Road lighting is an important part of urban lighting. Traditional street lamps are often used. High-pressure sodium lamps emit light at 360 degrees. The disadvantage of large light loss has caused a huge waste of energy. At present, the global environment is deteriorating day by day, and all countries are developing clean energy. Therefore, the development of new high-efficiency, energy-saving, long-life, high-color rendering index, and environmentally friendly LED street lamps is of great significance for urban lighting energy conservation. LED street lamps with the characteristics of directional light emission, low power consumption, good driving characteristics, fast response speed, high shock resistance, long service life and green environmental protection have gradually entered people’s field of vision and become the new generation that has the advantage of replacing traditional light sources in the world. Energy-saving light sources, therefore, every street light manufacturer pay most attention on the led street lighting.
The advantages of led street lights.
- Its own characteristics – unidirectional light, no light diffusion, to ensure lighting efficiency.
- The led street light has a unique secondary optical design, which irradiates the light of the LED street light to the area that needs to be illuminated, further improving the lighting efficiency and achieving the purpose of energy saving.
- The LED has reached 110-130lm/W, and there is still a lot of room for development, with a theoretical value of 360lm/W. The luminous efficiency of high-pressure sodium lamps increases with the increase of power. Therefore, the overall light efficiency of LED street lamps is stronger than that of high-pressure sodium lamps; (this overall light efficiency is theoretical, in fact, the light efficiency of high-pressure sodium lamps above 250W is higher than that of LED lamps.).
- The light color rendering of LED 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 LED street lamps is above 75. From the perspective of visual psychology, to achieve the same brightness, the average illuminance of LED street lamps can be It is more than 20% lower than that of high-pressure sodium lamps.
- The light decay is small, less than 3% in one year, and it still meets the road requirements after 10 years of use, while the high-pressure sodium light has a large decay, which has dropped by more than 30% in about a year. Therefore, LED street lights are designed in terms of power usage. Can be lower than high pressure sodium lamps.
- The led street light has an automatic control energy-saving device, which can achieve the maximum possible power reduction and save energy under the condition of meeting the lighting requirements of different periods. It can realize computer dimming, time-segment control, light control, temperature control, automatic inspection and other humanized functions.
- Long service life: It can be used for more than 50,000 hours and provides three-year quality assurance. The disadvantage is that the life of the power supply is not guaranteed.
- High luminous efficiency: The use of chips of ≥100LM or more can save more than 75% of energy compared with traditional high-pressure sodium lamps.
- Easy installation: no need to bury cables, no rectifiers, etc., directly connect to the lamp pole or nest the light source into the original lamp shell.
- Excellent heat dissipation control: The temperature is controlled below 45 degrees in summer, and passive heat dissipation is adopted, and the heat dissipation guarantee in summer is insufficient.
- Reliable quality: The circuit power supply adopts high-quality components, and each LED has its own over-current protection, so there is no need to worry about damage.
- Uniform light color: no lens is added, and uniform light color is not sacrificed to improve brightness, so as to ensure uniform light color without aperture.
- LED does not contain harmful metal mercury, which will not cause harm to the environment when it is scrapped.
Combining the above principles, the energy-saving effect is remarkable, and the replacement of high-pressure sodium lamps can save more than 60% of electricity.
Low maintenance cost: Compared with traditional street lights, the maintenance cost of LED street lights is extremely low. After comparison, all investment costs can be recovered in less than 6 years.
The shortcoming of led street light.
- The power of a single LED is low. In order to obtain high power, multiple parallel connections are required.
- Low color rendering. The color displayed under LED illumination is not as real as incandescent lamps, which is a technical problem to analyze from the spectral distribution.
- Light spot. Due to the defects in the manufacturing process of the white LED itself and the matching error with the reflector cup or lens, it is easy to cause the “yellow circle” problem.
- LED illumination uniformity problem. If the secondary optical design is not carried out, the illumination of the LED is relatively concentrated, so the secondary optical design must be carried out to make the light intensity distribution map in the shape of a bat.
- The problem of LED light decay. Compared with low-power LEDs, the light decay of high-power LED street lights will be much better. But low-power LED heat dissipation is very small. The high-power LED has the problem of heat dissipation that cannot be solved, and the brightness will be significantly reduced after heating, so the power cannot be increased.