>>>Sounds good. I suppose though you have to brake a lot to build up potential, thus needing to replace the brakes more often, with the power it requires to make new brakes. Ain't no such thing as a free lunch :-)
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>>Ah just look it up - it doesn't use brakes for breaking as long as it can use the momentum to turn the electric motor, using it as a generator. So it's not the heat that's transformed, it's the dynamic energy which is _not_ transformed into heat, but back into electricity. So it's still not a free lunch (had to use some gasoline at some point to produce that momentum); it's rather the part of the lunch which was previously thrown away.
>
>So I aught to force my kids to eat the crusts off their sandwiches to get them ready for the cars of tommorrow?

No force. Just start enjoying the crust yourself.

Though, if British bread is like the bread here, then I wouldn't call it crust. It's not worth the name.

>Anyway, look it up where? I see no ref's.

They call it "regenerative braking" - google it up, or go straight to http://en.wikipedia.org/wiki/Regenerative_braking for the definition (though they go into more detail on railway than cars).

>I was thinking of the car's momentum to drive a generator but then I thought, well cars have been doing that for decades - how come that hasn't been utilised? Then I figured that for some electro-mechanical reason that wasn't feasible/efficient enough.

That reason was cheap oil and market forces.