The effect of the back iron for a new-designed permanent magnet (PM) generator is explored in experimental and theoretical basis. The machine has been designed for wind energy turbines having a power range of 500W. It is a three phase generator with a stator at the middle and two rotors at both sides with 32 rare-earth magnets. The study includes the 3D finite element analysis with and without the back iron component. For two cases, electromagnetic analyses have been performed and output waveforms, power, and losses are calculated by finite element analysis and the experimental findings have been discussed. The comparison for two cases has been performed by adding different electrical resistive loads. It has been pointed out that the power from experiment and theory can change due to the air gap difference in the experiment; however, back iron plays an important role to increase the generated power and amplitude and it does not lower the losses significantly. The thermal feature of the new machine is promising, since the axial flux (AF) structure creates natural shear flow in radial direction due to the air channels inside the axis, which transfers air into the central region of the machine.