LED — Lighting The Way And Saving Energy
The introduction of LED (Light Emitting Diodes) lights was revolutionary in the way it reinvented the light bulb to become more energy efficient and power saving. It is a proven lighting solution which has a wide range of applications. From commercial lighting systems to the production of computer displays. LED technology has also found its way into smartphone displays, providing better contrast and higher quality imaging. The next generation of televisions and computer monitors will also incorporate LED for higher resolution displays that support features like HDR.
When it comes to lighting LED do not dissipate as much energy, thus the reason they are more efficient. Less energy is lost to heat when producing light compared to incandescent bulbs. An incandescent bulb produces only about 10% light while the rest is wasted heat. This makes LED ideal for commercial and industrial lighting use. This also makes LED more environmentally friendly by reducing emissions from energy consumption.
LED Light Assembly
LED lights are different from other light sources in many ways. They do not use a filament to produce light like in incandescent bulb or require the discharge of gases like in fluorescent bulbs (including CFL). LED produce light using an electronic component called the diode. This is a semiconductor that releases photons when a voltage is applied to a circuit and current flows.
A typical LED light bulb is similar to other types. It can have a glass or plastic dome diffuser that covers the diode. It does not need that type of enclosure though because LED are solid-state lights. It also has a basic screw-in base that is compatible for home and office light sockets. To absorb excess heat, a heat conduction plate acts as a heat sink. There are “smart LED” light bulbs which integrate some AI features that further save energy by controlling brightness based on whether there are people in the room.
A central component of LED lights is the driver. Its function is to rectify higher voltage AC to low voltage DC. The driver regulates the power to protect the LED from voltage fluctuations. It works similar to a ballast for fluorescent lamps or transformers for light bulbs. The driver itself is an integrated circuit component that is built into the light bulb. One of the reasons an LED light bulb doesn’t work is if the driver is damaged or missing.
The following are the main advantages LED lights have over other lighting systems.
- Energy Efficient — The primary reason is efficiency. LED consume less power which can save not only in energy consumption, but also reduce costs of lighting. This is due to its luminous efficacy which is the amount of light emitted per unit of power consumed by a light bulb measured in Watts (W). LED with ENERGY STAR ratings use at 75% less energy and last 25 times longer than incandescent lights. This results in significant savings on energy costs.
- Improved Safety — Since LEDs consume less power they can operate much better on low-voltage electrical systems. These are generally much safer, preventing the risk of fires from short circuits or faulty connections. Overloads in lighting systems can cause the circuit to burnout and in some instances fires if there is a short.
- Longer Lifespan — On the average an LED light bulb lasts 50,000 -100,000 operating hours. That is 2 to 4 times as long as most fluorescent, metal halide, and even sodium vapor lights and 40 times as long as the average incandescent bulb. Since they last longer, it also requires less maintenance.
- Operate Well In Extreme Conditions — LEDs operate well in cold or hot environments. LEDs can operate from -40 F to 180 F. LED also have no delay or required “warm-up” time to function.
- Directional Light — While most light sources are omni-directional, LED are directional. That means LED emit light which is much more concentrated and ideal for directed lighting. Examples of this include floodlights, spotlights and downlights. The floodlights output a much wider beam of light, up to 160 degrees. This spreads out over a much larger area with better illumination than other light sources. LED spotlights are also used for more directed lighting with a narrower beam of light. Downlights, which illuminate areas downward from a pole or ceiling, tend to have a wider beam angle to cover a larger area than spotlights.
- More Luminance — LED give the perception of more luminance due to the property of beam spread and directional lighting. This is the measure of the angle in which light is directed at an object. The wider the angle, the better the lighting. A 120 degree beam angle thus illuminates a larger area than a 45 degree beam angle.
- High Color Rendering Index (CRI)— LED have a high CRI which means that they can show more accurate colors of illuminated objects. The LED light reveals the actual color of objects when comparing it to natural light. This is a quantitative measure that is based on a value. LED have a CRI of 80 and above. The higher the value the better. Most LED that produce a white light are close to daylight on the intensity scale.
- Environmentally Friendly — LEDs still have a carbon footprint during the production process. However they do not have the same environmental issues common with traditional lighting like fluorescent or mercury vapor lights. The mercury requires special handling when the light bulb reaches its lifespan. This is considered as hazardous waste than can harm people’s health and the environment. Another obvious sign of its environmental friendly feature is it consumes less power, thus reducing carbon emissions from power plants (which can also be debatable depending on whether the source of power are fossil fuels or renewables).
