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  • Writer's pictureRenewSys India

Snail Trails

Updated: Sep 12, 2023

What are Snail Trails?

"Snail trail" is a term used to describe a type of defect that can occur on the surface of solar panels and can be seen with the naked eye. This defect appears as a thin, dark line that meanders across the surface of the panel in a spiral or snail-like pattern, hence the name.

Snail trail on Solar Panel

How are snail trails caused?

Snail trails can be caused either by some standalone factors or by a combination of factors- like temperature, power generation with moisture ingress, PID, degradation of the Solar PV Cells' 'Grid-Fingers', micro-cracks, etc.

These factors lead to the degradation of the module, a loss of performance, and efficiency. The dark lines that are referred to as 'snail trails', that appear on the surface of the panel, are a result of this degradation.

In general, snail trails can start to form on solar panels at any time between the first few months to several years after installation. The rate at which the defects occur chiefly depends on the moisture ingress into the solar module. This, in turn, is heavily reliant on the nature and quality of the encapsulant, and the ability of the backsheet to withhold moisture transmission.

With improvements in technology, grid-fingers are made more robust and relatively less vulnerable. However, the nature of the encapsulant and low MVTR of the backsheet (Moisture Vapour Transmission Rate) is crucial to improve the quality of the solar panel or solar module.

It's important to note that not all solar panels are equally susceptible to snail trail formation.

RenewSys, with its expertise in both Solar panel manufacturing and solar panel component manufacturing, has ensured that its CONSERV range of Encapsulants is formulated and produced to keep moisture ingress at bay. Our range of Backsheets - PRESERV with relatively lower MVTR also ensure that the possibility of degradation due to moisture ingress is abated.

Coming Soon - Whitepaper on Snail Trails - Subscribe here to receive a free copy

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kimberly sisk
kimberly sisk
May 16

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Solar Bhavnagar
Solar Bhavnagar
Mar 11, 2023

If panels are having snail trail, can we claim under warranty?

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