A radial gap motor/generator that may be air or liquid cooled. The motor/generator has a stator in radially spaced relation to at least one thin annular induction structure. The motor/generator has at least two spaced apart annular rings each having an inner surface and outer surface, the annular rings having a permanent magnet structure embedded between the inner surface and outer surface of the annular rings. The motor/generator has at least two spaced apart radial gaps, the first gap between the first annular ring and the induction structure and the second gap between the second annular ring and the induction structure, the stator being disposed between the gaps. The motor/generator may include multiple gaps and multiple annular induction structures to increase the overall power density of the system.