LED street light technology has matured

To say that LED street lamp (which is actually all the LED lighting) can not be nothing more than large-scale application of the following three reasons:
1, LED street light effect has not yet reached the level of sodium;
2, LED lamp life;
3, LED street lamp light distribution is not ideal.

Comes to LED lights, a lot of people will point out the obvious LED color rendering index CRI than the sodium lamp is much higher, thus can reduce the standard LED illumination lights, LED lights for the amendment called for a separate standard, in fact, from a macro point of view hope revised standard is unrealistic, and I think the existing road lighting standards are not possible nor necessary amendments. To make the LED light source to replace the other become a reality, the only LED lighting in the area rely on one's own efforts.

Light effect problem:
First, the sodium light effect is really high, I saw some good power lumen sodium products are in units of 110 or more, and do good LED current also in 90Lm / W or so, but also not to mention energy. But , when we compare the efficiency of lighting, the conclusion is not the same. because the general uniform 360-degree light source are light, and LED directional light, usually less than 180 degrees, so different, made of lights is not the same. sodium or traditional light sources made of street lamps light extraction efficiency is usually about 60%, while the LED lights more easily can reach 90%. then do the same A-weighted, sodium do street effective the light is 66Lm / W, while LED lights effectively out of the light can achieve 80Lm / W a.

Secondly, since it is the street, of course, the light only on the pavement is less than needed, it should be further up the road to see the flux, and to the national standard for a minimum H = Weff, for example, a better utilization factor of 0.3 sodium , if we can do LED's utilization factor of 0.8, then the current level of LED light efficiency, a 110W of LED lights to 250W can replace the sodium, if taking into account such factors as the actual project cost, usually according to H = 1.2 Weff to design, then the LED lights to replace the 100W sodium lamp 250W, at this stage can be achieved. to achieve the 60% level that there is enough energy saving effects. to achieve the 0.8 of the utilization factor, which depends on LED street light foundation with the designer, in fact, not hard.

Life issues:
If someone tells you that their LED lamp life of a 10 million hours or the 50,000 hours, 30,000 hours, you and regardless jump to listen to it, but remember to ask how to get, if is known, then you've heard even, if is measured to tell you, do ask about the number of hours is based on data, because no one is certainly made of thousands of hours of testing dollars because it can not, and will not be foolish to make such test, because it does not. Some people will tell you 1000 hours of data, then do not operands, because many thousands of hours in 1 LED tube light efficiency is rising within. Of course, when you choose the tube as well. Now International passage of thousands of life testing time is 1 +5 thousands of hours testing, thousands of hours to stabilize before a time, thousands of hours of data after 5 basis for calculating life expectancy, more than 5 thousand hours life 5 thousand hours in accordance with the fitting curve extrapolation . we actually test 1 +5 thousands of hours of light decline of 2.2%, and is linear, considering the number of margin, we set standards for products to thousands of small-time decline of 5 to 2.5%, such as the addition of light to push 50% effective life span will be 10 million hours, 70% of the light effect life expectancy of 6 million hours.

However, whether it is in accordance with the 50% or 70% of life is not important, in fact, is the most scientific methods used in many countries is to maintain the intensity of not less than the standard required to maintain illumination of life prevail. Such as the national standard maintain an average speed road illumination 20Lx, if the initial installation, the average illumination of street lamps 30Lx, should be calculated to 66% of the life of light effects, such calculation is 66,000 hours life. If middle of the night with light control, the actual use of time could reach 10 million hours. of course, can not really achieve this use of time, it may take 25 years to know