Potential Problems with Ethylene-Vinyl Acetate for Photovoltaic Packaging (Poster)
Photovoltaic (PV) devices are typically encapsulated using ethylene-vinyl acetate (EVA) to provide mechanical support electrical isolation, optical coupling, and protection against environmental exposure. Under exposure to atmospheric water and/or ultraviolet radiation, EVA will decompose to produce acetic acid, lowering the pH and increasing the surface corrosion rates of embedded devices. Even though acetic acid is produced at a very slow rate it may not take much to catalyze reactions that lead to rapid module deterioration. Another consideration is that the glass transition of EVA, as measured using dynamic mechanical analysis, begins at temperatures of about -15 C. Temperatures lower than this can be reached for extended periods of time in some climates. Due to increased moduli below the glass transition temperature, a module may be more vulnerable to damage if a mechanical load is applied by snow or wind at low temperatures. Modules using EVA should not be rated for use at such low temperatures without additional low-temperature mechanical testing beyond the scope of UL 1703.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC36-99-GO10337
- OSTI ID:
- 893115
- Report Number(s):
- NREL/PO-520-39977; TRN: US200625%%94
- Resource Relation:
- Conference: Prepared for the 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion (WCPEC-4), 7-12 May 2006, Waikoloa, Hawaii
- Country of Publication:
- United States
- Language:
- English
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