Lighting is believed to be energy efficiency’s low-hanging fruit in a building, but choosing lighting for energy efficiency isn’t as simple as replacing an old light bulb or fixture with a new one.
By Carol Brzozowski
Many factors abound in making comparisons as to what will offer the best efficiency in the long run, according to Magnaray. Those factors include a light source life, quality of light, initial cost, energy efficiency, color stability, replacement requirements, whether it’s “new” or “proven” technology, lumens maintained, reflective/direct glare, hazardous material, and availability of utility rebates.
The options can be dizzying.
Some facility owners or operators choose to consult with a Certified Lighting Efficiency Professional (CLEP) for assistance in lighting issues. A CLEP is someone who must pass a test to demonstrate their knowledge of energy-efficient lighting, proper light levels for the task, codes they must follow, and recycling hazardous waste requirements, says Rodney Heller LC, CLEP, of Energy Performance Lighting in Cottage Grove, WI.
“A building owner should be more comfortable with a person that has these initials because they have taken the time to be better at their trade than somebody who did not,” says Heller. “That’s not a blanket statement, but if you are playing the odds, you will get better results with a CLEP.”
He says fluorescent energy-efficient lighting is “getting much better with longer life, and it is still about 25% of the cost of a light-emitting diode (LED) upgrade.
“However, LEDs are coming on strong,” he adds. “I think the table will totally tilt towards LED in the next three to four years.”
That will include such options as organic light-emitting diode (OLED) and Light Emitting Chemicals (LEC). These latest technologies are addressing a number of challenges in lighting, such as lumens and watts efficiency, extension of maintenance cycles, and lighting control.
“You will be able to put the light where you want it,” points out Heller.
It also addresses human health issues. “You will see light color evolve to simulate natural daylight for greater human performance and health,” says Heller.
|Photo: Magnaray International
Inside or out, there’s plenty of opportunity to increase lighting efficiency.
Greg Davis is chief technology officer and cofounder of Lumetric, a provider of high-intensity discharge (HID) lighting for large areas through its SmartPOD systems. He recently spearheaded a Forester University presentation on how to choose from among different lighting technologies that best suit a facility’s needs and save energy.
As Davis points out, that task can be like comparing “apples to oranges”.
“In lighting in general, it’s about lumens per watt,” he says. “The layman’s version of that is how much power per watt am I drawing from the wall, and then you stand under the light and it’s how many lumens are heating my hand?
“If something is giving me 100 lumens per watt, then I say it’s great; it’s 100 lumens for every watt of energy I’m buying. We have to think of not just using, but buying. And if I go to another technology that’s giving me 70 lumens per watt, then obviously, I’m not getting as much bang for my buck.”
A few issues factor into that.
“For example, there’s the old high-pressure sodium lights like a lot of utilities companies have and a lot of people have in their backyards that put out that yellow light, so the quality of light plays a particular aspect in it,” says Davis, adding that most people usually find white light more pleasing.
Most lights now have good color rendering or quality, so the difference comes down to the lumens per watt, Davis says.
“There are a lot of tricks that can be played with lumens per watt,” he says. “It seems like some lights have a higher lumens per watt than they really do. But in general, fluorescents are about 65 to 70 lumens per watt, induction is around 70 lumens per watt, and LEDs are quite often as little as 45 lumens per watt. HID for lighting large areas can get anywhere from 80 to 100 plus lumens per watt.”
One of the reasons why his company turned to HID as a flagship product is “we saw a big hole in large area lighting where all of these old HIDs were being replaced because the ballast is inefficient,” notes Davis.
“But the lamp itself is the most efficient for generating light because it makes light like the sun does. It’s a plasma. We developed a new type of ballast around the light that’s energy-efficient, so it uses less power but generates more light, so we’re getting well above 100 lumens per watt.”
His company does provide other lighting technologies as well.
“I really like HID because it’s the one that catches most people off guard,” says Davis. “In the industry today, they’ll replace these 400-watt magnetic HIDs with a florescent fixture that provides less light, and thus less energy. It’s really hard to provide more light and use less energy, but in today’s technology with HID you can do that.”
In high-bay industrial applications, “LED has not even grabbed a foothold,” says Davis.
Larry Leetzow is president of the World Institute of Lighting and Development Corporation, a technical solutions company that seeks to provide the most economically viable and tested technology lighting systems available to the industry, of which Magnaray is a division. Newer technologies joining OLED on the market include Light Emitting Plasma (LEP) and LED flat panel light sources, says Leetzow.
