What Is ERS in F1? How Does It Differ From DRS?

The constant development of new and cutting-edge technology has always been the hallmark of Formula 1. Among the hundreds and perhaps even thousands of technological elements that go into a modern F1 car is the Energy Recovery System, simply known as the ERS. It’s a hybrid piece of technology that allows F1 cars to extract every last bit of performance and energy from its various components that would otherwise have gone to waste.

In this article, let’s dive deep into what makes the ERS system work and how is it different from the Drag Reduction System (DRS).

An Overview of the Energy Recovery System

Formula 1 thrives on pushing the boundaries of technology and engineering. Enter the Energy Recovery System (ERS), a hybrid system that first made its mark in 2009 with the introduction of the Kinetic Energy Recovery System (KERS). The concept was simple yet revolutionary–harness the energy lost during braking and convert it into a power boost when needed.

The ERS system in F1 has since evolved, and modern F1 cars have two essential ERS components. The MGU-H (Motor Generator Unit – Heat) and the MGU-K (Motor Generator Unit – Kinetic). These components work in harmony to capture the heat energy from the turbocharger and the kinetic energy during braking, transforming Formula 1 cars into energy-efficient powerhouses.

The MGU-H, connected to the turbocharger, plays a dual role as a generator and a motor. When operating as a motor, it eliminates turbo lag, ensuring optimal power delivery. On the other hand, the MGU-K, attached to the crankshaft, acts as an electric motor during acceleration and a generator during braking, adding an extra punch of power to the engine.

In F1, where every milliseconds matter, the ERS stands as a testament to the sport’s relentless pursuit of speed and efficiency.

What is Motor Generator Unit – Heat (MGU-H)

Now, let’s take a closer look at the first major component of the ERS–the Motor Generator Unit – Heat (MGU-H). This component works in tandem with the turbocharger, a critical player in the power-boost balance. Imagine a turbocharger as a duo–a turbine and a compressor connected by a shaft.

The exhaust gases from the Power Unit (commonly referred to as the PU) strike the turbine, setting it into a spin that, in turn, drives the compressor. This turbocharging process amplifies engine power and fuel efficiency. The MGU-H steps in as an electrical motor/generator nestled between the turbine and the compressor.

The MGU-H is a highly strategic system when it comes to Formula 1 cars. When operating as a motor, it ensures a seamless response from the turbocharger, eradicating the dreaded turbo lag during acceleration. As a generator, it converts the rotational energy from exhaust gases into electrical power, which results in flashing the red lights at the back of the car to signal energy harvesting to fellow racers.

However, due to the complexities involved and the high cost of manufacturing these systems, Formula 1 has decided that the MGU-H will no longer be used from 2026 onwards.

What is Motor Generator Unit – Kinetic (MGU-K)

The MGU-K is the second crucial component in the ERS. This unit, physically linked to the crankshaft, also plays a dynamic role. It morphs into a motor during acceleration and a generator during braking.

When the driver deploys the power, the MGU-K transforms into a compact electric motor, injecting up to 161 extra horsepower into the engine. However, there’s a catch. There is a limit on the duration of this power surge, allowing a burst of energy for only about 33 seconds each lap.

During deceleration, as the driver eases off the throttle or applies the brakes, the MGU-K seamlessly shifts roles into a generator. Harvesting kinetic energy from the still-turning crankshaft, the MGU-K generates electrical power, contributing not only to the energy store but also enhancing braking performance.

What is the Energy Store (ES) in Formula 1?

Now, let’s zoom in on the component that stores all the ERS magic. The Energy Store (ES) is essentially a lithium-ion battery, weighing between 20-25 kilograms, and serves as the core of the ERS, storing harvested energy from both the MGU-K and MGU-H.

The Energy Store’s role is not just about storage, though, it’s about strategic use of the stored power. When deployed, the battery releases 4 megajoules of energy per lap to the MGU-K, which offers a substantial boost to the Power Unit. Yet, there’s a balance–the recovery process from the MGU-K is capped at 2 megajoules per lap.

The Energy Store also ensures a delicate equilibrium between maximum and minimum states of charge, preventing excessive energy fluctuations during the race. This feature allows for gradual deterioration of the battery without the need for frequent replacements, a strategic nod to the efforts made by Formula 1 for a sustainable future.

READ MORE: What Is the Red Flashing Light at the Back of an F1 Car?

Now with all the components of the ERS out of the way, let’s take a look at how the ERS is deployed during a race weekend.

How is the ERS system used in Formula 1?

The utilization of the Energy Recovery Systems (ERS) in F1 is akin to a chess game on wheels. While the MGU-H remains tirelessly active, ensuring a continuous power supply, the MGU-K orchestrates a balance between harvesting and deploying the energy.

However, the real magic lies in the strategic deployment of this stored energy. Each team meticulously plans when and where to activate the MGU-K, determining its active duration for optimal energy allocation throughout the race.

Yet, plans are not set in stone. The unpredictable nature of racing introduces a strategic battle on the tarmac. Drivers may need to adapt their deployment strategy on the fly–a crucial overtake, a defensive move or a push for a podium finish can reshape the energy deployment strategies decided by the teams.

Enter the ‘strat modes’ or ‘SoC modes.’ You may have heard race engineers telling drivers over the radio to switch over to different modes. These are the modes they are referring to. They are essentially a set of predetermined power unit configurations. Charging mode prioritizes harvesting, Neutral mode balances energy, Deploy mode focuses on maximum energy usually used for qualifying laps, and the Overtake button on the steering wheel provides an instant power boost for critical maneuvers.

How is ERS different from DRS?

Now, let’s unravel the final piece of the puzzle–how ERS differs from the Drag Reduction System (DRS). Introduced in 2011 and still prevalent after rule adjustments from the start of the 2022 season, the DRS empowers the driver to manipulate aerodynamics for a competitive advantage.

The crux of DRS lies in the driver’s ability to open a flap in their rear wing when trailing within one second of the car in front. This deliberate adjustment reduces aerodynamic drag, enabling the pursuing car to achieve higher top speeds and potentially execute successful overtaking maneuvers. While both systems (ERS and DRS) aim to elevate the racing experience, they do so in distinct ways.

ERS is always available to the driver during a race as long as they have not used up the maximum energy deployment allowed per lap, offering strategic boosts at any moment, unrestricted by fixed activation zones. In contrast, DRS is a tactical tool, usable only when trailing within one second of the car in front to gain an aerodynamic boost by opening the rear wings. However, the DRS creates specific opportunities for overtaking.

On top of that, DRS can also not be deployed during the first two laps of a race, or after a mid-race restart, or after the end of a Safety-Car period. On the other hand, the use of ERS has no such restrictions. The differences extend even further, the DRS is disabled during wet racing conditions. However, drivers are still allowed to use the ERS as they please during wet conditions. Finally, ERS, rooted in energy dynamics, complements the car’s power unit, while DRS is all about manipulating aerodynamics for a speed advantage.

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As the technology evolves, so does the game on the track. The strategic deployment of energy and the nuanced balance between harvesting and boosting add layers of complexity to the sport we all adore.