[wbeaty]

Maybe you're missing a key part: all wires are already full of electricity (full of electrons.) When a current starts up, it's the wires' electrons which start moving. In a circuit, no electricity is created and no electricity is destroyed, instead it just flows around in a complete circle.

So, when energy moves from a battery and flows outwards on both wires, also the "medium" is flowing inwards on one wire, outwards on the other.

An electric circuit is like a leather drive-belt. A generator is like a pulley.

When we force the pulley to turn, the entire drive-belt must turn also. The electrons are the leather, and they go slowly in a circle. But the "work" or the "horsepower" zips instantly along the belt, moving fast as the belt moves slow.

And, if we WIGGLE the first pulley, the belt also wiggles back and forth. Yet the "work" only flys outwards from the pulley, zooming off into the distance, regardless of which way the belt is turning.