Leetzow contends that while he believes that LED lighting is “highly evolving”, it is not mature enough to take a prominent role in the market for about seven years, during which “all of the bugs we are currently experiencing should be worked out by that time.”
That includes system design issues encompassing dimming and other control systems. Standards need to be developed for dimming drivers, Leetzow adds.
“It’s getting better every day, but we’re not at the best part of what the LEDs should be—and could be—to even be in the market in our estimation,” he says.
The World Institute of Lighting and Development produces and promotes the Twin T-5 and linear T-5 florescent lights, which Leetzow says offer more than 50,000 hours of life with 90% maintained lumen output.
“LEDs, to get their 50,000 hours of life, are allowed to lumen depreciate—less light output down to 70% light output or 30% lumen depreciation—before they are called at their end of life,” he says.
|Photo: Energy Performance Lighting
“In lighting . . . it’s about lumens per watt.”
“One of my questions would be to the Department of Energy and to end users who have to pay the bills: if you could purchase a system that is less expensive to buy than an LED system that maintains light for a longer period of time, that’s less costly to operate and maintain, why would you want to have an LED system at this point in time?”
The most requested interior lighting in new construction is T-8 florescent lamps, says Leetzow, adding “they’re trying to move LEDs into those applications as well, and there are some products that are fairly good and some that are fairly bad, so you need to do your homework.”
For retrofit applications, Leetzow’s company sees a lot of retrofitting of T-8 lamps to T-5 lamps. Outdoor lighting retrofits are still being done with high-pressure sodium and metal halide lighting. Leetzow says newer metal halide lamps have a better efficiency and cost factor than LEDs. Adaptive lighting—in which light fixtures are controlled by motion sensors—is the latest improvement in outdoor illumination, Leetzow says.
“They can be controlled by energy management systems or by dimmers with overriding systems where if light isn’t used, it could be brought up to full grade in a short period of time. LEDs are good for that, but the twin T-5 fluorescents are adaptable for any of those control aspects as well,” he says.
Advancements in white LEDs take place every six months, says Jordon Papanier, marketing manager for LEDtronics. The company is engaged in ongoing testing of LED technology to provide a product with the highest lumens per watt, he says.
Evluma uses LED lighting in the products the company manufactures for outdoor, commercial, and industrial use. Utilities are the primary end-users of the company’s products, used mostly in outdoor applications, says Cathleen Shattuck, creative director for Evluma.
“Utilities are able to implement energy efficiency changes on a larger scale than an individual homeowner, and sometimes they’re able to see a return on investment a little bit more quickly,” notes Shattuck.
The company works with a lot of rural co-ops.
“Our initial product was an LED replacement bulb for mercury vapor, high-pressure sodium, and NEMA dusk-to-dawn, which some people like to call barn light,” says Shattuck. “This was an important change for a number of rural utilities because so many people still have mercury vapor fixtures and mercury vapor ballasts were phased out a number of years ago.
“Utilities still had these fixtures and wanted to maintain life of their investment in these fixtures, so being able to change out the HID bulb with an energy-efficient LED bulb was very helpful to them because they didn’t have to scrap fixtures that they already had in place.”
The ballast-in-arm retrofit works well in numerous fixtures, such as acorn fixtures municipalities tend to use, notes Shattuck. The soffit lighting is taking off in areas such as car dealerships and grocery store entryway lighting, she adds.
New products can also utilize algorithms and Bluetooth controls. “Maybe they would like the security light to use only 50% of the power between 1 a.m. and 4 a.m. That would be a new way people can save energy by taking advantage of new controls that are available,” explains Shattuck.
In early 2008, the Otsego Electric Cooperative in Hartwick, NY, found itself needing to replace 850 175-W mercury vapor NEMA dusk-till-dawn fixtures on member properties that served as security lights. The Energy Policy Act of 2005 had banned the importation and manufacture of mercury vapor ballasts in the United States effective 2008, meaning Otsego would be unable to get new mercury vapor ballasts to replace the old ones.
Jim Foote, Otsego Electric Cooperative’s director of technology and member solutions, sought alternatives that would be energy efficient.
“Although there are metal halide and other lights available, we thought the LEDs would be a new and efficient technology worth looking at, going forward, that we could replace our existing mercury lights with,” he says.
