Solar traffic lights are signalling devices powered by solar panels positioned at road intersections, pedestrian crossings and other locations to control the flows of traffic. They assign the right of way to road users by the use of lights in standard colors (red – amber/yellow – green), using a universal color code. Most of the solar traffic lights have battery back-up for functioning during night.
Most solar traffic lights use LED lamps as they are more reliable and have more advantages over other lighting devices like CFL lamps as they are more energy efficient, have a longer life span and turn on and turn off quickly. Solar traffic lights contain enclosures which house the batteries and the control panel circuitry. Existing solar panels can also be upgraded with an auxiliary power source using solar panels for use during power failures. The other parts in a solar traffic light include a charge controller to control the charging and discharging of the battery