Cell microcracks and cracks are damage that can occur during manufacturing, transport and installation of photovoltaic modules. Cracks can also occur during the operation of the modules due to impact or atmospheric factors such as snow loads, strong winds and hail [1].
Several types of cell cracks can be distinguished depending on their direction of occurrence:

• diagonal cracks,
• cracks parallel to the busbars,
• cracks perpendicular to the busbars,
• cracks in many directions.

Diagonal cracks and cracks in multiple directions have the greatest impact on reducing the efficiency of photovoltaic modules, as they can lead to the disconnection of parts of the cells from the busbars, and thus the loss of the total power generated by the module [2], [3].
In the places of micro-cracks as well as on the edges of cells, so called "snail tracks" can appear [4], which are the consequence of ongoing chemical reactions between elements from panel components and oxygen and moisture from the environment. Because different reactions can produce "snail trails," the term refers to a class of defects rather than describing one particular reaction event. One mechanism describing the formation of "snail trails" is based on the assumption that moisture and oxygen diffuse through the EVA film and reach the cell surface through microcracks. Reactions between oxygen molecules from the EVA film and the environment and silver molecules from the so-called cell fingers (the thin mesh visible on the front of the cell) produce compounds such as silver oxide, silver chloride, silver carbonate and silver acetate, for example [5]. An example of the reaction of creating so-called "snail trails" (silver acetate, \( AgC_{2}H_{3}O_{2} \)), due to solar radiation and temperature can be described as:

The cause of "snail trails" may also be the introduction of silver particles in the manufacturing process as contaminants, which may not be related to the presence of microcracks in the cell.