Utilities are the primary end-users of the company's products, used mostly in outdoor applications.
Foote had been watching for the development of viable LED replacements for some time and planned to try out several models and manufacturers before adopting any one technology.
“I happened to be online one day and stumbled upon Evluma’s website, and found they had this LED light that would fit into the existing sockets we have,” he says. “We didn’t want to replace the whole fixture.”
Using automated metering systems that allowed staff to trend energy use and demand, Otsego evaluated its existing energy usage, seeking an accurate look at what the existing lights were using for power over the course of the year.
In early 2009, Foote purchased a few samples of Evluma’s newly released LED retrofit, the 40-W Clearlight EcoSpot. He installed and metered the Clearlights, a metal halide fixture, and a fixture provided by another LED manufacturer, comparing the data daily. Foote says he knew the metal halide bulbs would have the same maintenance requirements of other HID bulbs. The predicted life of LEDs was longer than anything Otsego was using on its line.
Otsego has to send a lineman out to change a bulb when it burns out, or a ballast when it fails—and that lineman can sometimes be up to an hour away. Having not to do that quite as often would help the LED pay for itself. Clearlight also enabled Otsego to bypass the ballast. Initially, the linemen brought the fixtures in the shop and wired around the ballast, but as the need for replacements increased, they decided it would be just as easy to bypass the ballast in the field.
After Evluma released the 50-W Clearlight Beacon at the end of 2010, Otsego used the lighting technology for its retrofit. “It cast a wider light and seemed to be more suitable for our members,” notes Foote.
Foote liked that Otsego wouldn’t have to landfill 850 fixtures. Additionally, the utility is saving 560,000-kWh per year. Another factor in switching from mercury vapor to LED would be a 1% reduction in line loss in Otsego’s long-term efficiency efforts that considered line upgrades.
Initially, Otsego was going to do a bulb-for-bulb replacement as lights burned out, but Foote says the decision was made to do a complete retrofit.
“We looked at a few different reasons for going with LED lighting,” says Foote. “One is we feel that is the way lighting is going. They are more efficient. There weren’t a lot of options a few years ago at the time we were looking, but we felt that the Evluma was a good option for us, and they seemed to be willing take our feedback. We told them what we liked and did not like about it. They were listening to other people as well with feedback, and we liked that. We are fairly happy with how it turned out.”
Continental Control Systems manufacturers lighting controls that offer the ability to measure multiple single-phase points with one meter.
“Our meter measures consumption and is used to validate the consumption savings that energy-efficient light bulbs offer,” says Cynthia Boyd, director of sales for Continental Control Systems. “Sometimes they have to prove the ROI, and we can get down to the actual kilowatt reduction and prove the efficiencies in real-time.”
When ascertaining the right time to do a retrofit, most facilities owners consider the cost savings, Boyd points out.
“They recognize that their largest loads are probably their lighting loads, and it’s the lowest-hanging fruit,” she says. “Lighting companies are very innovative in these low-consumption lighting solutions. On paper, they can show the return on investment by these new light bulbs that cost more but consume less energy and the load. They’re not heat-generating.”
Several factors play in to knowing when it’s time to do a lighting retrofit.
An ideal time to retrofit is any time a facilities manager has to schedule the department’s time on changing out light bulbs, Papanier says.
“A quality LED bulb or LED T8 tube light should last five years if left on 24/7 or longer if the lights are only on eight to 12 hours a day with no more than 30% light loss,” he adds.
One sign it’s time to do a lighting retrofit is looking at the cost of maintaining current lighting, which is always underestimated, Heller says.
Second is to consider the lighting stock: its age and the number of different types of lamps.
“Most facilities should have less than five types of lamps,” says Heller. “Sometimes I see as many as 25 types.”
The time to retrofit is when a system is in the 10- to 15-year range, says Leetzow.
“That would be for interior, exterior, parking garage, and parking lot lighting,” he says. “When a facility is built, it is usually built with lighting all at one time, and there are places where an annex would be put on where the lighting is newer than in the original buildings, so whatever that system or time frame was from its beginning is when you look at retrofits.
“If your systems are five to seven years old, they should be working fine. It should be fairly efficient at this day in time and to gain more efficiency for what you’ve already got is now plateauing to a degree—there’s only going to be so much more efficiency that can be reached.”
Most of Evluma’s customers determined it was time to retrofit after doing a budget review, says Shattuck.
