This case study examines relationships among crystalline-Si cell microcracks, the formation of snail trails, the chemical processes involved, and resulting power loss of the modules under operating conditions in the tropical climate of Brazil. Snail-trail discolorations are imaged by ultraviolet fluorescence and are correlated with the electrical losses of the underlying microcracks by electroluminescence. Complementary microanalytical-techniques are used to compare the chemistry/composition of the encapsulant, contacts, and cell surface regions above and separated from snail trails. The formation of Ag-nanoparticles that react with oxygen, CO2, moisture, and the organic encapsulant result in the formation Ag-compounds (i.e., Ag2CO3. AgO2) accounting for the snail-trail discoloration. Bubble formation along the Ag-fingers are reported. Additionally, evolution of bubble trails along the microcracks is observed for the first time, and the resulting chemical interactions are identified. The processes are discussed in terms of the materials, condition of the backsheets, and local environmental and climate interactions. The modules are shown to exhibit additional power-loss at the higher operating temperatures (>50–60 °C) beyond that expected from the maximum-power temperature coefficient. This is attributed to the opening of the microcracks, with Pmax returning to near its original value upon cooling with observed to healing of the microcrack regions.