What are the advantages of LED street light compared to high-pressure sodium lamp?

Traditional road lighting often uses high-pressure sodium lamps. The overall low light efficiency of high-pressure sodium lamps has caused a huge waste of energy. Therefore, the development of new types of high-efficiency, energy-saving, long-life, high color rendering index, and environmentally friendly street lamps is very important for urban lighting energy saving. Significance. As the light source of LED street light, LED has many advantages compared with traditional high pressure sodium lamps.

1. High light efficiency and low energy consumption

Traditional street light sources generally illuminate the entire space, but only the roads of traffic and pedestrians need to be illuminated by street lights. Therefore, in the design of street lights, in order to project the lights as evenly and concentratedly on the road as possible, a curved reflector is needed. Collect the light and make it shine in the desired direction. In the process of light propagation, due to the blocking of the light source and the absorption of the reflecting surface, the light output efficiency of the street lamp is only 65%-70%. In contrast, LED street light, because of their good directionality, when using secondary optical lenses, the efficiency of the lamp can reach about 80%. If the optical design is performed three times, the light output efficiency of the lamp can reach 85%-90%.

High-intensity discharge (HID) street lamps generally can only be dimmed in a small range, while LED street light can achieve dimming control from 0%-100%, and can flexibly adjust the light output according to ambient light and traffic conditions. Reduce unnecessary energy consumption while ensuring lighting requirements. It can be seen that for road lighting, which accounts for about 15%-20% of the total lighting power consumption, the large-scale implementation of LED street light is of great significance for energy saving and carbon reduction.

2. Long service life

The life of street lights directly affects the maintenance cost of the entire road lighting. At present, the lifespan of high-pressure sodium lamps is generally about 20,000 hours, the lifespan of high-pressure sodium lamps for road lighting is only about 5,000 hours, and the lifespan of led street light is generally 50,000-70,000 hours.

3. Good color rendering

Although the high-pressure sodium lamp has the highest light efficiency among traditional light sources, its color rendering is the worst, with a color rendering index Ra of only about 20. Such poor color rendering can only help people perceive road conditions, but cannot help pedestrians to distinguish clearly. The color rendering index of LED street light can reach around 80, which is basically close to natural light, presents colors more realistically, and can better reflect the color of the object itself. The high color rendering of LEDs will undoubtedly help drivers and pedestrians identify targets and provide better traffic conditions under the same road brightness.

4. Fast start

The incandescent lamp lights up at one point, but the actual start-up time is 0.1 second-0.2 second. It takes tens of seconds or even ten minutes for gas discharge lamps such as high pressure sodium lamps and metal halide lamps to start to stabilize the light output.

After shutting down, you need to wait 3-6 minutes to cool down before starting. The start-up time of the LED is only tens of nanoseconds (ns), there is no waiting time for restarting, and the LED street light can work normally in a continuous on/off state.

5. Facilitate optical design

The LED is small in size and can emit light in a half-plane direction. It can be regarded as a point light source in the design of the luminaire. It is very suitable for the use of lenses or reflectors for optical design to obtain an ideal light distribution and achieve higher Lamp efficiency.

6. Strong plasticity and firm structure

The shape of the LED street light has strong plasticity, and the decoration and local humanistic characteristics can be reflected through the shape design, and the added value of beauty and urban image can be added. LED is a solid-state light source and does not contain vulnerable parts such as glass and filament. With reasonable design, LED lamps can be made very firm in structure.

Compared with high-pressure sodium lamps, LED street light has many advantages, but they also have limitations. For example, the effect of using in foggy days is not as strong as yellow light high pressure sodium lamps.