13 March 2013
LED Lights Raw Materials
Instead of using glass bulbs to contain gasses or filaments, LEDs are semi-conductor devices. The core of all LEDs is the diode (also known as the die or chip), which contains different layers of semi-conductor material. Two of the layers, the p-type and n-type layers, play a fundamental role in the emission of light. The n-type layer contains an excess of electrons and the p-type layer are deficient in electrons, so it creates “electron holes”. When a current is applied to the diode, it pushes the electrons and the holes towards the p-n junction, a layer in between the two semi-conducting layers. Since the holes are at a lower energy state than the electrons, when the electrons drop into the holes through a process called recombination, the energy gap results in a photon of light (Held, p. 2; IESNA Light Sources Committee, p. 1). The energy level and wavelength of the photons emitted depends upon the specific semi-conductor materials in which the p-type and n-type layers are made out of. There are a multitude of different semi-conductor materials that could be utilized (Held, p. 7); however, the crucial yet, non-widespread production elements among them are gallium, indium, and arsenic (Wilburn, p. 3).
The sources of gallium, indium and arsenic are primarily comes from being byproducts in aluminum and zinc production. Gallium comes from bauxite mining and aluminum production in Australia, China, India, and Brazil, as well as a small amount from zinc refining in Japan. Some gallium can also be recovered from scraps of gallium arsenide (GaAs) production. Indium can be generated from zinc ores mined in China, Peru, Canada, Australia and the United States. A minor contribution can also come from the mining of copper, lead and tin from various countries worldwide. In 2011, China produced 52% of the world's refined Indium from domestic sources. Japan, Korea and Canada all together produced 32% from imported sources (Wilburn, p. 5). Arsenic can be found in copper, lead and zinc ores, as well as in the minerals orpiment (As2S3) and realgar (As4S4) within China, Peru, and the Philippines. Arsenic can also be produced from the smelting of copper, gold, lead and silver, which results in flue dusts containing arsenic trioxide that can be reduced to get high-purity arsenic metal. The world's leading producer in arsenic trioxide during 2010 was China at 47% of the world's production, followed by Chile at 21%, Morocco at 15%, and Peru at 8.5% (Wilburn, p. 4). The United States has not been producing any domestic arsenic since 1985. Instead, the U.S. imports primarily from China and Morocco.
Many raw materials today are extracted in one location, shipped to another for further processing, and then manufactured into a product at another location. Indium, for instance, is produced as metal compounds of low purity and needs to be shipped to facilities in China, Japan, Korea, or the United States for refinement. Gallium has most of it sold to be processed into various alloys elsewhere as well. China is one of the few exceptions, as they are the world's leading producer of many raw materials, they can manufacture products with their own domestic supply of materials. The United States, on the other hand, had imported 166 metric tons of GaAs wafers for LED production in 2010 (Wilburn, p. 5).
Individual elements are not exactly useful as semi-conductors, they must be combined with other elements to be manufactured into wafers that could be sliced into chips. The core concept is that the component materials are melted, combined, and shaped into a cylinder or rod that is then sliced into wafers. However, in more details, that is actually quite a complex process. Originally devised in 1916 by Jan Czochralski, the process starts with using a small, high quality crystal of the material to be produced as a “seed”. That seed is placed into a molten pit of the same material and as the seed is pulled out slowly, the molten material surround the seed cools and solidifies, making the seed grow in size. The process is repeated over and over until the crystal becomes a cylinder of sufficient size called a boule, that then can be used to make wafers (Stevenson, p. 2). One of the drawbacks however, is that this process does not work with all materials.
Gallium nitride (GaN) is an important semi-conductor material that will not work with the Czochralski process. While physically possible, it will require a temperature of over 2200° C and a pressure of over 64,000 atmospheres (6.49 gigapascals), which is not realistically doable. Robert Dwilinski, during his graduate student years, had worked on a method to produce GaN by mixing gallium-based solutions and nitrogen in extreme pressures at 1500° C. While this super-high pressure method was successful at creating GaN crystals, they can create wafers no bigger than 20 mm (Stevenson, p. 3). With the preferred standard size for the production of LEDs being 50 mm, that method was not enough (Wilburn, p. 8).
