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 L₂=( 1-4 ) x 1 0⁻² m and R₂=( 0.5-3 ) x 1 0⁻² m at a fixed size of the first chamber (L₁=2R₁=10⁻² m), the buffer gas pressure PAr=(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 PAr=5 torr and L₂=R₂=2x 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 Pmax=8x 10⁻³ mW for these conditions. The obtained results give a good potential for designing a solar photoelectric converter.