Encapsulation films provide cushioning against mechanical stress and act as the first level of electrical insulation, safeguarding solar cells from damage and high operational voltages
Backsheets serve as the first line of defense against environmental exposure, blocking moisture ingress and providing UV protection to extend module lifespan
TaiyangNews' latest backsheets and encapsulation survey shows 14 out of 17 companies now offering encapsulation materials, reflecting their growing market dominance over backsheets
Encapsulation films and backsheets play a critical role in ensuring the performance, durability, and protection of a solar module. Encapsulation films protect the solar cells within a module by acting as a cushion against mechanical stress and vibrations, preventing damage to the delicate cells and interconnections. Encapsulation materials also act as the first level of electrical insulation for the cell matrix. Effective electrical insulation is critical because solar cells are connected in series, generating high operational voltages. Furthermore, they create an airtight seal, effectively blocking moisture ingress that could lead to corrosion of the metal-based interconnectors and cell surfaces when exposed to water vapor. Encapsulation solutions are the first line of defense to safeguard modules from the most common module degradation phenomena such as LID and PID. Beyond protection, the encapsulant also contributes to the structural integrity of a solar module by bonding the cells to the front glass and rear backsheet, preventing delamination. Traditionally, encapsulants are transparent, allowing light transmission. Now, some monofacial modules use reflective (white) encapsulants on the rear to enhance optical absorption and boost module efficiency. While the encapsulation segment does not offer as many options as backsheets, it still features a good variety of choices in polymer chemistry. Coextrusion is increasingly gaining acceptance for producing multilayer film stacks, offering a balance mainly between performance and costs (see Advanced Solar Technologies Drive Changes In Module Materials).
On the other hand, used on the rear side of a module, backsheets are its first line of defense against environmental factors. Like the encapsulant, the backsheet also acts as a barrier against moisture, preventing corrosion of the module's metallic components and blocking moisture ingress. They also offer UV protection to the modules on the rear side. Since modules operate under dynamic environmental conditions, backsheets must be able to withstand a wide range of environmental conditions, and the choice of materials and construction often depends on the specific climate and location of the installation. Traditionally composed of a 3-layer polymer structure, backsheets also come in twin and monolayer configurations, offering varying performance characteristics. Lamination remains the primary manufacturing method, but coatings and coextrusion are gaining traction as alternative technologies. With the rise of bifacial modules, transparent backsheets have become increasingly important to allow light to reach the rear side of the cells (see Solar Encapsulation & Backsheets Adapting To A Shifting Market).
In summary, encapsulation films and backsheets today are available in a wide variety of configurations, polymer chemistries, and manufacturing processes. These offerings are tailored to meet the specific needs of module manufacturers and end customers, balancing longevity, performance and cost considerations.
Survey Participants: This 5th edition of the combined market survey on backsheets and encapsulation materials received responses from 17 companies in total (see table below) , 3 more than last year. The survey features data for 184 products, an increase of 52 compared to the 4th edition). While our surveys typically include most of the market leaders in these segments, the current overview features 4 new companies: Betterial from China, 2 Indian companies, namely Alishan and Sunlink, and Satinal from Italy. Lucky Film from China did not respond to our inquiry and has, thus, been excluded from the survey.
Of these 17 companies, 14 are encapsulation material suppliers, and 11 are backsheet providers, highlighting that many companies supply both backsheets and encapsulation solutions. In total, 8 companies are promoting both product categories. This overlap is understandable, as both backsheets and encapsulation materials are polymers with complementary know-how and functionalities. Given the declining prominence of backsheets, it was a natural progression for companies to expand into the encapsulation segment – a trend that becomes obvious in this survey. In the previous edition, 8 companies represented the encapsulation segment and 10 focused on backsheets. In contrast, with 14 companies, encapsulation solutions dominate the current edition as opposed to 11 for backsheets. In addition to the 4 new companies featured in this survey, 2 previous participants – Jolywood and Endurans – have also ventured into encapsulation solutions. Meanwhile, Coveme, Aluminium Féron, and Shingi Urja remain exclusive backsheet suppliers.
As manufacturers focus on enhancing module durability and performance, material selection remains critical. The TaiyangNews Solar Technology Conference India 2025, on April 10-11, will feature a Day 2 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. Early-bird registrations are on 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.