Here are some use cases where LED lighting made a huge difference.
Los Angeles LED Street Light Conversion Project
The City of LA has been successfully installing LED lights on street light posts since 2012. During the first phase of the project, LED fixtures were installed on 141,089 street lights. By the time of project completion in 2020 it will have installed 17 Million street lights using LED. This was then hailed as the world’s biggest street light replacement project. The city had replaced the High Pressure Sodium (HPS) lights that were inefficient and consumed a lot of electricity. The LED lights consumed 63% less power and they also last much longer, saving time on maintenance. The change has also improved visibility at night for drivers. At full LED deployment the City of LA is estimated to save a total of $2.5 million annually on maintenance costs and $7.5 million on electricity.
Urban Lights LED Conversion Project
The LACMA (Los Angeles County Museum of Art), by replacing the incandescent bulbs for the “Urban Lights” exhibit, with LED lights saved power consumption by up to 90%. Initially it consisted of 309 incandescent light bulbs. By replacing it, in 10 years that saves approximately 3,173,047 kWh of power consumption. The retrofitted lamps of LED bulbs also match the intensity and color of the original, so it gives off a similar temperature of light as the incandescent bulbs.
Samsung is a leader and innovator in the development and branding of OLED (Organic Light Emitting Diodes) displays. The diodes represent pixels in the display. An OLED panel consists of individual pixels which are either in an on “1” or off “0” state, meaning that the light is controlled at the pixel or subpixel level. This makes back lighting (used in LCD panels) unnecessary, so you get a richer and more vibrant looking display that doesn’t affect the contrast. Blacks appear at their darkest, and whites appear at their lightest. OLED provides higher contrast ratio with support for features like HDR (High Dynamic Range) and wider color gamuts. OLED first appeared in consumer electronic devices like smartphone displays because they were energy efficient as well, saving battery consumption for consumer’s devices. Samsung has further made developments with AMOLED (Active matrix OLED), which adds a layer of semiconducting film behind the OLED panel making pixel activation much faster. That makes this ideal for larger higher resolution displays which have more pixels.
Perhaps to fair to say that LED decorative lights have saved consumers on cost and energy consumption during the holidays. Many Christmas lights now use LED technology to replace incandescent bulbs. LED lights are not only less power hungry, but safer and more flexible and durable. Incandescent lighting systems tend to be fragile, especially the glass in the light bulbs. Read more about holiday lights including LED types from a previous article at this link.
Residential And Commercial Lighting
The shift to LED for lighting in homes and businesses has become a practical solution. It not only cuts costs, but also appears to have better lighting. For commercial use in shopping malls and business districts, it appeals better to customers. While CFL and fluorescent have a similar light, they are not as efficient. Fluorescent lights also do not have the same lifespan as LED, so they will need to be replaced earlier thus requiring more maintenance. According to an Stouch Lighting use case, when the Franklin Institute retrofitted their parking garage lights with LED:
- Energy Reduction: 66% Reduction over existing lighting energy consumption
- kWh Reduction: 264,902 Kwh Reduction
- Annual Maintenance Savings: $7,674 dollars
- Greenhouse Gas Reduction: 896,935 lbs
LED lighting is also much brighter when compared to fluorescent lights, making them ideal for better visibility in public places at night. Since LED also have a higher CRI, people can see colors more accurately at night without the orange-reddish glow from sodium vapor lamps.
LED Specifications Guide
When choosing an LED, the FTC (Federal Trade Commission) in the US has come up with a Lighting Facts label. This contains the following information:
- Bulb’s brightness in Lumens
- Annual cost (based on 3 hours of daily use)
- Life expectancy or lifespan in years or hours
- Light appearance, or color temperature, measured in Kelvin (K)
- Color Rendering Index (CRI)
- Safety rating by the UL (Underwriters Laboratory)
- Energy consumed in Watts
- Energy Star certification
The Color Correlated Temperature (CCT) gives a rating of white LED bulbs. For LED, this may range from 4500K to 7000K. This means they will have a cooler and bluish looking light, for temperatures above 4500K. The lower the temperature, the more warmer and yellow or orange the light is, which is where incandescent light fall under. For LED, Lumens are also the way to measure brightness and not Watts. Watts is for the amount of power the LED light is consuming. The other indicators are self explanatory or were discussed in an earlier section.
The UL (Underwriters Laboratory) safety ratings for LED lights describes where the lighting can be used. Examples of this include UL Listed for Wet Locations (Wet Rated) or UL Listed for Damp Locations (Damp Rated). More information about safety ratings can be found from this link. For home lighting, it is important to know if the LED can be used for wet places like a shower.
