LEDsThe 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.)

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LEDsLEDs present a number of technical advantages over any other lighting systems, including:

1. LEDs produce a single color light, according to the specific application. Currently, they are produced in a variety of colors and temperatures.

2. Much of the energy utilized by the LED is converted to light instead of heat, and they don’t produce ultraviolet or infrared radiation.

3. LEDs concentrate (direct) the light flow and it is possible to focus it according to any need, making them more efficient.

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LEDsLEDs 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– An extremely efficient use of energy surpassing outdated lighting technologies.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.

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The 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.

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The 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!)

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Total = 4,055 Billion KWh

Electric Utility Plants = 63.0%

Independent Power Producers& Combined Heat and Power Plants = 37.0%

Efficient 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.

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1.4 Tons of Carbon Dioxide

Savings per Year per lamp

The Future of Lighting

• Because 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.

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The Future of Lighting Is Already Here

LED LIGHTING

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• Advances 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 Consumption– Minimal Lifetime Lumen Depreciation– Longer Lifetime – 50,000 hours +– Directionality

LED LIGHTING (continued)

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– Durability– No traditional maintenance costs of re-lamping and

re-ballasting in hard-to-access areas during the lifetime

– Utilizes a solid state lighting element, eliminating several risk factors associated with HID lamps

– Turns on instantly, and are dimmable– Generate significantly less heat when compared to

HID lamps– Reduce night sky light pollution

LED LIGHTING (continued)

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– Contain no lead mercury or other hazardous materials, and are made from fully recyclable materials

– Even though a lower lumen reading is obtained with LED vs. HPS or Metal Halide; the LED will produce more useful light.

Accurate way of measuring effective light

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• 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.

Accurate way of measuring effective light (continued)

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• 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

Human Vision / Seeable Light

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• 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

Photopic vision

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• Phototop 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.

Scotopic vision

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• The 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).

A true evaluation of lumen effectiveness

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• 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.

The Future isLED Lighting

Light 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?

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Light Temperatures • So, 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. 

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Color 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.

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Color Rendition or CRI index/number

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Get the picture?Find a Balance!

So what direction do you go?

• Evaluate current lighting• Maintenance costs.• Power costs.• Safety• Public opinion• Environmental Costs. Emissions and hazardous

materials effect• Environmental impact – People, Animal, Night Sky.• What about the FUTURE?

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What’s the Difference

Lamp Type• Lumen/

Watt

• Rated Life (hours)

CRI• Ignition

Time• CCT • Major Drawback

• Incandescent

11 – 15• 1,500 -

5,00040 • Instant • 2,800 • Very Inefficient, Short Life

• Mercury Vapor

13 – 48• 1,200 -

2,40045

• 2 - 15 min

• 3,200 - 4,000

• Least energy efficient

• HPS 45 – 110• 12,000 -

24,00025

• 2 - 15 min

• 2,000 • Low CRI

• LPS 80 – 180• 10,000 -

18,00020

• 2 - 15 min.

• 1,800 • Low CRI

• Metal Halide

60 – 100• 10,000 -

15,00075

• 2 - 15 min.

• 3,000 - 4,100

• High maintenance, high total ownership cost

• LED Lamp

1-150+ • 50,000+ 1-99 • Instant• 2600 -

6700• May have higher Initial Cost

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Metal HalideComparison

Metal Halide Lamps

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Properties• More versatile than high pressure sodium – better light quality, good

efficacy, range of size• Useful lifetime: light color shifts to greenish/bluish color appearance• Run-up time of 3-5 minutes; RE-ignition time of 15-20 minutes• Pay attention to limited burning positions!• Control gear required- special fixture and ballast

Efficiency

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Lighting efficiency 75 lm/W

The LUXEON® Advantage

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Luxeon Solid State Benefits

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Metal Halide Lamps

• Metal 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).

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Metal 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.

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Metal Halide Lamps (continued)

• Common operating conditions inside the arc tube are 70-700 PSI and 1000-3000 °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.

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Metal Halide Lamps - Pros

• Same as sodium vapor+– Better light quality than sodium vapor– Improved luminous efficacy over sodium vapor– Range of sizes– Wide spectrum, used for indoor growing applications &

athletic facilities– Lifetime of 15,000 - 20,000 hours

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Metal Halide Lamps - Cons

• Operate under high pressure and temperature, and require special fixtures to operate safely

• Risk of lamp explosion since failure of the arc tube is inevitably a violent event

• Color temperature affected by the electrical characteristics and manufacturing variances in the bulb itself

• Considerable initial light output loss within the first 6 months

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Metal Halide Lamps – Cons (continued)

• Color shift over lifetime to bluish-green appearance

• Limited burning positions. Improper orientation can reduce life by 5,000 hours

• Ongoing Maintenance Costs• Need to re-ballast to regulate the arc current and

deliver the proper voltage to the arc• Power-up time of 3-5 minutes. Re-ignition time of

15-20 minutes

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Metal Halide Lamps – Cons (continued)

• Bulb will exhibit “cycling” prior to the end of service life

• Hazardous waste disposal, as one 250-watt metal halide bulb can contain up to 38 mg of elemental mercury

• Broken and unshielded bulbs could cause eye and skin injuries as the result of unprotected exposure to ultraviolet radiation

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Incandescent andSodium Vapor

Incandescent Lamp (1879)

• 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.

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Over one hundred years of inefficient technology on Light generation:

Typical Radiation of an Incandescent Lamp

FilteredColors

VisibleLight

Color

Rel

ativ

e G

ener

ated

Hea

t

Light Wavelength

0nm 1000nm 2000nm 3000nm

Sodium Vapor Lamps

• A 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.

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Sodium Vapor Lamps

• High 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.

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Sodium 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.

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Sodium Vapor Lamps – cons

• High Temperatures for operation – potential fire hazard

• Hazardous 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).

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Sodium 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.

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“We will make electricity so cheap that only the rich will burn candles.…”

Thomas Edison

Thank you.Question & Answer