The thermovision thermographic method in the infrared region of the EM spectrum is used for estimating the efficiency of PV conversion. The temperature contrast images for different PV cells with forward and reverse (with respect to the pn junction) current direction are analyzed. It is shown that the inhomogeneity of temperature contrast is preserved after cutting the plate into parts. This confirms the localized nature of this inhomogeneity. The conclusions include the use of the proposed method for analyzing the area of homogeneity of the PV plate of PV conversion and hence the area of homogeneity of the plate technology with PV cell layer generation.