Despite the economy’s anemic recovery, hotels are spending a lot more time and money on environmental and sustainability initiatives, and integrating energy-efficient lighting is a popular place to start reducing both carbon footprint and energy costs.

Especially in times of economic hardship, making a quick return on investment (ROI) is critical. That makes lighting the low-hanging fruit when it comes to saving on energy costs, and demonstrating green leadership.

Plus, in terms of aesthetics, hotel guests may not perceive the sustainability of the low-VOC (volatile organic compounds) paint on the walls, but they will definitely take note of intrusive lighting that while designed for energy-efficiency has no regard for their visual comfort.

U.S. hotels, on average, spend nearly $4 billion, or $2,196 per available room, for energy each year – and lighting accounts for about 40 percent of the energy bill, according to the Environmental Protection Agency (EPA).

With U.S. energy costs averaging over $2 per square foot, according to the U.S. Green Building Council, there’s a big opportunity for hotel owners to boost revenue by using energy-efficient lighting products including compact fluorescent lights (CFLs), light-emitting diode (LED) fixtures and other green lighting products that provide significant savings.

Energy-efficient lighting systems also increase a property’s value and builds brand loyalty with customers as well as the fast return on investment.

For example, Boston’s Seaport Hotel, a 428-room luxury hotel, primarily serves groups and meetings (60- to 75-percent of the hotel’s business), using its 270,000 square feet of meeting space.

Boston's Seaport Hotel

It recently completed a CFL retrofit in each guest room realizing a 1.1-year return on investment due to reduced electricity cost. The CFL retrofit, coupled with the installation of a Smart Thermostat in each guest room, saves the hotel 1.9 million kWh in energy use each year.

Look at Wyndham Worldwide, one of the world’s largest hospitality companies, operating over 7,200 hotels on six continents. Its efforts integrating the use of CFLs and LED bulbs into their operations are hitting two goals at once.

“CFL and LED lights have continued to develop in quality, versatility, and color rendition, making them an increasingly attractive option to reduce energy use while enhancing the aesthetic environment for our guests,” said George Scammell, Wyndham’s vice president of design.

However, although CFL technology was a pioneer in green lighting technology, it is really just a temporary solution to energy-efficient lighting.

Its overall efficacy pales in comparison to LED technology — a comparable CFL lasts up to 10,000 hours, while quality white LEDs have a rated useful life of 50,000 hours or more — and CFLs are widely believed to lose any advantage over LEDs in the next five to ten years as LED lamps continue to be designed for more applications at a lower cost.

Indeed, enhanced guest satisfaction is a major driver for hotels implementing energy-efficient lighting upgrades.

Many of today’s advanced lighting products allowing guests to select light levels suitable and for specific activities. Research by Cornell School of Hotel Administration shows many guests tend to choose lower light levels, translating into greater energy savings.

InterContinental Hotels Group made replacing over 250,000 incandescent light bulbs with CFLs in guest rooms at company-managed hotels across its Americas region the cornerstone of its recent sustainability initiative.

The CFL lamps will save over $5 million in energy costs and have the environmental impact of removing carbon dioxide emissions equivalent to taking more than 17,000 cars off the road for a year.

Two ways Wyndham cuts energy use is incorporating energy-efficient bulbs and lighting fixtures with automatic sensors and standard procedures that turn off lights in areas not in use, such as restaurants after hougrs.

“Energy efficient lighting is now a best practice at Wyndham Worldwide,” said Faith Taylor, Wyndham’s vice president of sustainability. “Our brands and business units are increasingly selecting more energy efficient options, and as a result we have seen a continued reduction in our energy costs.”

Wyndham has achieved 16 percent energy savings through energy-efficient lighting products, according to its latest sustainability report.

Sustainability initiatives aren’t just for big hotels. Check out the Super 8 motel in Monroe, Wis. It installed energy efficient lighting throughout the building, along with motion-detection sensors in guest rooms, and cut energy usage by 10 percent.

Eco-friendly disposal of hotel lighting products

Another aspect of sustainable lighting for hotels is how to dispose of them in a safe manner, since many existing energy-efficient lighting choices contain toxic materials that can be harmful to public health and the environment if released. For example, incandescent lamps may contain lead and CFL bulbs and tubes contain mercury, which raises another reason LED technology is superior to CFLs – they contain no lead or mercury.

Despite the fact that growing demand for energy-efficient fluorescent lighting means the amount of mercury-containing waste produced is increasing, the EPA has concluded that shifting from incandescent lighting to compact fluorescent lighting will result in a net reduction in total U.S. mercury emissions due to the reduction of coal-fired electricity generation, a process that releases mercury into the atmosphere.

The Bulb Eater

When Marriott International, Inc. sought an environmentally safe process for disposing and recycling its fluorescent lamps on-site for 500 Marriott-branded hotels, it chose Air Cycle Corporation’s EasyPak Recycling Program and the Bulb Eater, a device that crushes over 1,000 fluorescent lamps (depending on size of lamps) and packs them into a 55-gallon drum – providing savings of up to 50 percent on recycling costs.

The process is fully enclosed and filtered, so that the glass, aluminum, and mercury vapors are contained. When full, the drums are picked up and transported to an EPA-approved lamp recycling facility.

“We believe that Air Cycle offers our hotels and easier and more eco-friendly option to dispose of fluorescent bulbs,” said Paul Hildreth, Marriott’s project director of engineering. “It’s a great solution for hotels in states where regulations are continuously evolving to meet environmental demands.”

One such state where lighting recycling regulations are already tough is California.

Concerned about the risk of mercury and lead exposure to the environment that could result from the disposal of used fluorescent and some incandescent lights, the California State Legislature enacted legislation in 2010 that limits the amount of mercury and other hazardous substances allowed in general purpose lights, i.e. “lamps, bulbs, tubes, or other electric devices that provide functional illumination for indoor residential, indoor commercial, and outdoor use.”

The legislation is modeled after European Union legislation called the RoHS Directive (Restriction of the use of certain hazardous substances in electrical and electronic equipment).

The law restricts the use of seven hazardous substances in the manufacture of electrical and electronic equipment:

• Lead (Pb)
• Mercury (Hg)
• Cadmium (Cd)
• Hexavalent chromium (Cr6+)
• Polybrominated biphenyls
• Polybrominated diphenyl ether (PBDE)
• Acrylamide

Sources used for this article:

• US Green Building Council
• Environmental Protection Agency (EPA)
• Wyndham Worldwide
• Cornell School of Hotel Administration
• California Department of Toxic Substances Control

A lighting ballast has three primary functions:

1. establish an electric arc through the lamp
2. limit current through the lamp after ignition
3. compensate for variations in line voltage and ensure consistent lumen output

Core-and-coil vs. Electronic Ballasts

The first lighting ballast technology used to operate MH lamps were electromagnetic, also known also as a “core and coil” ballast for bulky, heavy, magnetic core of laminated steel plates wrapped in copper windings.

In the 1980s, more energy-efficient, solid-state, electronic ballasts were developed using semiconductors as the primary means to control lamp starting and operation.

