10 Important Facts That You Should Know About Led ...

LED street lamp refers to the street lamp made of an LED light source, which has the unique advantages of high efficiency, safety, energy-saving, environmental protection, long life, fast response speed, and high color rendering index, which is of great significance to the energy saving of urban lighting.

If you want to learn more, please visit our website Philips LED Street Light.

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 shortcomings of large light loss cause a huge waste of energy. LED street lights have gradually entered people's field of vision with the advantages of directional light emission, low power consumption, good driving characteristics, fast response speed, high shock resistance, long service life, green environmental protection, etc. Therefore, LED street lights will become the best choice for energy-saving renovation of road lighting.

LED street lights based on 901 milliwatt output LEDs can typically produce the same (or higher) brightness as conventional lamps, but require only half the power consumption. LED illumination usually does not fail, but lowers the output until it needs to be replaced.

According to different shell designs, LED street lights can be divided into modular street lights and full die-casting street lights.

2.1 what is a modular design LED street light?

As the name implies, the modular street light adopts the LED modular design. The LED module can be disassembled freely without destroying the lamp body. Generally, plug-in waterproof connectors are used. The module power can range from 30-60w, such as 200W SA street lights, it can be done with 4 modules or 5 modules, the power matching is flexible, and the plug-in design at the same time, the replacement and maintenance of the modules in the future is very simple.

Figure 1: Modular design

Full die-cast street light means that all parts of the lamp housing are made of die-casting. The radiator is integrated with the lamp housing, and the LED light-emitting component is a single piece, which is fixed on the lamp body together with the optical lens by screws. If you want to replace the LED, Only the whole light board can be replaced, and the maintenance cost will be much higher than that of the modular street lights. For example, our SB, SE, SC, SD, SG, SI street lights all adopt the full die-casting design. I believe that the full die-casting street lights are the future. The mainstream direction of street lamp design.

Figure 2: Die-casting design

2.3 Video of SE Street Light

2.4 Download

Installation Manual_StreetLight_SE.pdf

Specification_SE_LED Street Light.pdf

As the main luminaires of urban road lighting, LED street lamps are widely used in places including urban streets, roads, country trails, parking lots, parks, shopping malls, highways, etc. 

The following are some projects cases sharing of MKLIGHTS road lighting:

Street lighting is the lamp with the longest use time and the largest power consumption. The use of LED light sources for street lighting will greatly reduce the shortage of electric energy in the city and save the country's energy. The following is the performance comparison of LED street lamps and HPS lamps.

4.1 Service life comparison

The HPS circulating in the market today have short lifespans due to quality and technical problems, generally less than 6,000 hours. The lifespan of LED street lamps is more than 100,000 hours, which is equal to more than 16 times the lifespan of HPS lamps. The cost of replacing the light source, maintenance costs, and the inconveniences caused by them are the most obvious comparisons. LED street light has no effect on the number of switches, unlimited, while the HPS lamp has a certain limit on the number of switches, generally only 4000 to 5000 times, and the life is over. The LED street light has no blackening phenomenon at any number of times of switching and the end of its service life, while the HPS lamp turns on and off after 1,000 switches or 1,000 hours of use, and the light efficiency is reduced by 16%.

4.2 Startup performance comparison

LED street lights are activated instantaneously, and it takes more than 10 minutes for high-pressure sodium lamps to start to reach normal brightness, and high-pressure sodium lamps consume a lot of electricity during this time. The input voltage of the LED street light can be between 90 volts and 305 volts and has no effect on the LED lights. The high-pressure sodium lamp cannot be started when the input voltage is less than 185V, and the power increases by 12% when the input voltage exceeds 245V. In this way, high-pressure sodium lamps have higher requirements on power supply lines.

4.3 Color rendering comparison

The CRI of high-pressure sodium lamps can only reach 20 to 30, while LED street lamps are generally above 70. In this way, compared with the traditional lighting, the driver can better identify the obstacles in the road and the surrounding environment of the road, and reduce the occurrence of traffic accidents. The level of color rendering directly reflects the difference in scotopic vision (S/P) between people's naked eyes. Therefore, the luminous flux emitted by the high-pressure sodium lamp must be multiplied by a correction value (0.64) to be the intensity felt by the human eye. The luminous flux emitted by LED lamps must be multiplied by a correction value (1.60) to be the intensity felt by the human eye.

4.4 Color temperature range comparison

The color temperature range of HPS lamps is 2000 to 2500, while the color temperature range of LED street lights is 2200 to 7000. If the color temperature is low, it will give people a warm feeling in winter, but it will give people a hot feeling in summer. If the color temperature is high, it will give people a cold feeling in winter and a cool feeling in summer. In general, people spend more time in summer evenings and less in winter evenings, and there is hotter weather than cold weather in a year. Therefore, relatively speaking, it is better to use white light with high color temperature as road lighting.

4.5 Light decay comparison

The light decay of LED street lamps is less than 2% at 10,000 hours, while the light decay of high-pressure sodium lamps is generally greater than 25% at 2,000 hours.

4.6 Environmental comparison

LED street lights do not contain mercury, no ultraviolet radiation, and the low working temperature effectively reduces heat emissions. Because of its power-saving, it saves coal for power generation and uses less coal to generate electricity, thereby saving carbon dioxide emissions! The high-pressure sodium lamp contains mercury and ultraviolet radiation. It emits a lot of heat during work, consumes electricity, wastes coal, and emits a lot of carbon dioxide! The PF of an LED street light is greater than 0.99, and the power factor of a high-pressure sodium lamp is about 0.44. In this way, the pollution of the LED to the power grid is very small, while the pollution of high-pressure sodium lamps to the power grid is very large! LED lamps have no stroboscopic and no light pollution, while HPS lamps have obvious stroboscopic and serious light pollution.

