Solar panel (also called solar module or solar photovoltaic modules) are assemblies which assembled from multiple solar cells. It is a core and most important partpart of solar power systems. Its working principle is to directly or indirectly convert solar radiation energy into electric energy through photoelectric effect or photochemical effect by absorbing sunlight. The main material of most solar panels is “silicon”. The structure of the solar panel is 1) tempered glass 2) EVA 3) battery sheet 4) back plate 5) junction box 6) silica gel. The service life of solar panels is determined by the material of the cell, tempered glass, EVA, TPT, etc., generally, the solar panel made by a manufacturer with a good material can last for 25 years.