 kW/kg
Battery energy-weight: 0.16 kWh/kg
Battery power-weight: 1.76 kW/kg
Four-wheel drive
Frame: Spark
Battery: Podium Advanced Engineering

The budget

The numbers are the best witnesses of the technological growth of Formula E from its foundation to today. In ten years we have moved from cars that were unable to complete the race distance to batteries whose capacity is even excessive compared to real needs. In detail, we went from 28 to 50 kWh of capacity with the Gen3, of which however less than 40 kWh is systematically used in the race. All this while in parallel the maximum power rises from 200 to 350 kW, bringing the overall power-weight ratio from 0.23 to 0.41 kW/kg. The Gen2 filled the main initial gap, that of the specific energy of the accumulator, bringing it from 0.12 to 0.19 kWh/kg, and then went down slightly with the 0.18 kWh/kg of the Gen3 and the 0.16 kWh/kg expected with the Gen4. The data is emblematic of how energy per unit weight is no longer the priority for Formula E, which instead focuses increasingly on absolute performance. The battery power-weight ratio of the Gen4, in fact, will be equal to 0.65 kW/Kg, almost tripling the values ​​of the Gen1. However, economic concerns are holding us back from opening up to the free development of the battery, a component still subject to standard supply. Research into accumulators could be the great theme for the next decade of Formula E, whose development frontiers appear difficult to predict.

*: battery capacity 51 kWh, energy actually granted in the race less than 40 kWh
**: not confirmed
***: Ratio calculated based on battery capacity of 51 kWh