Searching for the ultimate in higher lumens-per-watt technology to achieve stronger illumination, increase energy efficiency, and reduce costs
By David Engle
By broad consensus as well as by Congressional fiat, America needs to trim down energy consumption on a drastic scale. This is because at our current rate of growth we simply cannot build enough plants to keep up. Also, the cost of building runs as high as 16 times more than the cost of conserving, per unit of energy. Obviously, from the standpoint of good policy, anything we do to shave our usage is time and money well spent.
In the US nearly one-fourth of our total electricity consumption goes for lighting, according to one of the experts interviewed for this story. Old-fashioned incandescent bulbs in particular—four billion of them—still brighten 80% of residential light sockets. So guess what: these inefficient mainstays are now targeted for elimination.
How awful are they, efficiency-wise? Actually, really bad: about 98% of their energy is expended as heat, and only 2% converts to light.
The War on Incandescents—and the Resistance
With bulbs wastefully gobbling our grid power, Congress has ordered the phase-out of cheap, lowly incandescents. As outlined by Terry McGowan, a private consultant with Lighting Ideas Inc. and formerly with GE Lighting for nearly 40 years, the legislative “solution” arose after failed efforts to persuade us into buying efficient compact fluorescents (CFLs) voluntarily. So, beginning in 2012 and continuing in four stages to 2016, no more can we make or import the customary bulbs. Under the Energy Independence and Security Act (EISA) of 2007, these wasteful appliances dating from Edison’s time, are effectively illegal: first the 100-W ones, then the 75s, 60s, and 40s in turn.
As for comparative efficiency, the CFLs’ 50 or so lumens per watt (LPW) smashes the filament bulbs’ mere 15, notes McGowan. In practice, a 72-W CFL will replace the usual 100-W one, saving 28%. About 20% of a home’s electricity charges go for lighting; so a 28% saving lowers bills by only about 5%. This does save on consumption, but in terms of money it is erased by the CFL bulb’s higher cost.
Moreover, even with a heavy-handed mandate to launch them, the curly tubes are not ushering-in the Age of CFLs after all. Practical elimination of incandescents was envisioned, but it is not happening. For one thing, recently an incandescent bulb that meets the federal standard has hit the market; dubbed the “2x,” it’s so named because it doubles the efficiency of the bulb it replaces. Likewise, the latest halogen bulbs easily meet the standard, and for a few bucks a bulb they warm up with a familiar incandescent glow.
Given these developments, one of the lobby groups that pushed Congress to pass EISA now appears ready to concede the unlikelihood of a nationwide shift to the whitish tubular nemesis. In a November 2011 report, Noah Horowitz, senior scientist of the CFL-advocating Natural Resources Defense Council (NRDC), wrote that in view of the 2x, “Near term, [there’s a] potential that only a small fraction of available sockets, those without a CFL today, will get the more efficient CFL or LED [light-emitting diodes] inserted.” He cited another report predicting that “there will be very little switching of lamp purchases to CFLs” in the US. The same resistance from consumers also thwarted conversion campaigns in Europe, Korea, and Australia, the report noted.
Fluorescent Bulb Blues
Why do people yawn with indifference over energy-saving CFLs in their homes or on work desks? It’s probably because, besides carrying a higher price tag, the light they emit is relatively less likeable. Being lower in energy means CFLs emit a cooler, bluish glow. Most people seem to find the warm, incandescent yellow of before more pleasing.
By contrast to this reception, fluorescent lamps on ceilings of commercial offices and such are still going gangbusters. Yet even here, there’s a stirring for change.
Rodney Heller, a Certified Lighting Efficient Professional who cofounded and owns a company called Energy Performance Lighting, of McFarland, WI, describes two schools of thought within the lighting profession. These are spurring “a huge debate over the blue lighting issue,” he says. This is framed in terms of respective Kelvin Scale numbers, and scientific studies thereof. Critics of bluish light, as noted above, extol the pleasing warmth of slightly amber wavelengths in “the more relaxing and pleasant” 5,000-K range—akin to natural sunsets, fireplace hearths, and candlelight.
