Delamination shows up as bubbles or bright, milky patches where layers have come apart: front glass from encapsulant, or cell from encapsulant. The patches can be continuous or in spots. It is mainly found by visual inspection. Pulse thermography and scanning acoustic microscopy can also find it without damaging the module. The separated layers reflect more light, so the affected cells make less current. On an IV curve or in string data this shows mostly as lower short-circuit current. Moisture then gets in and causes corrosion, which raises series resistance. The resulting current mismatch can create local heating and trigger bypass diodes. Wavy bumps or ripples on the rear side point to backsheet delamination rather than front delamination. Advanced potential induced degradation can also show visible delamination. Check first whether the delamination reaches the module edge or the junction box. A continuous path there can let water in, lower insulation and cause leakage current trips. Delamination caused in manufacturing often affects many modules from the same batch, so inspect neighbouring modules as well.
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observed_asc1 drafted · lead Bubbles or milky areas
Front delamination shows as bubbles or bright, milky areas between glass and encapsulant or cell and encapsulant, continuous or in spots; found by visual inspection.
sec=h59 h=2b796b8e0a00tbl=9.r1 h=2b686438798ftbl=11.r1 h=206639225730c2 verified · fact Increased glass reflectance
New glass/air and EVA/air interfaces add reflection, about 4% interfacial reflectance per interface.
sec=2.3.2 h=5147bca98d09sec=h59 h=2b796b8e0a00verified by: review-workflowverified on: 2026-10-20
c3 drafted · lead Lowered Isc on IV curve
Pmax loss from delamination is mainly a short-circuit current reduction from optical loss and corrosion.
sec=2.3.2 h=5147bca98d09sec=h59 h=2b796b8e0a00review note: support check: partial - Passages say Pmax loss is via reduced Isc from optical loss and corrosion, but nothing on IV curve signals, comparison to peer inputs, or declining over time.
c4 drafted · lead Localized IR hotspot
Mismatched cells in delaminated areas heat locally; backsheet bubbles may run slightly warmer due to disturbed heat dissipation.
sec=2.3.2 h=5147bca98d09sec=h60 h=6cc7189f11a4review note: support check: partial - Mismatch causing local heating in delaminated area and backsheet bubbles running slightly warmer are stated, but IR hotspot observation itself isn't stated.
c5 drafted · lead High leakage current alarm
Water ingress along a continuous delaminated path can reduce insulation; the inverter may shut down due to leakage current.
sec=h59 h=2b796b8e0a00review note: support check: partial - Reduced insulation via continuous path/water ingress and inverter shutdown from leakage current are stated, but not a leakage-current alarm as an observation.
typical_power_lossc6 drafted · lead ≤ 20 PERCENT
Conditions: Pmax drop of a field-deployed EFG-Si module with edge delamination and discoloration in the first 3 years of deployment
sec=2.3.2 h=5147bca98d09review note: support check: partial - Pmax dropped nearly 20% in first 3 years for the EFG-Si module, but 'typical' and 'up to' framing is stronger than a single case; also attributed partly to moisture/corrosion.
c8 drafted · lead nominal 11.5 PERCENT
Conditions: PV system after 12 years of exposure, loss mostly attributed to cell/encapsulant delamination
sec=2.3.2 h=5147bca98d09current_dropc7 drafted · lead nominal 5 PERCENT
Conditions: Isc drop of the same EFG-Si module in the first 3 years, approximate figure
sec=2.3.2 h=5147bca98d09presents_as c13