Understanding LEDs James Solecki INTEGRA Bespoke Lighting Systems 2014
Understanding LEDs 1.0 The Basics: What is an LED? LEDs are Light Emitting Diodes; everyone knows that much. But it is the 'how' they emit light that seems to be relatively unknown. An incandescent lamp produces light when electricity flows and heats a filament in a gas sealed lamp. Fluorescent lamps emit light when voltage is transmitted by electrodes that allow electrons to excite phosphors as they pass from one end of a tube vacuum to the other, but what about LEDS? If there is no gas, filament, phosphor, vacuum or arc, how do they produce light? The LED produces light in a process called electro-luminescence. This is a relatively complex process that relies upon the physical properties of semi-conductors. We know that many metals like copper conduct electricity so they are known as conductors. There are other materials that do not conduct electricity, such as rubber for example, and these are known as an insulators, but there are materials known as semi-conductors that under normal conditions don t conduct, but under the right circumstances can conduct electricity. Now without getting too deeply involved in a lesson on atomic physics, let's just jump ahead and accept that a semi-conductor with extra electrons is called N-type (negative) material and a semiconductor with extra 'holes' is called a P-type (positive) material. Remember that opposites attract. When excited with a electric current the negative electron leaves its atom and the P-type material s positive attraction draws the free negative electron into its hole. As an electron travels to a hole it carries with it energy, but in order to fit into the hole it must release any extra energy. This extra energy is released in the form of a photon (light). Simple isn't it? * Source: Techlinea Inc. The wavelength of the light emitted from the LED (the colour) is dependent upon the type of materials that are used as the semi-conductors on the chip but we will get back to this a bit further on. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 2
1.1 The Basics: The physical nature of LED light: Now that we have a semiconductor producing a flow of photons, we must look at the nature and qualities of the light produced. In general a flat surface uncoated LED chip will emit light in a very narrow beam that is perpendicular to the chip itself. This is referred to as the light cone. Having such a narrowly defined, directional beam of light is not ideal for general illumination applications. As such the LED is generally potted, or encased in clear or coloured molded shells. These casings have three principal functions: 1: Provide for easier handling and mounting of the LED chip. 2: Protect the relatively tiny wiring from damage. 3: Act as a refractive intermediary or lens which helps to boost the light emission from the LED, diffuse the light output and generally provides us with a much wider angle of incidence or beam angle than the bare chip is able to emit alone. Through the use of the LED chip package we are able to protect the chip itself and also positively affect the type of light distribution that is produced. 1.2 The Basics: The colour of LED light: Another significant consideration in the type of light produced is the colour of that light. Unlike incandescent and fluorescent lamps, LEDs do not produce what is considered to be white light. Instead, LEDs emit nearly monochromatic light. This makes them excellent candidates for coloured light applications such as transportation markers, indicator applications, and theatrical uses. However, to be used in general illumination, white light is needed. At a basic level, the wavelength (colour) of the light emitted is dependent upon the band gap energy of the materials that are used to form the P/N Junction. By altering the materials used in the chip we can alter the base colour of light that is produced. Source: Washington University; Dept. of Chemistry Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 3
Although there are now a wide range of different semiconductor materials being used to make LEDs ranging in outputs from Infrared to Ultraviolet, the two main types of LEDs presently used for lighting systems are aluminum gallium indium phosphide (AlGaInP) for red, orange and yellow LEDs; and indium gallium nitride (InGaN) for green, blue and white LEDs. In the realm of high output LEDs for general illumination applications it is the InGaN based LEDs that offer a good combination of high light output and efficient operation. But producing a blue light is not going to serve our needs very well. There are two ways in which white light can be achieved with LEDs. One is to use individual LEDs that emit each of the primary three colours; Red, Green and Blue, and then mix all of the colours to form white light. These are commonly referred to as RGB LEDs. Although an effective solution, RGB LEDs require sophisticated electronic circuits to control the blending of different colours and typically require larger housings or fixture bodies and produce lower output solutions. As a result the market for RGB LEDs tends to be focused more in the commercial sectors such as dynamic architectural lighting, underwater lighting, and visual display lighting. The other way to achieve white light from LEDs is to use a phosphor conversion process. This method involves coating a short wavelength LED, typically a blue InGaN LED, with a phosphor of different properties that emits a complex, more broad wavelength of light. In simple terms, the phosphor coating reacts to the relatively narrow wavelength of light coming from the LED and excites, or shifts that light, emitting a yellow light with a relatively broad colour distribution. By using the phosphor conversion process, the LED manufacturers are able to adjust or tweak the composition and application of the phosphors that results in different white colour temperatures. This is how they are able to produce white LEDs that range in colour temperatures from 2500K all the way up to 6000K and also allows for the tight production control of different colour chips, a procedure known as binning. * Source: US Dept. of Energy; SSL website. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 4
