Alternative energy storage devices

[veloman]

Would it be possible to have a kinetic energy storage device such as a small flywheel, for small electric vehicles?

From the stats I found on the Flybrid system: http://www.flybridsystems.com/F1System.html

I calculated that in theory you would be able to store around 100 watt hours with that particular flywheel.

Is there any way to size down the flywheel and speed it up to REALLY high rpms for more compact lightweight, enduring storage?

The real benefit I see is you MIGHT be able to drop the entire electric system (outside of the wall charger). You'd run your bike off pure kinetic energy. Between the highspeed flywheel and your bike wheel, there would be an advance frictionless CVT transmission. The potential is that you'd have INSANE power capabilities - 20kw if you really wanted (you'd just need to recharge a lot sooner).

Could we get 300-400 watt hours (equal to a 10lb Lithium battery pack) stored in a flywheel? Is that feasible in any manner? You could "charge" the flywheel from a standard outlet in about 5-10 minutes at something like 2-3kw.

If we can get around the "toxicity" of current battery technology, we'd have a much stronger argument for electric bikes as being truly green.

(the folks at motorbiking.com argue that batteries are comparably bad to ICE exhaust - which I strongly doubt).

Or are current Lithium batteries already significantly low on environmental impact?

Does anyone have data on that?

 

[grindz145]

What is the self discharge rate on these? In other words, how much energy do you waste just sitting there? I imagine this is pretty high and why it would never be that useful in terms of bikes, in its current form.

 

[veloman]

Yeah, I suppose it would be quite high compared to batteries. It works well for regen, but not continuous storage.

Still 'could' be possible for short trips. Not practical likely.

 

[zap]

You'd also need to worry about the flywheel's gyroscopic effect... probably would need to be mounted in a gimbal.

 

[heathyoung]

Yes, it could make it interesting to turn corners

 

[zap]

[youtube]Cbfe2_2DDc0[/youtube]

 

[REdiculous]

They haven't started making a 20" version yet or I'd be tempted. I've been looking for a way to add a little weight to the front of my bike to improve stability and something like that would work perfectly..2 birdies and a single stone.

I'll probably end up w/ a front hub motor instead but I like the idea.

 

[maydaverave]

How effecient is an air drill? I wonder how far you could go with a 10 gallon compressed air tank and a pneumatic drive? :?

 

[veloman]

Everything I know about compressed air - is that it is not efficient or practical enough. There are some air-powered cars in Europe, city cars. It might be best used for regen only. Maybe a design could be made that is only like 3lbs, and added to bikes for stopping/accelerating. If you could get >50% efficiency, it would be worth it for city biking. That's one of my ideas that I've had. I also thought of using large weight lifting rubber bands for bike regen. Not for downhills, just normal stop/go with a charge/discharge cycle of less than 10 seconds.