PURPOSE: To provide a photovoltaic apparatus which generates a required alternating current electric power without an inverter.

CONSTITUTION: Rectilinearly polarized light obtained through a first polarizing plate 10 is made to impinge on a liquid cell 12. The liquid cell 12 enables light transmitted through it to change in plane of polarization corresponding to a voltage applied to it. Light is transmitted through a third polarizing plate 22 and a second polarizing plate 20 to which a voltage is applied. The output voltage of a first photovoltaic cell 24 is applied to the liquid cell 12. When a voltage is generated in the first photovoltaic cell 24 by light transmitted through the second polarizing plate 20, light is transmitted through the third polarizing plate 22 to generate a voltage in the second photovoltaic cell 26. These operations are automatically repeated, whereby a prescribed alternating current can be automatically obtained between output terminals A and B.