There are four main reasons electronic ballasts are superior to electromagnetic ballasts:

1. Increased light output increased – Electronic ballasts increase the mean lumen output of HID lamps. A 400 W metal halide lamp operated with an electronic ballast produced 15% more light output after 8,000 hours than the same lamp with an electromagnetic ballast.
2. Use less energy to operate – A typical magnetic ballast for a 400 W metal halide lamp consumes 50–70 W, whereas an electronic ballast consumes as little as 5–20 W.
3. Lamp life is up to 30% longer – Electronic ballasts keep MH lamps brighter for a longer period of time than the same lamps with magnetic ballasts, which lowers lamp replacement costs and makes them practical for high-bay, indoor applications.
4. Provide dimming option – Electronic ballasts with dimming provide additional savings when full light output is not required. Some electronic ballasts are continuously dimmable down to 50% of lamp power.

Other benefits of electronic ballasts include:

• improved efficiency and color stability
• lower warm-up and restrike times
• smaller size and lower weight
• much less lamp flicker
• less lamp noise
• improved lumen maintenance
• elimination of harmonic distortion in the supply current
• the capacity to operate multiple luminaires off one ballast

Probe- and pulse-start ballasts

When lamps are cold, the ballast’s operating voltage may not be enough to create an arc and rely on two primary starting methods: probe-start and pulse-start.

Traditional MH lamps use probe-start, electromagnetic ballasts technology, which employs the use of two operating electrodes and a third, starting probe electrode in the arc tube.

Probe-start ballasts start lamps when it discharges a high open circuit voltage between the starting probe and one of the operating electrodes. Once the lamp is started, a bi-metal switch shuts off the starting probe electrode from the circuit.

Market demand for probe-start ballasts began to wane once industry realized the third electrode and other moving parts such as the switch led to inconsistencies in the lamp’s lumen and color output over their lifetimes.

The development of pulse-start electronic and electromagnetic ballasts, which create arcs by generating a high-voltage pulse using a circuit called an igniter, also moved industry away from probe-start ballasts.

Benefits of pulse start Metal Halide lamps

A metal halide lamp using an electronic ballast is about 70% more energy efficient than typical standard HID electromagnetic ballasts with probe-start metal halide lamps.

Probe-start/pulse-start differences

Source: Department of Energy

Other benefits of pulse-start ballasts include:

• lifetime of up to 15,000 hours – 50% longer than probe-start MH lamp of same wattage
• maintain higher, consistent CRI than probe-start ballasts
• superior cold-starting capability, starting at temperatures as low as -40°F
• re-start, referred to as re-strike, times can be four times as fast as probe-start MH lamps

MH lamp warm-up and restrike times

Source: Department of Energy

New standards eliminate probe-start devices

The Energy Independence and Security Act of 2007 mandated significant changes for metal halide lighting fixtures using certain ballasts.

Starting in 2009, probe-start magnetic ballasts and lamps for operation of lamps up to 400 W were virtually eliminated from new luminaires to meet new efficiency standards.

The law requires a minimum ballast efficiency of 88% for pulse start ballasts and a minimum ballast efficiency of 94% for magnetic probe start ballasts. Compliant luminaires now bear a capital “E” printed in a circle on their packaging and ballast label.

Caption: Thousands of ceramic metal halide lamps installed on Chicago streets, alleys Credit: Philips.

When the city of Chicago was looking in 2010 for a new energy-efficient standard for street and alley lights, it chose ceramic metal halide (CMH) lamps, becoming the first large U.S. city to use the new lighting technology.

This relatively new light source, touted for being compact, efficient, and powerful, is part of the high-intensity discharge (HID) lighting category, which offers the highest efficacy and longest life of any lighting type, and saves up to 90% of lighting energy when they replace incandescent lamps.

Chicago finished installing 11,000 CMH lights in 300 miles of alleys and 5,300 streetlamps on famous Lake Shore Drive and Western Avenue in August 2011. The city estimates to save nearly $750,000 in annual energy costs and reduce carbon dioxide emissions by more than 6,600 metric tons every year.

High Intensity Discharge (HID) lighting

Metal halide lamps, both the traditional quartz and more recent ceramic types, have superior color rendition (80-96 CRI) among HID lighting types, and are increasingly in demand for large, high-bay indoor areas, such as big-box retail stores, gymnasiums and sports arenas, as well as indoor retail track and display lighting and even headlights in luxury cars. More outdoor areas, such as streets, security lights and car lots, are also being lit with HID lighting.

How HID Works

HID lighting produces bright, white light using electricity arcs between tungsten electrodes housed in a translucent or transparent fused quartz or ceramic arc tube, also called a burner, enclosed within an outer bulb.

CMH Bulb (courtesy DOE)

The tube contains a mixture of various gases and metal halide salts. For instance, CMH tubes heat a mixture of mercury, argon and halide salts.

As the arc heats up it vaporizes the metal salts to form a plasma, which intensifies the light produced by the arc and cuts down the power consumption. HID lamps are non-directional and, similar to fluorescent lamps, require a ballast to start and maintain their arcs.

Compared with incandescent and fluorescent lighting, HID lamps have a higher luminous efficacy (how well a light source produces visible light) since a bigger proportion of their radiation is in visible light, not heat.

Types of HID lighting

There are three common types of HID lamps:

1. Mercury vapor lamps (MV)
2. High-pressure sodium lamps (HPS)
3. Metal halide lamps (MH)
1. Quartz metal halide (QMH)
2. CERAMIC METAL HALIDE (CMH)

MH lamps have a more full light spectrum than HPS or MV lamps, the latter considered to be older and less efficient technology. And, although MH lamps use fewer watts, they are brighter than the yellowish light produced by HPS lamps.

Qualities of HID lighting types:

Source: Department of Energy

History of CMH lighting

The history of CMH lamps can be traced back to a 1962 General Electric patent for an arc lamp called a Multi Vapor Metal Halide. A British firm, Thorn Lighting Group, exhibited the world’s first CMH lamp at the Hannover World Light Fair in 1981. Despite the good color properties, marketing the lamp was not possible because it required a unique ballast that was not available on the market.

CMH lamps were not introduced commercially until 1994 when engineers at lighting manufacturer Philips overcame the problems heat was creating for the tube’s seals.

“We call them ‘halogen killers’ because their color is so good they can tackle retail applications like spots and tracks,” said Bill Ryan, HID product manager at Philips, at the time. Other manufacturers soon followed. “We’re very excited about CMH,” said Jerry Flauto, General Electric’s senior product specialist/HID. “It gives us great color stability, good efficacy and long life.”
Source: “Metal Halide – Advances & Improvements,” by David Houghton, PE, Contributing Editor, Architectural Lighting Magazine.

Quartz or Ceramic?

MH arc tubes are made of either quartz or ceramic. Traditional quartz metal halide (QMH) arc tubes are similar in construction and appearance to MV lamps but by adding metal halide gases to mercury gas inside QMH lamps, the result is higher light output, more lumens (a measure of the total amount of visible light emitted by a source) per watt and better color rendition.