1.3 The Basics; Electrical Properties and Requirements of LEDs Individual LEDs are low voltage devices and have a number of different and unique electrical properties and requirements in order to make them function. For instance, single indicator LEDs require anywhere between 2 to 4 volts of direct current, with current in the range from 1 to 50 milliamperes. Whereas a high output, illumination-grade LED can require similar voltage, but operating currents are much higher, typically several hundred milliamperes and up to 1 amp. A LED lamp or fixture that uses multiple elements will require a higher forward voltage corresponding to the larger number of individual elements in the device. And then you can get into the complexities of power conditioning and dimming. All together, any illumination grade LED lamp or fixture will an electronic component that provides the LED chips the precise measure of voltage and amperage that they require for peak operation. This electronic component is known as the Driver. An LED driver performs a function similar to a ballast for discharge lamps. It conditions and controls the electrical current flowing through the LED. Given all of the different LED chips on the market and all of their different requirements, most LED drivers have been specifically designed and engineered to be matched with a specific lamp or fixture. Great care has to be taken in the design and application of the LEDs driver in order to ensure its optimal output, performance, and longevity. An example of a miniature LED lamp driver circuit 2.0 The Argument for LEDs: So now that we have a better understanding of just what and LED is, how it produces light and the nature of the light that it produces, you may be wondering what all the furor is about. Why are LEDs so popular and seemingly taking over the lighting industry? LEDs offer the potential for cutting general lighting energy use by one-quarter, saving energy dollars and carbon emissions in the process. Their unique characteristics including compact size, long life and ease of maintenance, resistance to breakage and vibration, good performance in cold temperatures, lack of Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 5
infrared or ultraviolet emissions, and instant-on performance are beneficial in many lighting applications. The ability to provide dimming and color control is another benefit of LED lights. One of the key features of LEDs is directional nature of the light they produce. Directional lighting reduces the need for reflectors and diffusers that can trap light and this allows well-designed LED sources to deliver light efficiently to the intended location. In contrast, fluorescent and "bulb" shaped incandescent lamps emit light in all directions. Unfortunately much of the light that is produced by these types of lamps is lost internally, or escapes in a direction that is not required or necessary. For many fixture types it is not uncommon up to 50% of the total light output of fluorescent and incandescent lamps to be lost before it exits the fixture. Beyond the physical attributes of the LED light source, two of the main benefits of using LEDs for general illumination applications are energy efficiency and long life (long maintenance interval). 2.1 Energy Efficiency: LEDs The energy efficiency of light sources is typically measured in lumens per watt (lm/w) and is defined as luminous efficacy; basically the amount of light produced for each watt of electricity consumed. There are a number of high efficiency light sources available today, but few if any share the same physical properties as LEDs; namely their very small size and ease of output control and manufacture. When you combine the features of high efficiency, small size, dynamic output, and long life, it is easy to see why LEDs have become so popular. Below is a chart that compares the efficacy of several popular light sources: Typical LED Efficacy Compared to Conventional Lighting Technologies - 2010 Product Type Typical Luminous Efficacy (lm/w) LED "cool white" package 60-100 LED "warm white" package 40-70 HID (metal halide) Lamp & Ballast 50-90 Linear Fluorescent Lamp & Ballast 50-110 Compact Fluorescent (CFL) lamp & ballast 35-60 Halogen 15-20 Incandescent 10-18 * Sources: US DOE SSL Report, US DOE SSL Multi-Year Program Plan 2.2 LED "Lamp" Life: The lighting industry presently does not have a standard definition for LED lamp life. The lamp life definition for incandescent light sources is the time when 50% of the test samples have burned out. However, are different in that they do not burn out, but rather, their light output will slowly fade over time. Given that they are solid state devices, they can continue to operate even after 100,000 hours, continuing to use electrical power even if they produce very little useful light. For this reason, it is more Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 6