Dwilinski, now the current president of Ammono, uses an unique method that he and his coworkers derived from an old method of producing quartz crystals. This method requires an autoclave filled with ammonia. The upper half of the autoclave contains a feedstock of gallium nitride solution and the lower half contains gallium nitride seeds. When the autoclave is heated to 500° C, the ammonia boils into a supercritial fluid and dissolves the gallium nitride solution in the feedstock. Convection then drives the cooler fluid down to the GaN seeds. The addition of gallium in ammonia along with small traces of alkali metals causes a retrograde solubility, where solubility increases with decreasing temperature. Since the temperature is higher in the lower half where the seeds are, solubility decreases and the dissolved gallium nitride grows onto the seeds (Stevenson, p. 4). Their earlier attempts with imperfect autoclaves resulted in only a high purity powder, but it was enough to impress Nichia Corporation's S. Nakamura, who had made a great breakthrough in the field by inventing high-brightness blue and green GaN-based LEDs (Stevenson, p. 4; Liu, p. xvi). Under a joint research project, Nichia would fund Ammono, and today, Ammono can produce laser grade GaN substrates of up to 51mm, with plans to produce 75 mm substrates in 2013 and 100 mm substrates in 2015.
Besides the elements used for the semi-conductor substrates of the LED chip, phosphors also play an important role in getting the proper light. Unlike other forms of lighting, such as incandescent bulbs or CFLs, LEDs produce only monochromatic light. In other words, LEDs do not normally produce white light, which is a necessity if LEDs were to be used for general lighting applications. There a couple ways in which LEDs could achieve white light. One of which is using an array of red, blue, and green LED chips to mix the colors into white light. The other method, is to use a blue LED coated with a phosphor to convert the light (U.S. DOE “LED Basics”, p. 1). Phosphors are chemicals that possess the property of luminescence and are generally made from a variety of rare-earth elements (REEs).
The most commonly used REEs for phosphor production includes cerium, europium, lanthanum, terbium and yttrium, with the compound yttrium-aluminum-garnet (YAG) being the most common phosphor used in LEDs. Many REEs can be extracted from the minerals bastnaesite and monazite worldwide, with monazite capable of being mined in Brazil, China, Australia, India and Malaysia. Despite the geographic diversity of REEs, China produces over 95% of the world's supply of REEs. 98% of cerium, 90% of gadolinium, and 99% of yttrium production came from China in 2010 (Wilburn, p. 8). This is partly due to China having a variety of deposits, such as the aforementioned bastnaesite and monazite ores, in addition to deposits of xenotime ores and ion-adsorption clays. And also partly it is due to the complexity in the process of separating individual REEs from the ores. As such, 97% of the mining, 97% of the separation into oxides, and 99% of the refining into rare-earth metals are done in China (Wilburn, p. 6). After the extraction and refining of REEs, the actual manufacturing of phosphor powders are primarily produced in China, Taiwan, Germany, and India.
Even with the expansion of LEDs as they slowly replace the more traditional forms of lighting, the consumption of REEs used for manufacturing phosphors is expected to decrease. That is due to the fact that the amount of REEs used in LED phosphors is considerably less than the amount needed for phosphors used in CFLs or linear fluorescent lamps. Together with the LED's long useful lifetime, the LED's replacement of older forms of lighting will reduce the importing of REEs, as well as it going into the waste-stream.
While the amount of REEs in phosphors going into the waste-stream can only be reduced, semi-conductor materials can be recovered and recycled. Worldwide, the amount of potentially recyclable gallium is about 200 metric tons from GaAs semi-conductors and optoelectronic devices, such as solar cells, laser diodes, and LEDs. However, the amount that is actually recycled is much lower because of higher and higher economic costs to recover smaller and smaller concentrations. Indium is used considerably in flat-panel LCD TVs and the recycling of the TVs could recover indium among other materials. Some indium can also be recycled from zinc tailings and slag. Since arsenic can become a serious hazard to both human and environmental health, the extraction, processing, use and disposal of arsenic are highly regulated by the government. In LEDs, the concentration of arsenic are too low to be hazardous, but waste management by metal recovery facilities will prevent buildup of high concentrations and recycle any possible sources. Materials with higher risk are often shipped for processing overseas (Wilburn, p. 5). The use of LEDs, that are small device with a long lifetime can decrease the amount of waste generated.