“They were trying to find ways to reduce costs and implement energy savings, and for many people, that’s the primary trigger,” she says.
Revitalization projects are another opportunity.
“For a lot of municipalities, it might be more appropriate for them where they might have an historic or downtown area where they want to make it look a little bit more contemporary and revitalize the area by putting in new lighting or retrofitting the old HID lighting with LED lighting,” says Shattuck.
Davis says it’s time to retrofit when facility occupants want more light.
“Everyone is interested in saving more energy,” he says. “But we know a lot of facility managers who say their lighting isn’t good here and want to do something about it, so while they’re at it, they’d like to make it energy-efficient. In general, most facilities for some crazy reason do not relamp.”
Every light source has a life and as the light ages from the first day it is used, “you’re going to have the highest lumens per watt that’s it capable of having,” points out Davis.
“But every day you run that, it will put out less light and less light and less light, and if you run them long enough, they’re in the low end of the lumens per watt and the lighting doesn’t look so good,” he says. “People just get used to it because they don’t see that gradual degradation as time goes on, and if they’re really concerned about the lighting, they need to relamp. It’s a very inexpensive way of doing it. It doesn’t necessarily save you energy, but it kills that problem.”
If lighting looks good, facility managers and occupants have to consider whether they are willing to make an investment to be energy-efficient, says Davis.
“At that point, you’ve got to look at it in reverse,” he says. “You don’t want to sacrifice light quality for energy-efficient lighting. My favorite statement is that we do not put lights up in the ceiling to save energy, we put lights up on the ceiling so we can see. We want to do our work; we want to make sure people do it safely, and we don’t want to get into accidents.”
Like his counterparts, Davis cautions that those looking for new or retrofit lighting need to do their homework.
“Probably the biggest problem that I see when people do energy-efficient lighting is that they believe all of the speak, and there are some unscrupulous people who will say anything you want to hear,” he says.
One of the ways in which the numbers on lumens per watt can be “fudged” is that “as lights age, they put out less light and it goes by lumen maintenance and lumen depreciation—it depends on which way you’re looking at it,” says Davis. “The way you’re supposed to judge the light sources on the average light output is it gives the mid-life of the light, and that’s where you compare apples to oranges.”
Off the shelf, HID may offer 82 lumens per watt on day one, where 8,000 hours later, it may only be giving 55 lumens per watt, says Davis. Fluorescents will start out with a certain number of lumens and only drop about 10% at 8,000 hours, he adds.
Evluma uses LED lighting in the products the
company manufactures for outdoor, commercial,
and industrial use.
“It sounds much better, but the problem is fluorescents put out much less light than HID does,” he says. “You can’t just look at any one factor—you’ve got to look at them all to get what you need. What happens is somebody will put in a light source that puts out less light and on day one, that’s the brightest that will ever be, and they’re comparing it to existing lights because it didn’t relamp.
“It’s been there two to six years, and they’re not putting out as much light as they should, and they compare this new light to that and say they’re much brighter and look so much better. But as time goes on, those lights also dim and since they started out at lower initial light output, they get dimmer even worse than where they started, and then they suddenly realize they can’t see in there anymore.”
Energy savings can be lost when a facility installs more fixtures beyond a one-to-one retrofit, Davis says. Other factors to consider in lighting are the photopic and scotopic effect, Davis says. Of the photopic effect and lumens, “if you stick a light meter out there, it’s how many lumens hit that light meter, and you get a number,” he says. “The scotopic effect is where your eye can detect certain colors better than others, so you can read something more plainly. A layman’s example of that is that you have a light that’s very yellow, and you’ve got a light that’s more white. That’s the color quality, but it’s also somewhat the scotopic effect as well. That’s where the quality of the light plays in.”
Many fixtures may have only have 12,000 lumens, but its scotopic effect is 25,000 lumens, says Davis.
“That sounds good, but most of the time in real life, that really doesn’t play out so well because what that really means is your eye can potentially perceive something better, but there’s still less light there,” he says. “It still doesn’t make it that much better overall, and on top of that, there are other light sources out there that put out more lumens that also have a higher scotopic effect—scotopically, you can see better under LEDs.”
Light placement is important.
“LED light can be directed to a work area providing better lighting where it is needed and not waste light on areas where it is not needed,” says Papanier.
Heller says he favors low ambient light and more task light.
