Polymer Encapsulants for Photovoltaic Modules: Electrical Insulation Performance and Long-Term Durability under Accelerated UV Exposure

Notice

This is an unedited manuscript accepted for publication and provided as an Article in Press for early access at the author’s request. The article will undergo copyediting, typesetting, and galley proof review before final publication. Please be aware that errors may be identified during production that could affect the content. All legal disclaimers of the journal apply.

Year : 2026 | Volume : 14 | 03 | Page :
    By

    Rajendra B. Madake,

  • Digvijay B. Kanase,

  • Maoj D. Patil,

  • Prashant S. Mali,

  • Rutuja S. Pawar,

  • Suraj Pawar,

  1. Assistant Professor, Department of Electrical Engineering, Annasaheb Dange College of Engineering and Technology, Ashta, Maharashtra, India
  2. Assistant Professor, Department of Electrical Engineering, Dr. D. Y. patil Institute of technology, Pimpri, Pune, Maharashtra, India
  3. Associate Professor, Department of Electrical Engineering, Annasaheb Dange College of Engineering and Technology, Ashta, Maharashtra, India
  4. Assistant Professor, Department of Electrical Engineering, Annasaheb Dange College of Engineering and Technology, Ashta, Maharashtra, India
  5. Assistant Professor, Department of Electrical Engineering, Annasaheb Dange College of Engineering and Technology, Ashta, Maharashtra, India
  6. Assistant Professor, Department of Electrical Engineering, Annasaheb Dange College of Engineering and Technology, Ashta, Maharashtra, India

Abstract

Influence on the reliability and service life of PV modules is a major issue, which is influenced by the encapsulant degradation in long-term exposure to the sun’s ultraviolet (UV) radiation. A systematic accelerated UV aging study of Ethylene Vinyl Acetate (EVA), Polyolefin Elastomer (POE), and Polyvinyl Butyral (PVB) films under IEC 61215-2:2021 specified test chamber conditions of Q-UV is conducted. The material properties were tested at various exposure intervals including the dielectric constant, dissipation factor, volume resistivity, and dielectric breakdown strength, and tensile strength, elongation at break, optical transmittance, and Yellowness Index. The activation energies determined by the Arrhenius plot at five different temperatures were 44.0, 30.0, and 38.0 kJ mol⁻¹ for EVA, POE, and PVB, respectively. These values are comparable to the realistic values of UV-photo-degradation, while also significantly different from the thermal crosslinking activation value traditionally employed in lifetime prediction models. The overall performance of the materials tested was experienced as being the PVB material which showed the lowest Composite Degradation Index (CDI = 2.14), high Dielectric Breakdown Strength retention and the least degree of yellowing. The intermediate performance (CDI = 4.21) was obtained for EVA whereas unstabilised POE was the most degraded formulation (CDI = 6.88) due to higher chain-scission. The validation of the results of the laboratory exposures with the results of exposures in the field using naturally aged PV modules from Pune, India, yielded excellent percentage agreement, with a Pearson correlation coefficient around 0.99. At 55 °C, service-life predictions resulted in life-times of 42.5 years for PVB, 31.2 years for EVA and 18.7 years for unstabilised POE which formed a validated basis for encapsulant selection for long-term PV applications.

Keywords: photovoltaic encapsulant; UV aging kinetics; EVA; POE; PVB; dielectric breakdown; volume resistivity; Arrhenius activation energy; composite degradation index; IEC 61215

How to cite this article:
Rajendra B. Madake, Digvijay B. Kanase, Maoj D. Patil, Prashant S. Mali, Rutuja S. Pawar, Suraj Pawar. Polymer Encapsulants for Photovoltaic Modules: Electrical Insulation Performance and Long-Term Durability under Accelerated UV Exposure. Journal of Polymer & Composites. 2026; 14(03):-.
How to cite this URL:
Rajendra B. Madake, Digvijay B. Kanase, Maoj D. Patil, Prashant S. Mali, Rutuja S. Pawar, Suraj Pawar. Polymer Encapsulants for Photovoltaic Modules: Electrical Insulation Performance and Long-Term Durability under Accelerated UV Exposure. Journal of Polymer & Composites. 2026; 14(03):-. Available from: https://journals.stmjournals.com/jopc/article=2026/view=245062