Energy Star certified LED meet strict efficiency, quality, and lifetime standards. This tells consumers that the product meets the requirements for qualified LED lighting. This includes the following (taken from the Energy Star criteria):
- Reduces energy costs — uses up to 90% less energy than incandescent lighting, saving on operating expenses.
- Reduces maintenance costs — lasts 35 to 50 times longer than incandescent lighting and about 2 to 5 times longer than fluorescent lighting. No bulb-replacements, no ladders, no ongoing disposal program.
- Reduces cooling costs — LEDs produce very little heat.
- Is guaranteed — comes with a minimum three-year warranty — far beyond the industry standard.
- Offers convenient features — available with dimming on some indoor models and automatic daylight shut-off and motion sensors on some outdoor models.
- Is durable — won’t break like a bulb.
There are also ratings for LED as an equivalent to an incandescent light bulb at the same brightness level. For example a 60 Watt-equivalent LED bulb delivers about 800 Lumens, roughly the same as a 60 W incandescent. However, the LED bulb is delivering 800 Lumens at a lower wattage. The LED could be consuming just between 8 -12W to produce the same brightness as a 60W incandescent light bulb.
Synopsis: The Pros And Cons
LED are a much more efficient and cost saving solution for both home and business lighting. It is also much brighter but consumes less power than similar light sources. They are also much safer to use because they don’t emit much heat thus lowering the risk to injury. They also don’t require as much voltage and current to operate, which can lower the risk for fires and short circuits due to wiring problems. This has led to more adoption and thus reaching economies of scale which lowers the cost of LED light bulbs. Compared to incandescent lights, the typical LED light bulb is still more expensive but only initially.
After replacing most lights at home with LED, you may realize something off. Our eyes have gotten used to the warmer type glow from incandescent lights. It also presents a more joyful mood that is ideal for social settings, unlike dull white light. This is a reason incandescent are not about to go away entirely. Places which set a mood for a certain clientele like bars and restaurants will continue to use certain incandescent light fixtures because it has a more warmer glow. Social places tend to encourage a joyful atmosphere and traditional lighting systems work best. There are LED that have a lower CCT rating at 2700K called “warm white” light which can also be considered.
LED as a replacement for most lighting in homes, is already common. For reading it is a far better solution than a fluorescent (not bright) and incandescent lights (too warm for the eyes). The LED lamp for study halls is an example of this. LED spotlights on products in stores are also more ideal to show consumers a more actual representation of the item’s color. As for the incandescent light bulb, the US has actually rolled back light bulb standards (in the current administration 2016–2020). This is because the US Department of Energy (DOE) has not enforced their standards for light bulbs.
According to Popular Mechanics magazine:
“By choosing to go against recommendations to introduce limits on incandescent bulbs, Trump’s administration is continuing to take a stand against energy-saving innovations in general — even the ones that benefit consumers in a hands-on way.”
It does in a way help those who only have access to incandescent lighting, and that could be one component for that policy reversal. It also helps those who cannot afford the initial cost of LED lighting, but that is another matter for discussion. For everybody else, it makes more sense to buy LED and replace their incandescent light bulbs anyway. LED is still being adopted at a higher rate among consumers with incandescent light use in homes falling from 68% in 2010 to just 6% in 2016 (Reported by the New York Times).
Another thing that is a drawback are LED will not work with existing dimmer switches that were designed for incandescent bulbs. That is because those light bulbs require more power than what LED consume. LED require hardware specific to it in order to dim. The good thing about LEDs operating at less than their full power is they get more efficient as power is reduced.
There have also been studies that show the negative effects the bluish white lights of LED can have on people. The American Medical Association argues against these type of LED use for street lighting at night. This is because the lights from LED can affect the circadian rhythm in people. According to one study, LED “may have a harmful effect on our health because the blue light suppresses the production of melatonin, a hormone the body starts to produce naturally in the afternoon, reaching maximum levels during the hours of darkness.” The production of melatonin affects our circadian rhythm or biological clock. The study also indicates that the lack of melatonin production can lead to cancerous effects and other diseases on the body. This should certainly be further investigated and verified for public safety.
LED is going to eventually replace incandescent for most lighting solutions. It requires much less maintenance so it lasts much longer while offering more brightness while consuming less power. They are also becoming more smarter thanks to large scale integration in chip technology and AI applications. From the look of things though, LED benefits far outweigh the cons.