Electroluminescence Imaging of Solar Modules: Finding Cracks and Dead Cells

… more less Electroluminescence imaging, or EL, makes solar cells glow so a camera can see their flaws. A power supply pushes current forward into the panel, the way current flows in an LED. Inside the silicon, electrons and holes meet. Some release their energy as light when they recombine. Silicon glows faintly in infrared, near 1150 nm, which eyes cannot see. A dark room and a special camera pick it up. Good areas glow bright. Cracks, broken fingers and dead cells show as dark lines or patches. Current cannot reach those spots, or carriers recombine there without giving off light. Factories image every module after lamination. A cracked cell is found before the panel ships, so the module is fixed or sold as a lower grade instead of failing on a roof. Installers and owners also use EL after hail, rough transport or storms. The environmental side is about waste and lost output. Small cracks grow with heat cycles and can form hot spots, which cut power and shorten life. Catching them early means fewer early replacements, fewer panels in the waste stream, and less wasted factory energy. EL also helps decide if a damaged array needs repair or full replacement. After this Concept you can read an EL image, tell a crack from a dead cell, and judge a damage report.