Analysis of PV Modules by Electroluminescence and IR Thermography

Abstract

Methods for the interpretation of the combination of different image guided infrared measurements of PV modules are introduced. It is shown how certain defects that influence the series resistance or the short circuit current, manifest themselves in the illuminated thermographic image for different loads corresponding to certain states on the I-V characteristic. The thermal behavior of cells in a module in short circuit condition is explained. For the verification of the methods 8 modules of a 4.5 year old PV generator were demounted and analyzed. Four of them did show thermal aberrations during operation, while the other four did not. The defects were identified as shunts and defects in the interconnection.