PURPOSE: To provide a driving source for a turbogenerator, by producing compressed air through employment of an arrangement in which there is provided an arm rod which is supported at one end thereof in a pivotally movable manner and has a float fixed at the other end and a pair of air pumps are provided on the upper and lower sides of said arm rod.

CONSTITUTION: The arm rod 1 is extended in a direction parallel to the swell and one end of the rod 1 is supported in a pivotally movable manner. The float 3 is fixed to the other free end of the rod 1. Further, a pair of air pumps 4-4 are fixed to the arm rod 1 at a portion thereof near said one end supported in the pivotally movable manner such that they are located on opposite sides of the pistons 5 for these pumps 4-4 are connected to rod 1. With such an arrangement, when the arm rod 1 is moved vertically by the swell, vertical movement of pistons 5 is caused so that compressed air is produced by pumps 4-4. This compressed air is carried via valves 7-7 to a pressure accumulating tank 8 and supplied therefrom to the turbine 9 for driving the generator 13.