In 2012, the Audi R18 e-tron Quattro won the 24 Hour of Le Mans endurance race with the help of an electric flywheel that converted energy from braking into power for a supplementary electric motor. Called the GKN Hybrid Power Gyrodrive, the flywheel enabled the R18 to conserve fuel throughout the grueling race without sacrificing power.
Now, the company that designed the Gyrodrive is selling the technology to a British automotive and aerospace conglomerate that plans to install the devices on 500 buses over the next two years. In preliminary tests, the device was able to cut fuel consumption in buses by as much as 20 percent.
The Gyrodrive had to be re-tuned before it could be installed on buses, so the metro transit in London might not feel like a formula 1 racecar, but it will be able to operate far more efficiently. Because city buses make frequent stops during the course of their day-to-day operation, they are ideally suited for these regenerative braking systems. According to Wired, GKN Hybrid is also interested in retrofitting the device onto other municipal vehicles such as garbage trucks. The Gyrodrive weighs in at just over 100 pounds and can be outfitted onto a bus in just a few days.
GKN Hybrid hasn’t revealed what they’re charging transit companies for the device, but they have argued that the cost would be entirely recouped in gas savings over three years. The first Gyrodrive-enabled buses will hit the streets in London this year, followed soon by more in cities throughout England. You can see how the Gyrodrive works in the video below from GKN Hybrid.