Identifying and Validating Root Causes of Glass Breakage in PV Modules

SUMMARY 

A solar project developer engaged CEA to investigate glass breakage at multiple PV sites. Initial Root Cause Analysis (RCA) included on-site inspections, IR imaging, and structural assessments. Findings suggested impact damage and possible module strength issues. To validate this, laboratory testing was conducted using IEC 61215-2 mechanical load tests to determine if modules met expected durability standards. 

Examples of glass breakage

“CEA identified glass breakage in 2,600 modules and determined the likely root causes
of the breakage, which helped the client hold the right parties accountable.”

RESULTS

 Field Investigation Findings 

• Over 2,600 modules were found with glass breakage across multiple sites. 

• The breakage rates differed between the two manufacturers. 

• Some failures were linked to impact damage, but structural concerns remained. 

Laboratory Testing Findings 

• Four modules underwent static mechanical load tests. 

• All failed due to electrical continuity loss and internal cell cracking under stress. 

• Glass did not break, but weak module structure contributed to failures. 

• Mounting conditions (bumpers) impacted performance but were not accounted for in initial tests. 

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