Assessing the reliability and degradation of ribbon in photovoltaic module

Yellowing of modules represents the most evident visual defect. It appears on 98% of the plant modules and, for 63% of panels, it strongly covers their entire background tedlar. In order to see if this yellowing effects the output of the modules the surface oxidation composition and thickness were measured. This letter reports how AUO solar utilizes Highly Accelerated & Humidity Stress Test (HAST) to determine ribbon yellowing effect, and the expected surface oxidation composition. In the same time we identify the surface oxidation rate. The result indicates that ribbon yellowness is a result of surface oxidation, and the yellow appearance is only a cosmetic issue. Lead-free ribbons are more vulnerable to yellowing because lead does not build oxides, only Tin does. The higher concentration of Tin in lead-free solder suggests it will exhibit yellowing relatively faster and easier.