The TaiyangNews Backsheets and Encapsulation survey splits the backsheets into fluoropolymer and non-fluoropolymer types, with non-fluorinated options gaining traction since 2022
Coatings have become the dominant outer layer because of their lower cost and improving reliability, surpassing traditional film-based materials like PVDF
The outer layer is crucial for UV protection and durability, typically made from PVF, PVDF, PET, or proprietary coatings, and influences material selection
A backsheet is a multi-layered structure. Thus, in principle, the backsheet structure is both versatile and varied. We have discussed various backsheet structures in our previous article (see Different Backsheet Structures In PV Modules). However, for the survey, we have divided backsheets into 2 categories – fluoropolymers and non-fluoropolymers. Fluoropolymer backsheets are those that incorporate at least one layer of fluoropolymer chemistry, whereas non-fluoropolymer backsheets are entirely halogen-free. Fluoropolymers have historically led the market due to their strong weather resistance, but non-fluoropolymers have seen increasing interest since 2022.
The key component of a backsheet is its outer layer, which provides crucial UV protection to the PET core of the backsheet. The outer layer can be based on a diverse range of polymer chemistries, which also makes it a critical factor in choosing the right variant for the specific target application. Traditionally made from PET, the core layer has also seen a few innovations with some manufacturers exploring alternative materials like polyolefin and polyurethane. Additionally, the advent of coextruded structures, often based on PP, has transformed traditional multilayer configurations into more unified, single-layer designs. On the cell side, the current focus is mainly on the coatings, although backsheets using the same fluoropolymers and polyethylene were used in earlier generations.
As for coatings, be it on the cell side or the outer side, they are typically proprietary blends, and manufacturers generally do not disclose detailed formulations, which limits the potential for discussion about their development and comparison. Thus, the primary point of interest at the component level remains the outer layer, with key contenders being Tedlar (PVF), PVDF, PET, and coatings (see Glass Takes Lead Role In Rear Covers For Advanced Solar Modules).
Coatings have evolved as the predominant choice for the outer layer of the backsheets, outpacing their film-based counterpart. This shift is driven by their cost-effectiveness. Even when PVDF prices dropped significantly at the end of 2023, the price difference between PVDF and CPC backsheets remained at about 1.8 to 2 RMB/m2 and the latter’s price also reduced from 9.5 RMB/m2 in 2022 to about 6.4 RMB/m2 towards the end of 2023, which also emphasized its continuous cost optimization potential.
Initial concerns regarding CPC’s reliability have been alleviated through ongoing technological advancements. Coatings manufacturers have been improving their products for enhanced reliability. According to HANGZHOU FIRST, since their introduction in 2008, CPC backsheets have demonstrated reliable performance in power plants, with no quality issues reported over the past 10 to 15 years. The company says its CPC products, which account for 75% of its shipments, are preferred over those based on fluoropolymer films.
Jolywood also points out that the share of coatings-based backsheets is more than 65% of its total shipments. In 2022, Jolywood's backsheet products were dominated by CPC coatings with a share of 40%, followed by PVDF at 30%, and Tedlar with 10%. By 2023, PVDF's share dropped to less than 10% and Tedlar to 5 slightly higher than 10%, while coatings surged to about 65%. Non-fluoropolymer types, including PET and coatings, accounted for about 15%. In 2023, Jolywood shifted to non-fluorine-based coatings, responding to anti-dumping regulations impacting fluorine-based products, and began the production and sales of non-fluorine backsheets, with sales reaching around 1 million units by the end of the year.
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Day 2 will feature a session on "Advancing Solar Module Performance and Reliability Through the Right Bill of Materials." InYoung Suh, Director of Business Development, HANGZHOU FIRST, and Dr. Khushbu Patel, AGM, Business Development ALISHAN GREEN ENERGY, will discuss innovations in encapsulants and back sheets. Midway Bird special tickets are available here.
The text is an excerpt from the latest TaiyangNews Market Survey on Backsheets & Encapsulation Materials 2024/25, which can be downloaded for free here.