1. The light source efficiency of LED has currently reached 100lm/W, and there is still a lot of room for development, with a theoretical value of 250lm/W. The luminous efficiency of high-pressure sodium lamps increases with power, therefore, the overall luminous efficiency of solar street lamps is stronger than that of high-pressure sodium lamps;
2. Solar street lights have a unique secondary optical design, which directs the light from the solar street lights to the desired lighting area, further improving the lighting efficiency and achieving energy-saving goals;
3. The characteristics of solar street lights themselves - unidirectional light, no diffusion of light, ensuring lighting efficiency;
4. The color rendering performance of solar street lamps is much higher than that of high-pressure sodium lamps. The color rendering index of high-pressure sodium lamps is only about 23, while the color rendering index of solar street lamps reaches 75 or above. From a visual psychological perspective, to achieve the same brightness, the average illuminance of solar street lamps can be reduced by more than 20% compared to high-pressure sodium lamps (referring to the British lighting standards);
5. The light attenuation of solar street lights is small, less than 3% in one year, and still meets the requirements of road illumination after 10 years of use. However, high-pressure sodium lights have a large attenuation, which has decreased by more than 30% in about a year. Therefore, solar street lights can be designed with lower power consumption than high-pressure sodium lights;
6. Solar street lights have automatic energy-saving devices that can achieve the maximum possible power reduction and energy savings while meeting lighting requirements at different times.