appropriate to consider the process of Lumen Depreciation as a measure of "useful" life for the LED sources. Lumen depreciation is now used to calculate a LED's useful life and is typically based on the number of operating hours until the LED is emitting 70 percent of its initial light output. This metric is known as the L70. A great number of factors affect the working life of an LED, and these will be covered in detail further into the report. To give you a rough idea, a good-quality white LED in well-designed lamp or fixture is generally expected to have a useful life of 30,000 to 50,000 hours. In comparison, A typical incandescent lamp lasts about 1,000 hours; a comparable CFL lasts 8,000 to 10,000 hours, and the best linear fluorescent lamps can last up to 30,000 hours. Again, given the physical size and efficiency considerations already mentioned, and combine them with the exceptional life expectancy provided by LEDs and you can see why LEDs have taken the lighting industry by storm. 3.0 Critical Factors To Know & Understand On one hand it could be argued that the LED is a pretty simple device, however on the other it would have to be said that there so many highly technical factors that influence the performance of the LED that it is anything but a simple device. When LEDs are designed, engineered and manufactured correctly, they offer a highly efficient, effective, long lived, compact and dynamic light source. There are however some things that must be accounted for and 'done right'. Two of the most challenging tasks when considering any LED light source is to be able to understand the specifications (assuming they have been provided) and being able to do effective side by side comparisons between different LEDs. Stated below are some of the critical measures and technical considerations that you must become aware of and understand; at least to some degree, for you to make reasonable and informed choices. 3.1 Critical Factors: Lumens The lumen (lm) is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. All other light measurement units and protocols aside for a moment, the lumen has become the 'go-to' metric by which LED manufactures state how 'powerful' or 'bright' their products are. I won't get into the full discussion of measuring light output, luminance, illuminance, spectrum and chromacity and all of the associated terms and formulas, other than to say that for the purposes of LED evaluation and analysis, you will need to understand the lumen. One of the most challenging issues when evaluating LED light sources is 'equivalency'. Most often people are looking to replace a well known and understood incandescent light source with an LED; and as such are looking for an "LED equivalent" to a "20 Watt Halogen". There is no 'magic formula or straight forward comparison between watts and lumens. Unfortunately not much work was done in the past by incandescent lamp manufacturers in measuring the total lumens from various light sources. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 7
Also, the lumen output of any given type of incandescent lamp can vary, sometimes quite widely, from manufacturer to manufacturer and even between production runs from the same manufacturer. As a result, using Lumens as a LED - Incandescent comparison is pretty much impossible. However, the Lumen output provides us with a good comparison metric when looking at different types of LED light sources. Efficacy can also be quickly calculated for comparisons by simply dividing the total number of lumens produced by the total watts consumed = lm/w 3.2 Critical Factors: Correlated Colour Temperature (CCT) Correlated colour temperature (CCT) put simply is the colour temperature of the visible light produced by the LED source. CCT is conventionally stated in the unit of absolute temperature, the Kelvin and has a unit symbol of K. Colour temperatures over 4500K are called cool colours (bluish white) and those that are lower, between say 2700K and 3000K are called warm colours (yellowish white through red). When evaluating a LED light source, you will certainly want to know what the CCT (colour temperature) is, as you can get into all sorts of aesthetic and performance considerations when installing different colour lights into different applications. Typically, here in North America, residential applications rely heavily on 'warm white' light sources, ranging from the 2700K of incandescent up to around 3200K of some Halogen and newer Metal Halide sources. In commercial and industrial applications, the trend is to use slightly cooler white lamps that fall in the 4000K to 5000K range. Mixing up multiple colour temperatures can be effective and desirable in certain applications, but for most it is important to try and 'colour match' the various light sources on the same property as much as possible. Initially, most LED lamps and fixtures came in cool white, having a CCT of 4000K +, and resulted in LED light getting a reputation for being "cold" and "blue". As time passed and phosphor technology Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 8
improved LEDs were able to warm up the beam quite a bit, and provide bright, efficient light sources that hover around 3000K. As technology continues to evolve and develop we are now seeing very warm colours coming from LED sources that emulate the 2700K of traditional incandescent light bulbs. 