Porsche reveals 911 Hybrid

Actually, the flywheel system is apparently lighter than the battery system. At least that's what I was told by a McLaren F1 KERS engineer I met at a conference several months ago. The guy said that the flywheel system designed by Williams is lighter, the main negative effect being the inertia of the flywheel disrupting the car's handling.

The same applies for the "late" application of regenerated power. The battery can hold its charge for much longer than a flywheel (although this was not important in F1, since they used up regenerated energy almost immediately).

You are right that a flywheel system can regenerate more energy, because it is not so severely restricted by loading current as a battery is.

 

I've learned never to under estimate Porsche. I'm pleased Porsche has moved into the hybrid direction.

"When the driver wants the extra boost -- as much 160 horsepower -- from the electric motors, he presses a button the steering wheel. That extra power comes in addition to the 480 horsepower produced by the GT3's 4.0-liter six-cylinder engine. The extra boost can be useful in accelerating out of a turn or when passing another car."

Now that sounds sweet!

 

It sounds like the 'extra' boost part is the function that is being performed by the flywheels. The 'extra' is there for a limited duration until the flywheel(s) get re-charged.