Hi, I realised I didn't understand the physical model of something I know the theory of pretty well. I was considering the real power loss of an AC transmission line I2*R, then I realised that from source to load the electrons in an AC line don't actually move anywhere. (as far as I know) Yet if I'm running a three phase motor, it certainly draws current. WARNING: Personal interpretation >> I know that 'electricity' isn't really about the movement of electrons. I'm not sure if it's the negatively charged electrons that move to contain the electric field in the conductor, or if EM energy passes through like a sound wave through the conductive media, really...The mechanism by which energy actually travels down a power line is a bit of a mystery to me. I do remember learning about TE, TM and TEM transmission lines in Adv EM, but I don't know if a simple AC or DC line is one of these. (it would be good if someone could explain it. To make things more complicated I'm also trying to work out how a rectifier works, because I imagine that the electrons would have to jump across the PN junction very fast, but the drift velocity of an electron is about 8cms an hour. So yeah, in brief power lines can draw a lot of amps, which is a lot of electrons per second, so how does this happen, and how is there various levels of current in an AC TL? Sorry if I'm re-treading old ground, but I haven't found any succinct answers. Hope I've made the Q's clear, thanks!