Science Forums 2

[Boerseun]

Flywheels would be my bet...

Currently, flywheels have been tested as "generators" for electric-drive vehicles, at RPM's up to 150,000. Apparently, the energy density in a very low-friction flywheel turning at speed is quite a few times higher than the best batteries in production.

So what you do is suck energy from the flywheel when accellerating, which will drop its RPM's - you basically wrap the sucker in coils, and suck energy via induction - you have electric motors at every wheel. Then, when you're either going downhill or braking, you suck energy from the wheels and spin up the flywheel. Induction via moving shock absorbers adds some more fun to the party. Also, when you park, the flywheel keeps spinning - if you don't use energy from it, it'll literally spin for weeks. BUT, with your ride parked in the sun, solar panels keep speeding the flywheel up to partially replace lost kinetic energy. Every bit helps. For a quick charge, you can just plug in to the grid - but if you have time, you can just let your car stand in the sun for however long it takes.

Only snag here, is that a flywheel going at 150,000rpm is a bomb. A very nasty bomb, at that. Any manufacturing defects or cracks in the flywheel causing it to fly apart at such speed, will not only destroy the car and its passengers, but will cause considerable damage to other cars (and passengers) in the vicinity. A head-on collision between two flywheel-driven cars, both with fully sped-up flywheels, will be quite a sight - just make sure you stand very far away...

But that being the case, petrol-driven vehicles were also seen as driving bombs at the time of their inception. So, there probably will be a way around it. Advanced material technology could make the concept safe, or a sort of computerised "real-time X-ray analysis" of the flywheels as they turn, might simply shut down the flywheel on detecting hairline cracks or any other sort of structural problems with the flywheel, rendering it safer than they currently are.

But I think the energy density issue might swing the future car debate towards flywheels. Every other possible solution is also riddled with obstacles, and scientists worldwide are working in overcoming them.