A solar array reporting lower-than-expected output has several possible culprits, and delamination is only one of them — this troubleshooting sequence helps isolate whether laminate failure is actually the cause before any repair work begins.
Step 1: Rule Out the Non-Laminate Causes First
Before inspecting for delamination, confirm the drop isn’t explained by simpler causes: soiling from dust or pollen buildup, new shading from tree growth or a nearby structure, an inverter operating below its rated efficiency, or a tripped optimizer on a single module. Comparing current output against the historical baseline for the same time of year, adjusted for irradiance, quickly separates a genuine problem from normal seasonal variation.
Step 2: Isolate the Underperformance to a Specific String or Module
Array-level monitoring alone can’t distinguish one bad module from a system-wide issue. Pulling string-level or module-level data — or using a handheld clamp meter across individual strings if granular monitoring isn’t available — narrows the search to the specific string carrying the underperformance, which is the first real evidence pointing toward a localized physical failure like delamination rather than a systemic cause.
Step 3: Visual Inspection Under Raking Light
Once a suspect string is identified, a close visual inspection of each module under a low, oblique light angle reveals bubbling, milky patches, or discoloration that direct overhead light often hides. This step alone confirms or rules out delamination as a visible surface phenomenon, though early-stage cases can still be invisible to the eye at this point.
Step 4: Thermal Imaging to Confirm Localized Resistance
An infrared scan of the suspect string, taken under load and consistent sun conditions, will show hotspots where delamination has increased electrical resistance at a cell or interconnect. A hotspot that correlates with a visually confirmed delamination site is strong confirmation; a hotspot with no visible surface sign may indicate delamination progressing beneath the surface, not yet visible externally.
Step 5: Electroluminescence Imaging for Definitive Confirmation
Where the diagnosis remains ambiguous, electroluminescence (EL) imaging — typically requiring the module be taken offline briefly — reveals cell-level detail invisible to both the naked eye and standard thermal cameras, including micro-cracks and inactive cell regions caused by the mechanical stress of a failing laminate bond. This is the most reliable single diagnostic for confirming delamination as the root cause, though it requires specialized equipment most owners don’t have on hand. Teams without in-house EL capability can Email Us to discuss which diagnostic approach fits their situation and budget.
Step 6: Cross-Check Against IV Curve Data
An IV curve trace of the affected string, compared against a healthy reference string, often shows a distinctive “step” pattern when specific cells are underperforming due to delamination-related optical or electrical issues, distinguishing it from the smoother curve shift typical of soiling or uniform shading. This data point, combined with the visual and thermal findings, builds a confident diagnosis before committing to any repair spend.
Understanding Why Delamination Causes Output Loss in the First Place
The mechanism worth understanding at this stage is straightforward: when the bond between the glass and encapsulant fails, the resulting air gap changes the refractive index at that boundary, scattering incoming light away from the cell rather than transmitting it — an immediate optical loss distinct from any subsequent moisture or corrosion damage. This same principle — a failed bond changing how a joint or interface performs under stress — underlies how CTE mismatch causes adhesive bond failure across bonded assemblies generally, not just solar laminates.
When the Troubleshooting Points to Delamination
If the sequence above confirms delamination as the cause, the next decision is whether the affected area is small and early enough for a localized repair or advanced enough to justify module replacement — a separate assessment that depends on the extent of visible bubbling, corrosion, and cell cracking found during inspection. Material selection at this stage matters: Incure’s UV-curable bonding chemistries, including the Uni-Weld UV glass and metal bonder line, are engineered around the viscosity and tensile requirements relevant to glass-to-substrate repair work of exactly this kind.
When the Troubleshooting Sequence Comes Back Inconclusive
Occasionally, visual, thermal, and IV curve data all come back ambiguous — no clear bubbling, only a marginal hotspot, a curve shift that could plausibly be soiling instead of delamination. In these borderline cases, the right move is a scheduled re-check in a shorter interval than the standard maintenance cycle, rather than either dismissing the concern or committing to a repair based on incomplete evidence. A follow-up inspection a few weeks later, comparing fresh data against the original findings, usually resolves the ambiguity one way or the other.
Documenting the Diagnosis for Warranty and Insurance Purposes
Whatever the outcome, documenting each troubleshooting step — the monitoring data, the thermal images, the EL scan if performed — builds the evidence trail needed to support a manufacturer warranty claim, since most warranties require proof the failure stems from a material or manufacturing defect rather than external damage or normal wear.
A structured troubleshooting process prevents wasted repair spend on the wrong fix and gives fleet operators confidence in the actual root cause before escalating. Teams working through a suspected delamination case can Contact Our Team to discuss diagnostic approaches and material options for confirmed cases.
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