[puddleglum]

Originally Posted by RunningStrong

The big issue is friction. Lightweight flywheels need to work at 10s of thousands of RPM to be viable. The friction involved in such rotation in a moving vehicle is difficult to overcome with just bearings and lubricant alone. So you need vacuums and magnets, all the more complicated, all the more expensive.

I'm quite sure that the flywheel in the Pinto was running in a vacuum and had magnetic bearings. I'm sure the up front cost would be very high and I'm also guessing that any hard acceleration would kill it pretty quick. Still, it should virtually last forever with almost no maintenance. There have been many seemingly great ideas that, for whatever reason haven't made it into the hands of the general public. I'm assuming flywheel energy storage is just another one.