LEDs possess many properties that the traditional forms of lighting does not have, such as higher energy efficiency, longer useful lifetime, resistance to mechanical failure and the ability to cycle on-off rapidly. These characteristics were due to the fact that LEDs are semi-conductor devices that can generate different colors of light based on the semi-conductor material used for the die or chip. The main elements of importance are gallium, indium, and arsenic. These elements are primarily produced as byproducts of other materials such as aluminum and zinc, with China being the major producer. Many materials are extracted, refined and manufactured into wafers or products at different locations. To create wafer, the Czochralski method was one of the earlier methods. However, gallium-nitride will not work with that method. Instead a super-high pressure vessel can create GaN crystals up to 20mm. For larger sizes, a company called Ammono makes use of an autoclave and the principle of retrograde solubility to grow high-purity substrates. In addition to the semi-conductor materials, phosphors that can manufactured from various rare-earth elements can be used to generate white light. Once again, China also dominates this market. The consumption of REEs are likely to slow as the use of LEDs expands. Which will also reduce the amount of waste generated. Semi-conductor materials can be recycled from electronic waste as well.
Held, Gilbert. Introduction to light emitting diode technology and applications. Auerbach Publications, 2008. Print.
Liu, Sheng, and Xiaobing Luo. LED Packaging for Lighting Applications: Design, Manufacturing, and Testing. Wiley, 2011. Print.
Stevenson, Richard. "The world's best gallium nitride." Spectrum, IEEE 47.7 (2010): 40-45. Web. 18 Feb. 2013.
IESNA Light Sources Committee. IESNA Technical Memorandum on Light Emitting Diode (LED) Sources and Systems. TM-16-05, New York: Illuminating Engineering Society of North America, 2005. Web. 17 Feb. 2013. <http://www.nema.org/Products/Documents/ies-led-doc-tm16.pdf>.
U.S. DOE Energy Efficiency and Renewable Energy. "LED Basics" U.S. Department of Energy, n.d. Web. 18 Feb. 2013. <http://www1.eere.energy.gov/buildings/ssl/sslbasics_ledbasics.html>.
U.S. DOE Energy Efficiency and Renewable Energy. "Using LEDs to Their Best Advantage." U.S. Department of Energy, Jan. 2012. Web. 18 Feb. 2013. <http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/led_advantage.pdf>.
Wilburn, David R. Byproduct Metals and Rare-Earth Elements Used in the Production of Light- Emitting Diodes—Overview of Principal Sources of Supply and Material Requirements for Selected Markets. No. SIR-2012-5215. United States Geological Survey, 2012. Web. 19 Feb. 2013. <http://pubs.usgs.gov/sir/2012/5215/>.
March 13, 2013
Embodied Energy of LED Light
Light Emitting Diodes (LEDs) are a relatively recent addition to the lighting world. With a doubling in efficiency and light output taking place every 36 months since the 1960’s, LEDs are a fast moving technology still making huge leaps of progress. This report hopes to track this progress and assess the embodied energy for the entire life cycle of an LED light. The introduction to this report will familiarize the reader with the components of an LED and the most current forms of LED production, introduce the studies and sources referenced and their associated assumptions, discuss any setbacks in the compiling of a comprehensive embodied energy assessment, and explain the objective of the report.