4.7 Comparison of effective utilization of light

Due to the characteristics of the LED light source, which is like the point light source, the illuminated object emits light in directional light. There is basically no wasted light, so it has a very high light utilization rate, which can reach more than 92%. However, because the high-pressure sodium lamp emits light from all sides, part of the light is blocked by the light source itself and the light-emitting point is large, so it is not easy to do optical design, the efficiency of the lamp is not high, and the output The light spot will not be heavy with the required effective irradiation surface and waste part of the light source, so it will be projected to the surface of the illuminated object through the reflector of the lamp, and part of the light will be lost in the middle. Therefore, the effective light utilization rate of traditional lamps is 55~60%.

5. What are the common problems with LED street lights?

Usually, LED street lights are installed on light poles, and the height of the light poles varies from 5-15m, so the quality of LED street lights is very important because once a fault occurs, the maintenance cost is very high, and a lift must be rented for maintenance. So, what are the most common problems with LED street lights? Generally, quality problems are as follows:

5.1 Problem of Surge Protection Device

Street lights are used in outdoor places and are prone to lightning strikes, so street lights are generally equipped with a 10KV surge protection device which also is named SPD, the SPD can resist multiple small-scale surges, but each time it resists, the life of SPD will be shortened until it fails, the SPD is prone to failure in areas with dense lightning. SPD is generally connected to the lamp in a parallel structure, so after the SPD fails, the lamp will not stop work immediately, but when the lamp suffers the next surge, the LED driver will suffer from surge breakdown and fail. In order to save costs, some suppliers provide street lights without SPD, so buyers need to pay attention to whether the surge is standard when purchasing LED street lights.

5.2 Problem of LED driver

The LED driver likes the heart of the lamp and is one of the most important components. When the LED driver fails, the common phenomenon is that the lamp stops working or flickers. So how to ensure that the LED driver does not fail? The best solution is to use high-quality brand driver supplies. A High-quality LED driver can not only reduce the failure rate, but also have very good electrical parameters, high power factor, and low harmonic distortion. So, what are the reliable LED driver on the market?

The video comes from youtube about the flicker of LED Street Light caused by LED Driver failure

Top Seven Brands That Manufacture LED Drivers

a.PHILIPS Xitanium LED Driver

Philips is the leading manufacturer of residential and commercial lighting products. One of the aspects that give this company an upper hand is using new technology to produce innovative LED lights led drivers, bulbs, and many other products. The company started in 1891, operates in 70 countries, and employs more than 32,000 people.

Website: www.signify.com

b.OSRAM LED Driver

Osram Led Driver Osram Licht AG manufactures Osram LED drivers for companies and individual clients. The company started in 1919 in Germany to produce electrical products. Over time, it changed its production line to focus solely on designing and manufacturing modern LED products that match users' needs and expectations.

Website: www.osram.com

c.INVENTRONICS LED Driver

Inventronics was established in Hangzhou, China, in 2007. Similar to MOSO, Inventronic's main products are LED outdoor constant current, constant voltage, High bay drivers. they also provide full global approvals. with good designs in outdoor, lightning protection, and with 5 years warranty.

Website: www.inventronics-co.com

d. TRIDONIC LED Driver

TRIDONIC GmbH Co KG, lighting products and energy-saving company located in Austria. TRIDONIC produced the magnetic ballast for the fluorescent lamp early in 1956. And later with the electrical ballast in 1978.

Website: www.tridonic.com

e.MEANWELL LED Driver

MEANWELL Switching Power Supply MEAN WELL is a Switching Power Supply manufacturer in Taiwan – SMPS, SPS manufacturer, AC DC, DC-DC, DC AC, industrial power supply, Medical power supply, Din Rail power supply, LED power supply, LED driver, charger, inverter, adaptor, rack power, and modular configurable power.

Website: www.meanwell.com

f.MOSO LED Driver

MOSO Power Technology Co., Ltd, established in 2006, is a national high-tech company, a global advanced power solution provider, and a benchmarking enterprise in the domestic power supply industry, as well as a top brand in Shenzhen, a famous trademark in Guangdong Province and even in whole China. 

Website: www.mosopower.com

g.SOSEN LED Driver

SOSEN is one of the most competitive high-power LED driver brands in China. The products are widely used in outdoor lighting, horticulture lighting, industrial lighting, landscape lighting, industrial control, etc.

Website: www.sosen.com

5.3 Problem of LED Chips

The current drives the LED chip to generate light energy, so the LEDs are the most important part of the lamp. With the development of LED technology, the failure rate of the LEDs is much lower than the LED drivers, but low-quality LEDs are also a headache. At present, the LEDs on the market are very chaotic. To save costs, some manufacturers use plastic brackets when packaging the LED chips, so that the heat inside the LEDs cannot be effectively dissipated, and it is prone to deadlights over time. So, which LEDs brands on the market are trustworthy?

Top 7 Led Chips Manufacturer

a. LUMILEDS LED Chips

Lumileds is the light engine leader, delivering innovation, quality, and reliability with our LEDs and automotive lamps. It is an LED business unit spun off from PHILIPS.

Website: www.lumileds.com

b. OSRAM LED Chips

OSRAM Opto Semiconductors is the business unit and brand of OSRAM for Opto components, solutions-based semiconductor technology for lighting as well as sensor and visualization applications. For more than 40 years, OSRAM Opto Semiconductors has been a world leader known for the highest quality demands, taking innovation to new limits.

Website: www.osram.com

c. NICHIA LED Chips

Nichia standard LED is designed and developed as a calibration standard of luminous and radiant quantities for LED products in collaboration with the National Institute of Advanced Industrial Science and Technology (AIST). It has uniform spatial distribution and has achieved excellent temperature stability and lighting reproducibility.

Website: www.nichia.co.jp

d. Seoul Semiconductor LED Chips

Seoul Semiconductor is a global LED company with sales of approximately 1.1 trillion won and third place in the global LED market in 2020. they are flexibly responding to the rapidly changing LED market by building various product portfolios with differentiated technology through approximately 12,000 patents, and are currently providing high quality LED products

through 4 local subsidiaries, 4 production bases, and 40 overseas sales offices.

Website: www.seoulsemicon.com

e. CREE LED Chips

Cree is a market-leading innovator of LED Chips Our LED chips and dice deliver superior price and performance.

