Pre-laminates: enhancing flexibility in integrated-photovoltaic (IPV) manufacturing lines

PRE-LAMINATES: ENHANCING FLEXIBILITY IN INTEGRATED-PHOTOVOLTAIC (IPV) MANUFACTURING LINES Lison Marthey, Alessandro Virtuani, Hengyu Li, Loann Baume, Matthieu Despeisse 25.09.2025 2• CSEM INTEGRATED PV Integrated PV Variable string size Variable module size High degree of customiza tion Vehicle Building Agri-PV [1] [1]https://doi.org/10.1038/s44359-025-00059-9 Integrated PV: •Both functional and architectural roll •Local electricity production •Increase aesthetics 3• CSEM PRE-LAMINATION MOTIVATION Integrated PV Variable string size Variable module size High degree of customiza tion Vehicle Building Agri-PV Approach: Pre-laminates Definition: Intermediate assembly of strings and encapsulant, designed for storage prior to final PV module lamination Advantages: •Flexibility •Buffer process •Storage in air •Mechanical and environmental protection (O2& moisture) 4• CSEM PRE-LAMINATION PROCESS Pre-laminate Final module Pre-lamination Lamination Interlayer String Pre-laminate stack Storage Glass Encapsulant Pre-laminate Module stack What is the most adapted material? What is the impact of the storage at material level? What is the impact of storage at module level? 5• CSEM What is the most adapted material? Interlayer requested properties: •High transmittance •Provide environmental barrier •Stability with storage •Mechanical protection (high stiffness) •Compatibility with PV materials & processes APPROACH ✓Formulated on purpose ✓Good barrier properties ✓Rigid ✓Non sticky (easy stacking) ✓180um thin × UV blocking →lower perf V/S Developments at CSEM: •Material formulation •Characterization protocol •Materials & module processing •Several iterations ✓Commercially available ✓Known material ✓Compatible with PV materials × Sticky (difficult to stack) Commercial POE encapsulant CSEM developed interlayer PO (iPO) 6• CSEM MATERIAL TESTING Goal: evaluate materials properties change with storage time Bill of Material: Prelaminated iPO or POE What is impact of the storage at material level? Pre-laminate material iPO POE Storage time 0 day 1 month 3 months 6 months Characterizations: •180° adhesion to EVA & solar cell •Differential scanning calorimetry (DSC) •Fourrier transformed infrared spectroscopy (FTIR) •Rheology Experiment parameters: Storage conditions: 20°C, ~70% RH 7• CSEM Experiment parameters: Characterizations: LIV EL VI (visual inspection) MODULE TESTING Goal: Evaluate performance and reliability of modules with iPO and POE pre-laminates at different storage time Bill Of Material: Final stack ≈ EPE Compared with reference module GG/EVA conventional structure: Reference EVA Pre-laminate material iPO POE Storage time 0 day 1 month 3 months Degradation* TC: 600 cycles DH: 2000H Glass Glass EVA extra-layer EVA extra-layer Pre-laminate What is impact of the storage at module level? *Extended degradation: IEC standard 63209-1-2021 (sequences 1 & 4) 8• CSEM MATERIALS CHARACTERIZATION RESULTS Adhesion: •To cell: >100N/cm independently of storage time •To EVA : high for iPO and POE (samples slipping out of clamps) •Adhesion to cell remains good Rheology: •Viscosity is increasing after 6 months oMax Tan δiPO: -30% oMax Tan δPOE: -50% oCan still be processed DSC: •No pronounced variations in enthalpy reaction FTIR: •No pronounced peak change •Resolution not high enough 0 50 100 150 200 250 300 0 day 1 week 1 month 3 months 6 months Adhesion strength [N/cm] Adhesion to EVA iPO POE •Increase in viscosity with increasing storage time •No pronounced variations in other properties •Material can still be processed 60N/cm acceptable limit 9• CSEM MODULES INITIAL PERFORMANCE iPO POE EL Day0 Month1 Month3 iPO POE iPO: o-1% power (Isc) compared to EVAref oUV-blocking property of iPO→can be improved oSlightly yellow oGood EL POE: oPerforms better than iPO oFew interconnection losses →related to double lamination?