Assessment of Critical Laminate Temperature Increase by Fast IR-based Analysis of Hot Spots on Solar Cells

Defects in solar cell production can lead to thermal heating, posing a risk of damaging and degradation to solar modules in the field. Elevated temperatures can accelerate chemical reactions and material degradation. To address this issue, this contribution demonstrates an experimental approach to approximate the module temperature increase during a full cell shading situation already at solar cells within a measurement time of 100 ms. Fast IR-imaging is applied to determine the time-dependent temperature characteristic. Using a high frame-rate IR camera, single artificially generated hot spots on solar cells are detected and time-dependent temperature profiles extracted. A simplified physical model was used to extract the equilibrium temperature. The determined temperature increase of the encapsulated hot spot was found in a linear correlation to the non-encapsulated extracted value. It could be confirmed, that a 100 ms measurement time is sufficient to predict the module temperature. The contribution demonstrated that fast IR-detection could improve module reliability by enabling an IR-classification of solar cells for quality-driven sorting before module manufacturing.