For this report it is important to know what LEDs are and some of their main components. LEDs are semiconductor diodes, which means that they are made of a conductive material such as copper and a non-conductive insulate such as crystalline gallium nitride which form a connection that allows for the passage of an electrical current in one direction but doesn’t allow passage of that current in the opposite direction.1 A chip or “die” of this semiconducting material is housed with a bonding wire and a cathode inside of a silicone lens forming an LED package. For standard LED bulbs multiple LED packages are then placed within plastic or porcelain housing on an aluminum heat sink and sealed behind a plastic or glass lens. LED light bulbs are still currently being retrofitted with tin-plated steel Edison screw bases while we make the transition from older style bulbs to the newer LED technologies. This background knowledge on LEDs will be helpful in understanding the life cycle assessment and the energy that is required for each phase. Life cycle assessments (LCAs) are comprehensive tools that compile all the information of a product’s materials, energy usage, and emissions in a sequence of phases. A product’s life-cycle can be broken down into 6 phases: raw material acquisition, manufacturing and processing, distribution and transportation, use/reuse and maintenance, waste management, and recycling.1 To compile the embodied energy of all of these phases of an LED’s life we will be referencing several sources. The first major resource used is an LCA from the U.S. Department of Energy (DOE) and was last updated in August 2012. It compares the energy use and environmental impacts of Incandescent Bulbs, Compact Fluorescent Lights (CFLs), LEDs produced in 2011, and the projected specifications for a 2015 LED. The DOE LCA puts these lighting options on a standard scale of 20 million lumen-hrs (the average life of a 2011 LED), which requires 22 incandescents and 3 CFLs to match the power of one LED. The next LCA used is provided by OSRAM, one of the biggest global lighting companies. Their self-conducted LCA of their own LED lamp is one of the only product specific LCAs available for LED bulbs right now. We will also be referencing a study on “Reducing environmental burdens of solid-state lighting through end-of-life design” by C T Hendrickson et. al. This report breaks down three solid state lighting LED options to their most basic components and analyzes their end-of-life design while also projecting where the design of LEDs needs to go with regard to disassembly and disposal. Another key source we will be touching on is the Lumina Project, which discusses the embodied energy of off-grid LED lights as an alternative to kerosene powered lamps for off-grid users in Kenya. Being familiar with the studies used and their objectives will be helpful with understanding the way the information is framed and any assumptions that were necessary for the completion of the study. This is not to say the combination of these resources were successfully used to create a comprehensive study of an LED’s embodied energy. There were still many setbacks in the pursuit of a complete embodied energy calculation. LED technology is so new and rapidly changing that there are few resources available that cover the life-cycle or embodied energy of certain products. And even when there is sufficient information in a report it quickly becomes outdated or simply covers one type of LED in the vast range of LED products available. This wide variation in products is due to different materials used and different methods of production, especially with production of ambient white light LEDs. This demand for ambient lighting is a qualitative measurement rather than quantitative which is difficult to account for in calculating embodied energy. There is also limited information in the areas of materials processing, waste management and recycling. Due to the newness of the products and long lifetime, large-scale disposal and recycling systems for LEDs haven’t been set up or documented. The other major setback is that the study that is considered to be the most in-depth and comprehensive, the Carnegie Mellon/ Booz Allen report, is an extreme outlier in the context of other LCAs skewing the maximum consumed energy of manufacturing by more than 1000MJ/20 million lumen hours (From 484 MJ/functional unit to 1,490 MJ/functional unit).1 With these setbacks in mind and some assumptions that will be explained later in their appropriate phase, we are able to move forward with the report.
This next section will break down the life of an LED light and present the embodied energy for each phase of its life-cycle. Pulling from multiple sources, this report hopes to compile a comprehensive assessment of the total embodied energy in the life of an LED light to use as a tool for comparison with other lighting sources and diagnose the future of LEDs as a sustainable lighting source.