3.3 Critical Factors: Colour Rendering Index (CRI) The color rendering index (CRI) is a quantitative measure of the ability of a light source to reproduce the colours of various objects faithfully in comparison with an ideal or natural light source. Using the CRI rating of a lamp is practically very simple and is based on a 0 to 100 scale where 100 is providing perfect colour rendering. Interpreting what a CRI of 82 is, when using LED sources is a bit more complex mind you as there is some debate regarding the accuracy of CRI testing with LED light sources. That being said, for the time being CRI is the colour metric to look for when choosing or comparing LED light sources. Essentially you want to find the LED source that offers you the highest CRI within the specified CCT you are looking for and ideally you want to keep the CRI at or above 80. When you have a light source with a CRI of 70 or below, you start to get into some pretty obvious and serious colour rendering issues. A perfect example of this can be found in areas that have some High Pressure Sodium (HPS) area lighting mixed in with some Metal Halide (MH) lighting. The HPS lamps have a typically low CRI of around 24, whereas the new ceramic metal halide lamps boast a very high CRI of 96. If you have ever tried to examine a photo, read a magazine or enjoy a flowering garden under high pressure sodium street lights, you will know what low CRI does. Light Source CCT (K) CRI Incandescent Halogen 3200 100 Ceramic Metal Halide 5400 96 Quartz Metal Halide 4200 85 Warm White Fluorescent 2940 73 Cool White Fluorescent 4230 64 Coated Mercury Vapor 3600 49 High Pressure Sodium 2100 24 Clear Mercury Vapor 6410 17 Low Pressure Sodium 1800-5 Source: Wikipedia; CRI Recently CRI has been criticized for not always correlating well with subjective colour rendering quality in practise as It has some trouble with light sources that do not have full / smooth spectral outputs such as with most LEDs. A new metric is under development and review by the National Institute of Standards and Technology, called the Colour Quality Scale (CQS), but until such a time as the CQS has been adopted, you should try to find LED light sources that offer a high CRI. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 9
3.4 Critical Factors: Lamp Life (L70) This is the metric that tells you when the LEDs light output will drop down to 70% of initial lumens. It has been determined that once the LED source has depreciated to 70% there is a noticeable decrease in light output and that it is at this point that the LEDs should be replaced. When LED lamps and fixtures were first introduced to the market there were all sorts of wild claims made regarding lamp life. It was not uncommon to see claims of 75,000 and even 100,000 hours. These of course were completely unsubstantiated, un provable and roughly estimated projections of what should happen. In order to bring some stability and science to the market the Illumination Engineering Society (IES) developed a testing protocol called LM-80 which allows for "a reliable comparison of test results among laboratories by establishing uniform test methods." This testing protocol; LM-80 accurately addresses the measurement of lumen maintenance testing for LED light sources and had become the universal measure of LED 'lamp life'. Beware of those LED product where the manufacture lists an 'expected life', 'life expectancy' or other form of unsubstantiated claim about the life of their products. Only the LM-80 test protocol will provide you with and accurate L70 rating. 3.5 Critical Factors; Watts Watts are also an important metric for comparison and evaluation of LEDs. Watts are, of course, the total amount of energy consumed by the LED lamp or fixture while in operation. What is important to remember here is that LEDs are not 100% efficient, in that they do not convert 100% of their watts into light. There are losses to heat as well as to certain inefficiencies that can reside on the driver circuits that power the LEDs. Unfortunately we have no way of knowing (yet) if a manufacturer is stating the total watts consumed by the LED package or if they are just referring to the number of watts that the LED chips themselves consume. Fortunately this issues is does not cause all that much trouble when building circuits of LED based light sources and rest assured it will be dealt with as new, more stringent testing and labeling programs get introduced. 3.6 Critical Factors; Heat (junction temperature) It is a common myth that LEDs produce no heat. They do in fact produce heat, only at a greatly diminished level than traditional incandescent sources. The junction temperature of an LED is the highest allowable temperature of the actual semi-conductor in the LED assembly. In operation the junction temperature is higher than the case temperature or the exterior temperature and can generally only be accurately measured by use of a soldered thermocouple device that attaches as close as possible to the p/n junction on the chip. Maximum junction temperatures vary widely depending on the type of LED and are always provided by the LED manufacturer for easy reference. Excessive heating of the LEDs themselves is highly problematic as it results in accelerated lumen depreciation and can result in severe colour shifting and fading as the sensitive phosphors are degraded and burned off. The heat produced by the LED chips can even harm some electronic components on Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 10
drivers if they are mounted in close proximity to the high output LED chips. For this reason, the manufacturers of high power, high output LEDs require that their chips are mounted in applications that employ the use of heat sinks. Simply mounting LEDs to a circuit board and hoping that they will be sufficiently cooled by air convection alone is a recipe for failure. Unfortunately not many manufacturers of LED fixtures or lamps publish their actual junction temperatures. This is probably due to the fact that many of them have not actually done sufficient testing to find out what temperature the LEDs are operating at when installed into the device. More often than not, when requested, the LED chip manufacturers' maximum allowable temperature will be quoted rather than the actual temperatures generated by the LED package. None the less, you can employ a simple generic