Lumens per watt (lpW) is a ratio expressing the luminous efficacy of a light source. Check out the differences below of typical lamp efficacies:

• Thomas Edison’s first lamp – 1.4 lpW
• Incandescent lamps – 10-40
• Halogen incandescent lamps – 20-45
• Fluorescent lamps – 35-105
• Mercury lamps – 50-60
• Metal halide lamps – 60-120
• High-pressure sodium lamps – 60-140

(The values above for discharge lamps do not include the effect of the ballasts, which must be used with those lamps. Taking ballast losses into account reduces “system” or lamp-ballast efficacies typically by 10-20% depending upon the type of ballast used.Source: GE Lighting)

CMH arc tubes are more resistant than standard QMH tubes to the corrosion metal halide salts create within the arc tube. This allows CMH tubes to operate at higher temperatures than QMH tubes, boosting performance and quality-of-light characteristics as lumen maintenance (10-30 percent higher), lamp color-shift and spread stability, Color Rendering Index (CRI) and dimming.

CMH lamps have a CRI of 80-96. Light sources with a CRI of 80 and higher are considered to have excellent color rendering. Exact CRI depends on the mixture of metal halide salts in the arc tube.

Typical CRI values for selected light sources

Source: Department of Energy

Some low-wattage CMH lamps may also be used where incandescent lamps may have been preferred for their small dimensions and color rendering qualities, according to the DOE.

Other key characteristics of CMH lamps:

• CMH lamps emit white light in several correlated color temperatures (CCTs) ranging from 3000 to 5200 Kelvin
• 6,000-20,000 hour rated lifespan
• typical power ratings range from 20 to 400 W
• use as little as 20% energy compared to incandescent and halogen light bulbs

Drawbacks to CMH

CMH lamps do have limitations, however. Throughout their lifetime, all metal halide lamps experience reduced light output and some increase in power consumption.

They, and their standard counterpart, can also take up to 10 minutes to start, not making them suitable for use with motion detectors. Because of the delay in strike time, manufacturers advise not completely shutting off them except for extended periods of non-occupancy.

Competing in the market

CMH lamps are quickly grabbing market share from their HID-cousin, HPS lamps, in the marketplace for outdoor applications such as street lights. A main reason for this is the growing demand for the whiter light of MH lamps over the less-desired, yellowish color of sodium lamps, which also u.

That certainly appears to be the case for the city of Chicago. Each CMH fixture it purchased was estimated to cut electricity use between $40 and $70 annually, with a lifespan of two to three years longer than the typical high-pressure sodium street lighting, which lasts about 5 years, according to a release from the city’s transportation department.

The agency said the CMH lamps cut down on “sky glow” (light traveling up, instead of down) by between 50 to 100 percent, depending on the type of fixture. They also reduce “light trespass,” or light shining into unwanted areas, like nearby buildings or homes.

Reporting on the installment of CMH lamps in the city, the Chicago Tribune cited another reason city officials wanted to replace the street lights.

“Since the large-scale adoption of sodium vapor lights in the United States and elsewhere, studies have been done showing that they can hamper police identification of suspects because they decrease people’s ability to tell one color from another, because they make everything look orange at night,” the newspaper reported.

The future looks bright for CMH lighting in a growing number of applications as manufacturers ramp up innovation in the category.

For instance, General Electric’s ChromaFit are metal halide lamps, sold in both traditional quartz and CMH versions, that operate on high-pressure sodium ballasts, giving users the option of switching from the yellowish glow of HPS to the white color of MH lighting.

SOURCES:

• Department of Energy
• GE Lighting Institute
• International Energy Agency
• Rensselaer Polytechnic Institute’s Lighting Research Center
• City of Chicago, Department of Transportation
• Wikipedia: Ceramic discharge metal-halide lamp

RELATED ARTICLES BY LUMENISTICS:

• LUMENS: The new way to shop for light
• What is Color Rendering Index (CRI)

Merging photopic, scotopic vision cuts energy costs, boosts visibility perception

The science of measuring light, in terms of how the human eye perceives its brightness, is called photometry.

The eye has two primary light-sensing cells in the retina, known as photoreceptors, called rods and cones, referring to their geometric shapes.

• Cones process visual information under daytime, or photopic light levels
• Rods are used in near-complete darkness, referred to as scotopic conditions

Photopic light levels have excellent color discrimination, where colors seem the same under scotopic vision.

… lamps with high S/P ratios provide sharper vision both outdoors and indoors. So, a 200-watt magnetic induction lamp would appear just as bright or brighter than a sodium vapor or metal halide of twice the wattage.

The ratio of scotopic luminance (or lumens) versus photopic luminance in a lamp is called the S/P ratio, which is a multiplier that determines the apparent visual brightness of a light source as well as how much light a lamp emits that is useful to the human eye, referred to as visually effective lumens (VELs).

Scotopic and Photopic Ratios

Generally, lamps with high S/P ratios provide sharper vision both outdoors and indoors. So, a 200-watt magnetic induction lamp would appear just as bright or brighter than a sodium vapor or metal halide of twice the wattage.

Here’s the math showing a 50% energy reduction:

• A 400w Metal Halide lamp has a manufacturer’s rating of 54.6 lumens per watt; so, 400 x 54.6 = 21,840 lumens x 1.497 (S/P ratio) = 32,541 VELs.
• A 200w Induction lamp has a manufacturer’s rating of 81 lumens per watt; so, 200 x 81 = 16,200 lumens x 1.96 (S/P ratio) = 31,752 VELs.

Mesopic – combining rods and cones

Between photopic and scotopic light levels is a range called mesopic, which are low – but not dark – outdoor lighting conditions where both cones and rods combine photopic and scotopic response to process visual information. Most artificial light systems emit outdoor light levels in the mesopic range.

Mesopic

Now, as we mentioned in a previous article, the seven color bands produced when sunlight is refracted through a prism – red, orange, yellow, green, blue, indigo and violet – are part of the electromagnetic spectrum that’s visible to the human eye and all have different wavelengths.

To describe how the eye responds to those wavelengths, the lighting industry uses the term luminosity function, also called luminous efficiency function.

Photopic luminosity function best approximates the response of the human eye in daylight and scotopic luminosity function is used to describe the eye’s response to extremely low light (nighttime) levels.

Scotopic - Photopic - Mesopic

Commercial photometry is important for lighting installers and their clients in choosing the best locations to install fixtures as well as ensuring maximum efficiency of lighting systems.

Problem is, commercial photometry only considers the photopic luminosity function, which was established in 1924 by the International Commission on Illumination (CIE), and has almost always been recognized as underestimating how the blue and violet end of the spectrum – where the eye shifts in scotopic conditions – contribute to perceived luminance.

In the past, lighting manufacturers used light meters to determine lumen output, or luminous efficacy, of a fixture in order to gain maximum energy efficiency. But these devices relied only on photopic conditions, in keeping with the decades-old assumption that light sensitive rods only kicked in at low-light, or nighttime, conditions.

For lighting installers and their clients, that meant the effectiveness of certain lighting products used in nighttime applications, such as street lighting, in terms of energy efficiency and visual safety, was being underestimated.

LED Street Lighting

In addition, relying only on photopic luminous function to measure nighttime illuminations requires some light sources to use excessive energy to generate the necessary light level.

