What is the basis for deciding that, for example, 21W LED street lights can replace 50W HPS?
Through the analysis and comparison of the final luminous efficiency value, we can find that the luminous efficiency of 100W LED street lamp is almost 2 times higher than that of 250W high-pressure sodium light. That's why 100W LED street lights can be used instead of 250W high pressure sodium lamps.
Initial luminous flux of 1.100W LED street lamp 11000lm. Because the lens loss 10%, power loss 10%, the lamp luminous flux is actually 8910lm, the total power consumption of lamps is 110W. Therefore, the light effect of this LED street lamp is 81lm/W.2.250W high pressure sodium lamp initial luminous flux is 25000lm, the light source utilization loss about 30%, the power loss about 20%, the lamp luminous flux actual 12500lm, that lamp's total power consumption is about 300W. Therefore, the light effect of this high-pressure sodium lamp is 41.67lm/W.
The LED street light / tunnel lamp belongs to the area light source, the luminous surface is a single direction, the utilization rate of the light source is high, and the efficiency of the lamp is above 80%.Here we will take 100W LED street lights and 250W high pressure sodium lamp as an example to illustrate this problem.
High pressure sodium lamp belongs to point light source, which is 360 degree light. In fact, the light applied to the direction of illumination is very small, only about 30%. Therefore, the high pressure sodium lamp must reflect the light in the non irradiation direction through the reflector in the lamp, so as to achieve the purpose of higher light utilization. Due to the lamp design and cost issues, the sodium lamp efficiency is only 40-45%.
