Accredited laboratory testing means sending modules to an accredited PV test laboratory, which confirms whether they really produce less power than they should. It is listed as a corrective action: once the lab confirms the underperformance, the owner can claim for the missing power. Light induced degradation is a power loss caused by exposure to light, and it can be large enough to justify lab confirmation. An optional preventive step is independent third-party testing of sample modules at the factory gate or when they arrive on site, backed by a contractual agreement. Accredited labs also test non-standard mounting setups, such as facade mounting. Accurate IV measurements need test equipment and irradiance reference devices calibrated by, or traceable to, an accredited laboratory. Even in a lab, the certified accuracy of a module IV measurement has limits, and most PV laboratories find it hard to do better than a few percent.
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- sentence 3: support check: partial - LID is power change from light exposure with losses up to 30%, but passages do not link it to lab confirmation justification, and 'up to' is a bound.
- sentence 5: support check: partial - Passage mentions testing of non-standard mounting configurations by an accredited lab (e.g. facade) as a mitigation, but not that labs 'also test' them as general practice; close paraphrase though.
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