under normal circumstances, the hidden cracks of solar panels are not defects that can be directly found by the naked eye, and they need to be observed by detection methods such as el imaging. hidden cracks will reduce the power generation efficiency of the battery modules, and severely will also cause the hot spot effect, which will affect the service life of the entire photovoltaic modules. below, the editor of hesheng will introduce you to the reasons for the hidden cracks of solar panels.
1). causes of hidden cracks in solar panels
1. defects of raw materials
the defect of the raw material is the main factor that causes the component to crack, the quality of the raw material of the cell directly affects the quality of the product. cells are produced from silicon rods through processes such as growth, cutting, printing, and sintering. insufficient purity of crystalline silicon, excessive curvature of crystalline silicon cells, and excessive shrinkage of eva materials in the horizontal and vertical directions will cause cracks in the production of battery modules.
2. production process error
in the production of battery components, sorting, single string welding, and lamination are required. framing, cleaning and curing test, packaging and other links. incorrect processes used in the production process can also cause cracks in the battery components. for example, if the welding heating plate temperature is too low during single welding, the welding temperature is too high, the welding speed is too slow, the lamination parameter setting is unreasonable, the vacuum pressure is too high, and the vacuum pressure is too high, which will cause the components to crack.
3. improper device settings
in the production process of battery components, stringing machines, laminators, and framing machines all directly exert force on the battery components. if the equipment output is set improperly or the equipment fails, it will cause the battery components to crack. if the soldering iron tip used in a single series soldering process is used for a long time and is not processed in time, it will cause unevenness in the pit of the soldering iron tip, resulting in uneven force during soldering, and cracking of the battery assembly.
4. manual error
there are many hidden cracks caused by human factors in battery components, which occur in various links such as production, transportation, installation, operation and maintenance. although a large number of automated equipment is now used in production, manual transportation and fixation are still required in the processes of stacking, framing, and cleaning, and they will be pressed by fingers during the transportation process. the bumpy way of loading and unloading goods caused hidden cracks. in addition, the irregular operation of the workers during installation and cleaning can also cause the components to crack. for example, the construction personnel step on the components to install; the operation and maintenance personnel stａnd on the components to clean the components and other irregular operations.
5. weather and environmental impact
during the use of battery modules, due to the impact of the environment, the photovoltaic modules will also be cracked. for example, the components will vibrate violently in strong winds; the surface of components will be subjected to uneven pressure of snow after heavy snow; when the components are subjected to severe impact of hail in hail weather, it may cause cracks.