An optimization for the design of a two-chamber photoplasma has been carried out to investigate some parameters affecting the conversion of light radiation to electrical energy. For these purposes, 2-D simulation with Plasma Module in COMSOL for a cylindrical two-chamber cell at sodium pressure 0.02 torr and different pressures of buffer gas are carried out. A theoretical model considering plasma chemistry and resonance radiation transfer developed in our previous work was used. The effect of the second chamber dimensions L 2 = (1 - 4) × 10 -2 m and R 2 = (0.5 - 3) × 10 -2 m at a fixed size of the first chamber (L 1 = 2R 1 = 10 -2 m), the buffer gas pressure P Ar = (0.1 - 10) Torr, and nonhomogeneous spatial distribution of photoexcitation rate have been investigated. It has been established that an optimal value of electromotive force (EMF) 1.037 V takes place at P Ar = 5 torr and L 2 = R 2 = 2 × 10 -2 m. Also, for the same conditions, calculations of the I -V and P -V characteristics for the photoplasma device are presented. It was established that maximal output power P max = 8 × 10 -3 mW for these conditions. The obtained results give a good potential for designing a solar photoelectric converter.