Fungal biofilm growth

Fungal biofilm growth means colonies of microbes, mainly black fungi, growing in sub-aerial biofilms on the module front glass. As the biofilm grows it forms dark masses and catches other particles. This absorbs and scatters incoming light and cuts how much passes through the glass. The biofilm can also pit and etch the glass and give more dust a surface to stick to, so soiling builds up further. The main failure mode it causes is widespread fungal soiling losses. Unlike ordinary dust, these losses often stay after rain and can be mistaken for pollen, dust or a weather-normalization error. Growth is most likely in humid places, such as tropical and humid subtropical climates. Condensation from big swings between day and night temperatures supplies the water the biofilm needs. Expect it to recur at sites with a humid climate, nearby vegetation or nearby water. Usually only targeted or manual cleaning removes the deposits, and some studies suggest adding an anti-fungal agent to the cleaning routine. Treat cleaning as required maintenance at affected sites and check production after each cleaning to confirm it worked.

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• sentence 4: support check: partial - Persistence after rain and misclassification as dust, pollen or weather-normalization error are stated, but 'main failure mode' is only loosely supported.
• sentence 5: support check: partial - High humidity/tropical and condensation from day-night temperature swings are stated (São Paulo example), but humid subtropical as likely growth region is supported only via the field findings, and condensation is an example not a general rule. -->