The first stage in the life-cycle assessment is raw materials acquisition, which varies greatly with the different types of LEDs. A few materials that are integral to the majority of LED variations are aluminum and copper for the heat sink, plastic or glass for the housing, and gallium phosphide or gallium nitride as the semiconducting substrate.1 The variation is often in the semiconducting material where gallium is often substituted with indium or aluminum phosphides and nitrides. This change affects the color of light that is emitted for the LED.2 The average total mass of all of these materials for one LED is 175.11g with most LED variations falling within the range of 83-290g.3 Typically the aluminum and copper heat sink comprises over half of the total mass of each LED light with the actual LED package taking up less than 2% of the total mass.4 This is not representative of the energy needed to extract these materials however. Aluminum and gallium are both naturally found in bauxite, which is a relatively low energy substance to extract. It requires about 14.5GJ to extract one tonne of the alumina. The separation and purification of the gallium nitride substrate is much more complex and energy intensive. There are also methods of growing gallium nitride, but that requires about 100 atm of pressure with over 750º C of heat, adding a significant energy toll onto the process.6 In many of the studies, material extraction was lumped in with the processing and manufacturing stage, so this next section will cover some of the missing figures from this first stage of energy calculation. Processing and Manufacturing for LEDs requires much more energy than previous lighting options like CFLs and Incandescents. This often prompts a fear that it isn’t worth the added energy input. This however is an invalid fear because this phase of the life-cycle is still proportionally only on average 6.6% of the total embodied energy due to LEDs exponentially longer lifetime than CFLs and incandescents. Within that 6.6% percent it is broken down between the bulk materials (heat sink, housing, wiring etc) and LED package (chip, phosphate layer, cathode etc.). The LED package requires 75% of the energy needed to manufacture the LED with the bulk materials taking up the remaining 25%. And over half of the 75% needed for the LED package is devoted to the die fabrication process. So the die itself takes up almost half of the entire manufacturing energy and on average requires more than 3% of the embodied energy for the entire life of the LED.1 OSRAM presents their calculated energy demand (CED) for production to be 35.64 MJ for a 345 lumen output.2 If we put that on the 800 lumen output standard that the DOE LCA used then we can see that OSRAM’s figure of 82.64 MJ/800 lumens falls below the projected average of 2015 LEDs at 132 MJ. This is however well above the projected minimum energy projection of 25.9 MJ so with quickly progressing technologies this is likely an accurate calculation for a 2013 LED.3 The DOE LCA calculated an average of 343 MJ/20 million lumen-hrs for the 2011 LED. Because of the tremendous variation in LED production the calculated embodied energy of the manufacturing phase can range from the extremes of 0.1% to 27% of the total energy for LEDs.4 What is important to take from this section is that even though production is the most detailed phase of LEDs and is more energy intensive than production of CFLs and incandescents, it is still miniscule in comparison to the total embodied energy needed for the entire life of the product.
The next phase is the distribution and transportation of the product to the consumer. This phase contributes less than 1% of the total embodied energy of LEDs. For this calculation a number of assumptions needed to be made. It is impossible to accurately account for every truck and every bulb that travels across the world but based on the leading suppliers of LEDs we are simplifying this process. We are assuming the LED is both manufactured and assembled in Taiwan and then taken by container ship to Los Angeles. From there, a commercial truck will drive it to a retail outlet in Washington DC. These assumptions lead us to an energy demand of 2.71MJ/20 million lumen-hrs. The setback of this calculation is that transportation is only considered between manufacturing and use rather than between every phase. This is due to the clumping of the first two phases of the life cycle in most LCAs that were referenced for this report. This setback is minor due to the low impact distribution has on the total embodied energy compared to larger contributing phases like use and maintenance.
The use/reuse and maintenance phase of an LED’s life yields the highest energy demand by far. This phase can require anywhere from 73% all the way to 99% of the embodied energy of an LEDs life, averaging about 91%. This equates to an average demand of 3,540 MJ/20 million lumen-hrs for a 2011 LED, and a projected 1,630 MJ/20 million lumen-hrs for a 2015 LED.2 This fits OSRAMS CED of 2,368MJ for their 2013 LED.3 These numbers are provided based on calculated primary energy figures taken from Ecoinvent 2.2 that were then converted to secondary energy based on assumed country of origin’s electricity mix and then converted back to primary energy using the U.S. energy mix conversion factor.4 Energy consumption during the use phase is where LED lights shine in comparison to CFLs and Incandescent. A traditional incandescent bulb uses over 15,000 MJ/20 million lumen-hrs. That’s almost 5x the energy needed for a 2011 LED with a lifetime that is 25x shorter. CFLs come close with energy usage with only 3,780 MJ/20 million lumen-hrs but still show a lifetime 3x shorter than 2011 LEDs.1 Off-grid users in Kenya also noticed the benefits of LED lighting by using a goose-neck LED lamp with an estimated embodied energy of production of 62MJ. This low power lamp produced high powered results lowering energy use from 2000MJ of primary energy annually with kerosene lamps, to just 182.5MJ annually with their LED lamps.2 Maintenance of LEDs is minimal but there is a dirt depreciation factor that can affect the lumen output of lights over time. This however, does not affect the energy input but might require a very minimal amount of human labor. LEDs currently have an estimated lifetime of about 30,000 hours, but eventually they die and need to be disposed of which brings us to the next stage of the life cycle.
