Formula 1 ERS Explained – Motorsport Explained

Formula 1 cars are a cutting-edge example of automotive technology. This car is loaded with tech that will help them race more efficiently and faster. One of the most recent examples of this technology is the ERS (energy recuperation systems), which is a hybrid form of technology.

In this article we will be discussing the two types of ERS currently used in Formula 1 cars.

ERS Overview

Since 2009, ERS have been used in Formula 1 in one way or another. All ERS are similar in their basic concept: they enable the car to save energy and use it instead of being wasted. But their design has changed a lot since their creation.

KERS (kineticenergy recovery system) was the first ERS to be used in Formula 1. KERS utilized either a flywheel (or a battery) to store the car’s kinetic energy during braking, and then supplement the engine’s power when necessary.

Formula 1 cars now use two different ERS. The MGU-H, which extracts thermal energy from the car’s exhaust, and MGU-K which is an evolution the original KERS.

Let’s now take a look at both these systems and discuss what they do and how it works.


The MGU-H, or motor generator unit-heat, is one of two ERS that can be found in Formula 1 cars. The MGU-H is used in conjunction with the turbocharger. It can be used as either a generator, or a motor, depending on the situation. 

To better understand the MGU-H, you should know some basics about turbochargers. The turbocharger basically consists of two major components, a compressor and a turbine. These are connected by a shaft.

The turbo’s turbine connects to the exhaust of the car, while the compressor connects to the intake. The turbine spins when exhaust gasses pass through it. The compressor is then spun by the spinning turbine. It takes in air and compresses it before it sends it down the intake.

The engine’s power is increased by providing more air to it. Turbocharging aids in more complete combustion. Turbocharged engines are therefore more fuel efficient than naturally aspirated ones.

The MGU-H is now attached. The MGU-H attaches to the turbocharger. It is located between the compressor and turbine. The MGU-H, like the turbocharger is also powered using the exhaust gas from the car. Some of the gas that would normally pass through the turbine is instead directed into the MGU-H.

The MGUH-H has a number magnets. These spin around when exhaust enters the MGUH. This is how electricity is generated. This power then goes to the car’s energy storages, where it stays until it is used again.

However, the MGUH-H doesn’t function as a motor; it only provides power for the turbo. Turbo lag is when the turbo spins up after the driver presses the accelerator. This is usually what happens when the engine heats up. Turbo lag can cause the engine to produce a lot more power than normal, but it is not always noticeable.

This can be compensated by the MGUH, which acts as an alternative motor that keeps the turbo’s compressor turning even when the driver isn’t using the gas pedal. Turbo lag is thus virtually eliminated.

It is worth noting that these are the last years for the MGU-H Formula 1 unit; in 2026, all Formula 1 teams will be able to stop using the MGU-H. This is mainly due to the complexity and high cost of the units.


Formula 1 cars use the MGU-K as their second ERS. This ERS performs the same function as the MGU-H. However, it is activated at different times and works with different components. 

Attached to the crankshaft is the MGUK. When the driver presses the gas pedal, the MGUK acts as an electric motor. It adds its own power to the engine. The MGU-K, when active, adds 161 horsepower (or more) to the car’s total output of power. Drivers can only use MGU-K for a limited time per lap.

The MGUK turns off its function when the driver applies the brakes or takes the gas pedal off. Instead of powering your car, the MGUK uses the kinetic energy generated by the crankshaft to create electrical power with magnets. It works in the same manner as the MGUH. The MGU-K’s resistance helps to slow down the car slightly.

What are the uses of ERS in a race environment?

So we now know that ERS gives extra power to key parts of the car. In practice, however, how do these devices work? Can they be activated at any time during a race or are they always active?

MGU-H is active because it provides additional power to the car in an indirect way. It does this by keeping the turbo’s compressor turning all the time. But the MGU-K adds more power directly to the car’s engine by sending more power down its crankshaft. The MGU-K cannot be activated for more than a few seconds each lap.

Each team decides where they will activate the MGUK before the race starts and for how long. Drivers don’t have the obligation to use all power at once. For example, they may use 2 seconds of MGU-K power on one section, while 1 second for another.

The MGUK gives drivers an advantage on specific sections of the track and adds another layer to race strategy.