Website: www.cree.com

f. Samsung LED Chips

As a forefront pioneer of LED technology, Samsung LEDs marks a new era in a global industry. Our company delivers a product line that comprises core components for LED lighting systems including modules for various uses in displays, mobile devices, automotive, and smart lighting solutions.

Website: www.samsung.com

g. Bridgelux LED chip

Bridgelux manufacture leading-edge, high-performance light-emitting diode (LED) chips with superior quality and reliability. Bridgelux chips are the basis for LED luminaires including general lighting, signage, automotive applications, and camera flash for mobile appliances.

Website: www.bridgelux.com

5.4 Problem of Optic Lens change yellow

With the continuous improvement of the light efficiency of LED street lamps, the energy-saving rate of LED street lamps is also rising. Manufacturers are constantly pursuing good heat dissipation to solve the problem of LED light decay, but they have ignored a very important factor. The optical lenses used in the LED street lights are all made of PC material. When used outdoors, the LED street lights will be exposed to ultraviolet rays from the sun, and the PC lens will gradually turn yellow, resulting in a significant drop in the light output rate. Currently, the most adopted solution is to use an anti-ultraviolet PC. Material, but this will lead to an increase in cost, so buyers should pay attention to this problem when purchasing LED lamps.

5.5 Problem of LED street lamp head falling

The material of LED street lights is mainly die-cast aluminum. In order to meet the needs of heat dissipation, some manufacturers design LED street lights of large size and heavyweight. When encountering strong winds or the light poles near the bridges or railways, the LED street lamp heads will suffer very violent vibrations, If the structure of the lamp is not strong enough, the holder of the lamp is easy to break, causing the LED street lamp head to fall, which is a very dangerous problem. If someone or a vehicle passes under the lamp pole, it will cause serious personal injury or a traffic accident. Therefore, when buyers purchase LED street lights, the vibration test report should be a mandatory requirement.

6. How to choose the power of LED street lights?

For LED street light renovation projects, many customers will ask manufacturers to recommend the power of LED street lights. According to project experience, 80-100W LED street lights are usually recommended to replace 250W traditional street lights, and 120-150W LED street lights to replace 400W traditional street lights, but The most correct way is to use professional DIALUX lighting design software, according to the actual installation conditions of the road, such as the height of the pole, the distance between the poles, the width of the road, the length of the arm of the pole, the elevation angle of the pole, the position arrangement of poles, etc., the model will be built in the DIALUX, and then the IES file of the LED street light is imported into the software, according to whether the calculation results meet the road lighting standards of various road types to confirm the suitable power of LED street light, the standards of road lighting can refer to "BS EN 13201-2-2015"

DIALUX software download: www.dialux.com, commonly version is DIALUX EVO or DIALUX 4.13

7. Important parameters of LED street lights that are easily overlooked

How to choose a good LED street lamp? Usually, high quality LED and LED power supply, high efficiency is the most important reference, because these components and performance is the main reason for the stable operation of LED street lights and the impact of energy-saving rate. But beyond that, there's one component that tends to get overlooked. What are the most important components that are often overlooked? The answer is optical lenses, also named led light diffuser.

Road lighting affects people's travel and traffic safety, so in addition to reaching the specified illumination requirements, road uniformity and glare level are very important indicators. When the uniformity is poor or serious glare appears on the road, which is likely to lead to traffic accidents.

It is the optical lens that determines the uniformity and glare level of LED street lights. After the light of LEDs passes through the optical lens, it can produce the light distribution we want. There are various road conditions, some poles are high but the road width is very narrow, some poles are very low, but the distance between the poles is large, and some poles are installed on one side, but the road width is large, so in order to meet the road standards, it is necessary to use different light distribution, For example, according to North American IESNA standard, Type I is suitable for walking path with 1 lane, Type II is for 2 lanes and Type III is for an even wider road, Type V is for the parking lot, Lens with backlight shield is suited for high way or city residential road to avoid light waste or light pollution, so when buyers choose LED street light, they should choose the ones who have a variety of light distribution for optional. MKLIGHTS as a professional manufacturer of LED street lights, all LED street lights have more than 6 different optics lenses are available, and a professional lighting design team can provide lighting simulations to determine the best one.

8. How to install LED street lights?

LED street lights have different installation methods according to different application places. Most street lights will be installed on poles, but a small number of street lights will be installed on the wall as wall washers or parking lot lights. There is no uniform standard for the dimension of poles, but the diameter of poles of 60mm is more common in the market, there is also a demand for diameters of 40mm or 76mm, If the requirement is unconventional diameter, then we can only achieve the installation through the adapter; there are also many styles of poles, most of which are round, but there are also square poles, such as American parking lots, many light poles are square, then you need to add the adapter to Install. Even some street lights will be installed on the telegraph poles, then a customized fixed bracket is needed.

The following are commonly used street light installation adapters:

There are many factors that affect the price of LED street lights, including material, performance, transportation cost, brand, etc. Below I will analyze how various aspects affect the price of LED street lights.

9.1 Material is the most important factor affecting the price

There are three main parts of LED street light components, LEDs, LED driver, and housing. At present, the LED driver and housing account for the highest cost. The price difference between branded LED drivers and unbranded LED drivers is very large. The price difference is mainly in performance. For example, brand drivers generally have better electrical parameters, high PF, low THD, and passed strict international certification, and the unbranded LED driver will have much worse indicators in order to save costs, and most of them do not have any certification; the price of the branded LEDs and unbranded LEDs is also very different, mainly Due to the difference in internal materials and processes, unbranded LEDs use cheap brackets and rough production processes in order to pursue low prices; the LED street lamp housing is made of die-cast aluminum, and the weight of the housing generally determines the quality of heat dissipation and anti-collision grade. In order to reduce costs, some suppliers design the housing to be very thin and have no heat sink or insufficient heat sink. Such housing will lead to an extremely high working temperature of LEDs, large light decay, and a short lifespan.