Waste management and recycling are the final stages of a products life-cycle. Due to the recent application of new LED lights and their extremely long life, LEDs don’t have systems established yet for recycling and disposal. As of now, the manufacturer usually just asks that you send the product back to them for disposal. However, with innovation of the product comes innovation of the services surrounding it. Recycling programs are being conceived to retrieve the gallium, indium and phosphors within the LED package because these rare earth and other precious materials are expensive and finite in nature. This would require a restructuring of our assembly process that would be designed more for disassembly.4 Studies are also currently being conducted on the health hazards of LED light materials, which could require additional disposal specifications that would yield a higher embodied energy in this phase. The rapid progress in LEDs does create obstacles for disposal services, but it also creates numerous opportunities for reducing embodied energy in all other phases of the lifecycle as well.
LED technology is moving at incredible speeds, especially in light of new legislation. The Energy Independence and Security Act (EISA) of 2007 requires that lighting manufacturers start phasing out 100 watt bulbs, then 75 watt and then 60 watt over the course of the next few years.1 The process is already well under way with major benchmarks happening in 2014 and then in 2020. This legislation will cause an industry shift towards LEDs that will greatly increase awareness, knowledge and availability of resources on LEDs. When LEDs become the industry standard we will most likely see more non-retrofitted luminaires that have housing units that can fully utilize the benefits of LEDs. Also it is projected that in 2015 it will only require 5 LED packages to produce an 800 lumen output lamp while it takes 16 to produce the same lumen output for a 2011 LED.2 Other advances like OLEDs (organic LEDs) and quantum dot technology for producing ambient white light give us a taste of the immense possibilities that LEDs can offer us. These advancements show that the figures provided in this report will quickly become outdated but it is important to constantly document the specifications of our new technologies to understand our energy use and how we can cut it down.
LEDs constantly prove that they are the most sustainable lighting option out on the market today. Average total life-cycle embodied energy for a 2011 LED is calculated to be 3,890MJ/20 million lumen-hrs.3 This figure is drastically lower than both incandescent and CFLs when compared to their lumen output and lifetime. With projections for 2015 LEDs’ embodied energy being half of the 2011 calculation, LEDs are likely to become the global standard for both commercial and residential spaces. Hopefully this lifecycle assessment of the embodied energy of LED lights can be used as a tool for designers and researchers to reference in their advancement of LEDs and any related products.
Alstone, Peter. "Embodied Energy and Off-Grid Lighting." The Lumina Project no.9 (2012): Lawrence Berkeley National Laboratory, Shatz Energy Research Center (Mar 2, 2013).
"Bauxite World." The International Aluminum Institute. 2012. http://bauxite.world-aluminium.org/refining/energy-efficiency.html (accessed Feb 20, 2013).
Department of Energy. Energy Savings Potential of Solid-State Lighting in General Illumination Applications 2010 to 2030, 2010. Washington D.C., Navigant Consulting Inc., 2010.
Department of Energy. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products, 2012. Washington D.C., Navigant Consulting Inc., 2012.
"ENERGY INDEPENDENCE AND SECURITY ACT OF 2007 (EISA)." Environmental Protection Agency. http://www.energystar.gov/ia/products/lighting/cfls/downloads/EISA_Backgrounder_FINAL_4-11_EPA.pdf (accessed Feb 25, 2013).
Gonzales, Amanda. "What We Know and Don’t Know about Embodied Energy and Greenhouse Gases for Electronics, Appliances, and Light Bulbs." Natural Resources Defense Council (2012):.
Hendrickson, C T. "Reducing environmental burdens of solid-state lighting through end-of-life design." Environmental Research Letters 5, (2010):.
"LCA of an OSRAM LED Lamp." OSRAM. 2013. http://www.osram.com/osram_com/sustainability/sustainable-products/life-cycle-analysis/lca-of-an-led-lamp/index.jsp (accessed Mar 7, 2013).
"LED Lifetime in Practice - The ETAP Approach." ETAP Lighting. 21 Jan 2009. http://www.etaplighting.com/uploadedFiles/Downloadable_documentation/documentatie/whitepaper_LED_EN.pdf (accessed Mar 1, 2013).
Trieu, Simeon. "Light Extraction Improvement of GaN-Based Light Emitting Diodes Using Patterned Undoped GaN Bottom Reflection Gratings." bSchool of Physics and State Key Laboratory for Artificial Microstructures and Mesoscopic Physics (2009): California Polytechnic University, San Luis Obispo (Mar 11, 2013).
