First of all, let’s talk about the high-pressure sodium lamp, its light color is yellow, the color temperature and color rendering index are relatively low. The color rendering index of sunlight is 100, while the color rendering index of yellow light high pressure sodium lamp is only about 20. However, the color temperature of LED street lights can be freely selected between 4000-7000K, and the color rendering index is also above 80, which is closer to the color of natural light. The color temperature of the high pressure sodium lamp is for white light, usually around 1900K. And because the high-pressure sodium lamp is colored light, the color rendering should be low, so the “color temperature” has no practical meaning for the sodium lamp.

The start-up time of the high-pressure sodium lamp bulb is relatively long, and a certain time interval is required when it is restarted. Normally, it can reach normal brightness for about 5-10 minutes after power on, and it takes more than 5 minutes to restart. The LED street light does not have the problem of long start-up time, it can work at any time and is easy to control.

For the high-pressure sodium lamp, the utilization rate of the light source is only about 40%, and most of the light must be reflected by the reflector before it can illuminate the designated area. The utilization rate of the LED street light source is about 90%, most of the light can be directly irradiated into the designated area, and only a small part of the light needs to be irradiated by reflection.

The lifespan of ordinary high-pressure sodium lamps is about 3000-5000 hours, while the lifespan of LED street lamps can reach 30,000-50000 hours. If the technology is more mature, the lifespan of LED street lamps can reach 100,000 hours.