Recent Developments in PV Module Backsheets - What Do We Really Know about Them?

This paper offers a comprehensive overview of the scientific literature focusing on the reliability of backsheet designs in photovoltaic (PV) systems, with a particular emphasis on recent material advancements. Motivated by a perceived information gap regarding the latest developments in backsheet composition and a lack of understanding concerning long-term stability and compatibility with other solar module components, the authors conducted a literature review spanning 2018 to 2023. In recent years, there has been a significant shift in the architecture of backsheets used in the photovoltaic (PV) industry. Until 2020, backsheets made from polyethylene terephthalate (PET) laminated with polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF) dominated the market with a combined market share of around 85%, along with fluorine-free PET laminates. Meanwhile, alternative architectures like double-sided coated PET backsheets and coextruded backsheets held a smaller market share of 15%. However, by 2022, there has been a notable transformation, with the market share of double-sided coated PET backsheets reaching 50%. This shift signifies a move away from the traditional dominance of PVF/PVDF-laminated PET backsheets. The Scopus based literature survey identified a total of 296 hits, with an annual publication range of 40-50 papers. Authors with American affiliation are dominating the field of backsheet reliability research. Only one Asian stakeholder was found in the top ten list of affiliations. The analysis of the backsheet research revealed a significant misalignment between research interest and market reality. Notably, the focus on materials like PVF, PVDF, and PA contrasts with limited exploration of double-sided coated backsheets. Innovative designs' reliability data primarily originates from non-established market players outside China, suggesting potential gaps in addressing industry needs.