Glass and Other Encapsulation Materials

This chapter gives a summary of encapsulation materials for solar modules. The state-of-the-art technology for solar glass melting, glass formation, and glass processing is presented. Major advances of the past years are the use of an antireflective layer on the majority of solar glasses and thinner glasses (2.1 mm or below) for solar modules. Further, the physics and technology of light trapping glasses for solar modules are presented. Up to the year 2005, backsheets were predominantly a three-layer laminate of PVF–PET–PVF. The backsheets have since then evolved to a large variety of backsheet constructions and materials. Some backsheets still contain fluoropolymers as weathering stable outer layers, but there are also backsheets with a stabilized polyester, polyamide outer layer or a completely polyolefin-based backsheet. The encapsulant market is dominated by ethylene vinyl acetate. However, other materials like silicones, PVB, or TPOs are used as well. All polymer materials were evaluated with respect to their performance in solar modules and their long-term stability.