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)×10−2m and R2=(0.5−3)×10−2m at a fixed size of the first chamber ( L1=2R1=10−2m ), 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=5torr and L2=R2=2×10−2m . 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=8×10−3mW for these conditions. The obtained results give a good potential for designing a solar photoelectric converter.