References

1. Kempe MD, Jorgensen GJ, Terwilliger KM, McMahon TJ, Kennedy CE, Borek TT. Acetic acid production and glass transition concerns with ethylene-vinyl acetate used in photovoltaic devices. Sol Energy Mater Sol Cells. 2007;91(4):315–329. doi:10.1016/j.solmat.2006.10.009
2. Pern FJ, Glick SH. Photothermal stability of encapsulated Si solar cells and encapsulation materials upon accelerated exposures. Sol Energy Mater Sol Cells. 2000;61(2):153–188. doi:10.1016/S0927-0248(99)00107-3
3. Sinha A, Sastry OS, Gupta R. Nondestructive characterization of encapsulant discoloration effects in crystalline-silicon PV modules. Sol Energy Mater Sol Cells. 2016; 155:234–242. doi:10.1016/j.solmat.2016.06.045
4. Oreski G, Wallner GM. Evaluation of the aging behavior of ethylene copolymer films for solar applications under accelerated weathering conditions. Sol Energy. 2009;83(7):1040–1047. doi:10.1016/j.solener.2009.01.008
5. Badiee A, Ashcroft IA, Wildman RD. The thermo-mechanical degradation of ethylene vinyl acetate used as a solar panel adhesive and encapsulant. Int J Adhes Adhes. 2016;68:212–218. doi:10.1016/j.ijadhadh.2016.03.008
6. Jentsch A, Eichhorn KJ, Voit B. The effect of accelerated aging on the molecular and morphological properties of ethylene-vinyl acetate copolymers. Polym Test. 2015;44:242–247. doi:10.1016/j.polymertesting.2015.04.012
7. International Electrotechnical Commission. IEC 61215-2:2021. Terrestrial photovoltaic (PV) modules—Design qualification and type approval—Part 2: Test procedures for crystalline silicon PV modules. Geneva: IEC; 2021.
8. ASTM International. ASTM D257-14. Standard test methods for DC resistance or conductance of insulating materials. West Conshohocken (PA): ASTM International; 2014.
9. International Electrotechnical Commission. IEC 60243-1:2013. Electric strength of insulating materials—Test methods—Part 1: Tests at power frequencies. Geneva: IEC; 2013.
10. ASTM International. ASTM D882-18. Standard test method for tensile properties of thin plastic sheeting. West Conshohocken (PA): ASTM International; 2018.
11. ASTM International. ASTM E313-20. Standard practice for calculating yellowness and whiteness indices from instrumentally measured color coordinates. West Conshohocken (PA): ASTM International; 2020.
12. Czanderna AW, Pern FJ. Encapsulation of PV modules using ethylene vinyl acetate copolymer as a pottant: A critical review. Sol Energy Mater Sol Cells. 1996;43(2):101–181. doi:10.1016/0927-0248(95)00150-6
13. Wohlgemuth JH, Kempe MD, Miller DC. Discoloration of PV encapsulants. In: Proceedings of the 39th IEEE Photovoltaic Specialists Conference (PVSC); 2013 Jun; Tampa, FL. New York: IEEE; 2013. p. 3260–3265.
14. Eder GC, Voronko Y, Hirschl C, Ebner R, Ujvari G, Muhleisen W. Non-destructive failure detection and visualization of artificially and naturally aged PV modules. Energies. 2018;11(5):1053.
15. Kempe MD. Modeling of rates of moisture ingress into photovoltaic modules. Sol Energy Mater Sol Cells. 2006;90(16):2720–2738.
16. Ndiaye A, Charki A, Kobi A, Kebe CMF, Ndiaye PA, Sambou V. Degradations of silicon photovoltaic modules: A literature review. Sol Energy. 2013;96:140–151.
17. Peike C, Hadrich I, Weiss KA, Durr I. Overview of PV module encapsulation materials. Photovolt Int. 2013;19:85–92.
18. Jordan DC, Kurtz SR. Photovoltaic degradation rates—An analytical review. Prog Photovolt Res Appl. 2013;21(1):12–29.
19. Kempe MD, Jorgensen GJ. Progress toward standardized testing of photovoltaic module materials durability. Sol Energy Mater Sol Cells. 2010;94(2):183–184.
20. International Electrotechnical Commission. IEC 62788-1-4:2016. Measurement procedures for materials used in photovoltaic modules—Part 1-4: Encapsulants—Measurement of optical transmittance and calculation of solar-weighted photon transmittance, yellowness index, and UV cut-off wavelength. Geneva: IEC; 2016.
21. Pawar, A., Nikam, L., Choudhry, N. P., Rajak, R. K., Gadave, K., & Mandal, S. K. (2026).Influence of CuO on the structural, optical and thermal stability of MoS₂ nanocomposites. Materials Letters. https://doi.org/10.1016/j.matlet.2026.140652

Ahead of Print Subscription Original Research
Volume 14
03
Received 27/04/2026
Accepted 08/05/2026
Published 22/05/2026
Publication Time 25 Days
2

Login


My IP

PlumX Metrics