Glass corrosion or abrasion is damage to the front glass of a module or to its anti-reflective or anti-soiling coatings. It reduces or removes the benefit those coatings give. Corrosion comes from humidity or dew acting with pollutants, salt or ammonia on soda lime glass. Abrasion comes mostly from wind-blown sand and dust in deserts, and from harsh cleaning methods or cleaning agents. Affected glass changes colour and transparency, evenly or in patches, and can look hazy, milky or rougher than undamaged areas. Lower glass transmission causes a power loss that is usually a few percent and levels off over time. Losses can be larger if the glass starts to soil more easily. Confirm it mainly by visual inspection. IV curve tracing can help as a secondary check, showing lower Pmax and Isc. A reflectance measurement with a hand-held spectrometer can show whether a coating has been worn off. Damage to the glass can also raise operation and maintenance costs.
affectsc1 verified · fact Module front glass
tbl=35.r3 h=b0be2238bf5btbl=16.r3 h=b0be2238bf5btbl=35.r5 h=60bbe86a9d13verified by: joshuahamsaverified on: 2026-10-20
c2 drafted · lead Anti-reflective coating
Corrosion or abrasion can reduce or remove the benefit of front-side ARC, anti-soiling or multilayer coatings.
tbl=35.r3 h=b0be2238bf5btbl=16.r3 h=b0be2238bf5bsec=h80 h=8aab36b70d06caused_byc3 verified · fact Moisture exposure
Atmospheric humidity or dew dissolves sodium ions from the soda lime glass surface. This forms an alkali base that attacks the glass silicate.
tbl=35.r3 h=b0be2238bf5btbl=16.r3 h=b0be2238bf5bverified by: joshuahamsaverified on: 2026-10-20
c4 drafted · lead Atmospheric pollutants
Gases or particles such as pollutants, salt and ammonia act together with humidity.
tbl=35.r3 h=b0be2238bf5btbl=16.r3 h=b0be2238bf5bc5 drafted · lead Improper cleaning
Mechanical removal techniques or unsuitable cleaning agents can damage or strip the coatings. In brush cleaning tests, coated glass lost its ARC while uncoated glass showed no measurable effect.
tbl=35.r3 h=b0be2238bf5btbl=16.r3 h=b0be2238bf5bsec=h80 h=8aab36b70d06c6 verified · fact Sand abrasion
Mostly seen in deserts, where wind, sand and dust together abrade and frost the glass surface.
tbl=35.r3 h=b0be2238bf5btbl=16.r3 h=b0be2238bf5bverified by: joshuahamsaverified on: 2026-10-20
presents_asc7 drafted · lead Hazy or milky glass
The colour and transparency of the glass change, either evenly or unevenly.
tbl=16.r1 h=e6cd75ca03abtbl=35.r1 h=e6cd75ca03abc8 drafted · lead Dull or rough surface
tbl=16.r1 h=e6cd75ca03abtbl=35.r1 h=e6cd75ca03abreview note: support check: partial - Rougher appearance is stated, but 'dull' is not mentioned (hazy/milky only).
c9 drafted · lead Reduced STC output power
Lower glass transmission reduces power.
tbl=35.r5 h=60bbe86a9d13tbl=12.r8 h=85e789978c00tbl=12.r7 h=33a22e8988eac10 drafted · lead Reduced short-circuit current
Listed for both homogeneous and heterogeneous glass corrosion.
tbl=12.r8 h=85e789978c00tbl=12.r7 h=33a22e8988eac11 drafted · lead Distorted IV curve shape
Heterogeneous glass corrosion is listed with changes in Rsc and with inflection points in the IV curve.
tbl=12.r8 h=85e789978c00leads_toc12 drafted · lead Soiling Losses
Degraded glass can soil more easily, which can cause losses larger than the usual few percent.
tbl=35.r5 h=60bbe86a9d13tbl=16.r1 h=e6cd75ca03abtbl=35.r1 h=e6cd75ca03abreview note: support check: partial - Passages say increased soiling susceptibility can be observed and cause larger losses, but not that it leads to soiling losses as a failure mode in those exact terms; reasonably close.
detected_byc13 drafted · lead Visual inspection
tbl=16.r2 h=9f71f14c12d8tbl=35.r2 h=9f71f14c12d8c14 verified · fact IV curve tracing
Listed in parentheses, as a secondary method.
tbl=16.r2 h=9f71f14c12d8tbl=35.r2 h=9f71f14c12d8verified by: joshuahamsaverified on: 2026-10-20
c15 verified · fact Reflectance measurement
A rise in reflectance shows ARC removal. It can be measured in the lab with an integrating sphere or in the field with a hand-held spectrometer.
sec=h80 h=8aab36b70d06verified by: joshuahamsaverified on: 2026-10-20