Ten years ago, at the 2009 Hungarian Grand Prix, Lewis Hamilton was the first driver in Formula One to win a race with a hybrid engine. The Kinetic Energy Recovery System (KERS) was the first step towards the electrification of Power Units in Formula One. Today, we’re looking at the hybrid F1 Power Unit and the development journey that lead to one of the most efficient internal combustion engines ever made.
What makes the 2009 Hungarian Grand Prix the first hybrid victory in F1?
The 2009 Formula One regulations gave teams the chance to add a hybrid component to their powertrains – the Kinetic Energy Recovery System, known by its acronym KERS. Today’s regulations make a hybrid Power Unit mandatory; however, back in 2009, it was up to the teams to decide if they wanted to use KERS. Both Brawn and Red Bull, the two teams that had won the opening races of 2009, opted to run a conventional engine. However, Mercedes-Benz had developed a hybrid system that McLaren-Mercedes was running in 2009. So when Lewis won the Hungarian Grand Prix on 26 July, it was the first ever victory for a hybrid Formula One car. Indeed, KERS played an instrumental role in Lewis’ race: he made the decisive overtake on Mark Webber for second place with the help of KERS. When race leader Fernando Alonso retired a few laps later, Lewis took the lead and took his 10th grand prix win – and the first hybrid win in the sport’s history.
How does today’s hybrid system work?
The FIA distinguishes between six components in a Formula One Power Unit, four of which form the hybrid system officially known as the Energy Recovery System (ERS). Two of those ERS elements are electric machines that recover energy and deliver it in the form of additional performance. There’s the Motor Generator Unit-Kinetic (MGU-K) which recovers kinetic energy from the car under braking. While it’s more advanced and more powerful than the 2009 KERS, the basic principle is similar. The energy recovered by the MGU-K can then be used to propel the car.
The second electric machine is the Motor Generator Unit-Heat (MGU-H) which sits between the compressor and the turbine of the turbocharger, nestled between the two cylinder banks of the engine in the Mercedes design. The turbocharger itself is powered by the exhaust gases from the engine; however, once the compressor is powered up, there’s excess energy in the exhaust stream which can be recovered by the MGU-H. This electrical energy can then be used to keep the compressor running under braking so there’s no turbo lag when the driver steps on the throttle again. Both electric machines are connected through a three-phase cable to inverters that convert the electrical energy into DC voltage for the battery pack, better known as the Energy Store (ES) where the recovered energy is stored chemically in lithium-ion cells.
In terms of the energy journey, the machines turn rotational energy into electric energy which is then stored as chemical energy. The entire hybrid system, in fact, the entire Power Unit, is controlled by the Control Electronics (CE) which sit alongside the Energy Store in a single housing. Over the course of a race, the CE will complete over 43 trillion calculations on average – including what speed the electric motors should run at and how much power should be deployed while also looking after the ES to make sure it is optimised for peak performance.