Stability of EVA modules

Reported observations on laminated glass superstrate modules with crosslinked ethylene/vinyl acetate (EVA) encapsulant include increased crosslinking of EVA, discoloration of the encapsulant, and formation of acetic acid within the module, following lengthy service in the field. One firm has begun a study of its EVA modules, obtaining and analyzing samples that have been operating in the field for eight to ten years. The data show that even under roof-mounted conditions in the Southwest US (one of the worst-case scenarios) there has been no measurable loss in electrical output power and no significant degradation of encapsulant mechanical properties