9.2 Performance also affects the price of LED street lights

Further reading:
How to Choose led88?

For more Philips LED Spotlight 5.5winformation, please contact us. We will provide professional answers.

If buyers pursue high performance, such as high luminous efficiency, they can only choose high luminous efficiency LEDs, such as LUMILEDS 5050 lamp beads, the luminous efficiency will be much higher than ordinary lamp beads, but it also means the price will be much higher, so high performance Equivalent to high prices.

9.3 Shipping costs also affect the purchase price

Importers purchase LED street lights from overseas, usually, the goods will be shipped by sea, air, railway, or express delivery. When the project procurement volume is small, they will choose express delivery or air transportation. When the project procurement volume is large, they will choose sea or railway. The volume and weight are proportional to the transport cost. The large volume and heavyweight of the packaging means that the transportation cost to be paid is high, and the transportation cost is naturally included in the procurement cost. Therefore, when choosing LED street lamps, in addition to paying attention to performance, we should also pay attention to the size and weight of the lamps. Under the requirement of sufficient heat dissipation, try to control the product size as much as possible, and pay attention not to use too much foam when packing, only in this way, the container can ship a larger number of lamps, thereby reducing transportation costs.

9.4 Brand cost affects product price

Aside from the price, for buyers, the quality of products from well-known brands is definitely more guaranteed, but the larger the brand, the higher the additional brand cost of the product, because brand promotion requires a lot of money to be invested in advertising, media, etc. For promotional activities, these costs can only be added to the product price. Therefore, for buyers, it is best to find the same product quality, but is less well-known suppliers, because the quotations of these companies will not contain too much brand cost. Of course, if the buyer does not want to rush too much energy to find such suppliers, they would rather spend a higher price to purchase products from well-known brands, and such buyers also exist.

9.5 What is the approximate price of LED street lights on the market?

Take our SE Series street light as an example, the price as below:

The wattage of SE series LED Street LightUnit Price in USD20WUSD 70.00-77.00/pcs40WUSD 72.00-79.00/pcs60WUSD 75.00-82.00/pcs80WUSD 75.00-82.00/pcs100WUSD 96.00-106.00/pcs120WUSD 100.00-110.00/pcs150WUSD 120.00-132.00/pcs180WUSD 129.00-142.00/pcs200WUSD 131.00-144.00/pcs240WUSD 137.00-150.00/pcs

10. How to realize intelligent control of LED street lights?

After more than half a century of development, LED has developed from a simple illuminator to a commonly used lighting fixture and then to the current intelligently regulated lighting fixture. In addition to the often-mentioned high light efficiency, long life, energy-saving, and environmental protection LED street lamps also have the characteristics of easy dimming, color matching, and high controllability, which lays the foundation for the intelligent control of LED street lamps.

The so-called intelligent control of LED street lamps is to control the brightness of the lamps by controlling the current flowing through the LED lamps. Due to the characteristics of LEDs, the color change and adjustment of lamps can also be realized through the configuration of LEDs with different wavelengths.

Modern LED intelligent control can also use Wi-Fi or ZigBee technology to interconnect lamps with sensing equipment and control equipment to form an LED intelligent control system.

The LED intelligent control system adopts a fuzzy neural network control algorithm, which can adjust the lighting brightness of LED street lamps according to environmental factors such as usage scenarios, different time periods, weather conditions, traffic flow, and vehicle speed dynamics. 

At the same time, it is also possible to use the mobile phone to remotely control the LED lamps through the wireless network technology, control the lamp switch, adjust the brightness of the lamps, control the color of the lamps, turn on the scene lighting through the mobile phone APP, and even connect the LED street lamps with the electrical appliances and supplies in the home life, Linkage control. The intelligent control of LED street lamps has changed the pattern of single lighting of traditional lamps. The light distribution is determined according to the flexible scene definition, which can give users the best lighting experience. If you are interested, please contact the MKLIGHTS team, we can provide you with a complete lighting and intelligent control system solution.

11. Conclusion

As a professional LED street light manufacturer, MKLIGHTS has rich experience in LED street light design, production, installation, and maintenance. What are the common problems of street lights, and what details need to be paid attention to when buying LED street lights, the above has been explained in detail, if you encounter other problems, you can contact the MKLIGHTS team at any time. We have a design team that can provide you with a complete set of solutions.

12. Related Products

13. Related Products

14. People also ask

a. What percentage of street lights are LED?

Energy-saving technologies that make this possible? LED street lights. According to 2016 data from the U.S. Department of Energy, at least 221 cities around the world have switched their street lights to LEDs, including 30 percent of outdoor lights in the United States.

b. Why are street lights orange?

Street and industrial lights, such as those in parking lots or manufacturing facilities, emit yellow or orange light because they are sodium vapor gas discharge lamps. There are two types of sodium vapor lamps: high pressure (HPS) and low pressure (LPS).

c. How long do LED lights last?

LEDs are known for their extremely durable products. Many LEDs are rated for up to 100,000 hours of life. This is approximately 100 times longer than typical incandescent lamps, 40-50 times longer than typical halogen lamps, and 16-20 times longer than typical CFLs.

e. Do street lights change colors?

The color temperature (CCT) determines the color of the street lamp, but as the CCT increases, the color begins to change from yellow to white, and eventually to blue-white, or cool.

Photo: Photograph by Beth Sacca, Set design by Phillip Nuveen

This article was featured in One Great Story, New York’s reading recommendation newsletter. Sign up here to get it nightly.

The lightbulb was flickering over my head. Not the idealized cartoon lightbulb, the universal symbol for a flash of inspiration, but a Philips-brand 800-lumen A19 LED bulb. I’d put one in the bedroom-ceiling fixture only a few months before. In theory, it should have been the last I would put up there for years, maybe even a decade. Instead, the bulb was a dim, dull orange, its levels of brightness visibly fluttering through the frosted dome.

