Mechanical Studies of Solar Photovoltaics (PV) Backsheets Under Salt Damp Heat Environments

摘要： Solar Photovoltaics (PV) technology actually makes the most sense in tropical regions where the sunlight intensity is maximum. The environmental conditions in tropical countries makes the photovoltaics components vulnerable to salt mist and water vapour as well as acid penetration. Under moisture condition, the hydrolysis reaction of water vapour with backsheet materials release acetic acid, causing delamination and further corrosion of the encapsulant and inter-metallic connectors on solar cells by the salt mist leading to electrical shorts, heat accumulation and fire. Understanding the interface strength between backsheet and encapsulant materials and their degradation with typical environments in tropical and near-ocean regions is instrumental to enable robust and reliable solar PV technology for such regions. Quantitative characterization technique based on fracture mechanics was proposed and used to examine the delamination strength in multilayered structures of solar PV module. Single Cantilever Beam bending test method using Delaminator v8.2 Adhesion testing system has been used to quantify the delamination strength in multilayered PV module under extreme tropical environments inside environmental oven chamber. Quantitative interface delamination strength between backsheet and encapsulant over various amount of time exposure under salt damp heat and damp heat conditions are reported. Our preliminary results suggest that salinity weakens the interface adhesion strength between backsheet and encapsulant.