About solar street light working principle:

The solar street lighting relies on solar energy, which is clean, endless and environment-friendly. The system is mainly composed of solar panel, light source, controller and battery. In daytime, when there is sunshine, the solar panel can convert the solar energy to electric energy and store it in the battery. At night or rainy or cloudy condition, the battery shall supply power for normal lighting. The controller can judge the brightness of daylight and automatically switch on the light. The whole process is operating in completely automatic mode, without human action.