Realizing the potential cost-savings that an alternative measure of lighting scenarios could produce coupled with the fact that photopic and scotopic were not mutually exclusive and that rods were active, not only in low-light but also during interior light levels, researchers set out to develop a new measurement.

Bridging the gap between scotopic and photopic

Researchers at the Rensselaer Polytechnic Institute’s Lighting Research Center (LRC) developed a “Unified System of Photometry,” which integrates both the scotopic and photopic luminous efficiency functions into a measurement system that can be used for any light level, including mesopic, perceptible to the eyes.

LRC researchers estimated that about half of U.S. streetlights could cut energy consumption by about 50 percent – annually saving one billion kilowatt hours – using a Unified System of Photometry to design more energy efficient lamps, including LEDs, without sacrificing perceptions of visibility and safety.

Cutting energy consumption in street lighting

Field demonstration results in rural and suburban areas of Connecticut, Massachusetts, and Texas verified that by implementing the Unified System of Photometry the street lighting system consumed 30 to 50 percent less electric power and the residents believed they could see better and said they felt safer, when compared to lighting systems designed using the traditional system of photometry.

Commenting on the field tests, LRC’s Director of Energy Programs, Peter Morante, described how, in nighttime conditions, the human eye is more sensitive to short-wavelength light, which produces cool tones like blue or green, as opposed to long-wavelength light, which produces warm tones like yellow and red.

“By replacing traditional, yellowish high-pressure sodium (HPS) lights with ‘cool’ white light sources, such as induction, fluorescent, ceramic metal halide, or LEDs, we can actually reduce the amount of electric power used for lighting while maintaining or even improving visibility in nighttime conditions,” Morante said.

Sources for this article and further reading:

• http://www1.eere.energy.gov/buildings/spectrally_enhanced.html
• http://gaia.lbl.gov/btech/papers/42327.pdf
• http://www.lrc.rpi.edu/researchAreas/pdf/GrotonFinalReport.pdf
• http://knol.google.com/k/environmental-aspects-of-magnetic-induction-lamps
• http://www.gelighting.com/na/business_lighting/education_resources/literature_library/white_papers/download/photopic_scotopic_lb.pdf

Illuminance is the amount of light striking a surface – also known as incident light, where the “incident” is the beam of light actually landing on the surface.

Illuminance is calculated as the density of lumens per unit area and is expressed using footcandles (lumens/square foot) in the United States or the metric version, lux (lumens/square meter), elsewhere. Illuminance is measure using a light meter.

Illuminance is the amount of light striking a surface – also known as incident light, where the “incident” is the beam of light actually landing on the surface.

Lumens are a measure of the quantity of light, referred to as luminous flux or just flux, emitted by a light source. For example, a dinner candle provides about 12 lumens. A 60-watt incandescent bulb provides about 840 lumens.

Footcandles and Lux

A footcandle is a unit of illuminance, or light energy, produced by one lumen hitting a one-square-foot area. It literally means the amount of light on a surface one foot from a standard candle. One lux is equal to one lumen per square meter, so 10 lux is equal to about one footcandle.

For perspective, illuminances produced by daylight cover a broad range, from 150,000 lux on a sunny day in the summer to 1,000 lux on a gray, overcast day in winter. The typical illuminance that results from moonlight is about 0.3 lux.

When considering lighting applications, illuminance is used to measure the amount of light reaching an object such as a desk or wall.

For instance, the illuminance value for a typical home or office is between 30 to 50 footcandles (300 to 500 lux).

The closer to a light source the illuminated area is, the higher the Illuminance value. Horizontal illuminance describes the amount of light landing on a horizontal surface, such a desk, and vertical illuminance describes the illuminance landing on a vertical surface, such as a wall.

Illuminance values for lighting applications depend on how complex the visual tasks are being performed.

So, walking down a hallway range will require an illumination value much lower than a specialized task where visual performance is critically important, such as assembling small pieces of machinery or reading fine print.

Illuminance vs. Luminance

Don’t confuse illuminance with luminance. The former measures the incident of light, luminance measures what leaves, or is reflected from, the surface.

Luminance is also considered the human perception of brightness, or how bright we perceive the light that is reflected from the surface.

• Related Article: LUMENS: The new way to shop for light

Light, as we humans see it, is electromagnetic radiation that’s visible to the human eye. It’s the part of the electromagnetic spectrum we call “visible light”.

The electromagnetic spectrum is the range of all frequencies, or wavelengths, of electromagnetic radiation – from very low energy frequencies like radio waves, to radiation with very high-energy frequencies such as gamma rays.

Sunlight is described as full-spectrum light and includes the range of wavelengths necessary to sustain life on Earth: infrared, visible and ultraviolet (UV).

But the human eye only responds to the visible light component, which lies between infrared and ultraviolet radiation, and emits tiny wavelengths – just 400 to 700 nanometers (nanometer = billionth of a meter).

Visible light includes the spectrum of seven color bands produced when sunlight is refracted through a prism: red, orange, yellow, green, blue, indigo and violet.

For years, ever since the workforce largely migrated from farms to factories, the lighting industry sought to develop electric, artificial light sources that mimicked the properties of sunlight.

For years the lighting industry has sought to develop electric, artificial light sources that mimicked the properties of sunlight.

In the 1960s, photobiologist Dr. John Ott coined the term “full-spectrum lighting” to describe light sources emitting a full spectrum of natural light, which included both ultraviolet and visible light, and promoting the same health benefits of sunlight in humans, animals and plants.

When choosing artificial lighting products for office or home, the marketing term “full-spectrum” implies the lighting product emulates natural light in a continuous spectral power distribution (SPD), which represents the radiant power of a light source as a function of wavelength, without the ups and downs in radiant energy associated with fluorescent and metal halide lamps.

Drawbacks of full-spectrum lighting

Lighting sources marketed as full-spectrum are generally less efficient than conventional lamps. For instance, full-spectrum T12 fluorescent lamps have an efficacy of up to 40 percent lower than conventional triphosphor fluorescent lamps.And, full-spectrum lamps also cost a premium over light sources not marketed as full-spectrum but have a nearly identical SPD.

Today, there are numerous lighting products marketed as full-spectrum light sources that simulate both the visible and ultraviolet spectrum of natural light.

So, exactly what benefits do consumers get for going with more expensive full spectrum lighting, which has less efficacy?

The LRC’s National Lighting Product Information Program (NLPIP) reviewed promotional claims for full spectrum light sources from various manufacturer and retailer websites, which revealed these top claimed benefits:

• Improved color perception
• Improved visual clarity
• Improved mood
• Improved productivity
• Improved mental awareness
• Improved retail sales

Problem is, lighting manufacturers generally come up with their own definition of full spectrum lighting, according to the Lighting Research Center. That can create confusion for consumers, who simply have no way of knowing exactly what benefits, if any, they are receiving from full-spectrum lighting products.

Sources:

• Lighting Research Center

As advances in solid state lighting products, especially LEDs, continue to push into the marketplace displacing incandescent and fluorescent lighting products, it only stands to reason that evaluation methods for these products, such as the measurement of color fidelity, or CRI – now almost 50 years old – isn’t cutting it.

