An electric machine including a stator having a fully non-magnetic core and stator windings formed of a non-superconducting transposed conductor to reduce eddy current losses. It further includes a rotor having a fully non-magnetic core and superconducting windings or superconducting magnets which produce a magnetic field for interaction with the stator windings. A cryogenic cooling system is arranged to cool the stator windings to reduce conduction losses in the stator windings.