Volvo is currently experimenting with a new technology it has dubbed as flywheel energy storage technology, which according to the Swedish auto manufacturer, will help it improve fuel efficiency without compromising on performance. Volvo will be the latest addition to companies like Ferrari and Jaguar who are delving into kinetic energy recovery systems in a bid to increase their fuel economy and provide increased power.
This technology will be familiar to fans of Formula 1 racing who have seen the upheavals of this technology, from high to low and back again, in the last few seasons. However in the case of F1 system, which makes use of motors and batteries, the system which Volvo could provide is more simple and cheap.
The company’s Vice President of powertrain technology, Derek Crabb, said that this technology is quite cheap. It is possible to use it in a larger number of their models, compared to their other state-of-the-art technology like their plug-in hybrid.
Their system will have a carbon fiber 13lb flywheel attached to a front-wheel drive car’s rear axle. The flywheel is mounted in vaccum to help decrease friction. It is 7.8” or 20 cm in diameter and spins to 60,000rpm during braking. As the driver hit brakes, the engine shuts off, and the energy that is generated during braking is sent to the flywheel, where it is stored. Upon acceleration, the flywheel lets go of the energy by continuous variable transmission, powering the car’s rear wheels.
Crabb said that the energy stored in the flywheel is enough for powering the vehicle for short periods. This will however, have a lot of impact on the consumption of fuel. According to the New European Driving Cycle, the engine can probably be turned down half of the time during driving, according to estimates.
According to Volvo, their system will allow a 4 cylinder engine to have the acceleration of a 6 cylinder, while also decreasing fuel consumption by around 20%. This system will be most effective in places with a lot of traffic, wherein the fuel economy usually decreases.
Other car manufacturers have also experimented with similar drivetrains in road cars, like the Ferrari 599 Hy-KERS or the Jaguar which was fitted with a prototype having a flywheel system similar to that of Volvo’s. While these systems have been generating a lot of buzz recently, they are not something new. Public transits powered by flywheel systems have been seen in countries like Belgium and Switzerland among others, with the 1950’s gyrobuses.
Even Volvo used this system back in 1980 in their 240 diesel. However those efforts were not successful as they used up a lot of energy as well as increasing the vehicle’s weight. The current flywheel system used by Volvo is created by Flybrid Sytems, with the continuous variable transmission from Torotrak. This project received funding by the way of a grant from Swedish Energy Agency. Volvo intends to road test this technology later in the year.
Crabb said that if the technical development and tests go according to plan, they expect that cars outfitted with flywheel technology will be available in showrooms in a couple of year’s time.
