I think there is a caveat here: force on electrons is "EMF", https://en.wikipedia.org/wiki/Electromotive_force https://en.wikipedia.org/wiki/Electromotive_forc

I think there is a caveat here: force on electrons is "EMF", https://en.wikipedia.org/wiki/Electromotive_force https://en.wikipedia.org/wiki/Electromotive_force This scan be measure in volts, or joules. "potential difference" seems to be the relative difference between the "EMF" of two conductors, which is analogous to pressure-difference and is the relevant factor wrt current, power, etc.