By Michael Kempe, Scientist, Module Reliability Group, National Renewable Energy Laboratory
Back-sheet materials for photovoltaic modules serve several purposes such as providing electrical insulation, environmental protection and structural support. These functions are essential for modules to be safe for people working near them and for the structures to which they are attached. To ensure that all modules meet a minimum set of requirement, they must pass qualifications tests such as IEC 61646, 61215, 61730, and 62108. This paper puts forward the design and composition requirements of back- and front-sheet materials for achieving the highest possible quality performance from PV modules.