Improved photostability of NREL-developed EVA pottant formulations for PV module encapsulation

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:304443

Pern, F J; Glick, S H ^[1]

---

1. National Renewable Energy Lab., Golden, CO (United States). Center for Performance Engineering and Reliability

Several new formulations of ethylene vinyl acetate (EVA)-based encapsulant have been developed at NREL and have greatly improved photostability against UV-induced discoloration. The new EVA formulations use stabilizers and a curing agent entirely different from any of those used in existing formulations known to the authors. No discoloration was observed for the laminated and cured samples that were exposed to a {approximately}5-sun UV light (300--400 nm) from a solar simulator at a black panel temperature (BPT) of 44 {+-} 2 C for {approximately}3250 h followed by at 85 C for {approximately}850 h, an equivalent of approximately 9.4 years for an average 6-h daily, 1-sun solar exposure in Golden, Colorado. Under the same conditions, substantial discoloration and premature delamination were observed for two commercial EVA formulations. Encapsulation with the new EVA formulations should extend the long-term stability for PV modules in the field, especially when coupled with UV-filtering, Ce-containing glass superstrates.

• DOE Contract Number: AC36-83CH10093
• OSTI ID: 304443
• Report Number(s): CONF-970953--
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
COLOR
ENCAPSULATION
OPTICAL PROPERTIES
ORGANIC POLYMERS
PERFORMANCE TESTING
POTTING MATERIALS
SOLAR CELLS
ULTRAVIOLET RADIATION