The Thermoplastic Variant Of Polyolefins

• Quentys, the only thermoplastic based encapsulation solution in the survey from Borealis allows low temperature processing down to 120 ^oC
• The non-crosslinking nature of the encapsulant allows and module reworking to rectify any anomalies originating from module making process
• While the thermoplastic polyolefins can be used for any cell technologies, the solution is apt for HJT and perovskites based tandem architecture that require low temperature processing
• Borealis has developed a new version of its Quentys combining the adhesion of EVA and PID resistance of POE

Unlike with backsheets, where Austria's Borealis is following a "B to B" approach, in the encapsulation segment the chemical company is taking a "B to C" approach. It is the only company featured in our recent TaiyangNews' Market Survey on Backsheet and Encapsulation Materials that is promoting a thermoplastic polyolefin-based encapsulation solution directly to module manufacturers. What makes this Quentys solution from Borealis special is that it is a proprietary non-crosslinking type of encapsulation, whereas the more popular POE and EVA are crosslinking types. The key advantages are low processing temperature and no cross-linking. The solution also helps in reducing the lamination time, emphasizes Borealis. The thermoplastic nature of the material allows module manufacturers to rework on the laminate in case of any defects such as bubble formation. Above all, the material supports low-temperature processing, down to 120 ^°C. As to the question of stability of thermoplastic PO, Borealis business manager for solar Alper Muraben says the reliability is well tested and proven in a double glass configuration.

Modules based on BPO do not feature any creep at normal utilization temperatures. Moreover field tests have been conducted by third parties in deserts in South America and Middle East and demonstrated excellent module performance, according to Borealis' solar manager Alper Muraben. Borealis has also made further developments related to its encapsulation material, specifically for bifacial PERC glass-glass modules. The improved Quentys is aimed at combining the best of both worlds – EVA and POE; essentially the adhesion of EVA and PID resistance of POE. While the new encapsulant has completed internal validation, the results are due, which is also true for the  accelerated testing with HJT technology. In parallel, Quentys is also under evaluation for cell structures featuring perovskites, which prefer thermoplastic polyolefins due to a low processing temperature and the absence of peroxides. "Quentys has a wide spectrum of coverage, including the present PERC, advanced HJT and next-generation perovskites," said Muraben. Borealis expects its customers to benefit from local manufacturing in Europe, especially amid  the supply disruptions currently being faced (see Excerpts of Trends In Encapsulation).

HIUV's Vice President Colin Quan thinks that more than for HJT, thermoplastic polyolefins are better suited for perovskites due to their high water vapor barrier properties and, more importantly, low processing temperature. A few manufacturers have tried lamination temperatures of 140 ^°C with perovskites with other materials, which is causing considerable loss in efficiency, he said (see White EVA For Higher Module Output).

The Text is an excerpt from TaiyangNews' recent Market Survey on Backsheet and Encapsulation Materials 2021, which can be downloaded for free here.

An overview of the survey was presented during TaiyangNews Conference on Reliable PV Module Design. To learn more about the conference and view the presentations click here.