What amazes me about MRI machines is that the magnetic field is "free" in terms of energy cost. It takes some power to start up but then the current just runs i

What amazes me about MRI machines is that the magnetic field is "free" in terms of energy cost. It takes some power to start up but then the current just runs in a circle without losses, so you only have to maintain the cooling so the coils remain superconductive. Room temperature superconductors that wouldn't require any cooling would also make lots of use cases for strong magnets obsolete, increasing power and lowering mass for e.g. EV motors, generators, etc.