“Technically, you only need five foot-candles for safe passage, but I generally light higher, then use task light to illuminate the direct work spaces,” he says. “When doing this, I always use a minimum of 5,000-K light, because the more blue in the light, the more it suppresses melatonin, and this helps maintain alertness.”
In lighting placement, “one of the things we are very conscious of is glare,” says Shattuck. “After looking at an LED light, you certainly shouldn’t walk away with spots in your eyes. We’re very careful to diffuse our light source and to provide an even source to try to reduce glare.
“We work with our customers to find out what type of fixtures they are retrofitting and what height they are at, so they might prefer one product over another for that application.”
Evluma also offers different options for color temperature.
“Because our lighting products are primarily used outdoors, that gives them a little bit of a leeway on what color temperature they want,” she says. “We also have some higher CRI [color rending index] products that are very important to certain customers, like a car dealership, because they want to have the most accurate or most true representation of a color of a vehicle, and having a light source with high CRI lets them do that.”
While saving energy saves money—a factor that is always the top priority for the CFO—“when you dig deeper, the true value is human performance, productivity, and—last, but not least—human comfort,” says Heller.
“Happy, healthy, comfortable employees are any company’s strongest asset,” he says. “Let’s face it—we are here to make money or provide the tax payers a service. Let’s do it at peak performance, and the proper lighting will help us get there.”
There are multiple factors involved in the connection between energy-efficient lighting and improved productivity, Heller says.
“It’s all about our internal body clock, circadian rhythm, and how we evolved,” says Heller.
Until recently in human history, people spent 95% of their time outside under the blue sky, Heller points out.
“Now we spend 95% of our time inside under man-made light sources,” he adds. “We are just beginning to understand how we work and how light affects us physiologically and psychologically. With the right light, we can increase visual acuity, we can turn night into day and be fully adjusted, and we can increase alertness.”
The design of a lighting system that encompasses the placement of lights has an impact on eye health and productivity.
“You have to start out with a source that has good color rendering,” says Leetzow. “You have to have it put into an efficient luminaire that produces and spreads the light out in as wide and as uniform pattern as it can and produces the least amount of glare possible. That’s one of the reasons we went from incandescent lighting in the ‘40s and ‘50s to florescent lighting.
“When your eye has to compete with bright spots, dark spots, shadows, and things moving around all of the time, it gets very fatigued, and that’s where you can lose some production from some of your employees.”
A high color rendering, good distribution, uniformity factors, and control of the glare in office—like the glare that comes off computer monitors—is extremely important, Leetzow says.
“Those same factors should be carried into outdoor illumination as well,” he adds.
An ROI on energy-efficient lighting retrofits is based on operating hours and cost per kilowatt-hour/kilowatt demand, says Heller.
“To have just electricity pay for the upgrade, generally the rules are for 24/7, less than two years; for 24/5, less than three years, and for 10/5, four to five years,” he says.
Papanier says that depending on the LED lighting product, an ROI can be from 12 months to three years.
“With LED bulbs such as PAR bulbs, MR16 bulbs, or A19 style LED bulbs, the ROI is about 12 months,” he says. “On average, LED exit sign bulbs cost about $35; you save—depending on what a plant or office building pays per kilowatt, and what the labor rate is for the maintenance staff to change out light bulbs—$30 a year per exit sign.
“LED T8 tube lights’ ROI is between two to three years for large installations. LED streetlights and parking lot lights’ ROI is about three years. LED traffic light ROI is about 18 months.”
The money saved in energy costs gives facilities more capital to invest in other upgrades to the facility or plant or hire more workers, Papanier points out.
The bottom line: “there’s no single technology that’s better than the other,” says Davis.
“There are times that HID is better than florescent, and many times fluorescent is better than HID and LED are better than anything, and sometimes LEDs are the worst,” he says. “If you don’t have all of the information about each individual facility, you really can’t make the best choice possible.”
Since most consultants specialize in one technology, people will listen to a sales pitch and then wonder years down the road why a light looks so much different, Davis says. For those who don’t want to do their own research, “It’s best to hire an independent consultant who knows or recommends all product lines and is not the one selling you the lights,” he says.
“It’s best to educate yourself,” he adds. “You will serve your own interests better than anyone else will. Forester University is one of those ways. You can look on the Internet—sometimes it’s good, and sometimes it’s useless. The Illuminating Engineering Society is independent and is a good source of information.”
Author’s Bio: Carol Brzozowski writes on the topics of technology and industry.