2LEDs The most advanced and efficient Lighting Technology An LED (light emitting diode) is a semiconductor device that emits polychromatic light when it is polarized and excited by a very low amperage electric current.The first LED was developed by General Electric in 1962.The first white light and high brightness LED was developed in 1993 by Nichia Corp. in Japan.(not the first LED.)2
3LEDs LEDs present a number of technical advantages over any other lighting systems, including: LEDs produce a single color light, according to the specific application. Currently, they are produced in a variety of colors and temperatures.Much of the energy utilized by the LED is converted to light instead of heat, and they don’t produce ultraviolet or infrared radiation.LEDs concentrate (direct) the light flow and it is possible to focus it according to any need, making them more efficient.3
4LEDs LEDs present a number of technical advantages over any other lighting systems, including: The effective life (30% reduction in peak lumen output) of current LEDs is over 80,000+ hours, over 10 times the life of the best incandescent lamp (5,000 hours) and twice the life of the best fluorescent lamp (25,000 hours).Current technology has brought the LED light output to over 150 lumens per watt.An extremely efficient use of energy surpassing outdated lighting technologies.LEDs solid state technology makes them extremely durable, highly resistant to vibration or impact. Two factors that standard bulbs can’t withstand.4
5The Global Warming Effects The world’s energy consumption has increased by 25 times since last century.The generation of the world’s electricity still greatly depends on the burning of fossil fuels.The rapid growth of the “green house” gas emissions, such as carbon dioxide (CO2) is considered to be the main cause of global warming.Numerous scientific studies illustrate the very critical short and medium term consequences.5
6The Global Warming Effects The US obtains only 9% of its electricity from renewable fuel sources. The rest of its energy comes from coal, natural gas, oil and nuclear power. (nearly 50% from coal!)Total = 4,055 Billion KWhElectric Utility Plants = 63.0%Independent Power Producers & Combined Heat and Power Plants = 37.0%
7Efficient and Environmentally Friendly When installed to replace a 150w high pressure sodium vapor lamp, there is a net savings of up to 700 kwh per LED lamp each year.Utilizing just one energy efficient LED lamp can prevent the emission of 1.4 tons of carbon dioxide into our atmosphere.1.4 Tons of Carbon Dioxide Savings per Year per lamp7
8The Future of LightingBecause of all these positive attributes, LEDs are already being used, and will keep on replacing conventional lighting sources all over the world. This technology contributes significantly to saving energy and reducing harmful emissions into the environment and reduction in night sky pollution.8
10LED LIGHTINGAdvances in modern LED lighting have created new and exciting opportunities for many industries that depend on critical sources of electrical lighting and the accumulative operational costs associated with powering a lighting system.60 to 80% Less Energy ConsumptionMinimal Lifetime Lumen DepreciationLonger Lifetime – 50,000 hours +Directionality
11LED LIGHTING (continued) DurabilityNo traditional maintenance costs of re-lamping and re-ballasting in hard-to-access areas during the lifetimeUtilizes a solid state lighting element, eliminating several risk factors associated with HID lampsTurns on instantly, and are dimmableGenerate significantly less heat when compared to HID lampsReduce night sky light pollution
12LED LIGHTING (continued) Contain no lead mercury or other hazardous materials, and are made from fully recyclable materialsEven though a lower lumen reading is obtained with LED vs. HPS or Metal Halide; the LED will produce more useful light.
13Accurate way of measuring effective light Comparing the lumen output of LEDs to a discharge source is not an accurate way of measuring effective light output of a luminaire.HID lamp lumens are measured spherically, counting all the lumens being produced over 360 degrees.The discharge arc tube is not a point source and is difficult to optimize optically, making for poor light collection, efficiency and utilization.Many light fixtures have to redirect most of the lumens produced by a bulb, losing as much as 50% of the output.
