An electric generator device comprising a panel bearing one or more electric generating machines each including a stator and a rotor concentric and substantially co-planar. The rotor is supported in rotation by the stator and presents a central part bearing one or more blades of a fan. A flow of fluid causes the fan and in consequence the rotor (R) to rotate. The rotor bears along its periphery a plurality of magnetic poles whose magnetic fields link with windings borne by the stator, for the induction of an electric current in the windings. The rotor is supported in rotation within the stator through magnetic means of support.