As we mentioned in a previous article, CRI has been found to be an inaccurate, unreliable predictor of color preference of solid-state lighting products such as light-emitting diodes (LEDs), which emit a much different light than fluorescent or HID lamps, and can result in lower or even negative CRI values for some of them.

For instance, some LED products with a CRI as low as 25 can produce white light that actually make object colors appear more vivid. Also, CRI can give high scores to LED light sources that render some saturated object colors, particularly red, very poorly.

And because CRI only evaluates color rendering, also known as color fidelity, it ignores other aspects of color quality, such as chromatic discrimination and observer preferences.

Color Quality Scale debuts

To help remedy these drawbacks, CIE established a technical committee in 2006 to develop and recommend a new color rendering metric.

In June 2010, Wendy Davis, chair of the committee, debuted the Color Quality Scale (CQS), which she developed with colleagues at the National Institute of Standards and Technology (NIST), the federal technology agency that works with industry to develop and apply technology, measurements, and standards.

The proposed metric is believed to offer a superior indication of what humans perceive as superior color rendering compared to CRI specifications.

Where CRI relies on a evaluation of how a white light source illuminates eight pastel colors, CQS uses 15 colors, including samples with much deeper color – such as deep reds where CRI proves especially inaccurate.

15 color samples used by the Color Quality Scale (CQS)

Endorsing the new CQS measurement, James Brodrick, lighting program manager for the DOE’s Building Technologies Program, said, “Regardless of the type of light source, the CQS represents the color rendering qualities of white light more accurately than the CRI and is a far better predictor for colors that have a high red content, such as skin color and wood finishes – which is one of the CRI’s major weaknesses.”

The proposed CQS, still being debated at the CIE’s committee level, is intended to eventually replace the CRI as a new international standard for general illumination evaluation of traditional lighting technologies and solid state lighting sources.

But the new metric may never see the light of day.

Is CQS headed toward failure?

Wendy Davis, chair of the CIE’s TC-1-69 technical committee

While it gains support in the U.S. lighting industry, the committee is deadlocked between those who see it as a solution for measuring color quality of solid-state lighting and those pushing for a metric that is more similar to CRI, said Davis, who recently left her position at NIST to take a position as a senior lecturer and illumination program director at the University of Sydney.

“We’ve been working for over five years now and have been unable to reach an agreement, so far,” Davis told Lumenistics. “The CIE requires unanimous agreement to issue a recommendation, and this committee has [approximately] 40 members.  As you can imagine, it’s been tough. I’m not sure if the committee will be successful.”

It certainly hasn’t been in the past. The CIE has attempted to revise the CRI several times throughout the 1980s and 1990s “and every committee ended in failure,” Davis said. “If that happens now, which is very much a possibility, I wouldn’t be surprised if some other standards organization were to take up the issue.”

So, for now, CRI remains the only internationally recognized color rendering system. Whether the lighting industry, especially the solid-state category, will continue to use it for evaluating lighting applications remains to be seen.

####

Metric’s future in limbo as proposed new standard stalls in committee

There are two key measures used when evaluating lighting sources:

• Color Rendering Index (CRI)
• Correlated Color Temperature (CCT)

CCT measures the color of a light source using Kelvin (K) temperature, which indicates the warmth or coolness of a lamp’s color appearance. The lower the Kelvin temperature (2700–3000 K), the warmer the color of the light, while the higher the temperature (3600–5500 K), the cooler, and more bluish, the light appears.

Lighting Facts label

Typically, warm light sources are used in retail, restaurants and home applications to create a sense of comfort and warmth. Cooler lighting sources provide a higher contrast and are preferred for offices and similar applications to create a sense of alertness.

Rendering natural color

But CCT does not indicate how natural the colors of objects appear when illuminated by a light source. In fact, two lamps can have the same CCT but render colors much differently.

Natural and realistic color rendering, also called color accuracy, is essential for illumination applications such as retail, where it’s important that products render the correct color and appear inside the store just like they do outside in daylight.

Courtesy: Department of Energy

Natural and realistic color rendering is also called color accuracy and is essential for illumination applications.

Over 40 years ago, the Austria-based International Commission on Illumination (CIE), the standards-setting body of the global lighting industry, developed CRI to indicate how colors appear under different light sources, particularly fluorescent and high-intensity discharge lamps, and to best correspond them to a human’s perception of color quality.

Measuring color shift

Because most objects are not a single color but a combination of several, light sources lacking in certain colors can change the apparent color of an object, also known as color shift.

Specifically, CRI measures on a scale of 0 to 100 how a light source shifts the location of eight specified pastel colors compared to the same colors lit by a light source of the same CCT.

Eight color samples used in calculating CRI

A CRI of 100, or perfect color rendering, means the light source renders the eight colors exactly how the reference light source renders them. A light source with a CRI of 80 or higher is considered by the lighting industry to provide excellent color rendering for most indoor applications.

Typical CRI values for commonly used light sources:

8 color samples used in calculating CRI

Note: a. T8 lamps with CRIs in the 90s offer lower efficacy than other T8 lamps.

Source: Department of Energy

CRI: the color quality metric of choice?

CRI is the only color rendering metric used by the global lighting industry, and is generally considered to be a more important lighting quality than CCT.

Yet, over the years, as new technologies made their way to the marketplace, and demand for better lighting placed more scrutiny on the products available, shortcomings of CRI became evident and too big to ignore.

CRI Drawbacks

One problem industry has with CRI is that it can give rather high scores to light sources that render some saturated object colors, particularly red, very poorly.

CRI has also been found to be an inaccurate, unreliable predictor of color preference of solid-state lighting products such as light-emitting diodes (LEDs), which emit a much different light than fluorescent or HID lamps, and can result in lower or even negative CRI values for some of them. For instance, some LED products with a CRI as low as 25 can produce white light that actually make object colors appear more vivid.

And because CRI only evaluates color rendering, also known as color fidelity, it ignores other aspects of color quality, such as chromatic discrimination and observer preferences.

CQS Debuts

To help remedy these drawbacks, CIE established a technical committee in 2006 to develop and recommend a new color rendering metric.

In June 2010, Wendy Davis, chair of the committee, debuted the Color Quality Scale (CQS), which she developed with colleagues at the National Institute of Standards and Technology (NIST), the federal technology agency that works with industry to develop and apply technology, measurements, and standards.

The proposed metric is believed to offer a superior indication of what humans perceive as superior color rendering compared to CRI specifications.

Where CRI relies on a evaluation of how a white light source illuminates eight pastel colors, CQS uses 15 colors, including samples with much deeper color – such as deep reds where CRI proves especially inaccurate.

15 color samples used by the Color Quality Scale (CQS)

Endorsing the new CQS measurement, James Brodrick, lighting program manager for the DOE’s Building Technologies Program, said, “Regardless of the type of light source, the CQS represents the color rendering qualities of white light more accurately than the CRI and is a far better predictor for colors that have a high red content, such as skin color and wood finishes – which is one of the CRI’s major weaknesses.”

