Types and main differences of common solar panels Single crystal: from the appearance, the four corners are arc-shaped, dark blue, and the packaged one is nearly black. Polycrystalline: four corners are square, light blue. Other differences: different processes lead to different efficiency and cost. Standard test conditions: temperature 25 ℃ Atmospheric quality: AM1.5, illumination: 1KW/m ³ Maximum output power (Pmax): the product of the maximum output working voltage and the maximum working current, commonly known as the component power maximum working output voltage (Vmp) short circuit current (ISC): the current flowing during the positive and negative pole short circuit state of the battery Open circuit voltage (VOC): the voltage under the positive and negative pole open circuit state Maximum working current (Imp) We can provide various specifications of solar panels with power ranging from 10W-450W. The most widely used solar panels have the following specifications: 18V working voltage: 10W/30-180W (mainly used for portable small systems and off-grid systems) 30V working voltage: 280W-300W (mainly used for power stations and large water pump systems) 36V working voltage: 400W-550W (used for off-grid systems)