test yourself. Have the LED lamp or fixture you are considering powered on for at least an hour and then simply take a firm hold of it in your hand. If it is uncomfortably hot, in that you cannot bear to hold it for a few seconds, then you can be pretty certain that the junction temperature of the LEDs used is above the heat specification from the LED manufacturer. This is a typical graph that illustrates the relationship between Junction Temperature and L70 Lifetime for a LED 3.7 Critical Factors: Optics The optics of an LED lamp or fixture is not often a topic of discussion when it comes to critical factors in the evaluation or comparison of LEDs when in fact, for all intents and purposes, it really should be considered. The optical assembly or lens of the LED device can have as much influence on the lumen output, colour, quality of light and effect as any of the of the previously mentioned factors. You can put the best performing, brightest, most accurate LED into a lamp or fixture but if the device employs Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 11
poor quality optics, all will be lost. Knowing the transmissivity levels of the collimators on a lamp, or the lens on a fixture can be helpful in narrowing down truly efficient LEDs from those with poor output. You will also want to ensure that any lenses being used do not create aberrations, striations, or odd optical effects. Finally, you will want to know the beam spread of the LED lamp or fixture you are using. This is typically displayed in degrees and refers to the shape and pattern of the light beam that is produced. One of the reasons that Lumens are such an effective measure and comparison tool is that they are not affected by various reflectors, lenses, filters or other optical devices. This image shows the vastly different beam patterns from similar light sources. 3.8 Critical Factors: Physical Dimensions & Limitations: This is a factor that is not often considered or discussed, but is of particular importance when you are examining LED lamps for use in retrofit applications. It is critically important that not only the LED lamp fit into the fixture you want it to work in, but also that it has been designed and manufactured to work, over the long term, in the type of fixtures and environments that you are going to use it in. It sounds pretty obvious, but the market is filled with examples of LED lamps that simply will not meet these criteria.\ Most existing light fixtures have been designed to work with a specific type of lamp (light bulb). Take the MR16 for example. This is a very powerful, full featured technical lamp that has been adopted by most every manufacturer in the industry. An MR16, by design, has certain physical dimensions that have become standardized across the industry. Now along comes the relatively new LED lamp industry that is challenged to create similarly powerful and effective, high output LED lamps that will replace the MR16. The only problem is, that without some excellent design and engineering, it is quite difficult to 'squeeze' all of the necessary components into such a small lamp. The result has been a large number of LED "MR16" lamps that are not the same physical dimension as the original standard. They simply will not fit into the fixtures! Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 12
Three images of LED "MR16" lamps that do not have the same physical dimensions of standard MR16 lamps; These simply will not fit into most fixtures designed for MR16 lamps. Operational limitations are another area of concern when considering LED lamps. Quite often you will find LED lamps that clearly state limitations to their use. Things like "not for use in enclosed fixtures" and "not for use in outdoor applications" or "not for use in moist environments" are essentially red flags that should not be ignored. Especially when you are considered these LEDs for use in outdoor / landscape lighting applications. It is one thing to be able to build an LED that will work within specifications on a lab bench, and an entirely different thing to build an LED that will work in the broad range of fixtures and environments that exist in the 'real world'. When you encounter a warning about use in enclosed fixtures, it is really a comment that the LED will probably over heat and fail when installed in a fixture. When you see a warning about outdoor applications or moist environments, it is an indicator that the LED will likely fail from moisture ingress issues if exposed to high humidity and condensation. 4.0 Combining The Factors: Evaluation of LEDs and comparing apples to apples Given all of the different components and factors that are inherent in a modern LED light source, it is no wonder that there is so much confusion in the market when it comes to manufacturer claims and real world comparisons between different LEDs. In order to make informed, accurate comparisons, you really need to know each of the 'Factors' in section 3 for each LED light source under review. If you are missing some of the information, you will quickly discover that effective comparisons, at least on paper, are nearly impossible. For example; One lamp claims that it is a 5W LED MR16 that produces 450 Lumens. On the surface that sounds pretty impressive, and will expect it to be highly efficient and quite bright. Brighter than many 35W Halogen MR16s and close to a 50W Halogen. Well maybe. What about the quality of light produced? What is the CCT of that lamp? The cooler the colour temperature the more total lumens will be produced from the same wattage LED. Remember that lumens are simply a measure of the total light produced apparent to the eye. So yes this would be a very bright LED source, but the light produced could be very cold looking and not suitable for our applications. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 13