The proposed CQS, still being debated at the CIE’s committee level, is intended to eventually replace the CRI as a new international standard for general illumination evaluation of traditional lighting technologies and solid state lighting sources.

But the new metric may never see the light of day.

Is CQS headed toward failure?

Wendy Davis, chair of the CIE’s TC-1-69 technical committee

While it gains support in the U.S. lighting industry, the committee is deadlocked between those who see it as a solution for measuring color quality of solid-state lighting and those pushing for a metric that is more similar to CRI, said Davis, who recently left her position at NIST to take a position as a senior lecturer and illumination program director at the University of Sydney.

“We’ve been working for over five years now and have been unable to reach an agreement, so far,” Davis told Lumenistics. “The CIE requires unanimous agreement to issue a recommendation, and this committee has [approximately] 40 members.  As you can imagine, it’s been tough. I’m not sure if the committee will be successful.”

It certainly hasn’t been in the past. The CIE has attempted to revise the CRI several times throughout the 1980s and 1990s “and every committee ended in failure,” Davis said. “If that happens now, which is very much a possibility, I wouldn’t be surprised if some other standards organization were to take up the issue.”

So, for now, CRI remains the only internationally recognized color rendering system. Whether the lighting industry, especially the solid-state category, will continue to use it for evaluating lighting applications remains to be seen.

###
Sources:

• GE Lighting website
• US Department of Energy website
• National Institute of Standards and Technology website
• Lighting Research Center website

Starting Jan. 1, 2012, new federal regulations will require the most common light bulbs to be more energy efficient. Specifically, bulbs must produce the same amount of lumens (light output) for less wattage (energy consumption).

Lumens - the new way to shop for light

All packages of light bulbs sold in stores after the New Year will carry a new Lighting Facts label – modeled after the “Nutrition Facts” labels on food packages –  to help consumers compare the brightness and estimated energy costs of various types of light bulbs.

The new label will give consumers information about brightness, known as lumens, energy cost, lifetime, light appearance (“warm” or “cool” light), wattage, and whether the bulb contains mercury.

Traditional, incandescent light bulbs will not meet the new efficiency standards and will no longer be available at most stores.

Traditional 75 watt incandescent light bulbs will no longer be available as of Jan. 1, 2013, and traditional 40 and 60 watt incandescent light bulbs will no longer be available as of Jan.1, 2014.

To measure the brightness, or lumen levels, of lighting types use this rule of thumb:

• Replace a 100-watt incandescent bulb with an energy-saving bulb that gives you about 1600 lumens
• Replace a 75W bulb with an energy-saving bulb that gives you about 1100 lumens
• Replace a 60W bulb with an energy-saving bulb that gives you about 800 lumens
• Replace a 40W bulb with an energy-saving bulb that gives you about 450 lumens.

Understanding the fundamentals of solid state lighting

The light-emitting diode (LED), one of the most energy-efficient and rapidly-developing lighting technologies, has the potential to fundamentally change the future of lighting in the United States.

That’s according to the Department of Energy (DOE), which also predicts that by 2027 widespread use of LEDs, also called solid state lighting, could save the equivalent annual electrical output of 44 large electric power plants (1,000 megawatts each), and a total savings of more than $30 billion at today’s electricity prices.

“The potential of LED technology to produce high-quality white light with unprecedented energy efficiency is the impetus for the intense level of research and development currently supported by the U.S. Department of Energy,” the federal agency said.

Origins of LED

In 1962, General Electric researcher Nick Holonyak, Jr., invented the first practical LEDs, which were used as red indicator lamps in electronic devices.

While standard, incandescent bulbs produced light using a glass enclosure containing a filament, which would eventually burn out, the new LED technology used tiny light bulbs illuminated by the movement of electrons in a semiconductor chip, called electroluminescense.

Industry was interested in the new technology because of its advantage over standard light bulbs: uses less power, has longer lifetime, produces little heat, and emits colored light.

Over the next two decades, the evolution of the technology and improvements in manufacturing efficiency led to the development of more colors, wider acceptance in the marketplace, and the growth of more applications such as calculators, digital watches and lab testing equipment.

By the 1980s, new technologies were boosting LED light output and efficiency leading to new applications as indicator lights in DVD players, microwave ovens, and other domestic appliances. Soon after, LEDs were being used in more rugged applications such as traffic lights and automobiles.

Today, the high efficiency and directional lighting of LEDs makes them ideal for many industrial uses – offices, warehouses, signs and displays, restaurants and public spaces, just to name a few.

On the consumer side, Christmas tree lights are among the most popular and most affordable LED consumer products on the market. They save 90% or more in utility costs, operate at cooler temperatures, and have an operational life span of roughly 20,000 hours (enough to last for 40 holiday seasons).

Challenges remain

The availability of LED products in the market continues to grow, with new generations of devices becoming available about every four to six months, according to the Department of Energy.

The quality and energy efficiency of LED products also varies widely, and many lighting manufacturers face a learning curve in integrating LED technology into lighting products.

“Manufacturers vary in their ability to do this effectively,” the Department of Energy (DOE) said.

The LED difference

LEDs differ from other lighting sources such as incandescent bulbs and compact fluorescent lamps (CFLs) in various ways.

LEDs don’t suddenly burn out like incandescent or CFL lamps, but instead gradually fade in brightness over time, a process known as lumen depreciation. The useful lifetime of a LED product is based on the number of operating hours until the LED is emitting 70% of its initial light output.

A typical incandescent lamp lasts about 1,000 hours; a comparable CFL lasts up to 10,000 hours, and some linear fluorescent lamp-ballast system can last more than 40,000 hours. But quality white LEDs in well-designed fixtures are expected to have a rated useful life of 50,000 hours or more.

Not unlike incandescent bulbs, which release 90% of their energy as heat, and CFLs, which release about 80% of their energy as heat, LEDs also emit a significant amount of heat. So, why are they cool to the touch?

Incandescent bulbs are hot to the touch because infrared radiation heats the glass enclosure. The intense heat in LED devices is not from infrared radiation but instead produced by the semiconductor chip.

Since higher temperatures in LEDs will result in lower light output, referred to as lumen depreciation, the heat needs to be removed using a heat sink, which keeps the device cool by dissipating the heat.

“Most high power LEDs convert only about 15 percent of the input power into light with the rest being lost as heat,” according to Materials for Advanced Packaging published in 2008 by Daniel Lu and C. P. Wong.

White-light LEDs

Unlike incandescent and fluorescent lamps, LEDs are not inherently white light sources. They monochromatic LEDs emit colors (except white) depending on the materials it’s made of, which explains their efficiency in colored light applications such as traffic lights and exit signs.

To use LEDs as a general light source it needs white light. There are two ways to do this:

• Phosphor conversion: a phosphor, which exhibits the phenomenon of luminescence, is used on or near the LED to emit full spectrum white light
• RGB systems: mixes light from multiple monochromatic LEDs (red, green, and blue) to produce white light.

Courtesy: Department of Energy

Quality of LED lighting

A couple of key terms to keep in mind when considering aspects of lighting quality are color appearance and the Color Rendering Index (CRI).

