The object of the invention is an electric current-generating and/or electric power-plant device (50) in a sailing structure comprising at least one power plant and at least one battery pool, whereby said power plant comprises at least one heat engine (18), a reducer/inverter assembly, and particularly a shaft line (22) equipped with at least one propeller at its end, with the current-generating device (50) being inserted between the flange (66) of the engine cover (68) of said engine (18) and the flange (70) of the reducer/inverter assembly (20), where said device (50) is characterized in that it takes the form of a closed module (64) that can be inserted directly between the flange (66) of the engine cover (68) and the flange (70) of the reducer/inverter assembly without disassembly, total or partial, of its components.