Alternatively, you learn that the lamp in the example above is producing those 450 lm at 3000K. Sound almost too good to be true! But at what temperature is the lamp operating at? It is possible to overdrive the LED chips and get some pretty impressive initial output levels. However, if the junction temperature is at or above the LED chip's maximum temperature, then all of those initial lumens will quickly face as the lamp 'burns up' from within. The phosphor coating on white LED chips is temperature sensitive and can break down causing accelerated lumen depreciation and colour shifts. Also, high heat levels can damage the internal electronic components on the driver circuit. Remember, as a rule of thumb, if you cannot comfortably hold the operating LED lamp or fixture in your hand, in a tight grasp or pinch, for more than a 15 seconds, then it is operating at elevated and potentially damaging heat levels. Looking at another example; You find a 6 watt LED MR16 that is 2700K and "replaces a 20 watt halogen lamp". Sounds good so far. It will be more efficient, clearly states that it is warm white and is as bright as the 20W halogen. Well, maybe. Without a lumen measurement, how do you know how much light is being produced? Also, what is the CRI of the LED lamp? Just because it says the CCT is 2700K or warm white does not mean that it will offer good colour rendition. The phosphors used to shift the CCT to that full warm white spectrum can very well be of low quality, or applied in a haphazard fashion resulting in some pretty horrible hues and tones. The CRI of the lamp is an important metric and should be, at a minimum in the high 70s if not beyond. 5.0 LED Applications in Landscape Lighting; Lamps vs. Fixtures Over the past couple of years you will have undoubtedly noted that LED has literally invaded every facet of the lighting industry. The landscape lighting sector has become full to the brim with various LED offerings with almost all of the traditional manufacturers now offering LED in some form or another, along with a whole host of new companies coming on stream with their LED products. Basically you can divide the LED landscape lighting industry into two distinct categories; integrated LED fixtures and LED lamps. There are of course pros and cons to each category. 5.1 Pros for LED Lamps: - LED lamps can be retrofit into most existing fixtures, opening the huge retrofit/service market up to LED. - LED lamps allow you to continue to use tried, trusted and true fixtures that you have become familiar with. - LED lamps allow you to use the best fixtures from a wide variety of manufacturers, all the while maintaining a cohesive light output, colour, intensity and pattern no matter what fixture you use. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 14
- LED lamps provide the ability to easily change, alter, or upgrade the lighting system over time as the landscape changes, matures or as the technology advances. (You don't have to change out or dispose of the entire fixture when using an LED lamp solution) 5.2 Pros for LED Fixtures: - LED fixtures offer a top to bottom engineered product that solves specific needs. They pass most of the technical understanding / knowledge requirements back to the manufacturer to figure out. (They are easy) - LED fixtures are designed and built to suit the specific application requirements and thus overcome the miniaturization hurdles that affect LED lamp design. - LED fixtures offer a strong opportunity to greatly increase your revenues and gross profits as the technology + package tends to be priced at a much higher premium than 'traditional' fixtures + LED lamps. 5.3 Cons against LED Lamps: - Providing for adequate heat dissipation along with the miniaturization of driver components, all while maintaining ANSI form factor standards has proven to be a challenging endeavour, one which many LED lamp manufacturers fail at. - LED lamps must be installed into appropriate fixtures & environment that are suitable for the operation of the lamps. - Because of miniaturization issues, it is much more difficult to make LED lamps work with all types of power supplies and universal, effective dimming is still a big challenge. - A plethora of early adopters in the form of "off shore" manufacturers have flooded the market with lackluster, poorly performing products and have soiled the reputation of the LED lamp as a viable alternative. 5.4 Cons against LED fixtures: - Many LED fixtures have put function ahead of form and are produced in un-appealing shapes, sizes and materials. - Many LED fixtures have their focus solely on the LED technology and have done away with basic light fixture features such as protection from glare, functional aiming and knuckles, and beam spread variability. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 15