Color appearance, referred to as Correlated Color Temperature (CCT), measures color of the light source using Kelvin (K) temperature, which indicates the warmth or coolness of a lamp’s color appearance.

The lower the Kelvin temperature (2700–3000 K), the warmer the color of the light, while the higher the temperature (3600–5500 K), the cooler, and more bluish, the light appears.

For most indoor lighting applications and living spaces, warm white (2700K to 3600K) is preferred. Cool light (3600K to 5500K) is more appropriate for visual tasks because it produces higher contrast than warm light.

Until recently, most white LEDs had very high CCTs, often above 5000 Kelvin. High CCT light sources appear “cool” or bluish-white. While very high CCT LEDs are still common, products with neutral and warm-white LEDs are now sold on the market. They are less efficient than cool white LEDs, but have improved significantly, and the efficacy gap between cool and warm LEDs is narrowing, U.S. energy regulators say.

Types of White LEDs

Color Rendering Index, or CRI, is a widely accepted measure of how well a light source renders colors, compared to incandescent and daylight sources. The CRI scale of 0 and 100, with 100 representing perfect color rendering based on illumination by a 100-watt incandescent light bulb.

Since most objects are not a single color, but a combination of many colors, light sources deficient in certain colors may actually change the apparent color of an object.

A light source with a CRI of 80 or higher is considered acceptable for most indoor residential applications.

While CRI is generally considered by industry to be a more important lighting quality than CCT, it’s been found to be an inaccurate, unreliable predictor of color preference of LED lighting products as it can result in negative values for some LED lamps.

To address the shortcomings of the CRI for LED, or solid-state, light sources, a Color Quality Scale (CQS) was developed by the National Institute of Standards and Technology, an agency of the U.S. Department of Commerce. It is now being considered by the International Commission on Illumination (CIE) to replace the CRI.

Endorsing the new CQS measurement, Dr. James Brodrick, lighting program manager for the DOE’s Building Technologies Program, said, “Regardless of the type of light source, the CQS represents the color rendering qualities of white light more accurately than the CRI and is a far better predictor for colors that have a high red content, such as skin color and wood finishes – which is one of the CRI’s major weaknesses.”

They are also mono-directional, similar to a flashlight, which makes them ideal for applications such as recessed downlights and task lighting.

Other unique characteristics of LED lighting include:

• compact size
• long life and ease of maintenance
• resistance to breakage and vibration
• good performance in cold temperatures
• lack of infrared or ultraviolet emissions
• instant-on performance
• ability to provide dimming and color control

Typical LED Efficacy Compared to Conventional Lighting Technologies in 2010

Sources:

• 2011 DOE SSL Multi-Year Program Plan

For more information on the basics of LED Lighting:

• LEDs Magazine
• Department of Energy LED Basics
• What is Color Rendering Index CRI
• Is CQS an Improvement on CRI?

Lighting represents about 20% of all electricity use in the United States with the cost to businesses and consumers topping $50 billion a year, according to the Department of Energy (DOE).

That’s the same dollar amount the federal agency estimates is being wasted annually by the owners of 2.8 million U.S. commercial, industrial and institutional buildings that rely on outdated lighting systems.

A company maintaining a standard 50,000-square-foot commercial building can spend up to $45,000 annually on energy for lighting alone, according to a report prepared for the National Electrical Manufacturers Association (NEMA), which represents 95 percent of the U.S. lighting manufacturing industry.

Over three quarters of the nation’s five million commercial, industrial, and institutional buildings were built prior to the debut of many cost-cutting, energy efficient lighting technologies on the market today, the DOE said.

Now, demand for efficient lighting solutions is spurring the growth of new options in energy- efficient lighting technologies, which can reduce energy use by up to 75%.

Despite the initial higher cost of some modern lighting technologies, energy-efficient lighting last longer than traditional lighting, making them less expensive over their lifetime.

Returns on energy-efficient lighting technologies range from 30-50 percent, according to the NEMA report.

According to the DOE, a typical incandescent bulb, which wastes 90% of its energy as heat, lasts from 750-2,000 hours, while a comparable compact fluorescent lamp (CFL) lasts up to 10,000 hours. (source: http://www.energysavers.gov/your_home/lighting_daylighting/index.cfm?mytopic=12030#led) LEDs (light emitting diodes) can last from 35,000 to 50,000 hours or more, the agency said.

Meanwhile, new light bulb efficiency standards effective Jan. 1 will require incandescent light bulbs to be 28% more efficient, which effectively phases out 100-watt bulbs.

Lighting manufacturers have spent millions to comply with the new standards by transitioning to energy efficient lighting, now mandated by the Energy Independence and Security Act of 2007.

Lighting Facts label

Packages of most light bulbs sold in stores in 2012 will carry a new Lighting Facts label – modeled after the “Nutrition Facts” labels on food packages –  to help consumers compare the brightness and estimated energy costs of various types of light bulbs.

The new label will give consumers information about brightness, known as lumens, energy cost, lifetime, light appearance (“warm” or “cool” light), wattage, and whether the bulb contains mercury.

However, Congress voted in December of 2011 to withhold funding for enforcement of the new regulations for nine months.

NEMA said the Congressional action “undermines those investments and creates regulatory uncertainty … and creates consumer confusion resulting from a patchwork of state enforcement.”

Nevertheless, upgrading to energy efficient lighting can help companies achieve the sustainability concept of the triple bottom line in the form of lower energy costs, reduced environmental impact, and improved employee well being and productivity.

Given some of the complexities buyers face in making lighting decisions, it’s important to have the basics of some of the most energy efficient lighting technologies explained.

Consider lighting output, not energy consumption

Traditionally, when considering lighting purchases, consumers relied on the number of watts, a measure of how much electrical power the light source consumes. But with today’s modern energy efficient lighting technologies, consumers need to instead consider lumens – a measure of the amount of light produced.

For instance, buyers looking for an energy-efficient alternative to a 100-watt light bulb should consider a 1,600 lumen CFL or LED light; a 75-watt bulb is equivalent to about 1,100 lumens; a 60-watt light bulb is equal to about 800 lumens, according to the DOE.

Why the change? Using watts to describe the brightness of a lamp is akin to using gallons of gasoline to describe how fast a car can go, which wasn’t a problem when marketing incandescent bulbs that used only 10% of their energy to produce light, the rest wasted as heat.

With new energy efficient lighting products – using fewer watts to produce the same amount of brightness – entering the market, however, it makes sense for manufacturers to market these new products based on a value of brightness, or lumens.

Measuring Lighting Quality

A couple of key terms to keep in mind when considering aspects of lighting quality are color appearance and the Color Rendering Index (CRI).

Correlated Color Temperature scale

Color appearance measures color of the light source using Kelvin (K) temperature. The lower the Kelvin temperature (2700–3000 K), the warmer the color of the light. The higher the temperature (3600–5500 K), the cooler, and more bluish, the light appears.

CRI is an internationally accepted measure of how well a light source renders colors, compared to incandescent and daylight sources. The CRI scale of 0 and 100, with 100 representing perfect color rendering based on illumination by a 100-watt incandescent light bulb.