LED bulbs do this to me all the time. The two in my youngest son’s bedroom went near dark not long after I installed them. When I left them alone for a week, they inexplicably came back on at full blast. At story time, the LED in the clamp light on his bunk revolts if you cycle the power too fast. It sits there feebly glimmering, its perimeter a semicircle of white jelly-bean light blobs, until you turn it off and wait a while.

For most of my life, I expected energy-saving lighting to be bad. Traditional fluorescents, buzzing in grim-colored tubes, were synonymous with institutional austerity and migraines. A new generation of streetlamps somehow made city nights seem darker; CFLs shattered into mercury-flecked shards. New lighting tech was something people resented and worked around. My generation, presented with thrifty overhead fluorescents in ’90s dorms, countered by plugging in the newly popular halogen torchieres, whose 300 blazing watts would incinerate wayward moths or occasionally a stray curtain along with the university’s planned energy savings.

LEDs were going to be different. Their widespread appearance on store shelves was supposed to mark not another depressing trade-off but rather a Nobel-worthy breakthrough: They provided brilliant illumination at a fraction of the old energy costs and were nearly immortal by the old tungsten standard. The federal government has fully committed. Some rearguard action by the Trump administration delayed the process, but a new lighting-efficiency standard has finally taken effect. The Department of Energy is scheduled to start penalizing incandescent distributors and retailers this month, levying fines of as much as $542 per illicit bulb, with full enforcement of the ban beginning in August.

The plan is for LEDs to be the only available form of artificial lighting. Already, the old bulbs are dwindling to nothing on retailers’ shelves. You have to know where to look — mom-and-pop hardware stores, mostly — to get your hands on a beige-sleeved pack of Hungarian-made GE Básica bulbs or a yellow pack of GE Blanco Suaves, both with a bold stamp on the side reading, NOT FOR SALE FOR USE IN THE UNITED STATES.

Best in Class

The Best Bad Bulb

Illustration: Marcus McDonald

Strategist writer Erin Schwartz spoke to architects, designers, and LED enthusiasts to find the best lightbulb in a sea of bad options. Read about the very best LED lightbulbs here ➼

Years ago, I got a head start, joining the LED revolution with fervor. Screwing one into a socket vacated by an incandescent felt like the easiest good-citizen points I’d ever earned, as if I could keep on doing things exactly as before but with better and greener results. And the light coming out of the things was — well, it was light, right? I don’t remember how long it took to notice, or think I had noticed, a series of letdowns: a faded look to the page of a storybook, a flicker in the corner of the eye, those sudden unexplained failures or half-failures. A slate-blue sock that was indistinguishable from a charcoal-gray one till I brought them over by the window. A certain unreality was creeping in.

We were renovating our apartment, and one day our contractor summoned me to the bathroom in dismay. He adjusted the dimmer switch he’d just installed, and a new LED fixture began strobing like we were in a seven-by-eight-foot basement dance club. We gave up and had him install a normal switch. The quirks were becoming malfunctions were becoming betrayals. Things I might once have ignored caught my eye. Out in the world, I noticed more and more public spaces had a frigid cast and a liminal flicker. The interiors of bubble-tea shops and ice-cream parlors took on a queasy aspect. Getting up in the early-morning darkness in a San Francisco Airbnb, I could see the bedside lamplight trembling.

I started to confide in people that I was seeing things, that the light was wrong, and usually they knew exactly what I was talking about. Over lunch, a friend unspooled an epic account of his quest for dimmable bulbs that would actually dim. A stranger in a shared taxi forwarded me a blog post he’d written about his conviction that the color of objects lit by LEDs was washed out and about his incredulity at how fast they failed.

A technology that was once the epitome of simplicity (“How many people does it take to change a lightbulb?”) has become an ever-branching set of complications. Where before I would pick up a pack of 60-watt soft-white incandescents at the hardware store, I now search the internet for the highest-rated equivalent LEDs, then systematically cross-check those equivalences point by point. Everything you used to know about indoor illumination is outmoded. For 60 watts’ worth of incandescent light, you’re looking for about 800 lumens of LED output. To make that light come out the approximate color that the old bulb generated, you need to check the listed bulb temperature and make sure it’s 2,700 degrees Kelvin.

Got it? Hang on. If you want the objects that the light shines on to look the same, you’re getting into a different color question, specifically the color-rendering index. Your incandescent bulb — a glowing analog object, its light coming from a heated wire — had a CRI of 100 for a full unbroken spectrum. Your typical LED bulb, shining with cold digital electroluminescence, will not. Some colors will be missing or just different. If you’re lucky, the LED will have a CRI of 90 or higher. The box may not list any CRI at all.

Oh, but: Experts agree that the color-rendering index doesn’t really index how colors are rendered. Some bulbs with a 90 CRI make things look wan; some with an 80 are passable. There are better, more useful metrics, but you can’t have them. Nobody puts them on the packaging. One lighting professional — an LED advocate, no less — told me he sometimes calls up the manufacturer and asks to talk to an engineer to get the real specs.

To study this stuff, to attempt to stare at light and understand it, makes you suspicious of any claims to objective truth. Snap a picture of an oddly tinted space and Apple’s software will convert the image according to what it has machine-learned that white ought to be. The eye-brain system does its own constant white balancing, too. I downloaded an extremely erratic color-temperature app to try to get some grounding, an amateur feel for what professionals are trained to spot. I interrogated lighting designers, engineers, decorators, and researchers.

Most of them were enthusiasts about the technology. They praised LEDs, at their best, for their unmatched efficiency, precision, and practical power. They also said things like “There’s a lot of nonperformance” and “Super–beta phase” and “Don’t give up on beauty” and “You’re going to spend $200 on four bulbs at Home Depot” and “You start seeing grayness.”

Grayness — I was definitely seeing grayness. There ought to be a term for what happens when the light gets weaker and everyone acts as if it’s as strong as always. By the science, by the ethics, even by law, the reign of the LED is a certainty. It is taking the place of the most standard and omnipresent technology we know. And yet, when you flip the light switch, you don’t know what’s going to happen.