March 13, 2011
Waste and Emissions of Light-Emitting Diodes
Lighting is a very new thing is this world, yet the progress that has been made is astounding. From fire, to oil, and then electricity, much has changed in the way we see things. The most recent change in how we light our homes, businesses, cars and other things is the LED or Light Emitting Diode. Only recently the LED has been put into mass production because of the outweighing advantages of using it. The amount of waste that comes from this source of light it very little, and in turn has a very small amount of emissions compared to other forms of lighting. Since the LED is so new there is only limited information on the waste management ad emission factor, therefore our only solution to the problem as of now is to either Recycle the LED, or throw it in a landfill and then plan for the future.
To understand where Light-emitting Diodes are at in the present and where they are going in the future it is important to understand their history and the information that has come from it. In 1907 H.J. Round originally discovered the first known LED on accident. While trying to research Radio waves with a cat whisker detector he stumbled upon the Light-emitting diode (Cunningham) The piece of Silicon Carbide crystal that he was working on began to light up in certain spots when touched with the Cat Whisker tool because of the flow of electricity. Unfortunately there was no further research done on LEDs until 1962 by Nick Holonyak. (Doubulb) After continued understanding and research the LED was developed into the mass marketed object that we have today. The LED can still be found in its original places such as indicator signs or located on many appliances in both the home and laboratory. (Doubulb.)
Currently Light-emitting Diodes are the best option to purchase for lighting. They have a phenomenal life span, over 50,000 hours without going completely out. This great efficiency is due to their design and materials. The Light-emitting diode is created with some very complex materials and procedures, which is exactly where the waste and emissions portion of their life span starts. Some of the materials include: an Epoxy dome, a silicone lens, a transient Voltage Suppressor, wires for the anode and cathode, a semiconductor, and chemicals to determine hue. (LED Basics) These materials are much different from the traditional incandescent light bulb. In an incandescent light bulb there is a glass bulb, a base and a filament, which burns and produces light. ("How Products Are Made.") The incandescent bulb produces much more waste, close to 4,500 pounds of CO2 a year, than the LED. The Light-emitting Diode produces a mere 451 pounds a year because of the design of the light. (Design Recycle Inc.) The electric current flowing through the semiconductor lights up the LED which promotes a long life span, and rarely puts the light out completely allowing you to change the bulb when it gets dim instead of loosing all illumination. (Doubulb)
Even though Light-emitting diodes are very efficient which decreases their emissions, there is always waste involved with the production. LEDs are very similar to computer chips in the sense that they have a great deal of sanitation and quality involved with the procedure. The manufacturers need to have a very clean area and are dressed in lint free outfits; similar to those that doctors wear. (Page) When the LED circuit boards are created there is a lot of heat involved, which is part of the emission process yet I could not find information sharing the statics of heat and emission involved with this process. (Page) “The lights start out as bare printed circuit boards.” (Page) The boards are then fixed to the shell where they become small LEDs. The waste that comes off of these procedures is mostly from the cutting procedure. Cutting the circuit boards is not an easy task and this step generates some of the most waste. The waste that is “generated [is] 89 pounds of waste--4,500 times the chips' own weight.”(Ryan, J., and A. Durning.) This amount of waste is massive but there is no solution as of now to make it less than it is. The detail and quality of work cannot be reduced or the LED circuit board may not work properly and in turn could reduce the sales of the most efficient light bulb on the market.
Other than production waste, there is also the waste and emissions that come from transportation. So far the most expensive part of production is dealing with the semiconductors, which are made from rare earth metals like Aluminum, or Gallium.
These rare earth metals are mostly owned by China (Dillow) and in turn means that in order to obtain these materials there is an increase of emissions because of the transportation process. If you were to transport the average weight of a a trans-pacific import (World Shipping Counsel) of 9 tons of rare earth materials from Shanghai, China to Davis, California by boat, you would emit 50.26 tons of CO2 of Carbon Dioxide. (Carbon Fund) This shows that making anything with rare earth materials is very expensive, and harmful to the planet.
