A power generation system comprising: at least one power generating device comprising an electromagnetic generator or a motor that is configured to generate electric power by rotation of an input shaft; a power storage circuit including at least one capacitor (C1 to C4), that is configured to store energy of the electric power generated by the power generating device; and a hinge device comprising a first and a second hinge components (1, 2) having a common reference axis (A-A'), wherein the first and second hinge components (1, 2) are engaged with each other, so as to be rotatable about the reference axis (A-A') relative to each other, and so that one of the first and second hinge components (1, 2) supports the other, wherein a housing of the power generating device is fixed to the first hinge component, so that the input shaft of the power generating device is positioned on the reference axis (A-A'), and characterized in that, the input shaft of the power generating device is restrained to the second hinge component with respect to a direction of rotation about the reference axis (A-A'), so that the input shaft of the power generating device rotates by as much as rotation of the second hinge component when the second hinge component rotates about the reference axis (A-A'), wherein the power storage circuit has a capacitance equal to or near an energy-maximizing capacitance (Cp), the energy-maximizing capacitance being a capacitance maximizing an upper limit energy in characteristics of energy to capacitance, the characteristics of energy to capacitance being calculated as the upper limit energy to be stored in the power storage circuit, with respect to the capacitance of the power storage circuit, and wherein the characteristics of energy to capacitance are calculated based on: the capacitance of the power storage circuit, an electromotive force of the power generating device, an internal resistance of the power generating device, and a duration of one power generating action of the power generating device, wherein the characteristics of energy to capacitance is obtained by: W E 1 M = 1 2 C 1 V 01 + E m 1 − V 01 1 − e − t / τ 1 2 wherein, "C 1 " denotes a capacitance of the capacitor (C1 to C4) of the power storage circuit; "V 01 " denotes a lower limit voltage of the capacitor (C1 to C4); "E m1 " denotes the electromotive force of the power generating device; "t" denotes the duration of one power generating action of the power generating device; and "τ 1 " denotes a time constant, based on the capacitance C 1 of the capacitor (C1 to C4), and an internal resistance of the power generating device. at least one power generating device comprising an electromagnetic generator or a motor that is configured to generate electric power by rotation of an input shaft; a power storage circuit including at least one capacitor (C1 to C4), that is configured to store energy of the electric power generated by the power generating device; and a hinge device comprising a first and a second hinge components (1, 2) having a common reference axis (A-A'), wherein the first and second hinge components (1, 2) are engaged with each other, so as to be rotatable about the reference axis (A-A') relative to each other, and so that one of the first and second hinge components (1, 2) supports the other, wherein a housing of the power generating device is fixed to the first hinge component, so that the input shaft of the power generating device is positioned on the reference axis (A-A'), and characterized in that, the input shaft of the power generating device is restrained to the second hinge component with respect to a direction of rotation about the reference axis (A-A'), so that the input shaft of the power generating device rotates by as much as rotation of the second hinge component when the second hinge component rotates about the reference axis (A-A'), wherein the power storage circuit has a capacitance equal to or near an energy-maximizing capacitance (Cp), the energy-maximizing capacitance being a capacitance maximizing an upper limit energy in characteristics of energy to capacitance, the characteristics of energy to capacitance being calculated as the upper limit energy to be stored in the power storage circuit, with respect to the capacitance of the power storage circuit, and wherein the characteristics of energy to capacitance are calculated based on: the capacitance of the power storage circuit, an electromotive force of the power generating device, an internal resistance of the power generating device, and a duration of one power generating action of the power generating device, wherein the characteristics of energy to capacitance is obtained by: W E 1 M = 1 2 C 1 V 01 + E m 1 − V 01 1 − e − t / τ 1 2 wherein, "C 1 " denotes a capacitance of the capacitor (C1 to C4) of the power storage circuit; "V 01 " denotes a lower limit voltage of the capacitor (C1 to C4); "E m1 " denotes the electromotive force of the power generating device; "t" denotes the duration of one power generating action of the power generating device; and "τ 1 " denotes a time constant, based on the capacitance C 1 of the capacitor (C1 to C4), and an internal resistance of the power generating device.