One Bulb, Three Temperatures: Illuminating a doll-size I Love Lucy kitchen. From left, 3,000 Kelvin, 4,500 Kelvin, and 6,000 Kelvin.

Photo: Beth Sacca

Ecologically, the case for LEDs is unassailable. Economically and practically, too, they’re a godsend. Integrated LED fixtures are little miracles: In our kitchen and living room, which were gloomy and fixtureless, respectively, the contractor put in can lights without the can, thin as saucers, brilliant, and free from the oppressive heat of recessed incandescents.

The heat! Most of the watts of electricity that flow into an incandescent bulb don’t come out as visible light at all but as infrared. It’s a handy feature if you’re using a bulb to incubate chicken eggs or power an Easy-Bake Oven but otherwise pure waste.

Every LED that replaces an incandescent reduces that baseline waste by as much as 90 percent. Multiplied by dozens of sockets in a household, 125 million households in the country — the difference is millions of metric tons of carbon. As habit, inertia, and malfeasance keep the planet’s carbon-consumption graphs veering upward toward collapse, the change from incandescent to digital lighting is one thing pulling measurably downward on the curve. And joining in will save the average American home an estimated $225 a year. LEDs, in this light, start to seem almost Promethean. Walk by a film shoot on Henry Street and you’re no longer stepping over cables running from a generator truck. The lighting crews don’t need to haul their own power supply with them anymore. In place of sweltering fire-hazard tungsten lights, they can now hold fixtures in their hands, right on top of the actors.

I started to confide in strangers that I was seeing things. Usually they knew exactly what I was talking about.

This change happened incredibly quickly. Less than a decade after the Nobel physics committee honored Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura for using gallium nitride to create powerful and efficient blue LEDs, their breakthrough work is everywhere: in headlights, streetlights, and flashlights; in construction-site tripods and Broadway rigging; in regal architectural coffers and the exploratory ends of colonoscopes.

And in my home. When they shine, that is. When they don’t — when this basic piece of household equipment gets finicky or when the colors of things start slipping away — I feel my thoughts flickering somewhere darker, too. It’s embarrassing to resent a product that’s doing this much good, knowing all the while how grievance politics has dragged energy efficiency into the culture wars to the point where people who don’t even cook are fetishizing gas stoves. It’s literally a Donald Trump rally line: “I say, ‘Why do I always look so orange?’” The broken clock, twice a day. “You know why. Because of the new light. They’re terrible. You look terrible.”

There is a world, almost within reach, in which LED lighting could be aesthetically fabulous. But right now, it’s one more thing that overpromises and under-delivers. What we’re starting to glimpse is a new phase in which good light, once easy to achieve and available to everyone, becomes a luxury product or the province of technological obsessives. The rest of the world will look a little more faded.

Metropolitan Museum of Art. Second floor, European Paintings, Gallery 614. I was standing in front of Jacques-Louis David’s 1816 portrait of General Étienne-Maurice Gérard, and I was gazing not at the depicted light falling on Gérard’s pale brow, or at the muddled play of clouds and gold in the sky behind him, but past the frame to the ceiling. Up there, mounted behind the glass of a frosted laylight, were rows of LED spotlights forming bright blurry circles. They should have been uniform. Some were white; others were turning a sickly magenta or green. The person who had directed my attention to them was Amy Nelson, the museum’s head of lighting design. “The quality of the light,” she said, “is just not what we want it to be.”

Nelson is in charge of the Met’s ambitious project to overhaul the museum’s lighting for the LED age — a long, piecemeal process that can involve anything from workers simply swapping out bulbs to architects and designers entirely rebuilding displays. Among the goals, Nelson said, is to eventually fill the museum with a standard white light — 3,000 degrees Kelvin, slightly crisper and cooler than the 2,700 of a soft-white incandescent bulb.

That was the theory. Now we were looking up at the reality of one of the Met’s early LED installations from the mid-2010s. “The galleries looked beautiful when they opened,” Nelson said. But the lamps had gone screwy. They were meant to have a life span of at least seven years, but even before that, their color had started to visibly decay. We walked on, through more of European Paintings, under still more fixtures that were shining past their point of practical failure. “It just looks like Christmas lights up there,” Nelson said.

What Nelson had discovered is that LEDs are not good or bad but more like weird. The finickiness reflects the fundamental nature of the product. The LED bulb is the shape of an old lightbulb, and it fits into a lightbulb socket, and it gives off light, but it’s not so much a lightbulb as a lightbulb emulator. What it is is a computer.

Where an old-fashioned tungsten filament can generally be trusted to be either intact or broken, the drivers and diodes inside the new bulbs are subject to the kinds of glitches and compatibility errors you get from other electronics, especially once dimmers get involved. They can crash or hang, or audibly buzz from electromagnetic interference, or go haywire from being fed the wrong kind of power signal.

LEDs, in other words, can be broken even when they appear to be working. “It’s still on. You still have light coming out,” Nelson said. “They don’t just fail or burn out like a halogen source does. Oftentimes, there’s light loss or there’s color shift.” When an LED bulb package says it’s supposed to last a certain number of years, that doesn’t tell you when the light will go dark. It’s a guess about an arc of degradation. The end date is when the bulb is estimated to be 70 percent as bright as it started out.

The impetus is on you to decide when things have started to look uncanny. “I wish that would be addressed by the industry — like, maybe if it reached a certain light-loss factor, it would just shut down, you know?” Nelson said. “Or if it shifted in color past a certain point, it went into failure mode.”

Earlier, in a gallery of ancient Chinese objects lit by halogens, Nelson showed me a Shang-dynasty bronze in a display case. When the setup was created, her designers were able to get focused four-degree spotlights to isolate items from their backgrounds. But lighting manufacturers are abandoning halogen as an obsolete technology, creating a shortage of reliable parts as they retool for an all-LED future. “Now, the tightest beam we can find is a 12-degree,” Nelson said. The bronze sat in a loose puddle of light, making the sides and back of the display as bright as the object itself, and stray purple rays spilled out of the halogens on the ceiling. “It’s very hard to come by quality,” she said.

