Links checked June 2016
Electrostatic charging by friction, and discharging, with John Travoltage. Insane.
The National Grid has some excellent real-time information.
And how about this Generator with the graph of voltage out, ability to pause, and change frequency of rotation. You can remove the field, current, and force, directions to start with - ask the pupils.
Resistivity formula quite nicely illustrated; not exciting, but useful.
Electron Microscope - explanation from Cambridge