Once Tedlar dominated the backsheet segment, but these days are over for quite some time. Are we now seeing the end of the era for Tedlar’s successor, PVDF? PVDF based backsheets were the segment leader for almost a decade. They were still the first choice when we published the previous edition of this market survey about 1 year ago. A lot has happened since. Due to strong demand from the battery segment, PVDF saw huge price increases (see High Price Of PVDF Is The Hot Topic), which were a key catalyst that instigated many of the recent techno-commercial developments in the backsheets segment.
As a result of the high prices for PVDF, the market has silently shifted – and the main beneficiary has been double-side coatings based backsheets (CPC). It almost appears as if PVDF and CPC have interchanged their market positions in this 1 year. PVDF’s share dropped from about 55% to 22%, while CPC has now captured about half the market from a mere 13% previously.
The change in guard happened very rapidly – and it remains to be seen what that means in terms of module reliability, at least a few PVDF backsheet producers highlighted that the industry has turned blind to the weak points of the coatings-based structure. On the other hand, coatings proponents emphasize that CPC backsheets have proven themselves in the field for more than a decade. When done properly, coatings can be as reliable as film-based backsheets, they emphasize.
However, it needed the PVDF price spike before coatings could play out their price advantage. Coatings-based transparent backsheet is the only backsheet structure that can beat glass on pricing, with a price advantage of 20 to 30%. And there is also quite a wide knowledge base and knowhow in the coatings section. Most of the leading backsheet suppliers do have some experience with inner coatings on the KPC structure, which was the previous leading configuration.
The rising PVDF prices even influenced the market leadership. Just 2 years ago, Cybrid was leading in shipments with its KPf configuration. Now, Jolywood is the new number one with its CPC products. Glass as rear cover also benefited from the situation. While glass was already gaining ground on backsheets in general, the price increases led some module makers to shift to glass directly, instead of tyring other backsheet structures.
Another side effect of PVDF’s high price, and a positive one, is that non-fluoropolymers have started gaining traction, even in China. As ESG is gaining in importance among large project developers, topics such as sustainability, low carbon footprint, recyclability have started resonating among Chinese module manufacturers as well. A sure indication of that is evident in a few Chinese backsheet makers mainly promoting non-fluoropolymer and leading backsheet makers expanding capacities for the same. PET is the main choice here; however, coextruded PP backsheets are also garnering some attention (see Coatings And Non-Fluoro Are Gaining Traction).
The prices of PVDF seem to have peaked and are coming down. Whether they would reach their 2020 levels is a question yet unanswered. Some backsheet producers are optimistic, while other players think this is just short term. Even if and when they drop to previous levels, will the industry shift back to PVDF? The answer to that is not clear either. Most of the module producers, and thus the backsheet market, seem to have moved on. That’s because, a majority of the module producers have certified their latest generation products, especially the ones based on larger wafer formats – M10 and G12. Changing the backsheet requires recertification, which costs money as well as time. Many backsheet suppliers opine that module makers are not inclined to shift back to PVDF unless their clients insist on such products.
However, it is still too early to call it a day for PVDF, a lot will depend on its price development. But its recent price hike has offered a big opportunity for others – and it will be interesting to see how they perform. The entire exercise emphasizes how dynamic the PV industry is and how fast it can change course where there is a need.
Coming to encapsulation, the crux of innovations in the segment is driven by their compatibility to advanced cell architectures. Encapsulation material suppliers are launching specific solutions for every cell technology and then also the position in the module (front or rear). For example, white EVA is the state of the art for the rear side of monofacial modules and EPE for bifacial, while it is transparent EVA for the front side of both the variants. For HJT, EPE on both sides is a compatible encapsulation solution (see Encapsulation Solutions For HJT). In addition, encapsulation material suppliers have come out with an innovative light conversion film that converts UV light into the absorption band of the HJT cell which is now entering high volume production.
For TOPCon, EPE is typically used on the rear side and pure POE film on front. There is an industry-wide concern that POE resin may be in short supply if all TOPCon announcements were to come to fruition (see Encapsulation Solutions for TOPCon). While the resin suppliers are trying to debottleneck the production, the encapsulation suppliers are working on alternatives to reduce POE consumption. An EP structure is one example of a step in this direction. However, as we have just seen with backsheets – there are many packaging alternatives for solar module manufacturers.
For more details, download the TaiyangNews 4th Market Survey on Backsheets and Encapsulation for free here.