In some places, newer and more finely tuned LEDs work magic. Nelson pointed out a Winslow Homer with watercolor oceans in stunning blues, brought to vibrant life even at the low foot-candle output required to protect the art. But not everybody, of course, has the Met’s resources.

And once you know what to look for, you can’t unsee it. A few weeks after I visited the museum, I watched a small ensemble of musicians run through new pieces by teen composers in a midtown studio. The facility was built 11 years ago, and the room still looked brand new, but when my eye went up to the ceiling, I could see the same color decay as at the Met. The shadows on the floor, pointing this way and that, were in pinks and greens. The light was coming apart.

For something you may assume is universal and constant, light turns out to be a culturally mediated and often paradoxical phenomenon. Our ideas about it start 93 million miles away — eight minutes and 20 seconds as the photon flies — with our friend the sun. The sun is close to what physicists call an ideal Planckian blackbody radiator, delivering a smooth and broad electromagnetic spectrum from radio waves up through infrared, visible light, ultraviolet, and X-rays. A hot tungsten wire does the same, only with a much narrower range of output tilted toward the red and infrared.

But here, unfortunately for the layperson, the terminology reaches a point that is profoundly counterintuitive. In physical light-emission terms, blue is a hotter temperature than red. The sun looks yellow up in the sky, but with a surface temperature of 5,772 degrees Kelvin, or about 10,000-degrees Fahrenheit, it has much more blue in it than an incandescent filament at 2,700 degrees Kelvin does. (A red-hot steel bar, in turn, would be somewhere down around 1,000 degrees Kelvin.) The higher the color temperature, the colder, in everyday speech, we say the light looks.

“Warm” colors are the colors of the things humans experience as being warm. Obviously enough, through millennia of human existence, the point of reference for artificial illumination was firelight or lamplight. But they don’t burn at the same temperature as a star. If you bring a light source that is actually the color of the sun indoors, it stops looking golden and appears strikingly, severely blue. What to do about this fact is a debate that’s been unresolved for well over a century: Should the ideal artificial light approximate the sun, or should it approximate a flame?

From an engineer’s point of view, the answer seems clear. Blue light is rational: These are the literal technical specifications of our ultimate light source. A bulb “with its proper proportions of violet light as determined by our natural illuminant the sun is to be desired and not avoided,” declared a piece in the July 10, 1897, issue of the journal Western Electrician. But with certain exceptions — the incursion of fluorescent tubes, the creation of blue-tinged “daylight” incandescents — it was the warm-light faction that ruled most of the electric age. The tones of a standard incandescent bulb may have been too warm, scientifically speaking, spilling emissions right off the bottom of the visible spectrum into useless waves of heat, but they were what the lightbulb-using public expected.

LEDs can be broken even when they appear to be working. The impetus is on you to decide when things have started to look uncanny.

Still, today, this preference for orangish light over bluish is not universal. Hervé Descottes, the founder of the high-end lighting-design firm L’Observatoire International, told me that he once worked on two projects at the same time: a museum in Helsinki and a shopping center in Hong Kong. He flew to Helsinki for a meeting, “and in the meeting room, in the center of the table, they light a candle,” he said. “It’s very Scandinavian, you know. Get the warmth.” He then flew to Hong Kong, where the temperature and humidity, he recalled, were both in the 90s. That meeting was held in a space with no windows and ceiling lamps cranking out 5,000 degrees Kelvin. “Because when we’ve put in cool light, we feel that it’s cooler outside,” he said. Another time, in Singapore, Descottes found himself arguing with clients who wanted the coldest, brightest lighting for the executive floors of a tower to signify abundance.

Medical science, surprisingly, comes down on the side of the cozy candle-burning romantics. The body’s internal clock is tuned to sunlight, and when artificial light imitates the sun, as the warnings about using your phone at bedtime tell you, things start going wrong. At the start of this century, biologists pinned down the workings of intrinsically photosensitive retinal ganglion cells — a whole separate sensing apparatus in the human eye beyond the brightness-sensing rods and the color-sensing cones you learn about in school. As with the taste buds that detect umami, the retinal ganglion cells were there, but generations of scientists had left them out of their perceptual models.

These cells are keyed to light between blue and green, with a peak sensitivity to wavelengths of about 480 nanometers, around cyan. “They’re not actually connecting to our visual cortex,” said Michael Royer, a color expert at the Department of Energy’s Pacific Northwest National Laboratory. “They’re going to other parts of our brain — the prefrontal cortex, the hypothalamus, these parts of the brain that are really critical to all our other functioning. And they’re just sending signals: Hey, it’s daytime right now, so it’s time to be alert.”

If blue light is overstimulating and clammy, it’d be better for our brains to have less of it in indoors, especially late at night. But blue light is also cheaper. Adding warm tones to a blue LED requires extra material and effort. To get something in the whitish color range of traditional indoor lighting, manufacturers coat the underlying blue elements with phosphor, which shifts some of the photons to longer wavelengths — that is, greens and yellows and reds. (This coating partly explains why LED color varies over time. As the diode heats and cools again and again, “maybe the phosphor will curl a little bit,” says Royer. “And those tiny changes will allow a different amount of blue photons to escape versus yellow.”)

Last year, the New York Times warned in a front-page story that “lower-end retailers like dollar stores or convenience shops still extensively stock their shelves with traditional or halogen incandescent bulbs, even as stores serving more affluent communities have shifted to selling far more efficient LEDs.” This was, the Times fretted, preventing poorer people from receiving the benefits of energy efficiency. The studies the newspaper cited, finding incandescent bulbs on discount-store shelves, were both a few years old. I checked my nearest dollar store and discovered that there were plenty of LED bulbs to be had there. Their color temperature was 6,400 Kelvin — the harshest, cheapest possible light, a light so blue that when I Googled it, what came up were grow bulbs. The efficient future of lighting now includes poor people; it just does it by making lighting one more form of privation.

