What are the advantages of LED street lights over high pressure sodium lamps?

1. Energy efficiency advantages:
Although the high-pressure sodium light source itself has a high light efficiency, up to 140 lm/W, its light source can emit 360 light, in addition to a small part of the light reflected by the reflector to the road surface to form effective light, a large part of the light is absorbed by the reflector of the lamp, no effective light is formed, the lamp efficiency is not high, combined with the power consumption of the rectifier, the effective light efficiency of the actual rectifier lamp is around 75lm/W, while the LED street lamp is unidirectional.Light emitting, high light utilization, full light effect up to 150 lm/W.Therefore, the whole-light LED street lamp is twice as effective as the traditional sodium lamp, and the energy-saving effect is very significant.
2. Long-life advantages:
High-pressure sodium lamps include light sources, electrical accessories (mainly ballasts, triggers) and lamps. Sodium lamps are used for street lamps with an average life of 1-2 years, as are lamps.The life span of LED street lamp is about 50,000 hours, and road lighting can be used for more than 10 years according to 12 hours per day.High pressure sodium lamp replaces the light source in an average of 1 to 2 years. There are many times the cost of light source purchase, and the street lamp installation location is high. It is very difficult to replace the light source and the maintenance cost is very high.However, LED street lights require little maintenance except for the rare power damage during their service life.So overall, LED street lights have a much longer lifetime than traditional sodium street lights, and the maintenance costs have been greatly reduced.
3. Color rendering advantages:
The color rendering index (Ra) of high pressure sodium lamp is only 23~25, which results in very poor color rendering performance; while the color rendering of LED street lamp can reach Ra70~80, which results in very good color rendering performance.From a visual psychological point of view, to achieve the same brightness, the illumination of high-color LED street lights can be reduced on average than that of low-color high-pressure sodium lamps (refer to UK road lighting standards).
4. Advantage of low light loss:
The LED street lamp has a low light decay, less than 3% in a year, and still meets the road illumination requirements in the service year. However, the high-pressure sodium lamp has declined by more than 30% in a year or so, so the LED street lamp can be designed with lower power than the high-pressure sodium lamp.
5. Controllability advantages:
The traditional sodium lamp has a long start-up time and cannot adjust the brightness. The LED street lamp can start instantly and adjust the brightness. It can reduce the power as much as possible to meet the lighting requirements of different time periods through automatic control of energy-saving device, and further save energy.
6. Easy light distribution advantages:
LED street lights can easily and conveniently control the spot through secondary optics, with small glare and high utilization rate. The spot of high-pressure sodium lamp is irregular diffusion type, the difference between brightness of spot center and edge is large, the effective utilization rate of light is low, and light pollution is serious.
7. Environmental advantages:
The high pressure sodium light source itself is fragile, and the light source contains harmful substances such as mercury, which can easily cause secondary pollution to the environment. The LED street lamp is lead-free, mercury-free, infrared-free, Ultraviolet-Free and green.
8. High power factor advantages:
The power factor of the sodium lamp is only 0.45, the additional power can only reach 0.85, the effective utilization rate of the power grid is low, while the power factor of the LED street lamp can reach 0.95, and the effective interest rate of the power grid is high.
In summary, compared with traditional high-pressure sodium lamp, high-power LED street lamp has obvious advantages in all aspects, especially in energy saving, energy saving rate of more than 60%; maintenance costs have decreased significantly, and green environmental protection, has perfectly ended the traditional sodium lamp, becoming the second choice for road lighting.