14Accurate way of measuring effective light (continued) LEDs on the other hand are directional and have practically no wasted lumens .Virtually every LED lumen is directed and placed to maximize efficiency.A more accurate evaluation is to measure actual foot-candles or lux on the ground.Delivered light rather than generated light
15Human Vision / Seeable Light Photopic: relating to or being vision in bright light with light-adapted eyes that is mediated by the cones of the retina.Scotopic: relating to or being vision in dim light with dark-adapted eyes which involves only the retinal rods as light receptors.Mesopic: of or relating to vision under conditions of intermediate levels of illumination
16Photopic visionPhototop lumens refers to the amount of light emitted from a light source as measured by a light meter. The typical light meter is most sensitive to the yellow-green part of the color band.
17Scotopic visionThe rod receptors in the eye also receive light, called rod activated or scotopic vision.Scotopic light, which is rich in the blue portion of the spectrum, isn't measured by the typical light meter.Therefore, until now, lighting manufacturers have only measured light output based on the eye’s sensitivity to one type of vision (photopic).
18A true evaluation of lumen effectiveness Comes from the combination of the light received by the rods and cones (photopic, mesopic, and scotopic); or ‘seeable lumens.’Therefore, measuring only photopic lumens is misleading when comparing different colors of light.This is why even though a lower lumen reading is obtained with a LED vs. HID; the LED will produce more seeable light.
20Light temperature, Color Index and Intensity Emitted light has different colors detectable to the human eye.Light Color emitted effects how well and what we see.Color is important to safety and good usable visibility.Perception varies by individual. Actual is measured.How much light is enough?How much light is too much?Is the light really necessary, needed or in the right place?
21Light TemperaturesSo, why do we measure the hue of the light as a "temperature"? This was started in the late 1800s, when the British physicist William Kelvin heated a block of carbon. It glowed in the heat, producing a range of different colors at different temperatures. The black cube first produced a dim red light, increasing to a brighter yellow as the temperature went up, and eventually produced a bright blue-white glow at the highest temperatures. In his honor, Color Temperatures are measured in degrees Kelvin, which are a variation on Centigrade degrees.Color Temperature is a measurement in Degrees Kelvin that indicates the hue of a specific type of light source.
22Color Rendition or CRI index/number The Color Rendering Index , or CRI , of a source indicates how well it renders eight standard colors compared to a perfect reference lamp of the same color temperature. The comparison is only valid for lamps of the same color temperature. The CRI Index ranges from 1 to 100. A lamp with a CRI of 80 will render colors better than a lamp with a CRI of 50.
23Color Rendition or CRI index/number Get the picture?Find a Balance!
24So what direction do you go? Evaluate current lightingMaintenance costs.Power costs.SafetyPublic opinionEnvironmental Costs. Emissions and hazardous materials effectEnvironmental impact – People, Animal, Night Sky.What about the FUTURE?
25What’s the Difference Lamp Type Lumen/ Watt Rated Life (hours) CRI Ignition TimeCCTMajor DrawbackIncandes cent11 – 151, ,00040Instant2,800Very Inefficient, Short LifeMercury Vapor13 – 481, ,40045min3, ,000Least energy efficientHPS45 – 11012, ,000252,000Low CRILPS80 – 18010, ,00020min.1,800Metal Halide60 – 10010, ,000753, ,100High maintenance, high total ownership costLED Lamp1-150+50,000+1-99May have higher Initial Cost
27Metal Halide Lamps Properties More versatile than high pressure sodium – better light quality, good efficacy, range of sizeUseful lifetime: light color shifts to greenish/bluish color appearanceRun-up time of 3-5 minutes; RE-ignition time of minutesPay attention to limited burning positions!Control gear required- special fixture and ballast
31Metal Halide LampsMetal halide lamps, a member of the high-intensity discharge (HID) family of lamps, produce high light output for their size. By adding rare earth metal salts to the mercury vapor lamp, improved luminous efficacy and light color is obtained.Since the lamp output is omni-directional, luminaires are used to direct the light for different applications (flood lighting outdoors, or lighting for warehouses or industrial buildings).
32Metal Halide Lamps (continued) Like other gas-discharge lamps - such as the very similar mercury, vapor lamps - metal halide lamps produce light by passing an electric arc through a mixture of gases.In a metal halide lamp, the compact arc tube contains a high-pressure mixture of argon, mercury, and a variety of metal halides.The heat generated by the arc then vaporizes the mercury and metal halides, which produce light as the temperature and pressure increases.