Checking for spares in my mom’s basement recently, I discovered that she had picked up a pack of 5,000 Kelvin bulbs to replace her living-room floodlights. Of all the people to have made this mistake! Mom used to teach schoolchildren about color perception, showing them how that part of their vision faded in the periphery or how a wheel of colored panels mounted on a salad spinner would turn gray. But she had no idea what 5,000 Kelvin meant, and the package had no color-rendering index at all. Had she ever put the things into her ceiling, she’d have ended up with a living room that looked like the inside of a refrigerator.

It’s true that CRI numbers are kind of useless. All else being equal, if light on an object gets dimmer — if you start with an object outdoors, in full sunlight, then bring it indoors to that same daylight, but less of it, now coming through a window — the object will appear more gray. The way color rendering is defined, the diminished light is performing at the same level as it did outside. The color-rendering index scores it the same. But the object looks worse.

In lower light, people prefer to see the vividness of colors boosted, especially in the reds. Incandescent lights naturally boost reds as they get dimmer and the temperature of their filament gets lower. LEDs, again, operate in a fundamentally different way. Many cannot dim at all; those that are advertised as dimmable do not reduce their temperature or even reduce the intensity of the light they put out. Instead, a common method is to adjust how frequently they switch off and on, which is dozens of times per second. Extra-sensitive people can sometimes detect this flicker or find themselves with unexplained headaches and dizziness. For everyone, the light gets even duller looking than before.

Royer is a fellow at the Illuminating Engineering Society (motto: “Improving Life Through Quality of Light”), which has created an elaborate alternative to CRI called TM-30. In this scheme, bulbs are classified under three separate but interrelated categories: P, V, and F, for preference, vividness, and fidelity, each of which is further broken down into subcategories indicating performance level. Manufacturers and retailers have not agreed to this new scoring system. “They don’t want to provide a lot of information that might confuse consumers,” Royer said. “But consumers aren’t going to understand information until it’s provided to them.”

If you don’t mind spending extra money — say, three or four times as much per bulb, plus a $60 controller — and fooling around inside an app, you can get color-tunable lightbulbs today. They have different colored LEDs inside, instead of simply phosphor-treated blue ones. The Department of Energy notes that programming the bulb controls “may not be intuitive,” that tunable whites won’t necessarily match any other whites, and that colors may come out “cartoonlike.” And they won’t save as much electricity. The LED industry is still trying to develop an efficient green LED to go with the red, blue, and amber ones. Royer remains hopeful and is encouraged by the continued search for improvement. Tunable LEDs may overtake phosphor-converted bulbs in efficiency by the 2030s.

Until then, there’s amber nail polish. Ordinary, transparent amber from the drugstore. “I highly recommend every person who reads this story buy this nail polish and start painting it on their LED bulbs,” said Robin Standefer. “It is a game changer.” Standefer is one of the founders of Roman and Williams Buildings and Interiors, a design company that works with Descottes and L’Observatoire. We were talking on Zoom, and behind her was a paper Noguchi lamp. “It’s the most beautiful light in the world,” she said, “but you put an LED in and it’s not that beautiful.” To compensate, she’d wrapped the bulb in a filter.

I wanted to see the best possible application of LED lighting, so Standefer said I had to go downtown. At dusk, I took a blazingly lit N train (my light-meter app reported 4,292 Kelvin) to the Roman and Williams Guild and La Mercerie, their combined retail store and restaurant on Howard Street. The light inside was opulent and gorgeous. Tall candles flickered on the dining tables, but everything else was LED. As I studied the fixtures in the store — in burnished bronzes with glass that was dark and pearly, or a delicate nude pink, and with prices starting in the low four figures — I realized that the surrounding lighting had subtly dimmed and warmed, shifting its Kelvin temperature for nighttime. In the restaurant, copper pans gleamed and a row of double-magnum bottles of rosé glowed extra pink. The bread’s crust was shaded in lush browns. Stacked white towels were creamy, and spotlights from tracks overhead threw the shadows of the candles this way and that on the tables.

It was sublime. And if I really wanted to experience LEDs at their most exquisite, Standefer said, I should see what Descottes and Roman and Williams had done at Le Coucou, another client. I walked two blocks east and stepped inside. The restaurant was wonderfully dim, the dimness alive with color and warmth. Huge chandeliers hung with rings of dozens of flame-tipped bulbs in rose-pink inverted glass cups. That glass, Standefer had told me, was Roman and Williams’s special formula for LED bulbs, the work of a septuagenarian glassblower in Brooklyn. “If she stops blowing this glass, I don’t know what I’ll do, because she’s been the only person to achieve a very beautiful color in the glass,” she said.

Inside the bulbs were the little V’s of filaments. You can do remarkable things with LED filaments these days, reviving old-timey clear bulb shapes with all sorts of whorls or zigzags. I swore they looked just like the real thing.

I was trying to figure out how to describe the particular color the light made on the white ductwork above — the color of the flesh of a white peach, I decided — when I ran into John Barclay, the facilities manager for Le Coucou and its sister restaurants. Barclay studied theater lighting in college before going into hospitality, and when LEDs arrived, he gave himself a crash education in the technical ins and outs. Now he was near evangelical about the LEDs. He ran through the interplay of the lighting sources: The chandeliers were at about 1,700 Kelvin, he said, while spotlights above the tables were at 2,400 and task lighting in the kitchen was slightly colder, at 2,700, to give the staff a precise look at the plated food on the way out.

I’d been told I had to see the restroom. I went to see the restroom. The all-pervading glow was so honeyed I couldn’t tell if the grab bar by the toilet was mere steel or luxurious brass.

Maybe I was wrong about LEDs. Maybe I just had to be patient — to wait and let this luminous future trickle down to the rest of us. Later, upon follow-up questioning, I learned that the warmly glowing filaments in the Le Coucou chandeliers are not, in fact, LEDs. They are hot wire filaments. Inside the LED-optimized glass of the chandelier fittings, the LED-forward restaurant is still using incandescents for that ineffable and as yet irreplaceable glow.

I asked Barclay how he would navigate the future. “In the near term,” he said, “I have a large stock of those bulbs.”

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