Color appearance and CRI values for energy-efficient lighting technologies:

• Incandescent bulbs: 2,700 K, 100 CRI
• Cool white fluorescent tube: 4,100 K, 62 to 80 CRI
• Noon sunlight: 4,500 K to 5,400K, 100 CRI

Energy Efficient Lighting Technologies Compared

Here are the top technologies in energy efficient lighting and how they compare to standard incandescent bulbs:

Fluorescents/Compact Fluorescent Lamps (CFLs)

Fluorescent lamps use about 25% of the energy used by incandescent lampsto provide the same amount of illumination. CFLs are short, curly versions of long tube fluorescent lights

• use 75% less energy
• produce 75% less heat
• last 10 times longer than comparable traditional incandescent bulbs
• fluorescent bulbs contain a small amount of mercury. Many retailers recycle CFLs for free.

Halogen Incandescents

Halogen incandescents are smaller version of incandescent bulbs and highly energy efficient

• use 25% less energy than traditional incandescent bulbs
• lasts up to three times longer than traditional incandescent bulbs
• some models can last up to three times longer than traditional incandescents

Light Emitting Diodes (also referred to as Solid State Lighting)

Magnetic Induction Fluorescent

“Induction lighting is one of the best kept secrets in energy efficient lighting.”
~ Department of Energy

Ceramic Metal Halide (CMH)

Lighting Type Summary

The following table illustrates the relative differences in color, efficiency, and lifetime of various energy efficient lighting technologies:

Source: Department of Energy

• EPA – Lighting Fundamentals [PDF - 28 pages]
• EPA – Lighting Upgrade Technologies [PDF - 44 pages]
• Energy Savings Modeling and Inspection Guidelines for Commercial Building Federal Tax Deductions [PDF - 54 pages]
• LED Frequently Asked Questions [PDF - 2 pages]
• DOE SSL Lighting Facts Program [PDF - 2 pages]
• DOE Update on the DOE Lighting Facts Program [PDF - 17 pages]
• DOE Guide to Energy Efficient Lighting [PDF - 2 pages]
• DOE / FEMP – Economics of Energy Effective Lighting for Offices [PDF - 4 pages]

Web Sites

• NLB.org High Benefit Lighting Library
• DOE Building Technologies Program
• Lawrence Berkeley – Efficient Lighting
• NEMA – Enlighten America
• Facilities.NET / Lighting Upgrades Bring Energy Savings
• NEMA – Lamp Energy Efficiency

FAQ

How much electricity is used for lighting in the United States?

EIA estimates that in 2010, about 507 billion kilowatt-hours (kWh) of electricity were used for lighting by the residential and commercial sectors. This was equal to about 18% of the total electricity consumed by both of those sectors and 13.5% of total U.S. electricity consumption.

Residential lighting consumption was about 207 billion kWh, equal to about 14% of all residential electricity consumption. About 300 billion kWh was consumed for lighting by the commercial sector, which includes commercial and institutional buildings and public street and highway lighting, equal to about 22% of commercial sector electricity consumption.

EIA does not have an estimate just for public street and highway lighting.

EIA estimates and forecasts for energy end-use and in residential and commercial sectors.

EIA’s most recent data available indicates that in 2006, 63 billion kWh were consumed for lighting in manufacturing facilities, which was equal to about 2% of total U.S. electricity consumption in 2006.

Historical U.S. annual electricity consumption by sector.

• Source: EIA Last updated: July 19, 2011

===

Energy Audit Links

GUIDES

• Energy Audit Data Collection Forms
• Boiler Site Assessment Guidance (MS Word)
• Building Envelope Site Assessment Guidance (MS Word)
• Chiller Site Assessment Guidance (MS Word)
• Domestic Hot Water Assessment Guidance (MS Word)
• Emerging Technology Checklist (MS Word)
• HVAC Checklist (MS Word)
• Lighting Site Assessment Guidance (MS Word)
• Metering Site Assessment Guidance (MS Word)
• Motor Assessment Guidance (MS Word)
• Plug Load Site Assessment Guidance (MS Word)
• Pump System Assessment Guidance (MS Word)
• Renewable Energy Site Assessment Guidance (MS Word)
• Water Site Assessment Guidance (MS Word)

FORMS

• Energy Audit Data Collection Sheet (MS Word)
• Air Handling Unit Data Collection Form (MS Word)
• Chiller Data Collection Form (MS Word)
• Grid-Tied PV Data Sheet (MS Word)
• Heating System Data Collection Form
• Domestic Hot Water Data Collection Form (MS Word)
• Motors Data Collection Sheet (MS Excel)
• Plug Load Equipment Inventory (MS Excel)
• Water Data Collection Sheets (MS Excel)
• Water Inventory (MS Excel)

Internet Links

The following links take you to helpful Internet sites that lead to even more resources.
Introduction

• Department of Energy (DOE)
• DOE Office of Energy Efficiency and Renewable Energy (EERE)
• EERE Federal Energy Management Program (FEMP)
• National Renewable Energy Laboratory (NREL)
• American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)
• ENERGY STAR
• ENERGY STAR: Portfolio Manager
• International Energy Conservation Code (IECC)

Lighting. It’s not as sexy as electric cars, solar thermal plants or biofuels, But it’s a key component of greentech. Kaj de Daas, chiarman of Philips Lighting North America (a subsidiary of Royal Philips (PHG)), provided an overview of the lighting market at the Dow Jones Alternative Energy Innovations conference today and here’s what he said:

• $75 billion: the overall size of the global lighting market. The U.S. accounts for 20 percent of the total. (Philips does about $3.5 billion a year.)
• 52: The average number of light sockets in a U.S. home. Put another way, there are 4 billion screw-in light sockets in this grand land of ours. Although the U.S. is the largest market, it’s the slowest when it comes to adopting new technologies.
• 40: The average number of sockets in a home in the Netherlands.
• 5, now 18: The average number of sockets in the recent past (5) in a home in Shanghai compared to the present.
• 2012: The year, in some nations, that traditional incandescent bulbs will no longer be sold.
• 45 lumens per watt: That’s the minimum level of efficiency he’d like to see mandated.
• 5 milligrams: The amount of mercury in a compact florescent.
• 3: The number of universities in Shanghai that have well-regarded departments in lighting. If you want to know why Philips is conducting more research there, that’s the answer.
• $1 to $3.50: The average price of LED chips. It’s too high, den Daas said. Technically, companies can make LED bulbs that can dim and put out as much light as a traditional bulb. Economically, it’s just not feasible right now.
• The Whole Enchilada: LEDs can last 50,000 hours. Thus, light bulb makers will lose their replacement market when LEDs go mainstream. The solution? Philips is shifting to making entire lamps and light fixtures. “I need ot offer something big to offset replacements,” he said.
• $17: The amount of kerosene bought by households in Ghana to fuel lamps. Philips has started to sell cheap LED lamps in that country to reduce the danger and fossil fuel consumption presented by these lights.
• November 5 [2008]: The date that Philips will release a new line of LED lamps for the hotel industry.

source: The Global Lighting Market by the Numbers, Courtesy of Philips – Seeking Alpha.