Recently, a novel and puzzling phenomenon has appeared on the streets of many cities: some Street lights are no longer emitting their normal white light, but have turned purple. This phenomenon has not only aroused the curiosity of passers-by, but also made many people start to pay attention to the reasons behind. After all, street lights as an important facility of urban lighting, its state is directly related to the safety of everyone’s travel, and the emergence of purple street lights, undoubtedly breaks the conventional perception of street lights.
One of the most significant advantages of LED street lights is their long lifespan, with the lifespan of a single LED reaching about 50,000 hours. This means that over a long period of time, there is no need to frequently arrange for staff to climb up to replace street lights, greatly reducing the interference with urban traffic and residents’ lives. Moreover, the brightness of the LED street light remains stable throughout its use, unlike traditional street lights that slowly dim with use, affecting the lighting effect.
LED street lights emit cool white light (4000K-5000K) with excellent illumination effect, just like turning on the HD mode for the surrounding environment, allowing pedestrians to clearly see the road surface, and allowing drivers to spot obstacles or pedestrians on the road in time. In contrast, traditional yellow Street lights have a limited range of illumination and a soft light, which tends to obscure some details and increase the safety risks of traveling.
Of course, LED Street lights are not perfect, and their upfront investment costs are higher than those of traditional Street lights, which makes some cities hesitant to promote them. Moreover, when replacing traditional Street lights with LED Street lights, there may be mismatches with the old infrastructure, such as insufficient load-bearing of old poles, incompatible wiring systems, etc. In addition, if the LED Street lights are not well designed, they may not be able to be replaced. In addition, if LED Street lights are not properly designed and protected, they may produce glare, affecting the vision of pedestrians, and may also cause light pollution. However, from a long-term perspective, the savings in energy and maintenance of LED Street lights will gradually offset the initial investment, which is generally cost-effective.
From the environmental point of view, LED street light is very friendly. It does not contain mercury and other environmentally harmful substances, and will not pollute soil and water after use or disposal. Moreover, LED street light is a recyclable product and can be used again after disposal. At the same time, it has low energy consumption in the process of use, which can reduce energy consumption, thereby reducing greenhouse gas emissions and contributing to environmental protection.
solar led street light
LED Street lights are far more energy efficient than traditional Street lights, consuming 50%-70% less energy than older sodium vapor lights. This advantage brings obvious benefits, on the one hand, it can significantly reduce the city’s electricity expenditure, saving money for the municipal government; on the other hand, because of the lower energy consumption, the carbon emissions generated in the process of power generation will be reduced accordingly, which is of positive significance to the mitigation of climate change.
Although LED Street lights have gained a firm foothold in urban lighting by virtue of their many advantages, and have become the mainstream choice for replacing traditional Street lights, it is not without its twists and turns in the actual use process. In addition to known challenges such as upfront costs and infrastructure adaptation, a new situation that has recently aroused widespread concern – some LED Street lights have inexplicably turned purple, a phenomenon that has confused many people and raised new questions about the stability of LED Street lights.
To understand why street lights turn purple, we must first know how white LED street lights emit light. LED do not emit white light directly, but rather emit pure colors such as red, green, yellow, and blue. These light wavelengths are different. The white light of a white LED light is formed by mixing different wavelengths of light, just as sunlight is formed by mixing multiple colors of light.
At present, there are mainly two ways to produce white light: one is to be able to emit red, green (or yellow), blue three kinds of light micro LED integrated together, according to a certain proportion of the white light emitted after mixing, this way is common in the OLED display and color-changing light bulbs; the other is to use the blue LED, the surface of the chip is covered with a layer of phosphor, when the blue LED emitted by the blue light through the phosphor, the phosphor will absorb part of the blue light, releasing red and yellow light. When the blue light from the blue LED passes through the phosphor, the phosphor will absorb part of the blue light and release red light and yellow light, which are mixed with the rest of the blue light to form white light, and this way is mostly used in the lighting industry.
LED street lights appear purple blue light core reason, is the LED chip native blue-violet light has not been fully processed and direct leakage — under normal circumstances, the chip issued by the blue-violet light will be absorbed by the surface of the phosphor and converted to yellow light, both of which are mixed to form white light. Mixed to form white light, and when the phosphor layer has a small crack, a small amount of blue-violet light will be transmitted from the gap (difficult to detect with the naked eye); if the phosphor layer and the chip is separated, the absorption efficiency of blue-violet light has decreased dramatically, and more blue-violet light escapes, so that the light color is bluish violet; when the chip is completely exposed, the phosphor loses its role, and a large number of the blue-violet light of the chip is directly released, and at this time the naked eye can clearly see the obvious violet-blue light.
Purple street lights have a great impact on travel safety. On the one hand, its illumination will be reduced, and purple light will make people produce visual discomfort, pedestrians walking under such street lights, it is difficult to see the potholes on the road, obstacles, drivers are also difficult to judge the road conditions. On the other hand, the loss of fluorescent layer of LED street lamps, blue light can not be converted into red and green light, and the human eye is more sensitive to red and green light, which makes the street lamp luminous flux decline, the original street lamps in line with the design standards of road lighting, become no longer up to standard. At the same time, the lack of green light, red light and yellow light in the spectrum of purple street lights, low color rendering index, will make it difficult to accurately identify the color of the object, such as pedestrians wearing dark clothes may be confused with the surrounding environment, increasing the risk of accidents.
solar street light
Purple light contains a large amount of blue light, which is harmful to human health. It will inhibit the human body’s melatonin secretion, which is an important hormone for regulating sleep. Once the secretion is disturbed, a person’s biological clock will be disrupted and insomnia may occur. Prolonged exposure to such a light environment may also trigger headaches, anxiety and other problems, affecting people’s physical and mental health.
The blue-violet light in violet light has a great impact on organisms such as insects, birds and reptiles. These creatures are very sensitive to blue-violet light and are attracted to purple street lights. This will disrupt their normal rhythm of life, for example, insects may not be able to feed properly because they are circling around the street light, birds’ migration routes may be changed due to the attraction of the street light, and reptiles’ mating behaviors may be interfered with, which will in turn affect the balance of the whole ecosystem.
If you have come across a purple Street light in your life, don’t worry too much as most of the problematic Street lights have been put on the replacement list by the relevant authorities and are being gradually replaced. However, if you see a purple Street light when you’re walking in the evening, late at night after work, etc., it’s essential to report it promptly. Reporting it gives the supplier a fuller picture of the situation and prevents any missing Street lights. You can look for them on Street light poles, which usually have the operator’s contact details on them, such as a phone number or QR code, which can be scanned or called to give feedback. If you don’t find it, you can also report it through local government APP, and other channels, which can speed up the repair progress and return the Street light to normal lighting as soon as possible.
The appearance of purple street lights is the result of the failure of the phosphor layer of LED street lights leading to the leakage of blue-violet light. It reduces the lighting effect, affects visual judgment, and may interfere with the biological clock and ecological balance, but it is not insurmountable — when it is found, it will be reported through the contact information of the Street light pole or government channels, and the relevant departments will replace it in a timely manner. Although there are occasionally such small conditions, LED street lamps, energy saving, long life and other advantages still make it become the preferred choice of urban lighting, and the public’s timely feedback, can make these “purple hiccups” faster exit, so that the street lamps continue to safely guard the night travel.
