Critical Constraints Responsible to Solar Glass Mirror Degradation

• Main Authors: Girard, R., Delord, C., Disdier, A., Raccurt, O.
• Format: Conference Proceeding
• Language: English
• Subjects: artifial ageing; CSP mirrors; degradation; FTIR ATR; lifetime; paint coat
• ISSN: 1876-6102; 1876-6102
• DOI: 10.1016/j.egypro.2015.03.103

The degradation of solar glass mirrors is analyzed as a function of various constraints such as temperature, humidity, rain and solar irradiation. In order to understand the degradation mechanisms, two kinds of tests have been performed: simple tests to identify the effect of each constraint and complex tests to highlight the effects of synergy and to reproduce the natural ageing. The study of the paints coat degradation evidences that UV exposure is one of the most aggressive constraints for paint binder. But results show also a strong effect of liquid water on paint degradation and particularly on pigments loss and blistering phenomenon. Whereas temperature in dry environment is not a very degrading factor for coats, presence of liquid water is a strong accelerating constraint at high temperature. Agreement between outdoor ageing and indoor ageing with a new procedure involving UV, temperature and rain also shows that liquid water is the critical constraint responsible to edge corrosion of silver layer and paint delamination. This work shows also that relation between paint degradation and corrosion of silver layer is not obvious. Homogeneous corrosion by pitting was observed without any deep chemical deterioration of the paint coat system.