Electroluminescence (EL) is an optical phenomenon and electrical phenomenon in which a material emits light in response to the passage of an electric current or to a strong electric field. This is distinct from black body light emission resulting from heat (incandescence), from a chemical reaction (chemiluminescence), sound (sonoluminescence), or other mechanical action (mechanoluminescence).

This light can be captured as an electroluminescence image, resulting in a picture which allows evaluation. All electrical active zones will start to emit infrared light. This infrared light will be acquired by the cameras. This allows us to visualize all electrical active and non-active areas of the solar module.

(source: wikipedia.org)

EL test (Electroluminescence) avoids the Micro cracks and other invisible defects for solar panel, such as Material defects, Pollution, Soldering etc.

All Sungold Solar Panels electrical circuits are evaluated with an EL test machine.