5 degrees to 15 degrees. The starting threshold of solar automatic tracking system should consider the weather conditions of the day and the position of the sun to determine the optimal value. Generally speaking, the starting threshold should be set to start the tracker when the sun elevation angle is greater than or equal to 5 degrees. In addition, considering the energy consumption of the system, the starting threshold can also be set higher, for example, the solar elevation angle is greater than or equal to 10 degree or 15 degree.