Volvo Flywheel Hybrid System (aka KERS) Tests Completed Successfully

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If you follow Formula One racing, you'll have heard of KERS, or Kinetic Energy Recovery System.

There are several techologies being used, but among them is flywheel KERS, using a spinning flywheel to capture energy which can then be used at a later time.

Volvo has been trialing such a system for its road vehicles for the last two years, and has now announced the successful completion of its testing program.

According to our sister site Motor Authority, Volvo's tests showed the system can offer 25 percent fuel consumption cuts over a turbocharged six-cylinder engine, when paired with a regular four-cylinder turbocharged unit.

That's while offering performance comparable with the larger engine, a typical benefit of hybrid systems.

Flywheel KERS works by spooling up a flywheel when a driver brakes, and then using that kinetic energy to assist the car under acceleration, both boosting performance and reducing fuel use.

The energy in Volvo's flywheel is equivalent to 80 horsepower. In Volvo's S60 test car, the extra power to the rear wheels is enough to launch the car to 62 mph in just 5.5 seconds.

Like many hybrid vehicles, the system is said to work best in urban conditions. The flywheel stores only limited energy--albeit enough to power the car alone for short periods--so the constant stop and go of urban traffic allows it to be used most effectively.

It's also cheaper, easier to maintain and lighter than a typical battery-based hybrid.

Volvo says the system will now be implemented in prototypes for its future vehicles, helping the company evaluate a possible production model.


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Comments (8)
  1. In F1, Williams was developing a flywheel KERS (kinetic energy recovery system), but never raced it in F1. They ended up doing a battery based KERS system like all of the other teams.

    However, Williams has licensed this technology to be used by Porsche and Audi in Le Mans style sports car racing.

    Williams is also working on other applications outside of racing with their side business "Williams Hybrid Power".

  2. Sixty years ago I had a six inch toy car with KERS ;) little did I realise then it would make it into a full size vehicle.

  3. hahah. I can buy one today for about $5 for my kid as well... :)

  4. So, how do they solve the Gyro effect of the spinning fly wheel on the corners or turns?

  5. Same question for me, but admittedly I haven't really studied this too carefully. Wouldn't a vertical rotation axis for the flywheel make more sense if it's storing that much angular momentum? Someone's thought this through and can explain it, I imagine...

  6. It makes more sense for average turning. But when you hit a pot hole or a bump, then the effect on the spinning wheel can be just as devastating...

    I guess if they make it slow enough, it might work...

  7. I'm confused, it looks like it is spinning "vertically" to me, which would fight/prevent the car from turning. "Horizontally" (like a toy gyroscope) would tend to fight motions that cars don't have much of (forward-aft pitching and side to side pitching) horizontal is the best method it seems to me...and is safer if it fails.

  8. Would be interesting to see this paired with Ford's 3-banger....or an Atkinson cycle engine (4-banger).

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