Examine critical encapsulant degradation mechanisms and prevention strategies for long-term module reliability. Explore EVA yellowing from polyconjugated double bond formation, acetic acid generation accelerating PID and corrosion, and UV-induced chromophore development. Learn UV cutoff strategies using selective glass substrates and stabilizer formulations. Understand POE advantages including superior moisture barriers, elimination of acid byproducts, and enhanced PID resistance. Review EPE multilayer structures combining EVA adhesion with POE protection for optimal performance. Discuss accelerated testing protocols, oxidation measurements, and field degradation correlations. Essential for module engineers and quality managers optimizing encapsulant selection for various cell technologies and climates.