33Metal Halide Lamps (continued) Common operating conditions inside the arc tube are PSI and °C.Like all other gas discharge lamps, metal halide lamps require auxiliary equipment to provide proper starting and operating voltages and regulate the current flow in the lamp.
34Metal Halide Lamps - Pros Same as sodium vapor+Better light quality than sodium vaporImproved luminous efficacy over sodium vaporRange of sizesWide spectrum, used for indoor growing applications & athletic facilitiesLifetime of 15, ,000 hours
35Metal Halide Lamps - Cons Operate under high pressure and temperature, and require special fixtures to operate safelyRisk of lamp explosion since failure of the arc tube is inevitably a violent eventColor temperature affected by the electrical characteristics and manufacturing variances in the bulb itselfConsiderable initial light output loss within the first 6 months
36Metal Halide Lamps – Cons (continued) Color shift over lifetime to bluish-green appearanceLimited burning positions. Improper orientation can reduce life by 5,000 hoursOngoing Maintenance CostsNeed to re-ballast to regulate the arc current and deliver the proper voltage to the arcPower-up time of 3-5 minutes. Re-ignition time of minutes
37Metal Halide Lamps – Cons (continued) Bulb will exhibit “cycling” prior to the end of service lifeHazardous waste disposal, as one 250-watt metal halide bulb can contain up to 38 mg of elemental mercuryBroken and unshielded bulbs could cause eye and skin injuries as the result of unprotected exposure to ultraviolet radiation
39Typical Radiation of an Incandescent Lamp Relative Generated Heat Over one hundred years of inefficient technology on Light generation:The visible light generated represents only 5-10% of the consumed energy, the remaining 90+% of the energy used is not visible light. It is wasted as heat!Only a small portion represents the visible color light wave that is intended to be emitted.Typical Radiation of an Incandescent LampVisible LightFilteredColorsColorRelative Generated Heat0nm1000nm2000nm3000nmLight Wavelength39
40Sodium Vapor LampsA sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. There are two varieties of such lamps: low pressure and high pressure.Low Pressure Sodium Lamps (LPS)Spectrum of a low-pressure sodium lamp.The intense orange band on the left is the atomic sodium D-line emission, comprising about 90% of the visible light emission for this lamp type.
41Sodium Vapor LampsHigh pressure sodium (HPS) lamps are smaller and contain additional elements such as mercury, and produce a dark pink glow when first struck, and a pinkish orange light when warmed.Some bulbs also briefly produce a pure to bluish white light in between. This is probably from the mercury glowing before the sodium is completely warmed.The sodium D-line is the main source of light from the HPS lamp, and it is extremely pressure broadened by the high sodium pressures in the lamp; due to this broadening and the emissions from mercury, colors of objects under these lamps can be distinguished.Spectrum of high pressure sodium lamp. The yellow-red band on the left is the atomic sodium D-line emission; the turquoise line is a sodium line which is otherwise quite weak in a low pressure discharge, but become intense in a high pressure discharge. Most of the other green, blue and violet lines arise from mercury.
42Sodium Vapor Lamps – Pros Around for long time.High Lumen output per watt.Many different types of fixtures available.Reasonable cost per lamp unit.Reasonable cost per replacement bulbs.Parts easily available.More energy efficient than Mercury Vapor.
43Sodium Vapor Lamps – cons High Temperatures for operation – potential fire hazardHazardous Waste disposal required.Old Technology, Based on current trends-Time is limited for a mandated change out.Fixed or very limited Light color temperatures.Re-lamp or re-ballast (ballast expensive) required at 18K to 20K hours.High maintenance costs.Current fixtures have Limited flexibility (can’t dim) and adjustability (IDA compliance).
44Sodium Vapor Lamps – cons (continued) Easily vandalized – fragile technology.Not very friendly (high intensity) for Dark Sky compliance – not directional lighting.Sensitive to installation procedures – loose wires, connections effect life (vibration).Bulb manufacturing is not consistent – bulb life may vary considerably.May have cycling issues depending on electrical sources/interferences.Very little to no color rending with the light produced.
45“We will make electricity so cheap that only the rich will burn candles.…” Thomas Edison 45