A self-consistent study of two-chamber photoplasma has been carried out to quantitatively investigate the conversion of light radiation to electrical energy. The main idea is to perform photoionization of alkali metal atoms in the first chamber by light irradiation, and then creating a potential difference due to the significant electron density gradient between two joint chambers. A 2-D simulation using COMSOL for a two-chamber cell with a Na-Ar mixture has been fulfilled and the basic photoplasma parameters (charged and excited particle densities, electron temperatures, and electric potentials) have been obtained. Plasma chemistry included the photoexcitation of sodium atoms, radiation trapping, energy pooling, penning and associative ionization, electron-atom impact reactions, stepwise ionization, and dissociative and collision-radiative recombination. Strong space nonuniformity for the electron density in this cell has been found. The possibility to obtain an electromotive force (EMF) (electric potential difference between two chambers) with resonant radiation pumping has been established quantitatively. For cylindrical geometry, where both chambers have equal radii R₁ = R₂ = 0.5 cm but different lengths L₁ = 1 cm and L₂ = (0.5-3) cm, the EMF could reach 0.59 V at L₂ = 3 cm for gas pressures PAr= 1 Torr and PNa= 0.02 Torr with a homogeneous spatial profile in the first chamber of the photoexcitation rate of resonant sodium atoms. The effect of changing the second chamber length has been investigated. The obtained results can be used for the design of renewable ecological sources of electrical energy in solar photovoltaics.