Photovoltaic solar glass defects

The relative amount of glass defects ranges from several percent up to one of the most prominent failures of registered PV failures. A customer complaints research, on PV modules after two years of operation, observed glass breakage for 10% of the failure cases [ 28 ].

Glass defects impact the economic performance of a PV system in multiple ways. The most obvious effect is the potential (in)direct performance loss of PV modules, which results in reduced economic revenues. Secondly, PV modules that suffer from glass defects may no longer meet safety requirements, therefore these modules are replaced.

Glass defects in PV modules refer to cracked or broken glass layers that are caused by human factors or extreme weather such as hailstorms and high wind- or snow loads [ 21 ]. The majority of the glass defects arise due to human force during installation, maintenance and primarily during on-site transportation of the PV modules [ 22 ].

Unfortunately, glass-glass PV modules are, similar to regular PV modules, subject to early life failures. A failure of growing concern are defects in the glass layer (s) of PV modules. The scale of decommissioned PV modules with glass defects will increase with the development of solar PV energy [ 7 ].

Furthermore, the research analyzed the economic and energetic impact of glass defect reparation in comparison with regular substitution. We found that glass-glass PV modules which endured glass defects did not show performance loss, nor internal damage to the PV cells.

With the trend towards double glass sided modules as seen in Bifacials, or TOPCon with double glass sided construction, the changes in solar PV module design and materials mean breakages are now a bigger risk than ever. These breakages can be due to many reasons and no single factor bears the sole responsibility of operators' woes.