Moving on to another form of waste, LEDs are mainly thought to be non hazardous, or so studies have shown that they are not harmful. (Design Recycle Inc.) Since they are not harmful they do not produce hazardous waste, which is beneficial to the planet, and means that we most likely find a way to recycle the lights. The only problem with this situation is that since Light-emitting diodes are so new that we have little to no information on the topic of getting rid of LEDs. When inquiring to companies that make the LED I asked what the best way to get rid of LEDs would be, and if they had any suggestions on how I should recycle them. My favorite response, which was similar to many others, was from the Sewell Lighting Company, and they said, “We would recommend performing research on Google, or contacting another company.” The option of recycling the LED is so far the best option because companies do not want to waste the rare earth metals that are found inside of the LEDs and they also have the technology to collect it. Rare earth metals are not the only things that can be recycled in a LED, but the whole thing can be reused.
When recycling other materials in a Light-emitting Diode besides the rare earth materials, there are more options because of the information on them. The epoxy can be recycled in to many things such as flooring, cement, and countertops. . (Davis) This is because epoxy is actually glue and when combined with other compounds it allows the mixture to be more durable than without the epoxy. The wire used in the Light-emitting diode can be melted down in order to be reused. (Williams) The LED also reduces the wastes of other things like labor costs, and electricity spending.
All across the United States, companies focus on visual advertising; a great example of this is Time Square in New York City. The area gets millions of people every year as a set destination, which is a great opportunity to advertise, and what better way to gain peoples attention than with lights. (Kleege) From personal experience the whole show is rather magnificent, and I even caught myself saying, “Check out how cool [insert brand name here]’s sign, it’s so bright.” With LEDs being so efficient they have reduces the waste involved with the usage of other bulbs. The only increase caused by the introduction of the LED is the price of advertising, which has made both real estate and business owners more competitive. (Kleege) LEDs have also reduced the spending on labor costs, which I have heard referred to it a waste of resources because of the loss of money. Instead of using many people to change light bulbs, they need just a few people to be digitally savvy which saves many “resources” (Kleege)
My failures in this project out numbered my successes when trying to find information on the wastes and emissions of a Light-emitting Diode I was hindered by the incredibly newness of the LED. The books that were written on the subject of LEDs were already out of date, and there was a lack of studies that had been finished on the topic, but instead I found more proposed questions and ideas. As mentioned earlier even the companies that I had emailed did not know exactly what to do but suggested either sending the used LED to the manufacturer or Googling another option. Other failures included not finding information about the detailed process of making the LEDs. The sole benefit that I found with this lack of research was that there is an understanding that the Light-emitting Diode is revolutionary and so efficient that the length of a study is much longer so the information cannot be used yet.
While looking into the future the LED is being examined very closely. Instead of being content with the idea that the LED is the perfect bulb and will never harm the environment, many people such as the American Chemical Society are starting heavy duty studies on the question “Is the Light-emitting Diode really safe for the environment?” Also it is known by the name that rare earth metals are hard to find. How do we know that they will last long enough to keep producing LEDs and other products that require them? Then to follow this question, how will LEDs become cheaper if rare earth materials become more expensive? Can we design a new way to produce LEDs with new materials that are more common? These questions may not be answered in the near future because of the lack of studies and also because the lack of popularity that Light-emitting Diodes throughout the world. Once the popularity increases there is a good chance that the information on LEDs will increase, and knowledge on the topic of the light source will become abundant.
Luckily for LEDs there is a good connotation connected with the word. More and more people are expected to start using them because of all of the uses and advantages of them. Some of these advantages include the life span, the efficiency and the abundant uses for them such as: flash lights, rail way crossings, exits signs and more. (Doubulb)
LEDs can drastically decrease your emissions and your carbon footprint. “By doing nothing except installing LED's in the house it is possible to reduce one’s carbon footprint by a whopping 6 tons per year” ("Led Lights Reduce Your Carbon Footprint.")
As the technology develops I am sure that the uses and advantages of using LEDs will grow as well.
In conclusion Light-emitting Diodes are a revolutionary new source of lighting that has very little emissions, waste by-products or information that could be found on the subject. Through many struggles and a lot of time put into research it shows that sometimes things are too new to be understood completely. Luckily with the information that did come up it can be proven that Light-emitting Diodes are indeed the best choice of a lighting source on the market. With more research there is a good chance that LEDs will become cheaper, and give off less emissions than they do now which is still very little to the incandescent bulbs that are traditionally used globally. If you had the choice I would urge you to purchase LED lights to help reduce your carbon footprint.
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