Wikipedia has this to say about joule heating: "Joule heating is caused by interactions between the moving particles that form the current (usually, but not always, electrons) and the atomic ions that make up the body of the conductor. Charged particles in an electric circuit are accelerated by an electric field but give up some of their kinetic energy each time they collide with an ion. The increase in the kinetic or vibrational energy of the ions manifests itself as heat and a rise in the temperature of the conductor. Hence energy is transferred from the electrical power supply to the conductor and any materials with which it is in thermal contact..." https://en.wikipedia.org/wiki/Joule_heating Can we critique that explanation? For example, it's difficult for me to believe that slowly moving drift speed electrons are causing much of a vibration of atomic lattice ions. Are there some more fundamental interactions here that are glossed over? Seems like the last sentence is a good one....that the power from the source is dissipated as heat in the resistive material, but I suspect just how this occurs is a bit more complex than described. Doesn't the lattice structure also play an important role? What Determines Resistivity Here Wikipedia seems to get more of what I would expect: "...Loosely speaking, a metal has large numbers of "delocalized" electrons that are not stuck in any one place, but free to move across large distances, whereas in an insulator (like teflon), each electron is tightly bound to a single molecule..." https://en.wikipedia.org/wiki/Electrical_resistance_and_conductance#What_determines_resistivity.3F So it would seem a tightly bound conductor electron requires more energy to 'drift' than a loosely bound one, but I am not clear on just how that results in more heating. Does an ion losing a tightly bound electron 'vibrate' more than one which has lost a loosely bound one? Doesn't seem likely. Thanks for any assistance.