- Many LED fixtures are factory sealed assemblies that do not allow for any field service of their components. - It is more difficult and costly to change out the optics of a LED fixture, and it requires an inventory of various manufacturer specific parts (lenses, covers, bezels, etc) - The contractor becomes beholden to purchase all of their fixtures from one manufacturer in order to maintain similarity and symmetry in terms of intensity, colour temperature, CRI and materials composition and finish. Clearly there is a lot to learn, understand and consider when making a switch over from incandescent to LED lighting systems, with arguably an equal number of Pros & Cons for both LED lamps and fixtures. Ultimately, it will come down to finding the products that work best for your business, in your market. As the market continues to advance and adapt you will probably find yourself relying on mix of products to provide you with all of the LED solutions you require. 6.0 LED Lamp Applications; Considerations for use in outdoor lighting systems. LED lamps offer the outdoor lighting system designer/contractor some fantastic opportunities for renewal, advancement and profitability. Through the adoption and use of quality LED lamps, you are able to offer your clients modern, efficient technology that will significantly enhance the economics of ownership and operation of their new outdoor lighting system; i.e. they WILL save money! While at the same time, you are able to offer all of your existing clients, and those of your competition, the opportunity to update and renew their lighting systems with the latest and greatest in technology, giving them most of the advantages that a new LED installation provides. On new installations, LED lamps offer you the flexibility to continue to use the fixtures you have come to know and trust. This is a very important consideration. Not only do you not have to research all new fixtures and vendors and then test and evaluate all those new fixtures, but you also have the benefit of being able to tailor the light output from the fixtures on the fly; typically when you are aiming and adjusting. By using quality LED lamps you don't have to worry about matching intensity, colour, or CRI between different fixtures from different manufacturers in the same system. For retrofit and service applications, LED lamps are the win / win solution. The client wins in that they are able to update, refresh and even expand their lighting systems affordably, while also getting the benefit of significantly reduced operating and maintenance costs over time. Expansion is now particularly attractive to the client as they do not have to re-invest in new, larger transformers, or even in greatly expanded or beefed up wiring systems. They can simply have their old system converted to LED lamps and expand at will, with more fixtures using LED lamps, generally relying on the existing power system. The contractor wins in that they are able to offer their clients new technology solutions that sell through at very attractive margins. The opportunity to expand on existing systems is also of great advantage to any lighting business as it is far easier and profitable to sell to existing clientele than it is to attract and gain new clients. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 16
Quality LED lamps are now available to fit most fixtures and work effectively in most applications. In some rare instances, when dealing with older, poor quality fixtures, you may find it necessary to replace a fixture in order to ensure that the LED lamp with operate properly. This is also a 'positive' in that it will spur the client on to replace outdated, poorly performing, broken, leaky and unsightly fixtures with something newer and better; just another opportunity for the savvy contractor to enhance their sales. Finally, by offering a complete line of quality LED lamps, you will enhance your positioning in your market and open yourself up to increase traction over your competition. It is no secret that in technical sectors such as outdoor lighting, clients seek out those who are ahead of the curve and offer the latest, greatest, most efficient and 'green' products. Even if you have made a strategic decision to offer LED fixtures for all of your new installations, it is still a prudent move to offer your existing clients the opportunity to upgrade to LED. 6.1 Lamp Applications: Selling the LED - TCO While in conversation with many lighting contractors one of the most common obstacles or hurdles that we hear in regards to selling LED lamps is that they "cost too much". Customers are hesitant to commit to spending the money that is required to upgrade their systems to LED or include them with a new installation. What we also find is that those contractors who are having trouble selling LEDs are those who are not properly prepared with the right information to make LEDs a value proposition to their clients. One of the most effective means by which to communicate the LED value proposition is to provide your client with a Total Cost of Ownership (TCO) analysis such as the one illustrated below. It is important to remember that most of the cost components in the TCO are variable and will fluctuate depending on your location, market, vendors, etc. Be sure to update this example with real data from your operations and market. Assumptions: 1 - Incandescent source is a 20W load that has a field life of 4000 hours. 2 - LED source is a 6W load that has a field life of 40,000 hours. 3 - Be sure to include the 'real cost' of electricity in your market. This includes the electricity, delivery charges, debt retirement charges, surcharges, taxes, etc. (Take your household bill and divide the total number of KWh used into the total amount of the bill) Per Fixture Cost of Operation: Halogen Lamp Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 17
