Stability of black interconnect coatings for solar photovoltaic module applications

Abstract

Building-integrated photovoltaics (BIPV) are dual purpose, providing both energy and building functions. Aesthetics play a crucial role in the BIPV market, with increasing demand for uniformly colored modules for building skins. Achieving this requires hiding ribbons and metal connections while not compromising durability, and ink coating offers a potential automated solution. This work presents a comparison of three coated metallic ribbons: one commercially pre-coated and two coated with UV-curable-inkjet printing. Glass/backsheet samples with standard or UV-blocking encapsulant were tested through accelerated ageing UV exposure. Results show that the commercially coated ribbons remain stable after 120 kWh/m2 of UV, but the UV-curable-inkjet tested inks show color changes in the encapsulant surrounding metallic interconnects in all cases. Yellowing is attributed to photodegradation of the ink's #1 main component, 2-phenoexyethyl-acrylate. However, PV module performance remains stable despite the color shift, with less than 3% power loss after exposure to 360 kWh/m2 of UV.