A: (20W X 40,000 hours) / 1000 = Total KWh consumed X $ per KWh = Cost of Electricity used by Halogen lamp for the purposes of this analysis. B: 40,000 hrs / 4000 hrs = 10 Lamp Changes X $(cost of lamp to client) = Total Lamp Change Cost to client. C: Man hours labour per lamp change X 10 Lamp Changes X Labour Rate = Total Labour Cost to client. Add up A+B+C = Total Cost of operation to the client for Halogen Lamp for 40,000 hours of operation. LED Lamp A: (6W x 40,000 hours) / 1000 = Total KWh consumed X $ per KWh = Cost of Electricity used by LED lamp for the purposes of this analysis. B: Initial Cost of LED Lamp to client. Add up A+B = Total Cost of operation to the client for LED Lamp for 40,000 hours of operation. Cost Benefit Calculation. Subtract the Cost of operation of the LED Lamp from the Cost of operation of the Halogen Lamp. The remainder is the savings the client will realize per fixture if they choose to go with the LED lamp over the lifetime of the product. This calculation can be easily adapted to your market and other LED technology by changing the variables and costs. Here is an example. Halogen MR16 Lamp A: (20x40000)/1000 = 800KWh x $0.14 = $112.00 B: 40000/4000 = 10 x $9.75 = $97.50 C:.3 x 9 x $65/hr = $175.5 (initial lamp installation is included with fixture cost) A+B+C = $385.00 (cost of operation for a halogen lamped fixture for 40,000 hours) Illumicare LED MR16 Lamp A: (6x40000)/1000 = 240 KWh x $0.14 = $33.60 B: $64 A+B = $97.60 (cost of operation for a LED lamped fixture for 40,000 hours) Results: $385.00 -$97.6 = $287.40 In this example, if the client goes ahead with installing LED lamps in their system, they will save about $287 for each lamp used over the course of the LED lamp's life. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 18
6.2 Lamp Applications: Selling the LED - Maintenance Concerns The second most common obstacle we hear is that contractors are worried that if they start using LED, they will lose out on a significant amount of service revenue in their operations. Again, this fear is for the most part unfounded and in actuality, most contractors who do sell LEDs end up finding themselves running more streamlined, more efficient and more profitable service divisions. The fact is that LEDs do cost more than their incandescent cousins. However the customers, once properly informed, are more than willing to pay the premium in order to achieve the long term savings (as illustrated above). Since most successful contractors are operating on a markup/margin basis on the materials they install, the argument that a super long life lamp will cut into their regular service revenue just does not hold water. As an example: Contractor John currently buys Halogen MR16 lamps for $5 each and sells them to his clients for $9 each, achieving a 44% margin and a gross profit of $4 each. Over the course of some 40,000 hours of operation he will sell 10 of these lamps in total, accounting for some $40 of gross profit - over the course of 15 to 17 years! Now his competitor, Contactor Mike buys his LED MR16 lamps for $32 each and sells them to his clients for $58 each, achieving the same 44% margin and a gross profit of $26 each. Now over the course of those same 40,000 hours of operation, he will probably only sell one of the LED lamps, accounting for $26 of gross profit, however he attains 100% of that profit immediately and does not have to wait 15 or more years to realize it. Clearly the contractor who makes $26 today is further ahead of the one who makes only $4. Furthermore, using LEDs will not eliminate the need to service any outdoor lighting system. The contractor should still return to each job on an annual basis (at minimum) to clean, aim, repair, adjust, and relocate the fixtures and components; keeping the system working and looking 100% for the client. Service calls still happen, money is still made and by offering LEDs to the clients, a greater opportunity is opened for the expansion and additions onto the existing system. Clearly those contractors who are now offering their clients LED solutions, both in their service work and for new installations, are ahead of the crowd in many ways. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 19
7.0 Summary: Now you are armed with more information in regards to the technical workings of LED light sources, how to make fair comparisons, the pros & cons of different types of LEDs and some interesting knowledge on how to sell and profit from the use of them in your business. It may all sound somewhat confusing at first, but as you begin to look closely at more products you will start to identify the relationship between the data and should be able to make better decisions based on this data alone. While it is possible to make effective lamp and fixture decisions based on specification sheets alone, remember that there is no better way to compare two different light sources than to sample them side by side. Also remember that when it comes to LEDs, the success is in the details. Always ensure you get full product specifications, photometrics and certified labelling before you purchase. Ultimately, you should be wary of anything that sounds too good to be true. The number of false and unsubstantiated claims seems to grow every day. Highly effective, high brightness LEDs are not a low cost proposition. If you think you have found the holy grail of LED lamps, and they are a steal at $12 bucks each, chances are something is amiss. We recently reviewed a line of miniature SCB lamps that claimed to be replacements for 20 to 25 W halogen lamps only upon further investigation they were found to produce only 65-70 Lumens of light not even as bright as a 10W and came with no photometric data, no CRI data and no thermal operation data. Then again, they were being offered at $10 each; too good to be true. LED lighting is no longer the future of lighting, it is in fact a viable alternative today. It is an sector that has made great strides in the past few years and one that continues to develop and improve with every passing quarter. Please continue to educate yourself on this business, and begin to adopt them into your systems. The advantages far outweigh any perceived disadvantages once you have found the suitable products for your application. Prepared by James Solecki - INTEGRA Bespoke Lighting Systems - Page 20