On the other side, advocates of blue light, especially used in the workplace, “say science is on our side.” At this end of the spectrum, 8,000 K is bright and cerulean like a clear sky at noon.”
“People see better and feel more energetic” then, observes Heller.
Ultimately, though, it isn’t Kelvin’s numbers or occupant moods that launch retrofits. It’s the money to be saved. Projects are not evaluated by workers, but by accountants and financiers. Decisions come down to simple payback. In turn, this is driven by how many hours the lights burn, at what kWh charges. On average, sites running a single shift will recoup a retrofit outlay in four or five years, Heller suggests; workplaces going round-the-clock will get into the black in two or less. For the decision-making CFO, he says, “that’s really all they need to know.”
In response to this perhaps simplified equation, Jennifer Veitch, an environmental psychologist and researcher at the National Research Council of Canada, reports on a consensus among practitioners favoring “giving people individual control over their lighting,” based on “the benefits that accrue to that, at several levels.” Specifically, having autonomous control yields positive work moods, organizational commitment, longevity on the job, fewer complaints of discomfort, and higher office morale. Ultimately, staff turnover is reduced. This alone saves significant costs.
Moreover, she adds, installing individual light controls—dimmer switches—tends to shave about 10% off an energy bill on average, over fixed lighting.
There’s also a flexibility option to consider in the debate, meaning a hybrid approach: you can provide personally controllable down lighting, combined with a fixed up lamp for ambient light.
Heller comments: “It is a great idea to be able to personalize lighting. The only issue, though, is cost-benefit. When you personalize lighting, the costs jump up dramatically.”
Getting projects approved “is not easy” then. “A CFO will say, ‘You can’t measure human comfort, but I can measure dollars and cents.’”
However, he adds, as affordability improves, acceptance will likely increase “because it won't cost much more.”
Light-Emitting Diodes: Still the Industry Darling
LEDs, for whatever else they can or cannot do, have re-energized a lighting industry that was stuck in a long tech rut before they came along, observes Bill Warren. He’s a consulting engineer who writes the “Energy Advisor” column for the LD&A magazine, and also sits on the New York City electrical code committee and on the mayor’s Green Task Force.
Since the arrival of cost-justifiable LEDs not too many years ago, Warren says, “it has turned everything upside down,” in a good way. LEDs now hold about 20% of the commercial lighting market, and the share is growing. LEDs are especially superb “for outdoor and street lighting, having a more concentrated, energy-saving 10-degree beam that can project a longer distance,” he says. Hence, LEDs “conserve energy even when replacing [more efficient] sodium or HID [high intensity discharge] lamps which throw light in 360 degrees.” LEDs hold a competitive edge in applications where such “spotlighting” can be tailored to the illumination need.
For this reason, he continues, in New York, LED reflector lamps are now being used quasi-experimentally in auditoriums and gyms. One hugely appealing factor here is the greatly lengthened bulb life and much easier maintenance.
“They’re replaceable with a stick—there’s no need for a scaffold—and they are dimmable,” says Warren. Screw-in bulbs and some fluorescents require twice-yearly replacement in a difficult, “brutal” process of laboriously shifting scaffolds around. LEDs, lasting 25,000–50,000 hours, won’t be needing replacement for years, and in some cases will probably outlast their buildings.
If used instead an incandescent lamp, he continues, “they may save about 70 or 80%” on energy consumption. In one especially noteworthy example, a school in Brooklyn, which currently has 300-W incandescents, will soon replace them with LEDs of only 60–W; yet, due to the above-noted focus effect, light-levels should actually improve.
In response, a couple of major manufacturers of fluorescent tubes have designed a fluorescent compatible LED lamp, he notes, “without the fluorescent technology inside.” Rather, “It’s got a strip of LEDs, so that instead of light going out in 360 degrees it can be aimed.”
Coming in the not-too-distant future will be a very exciting technology called organic LED (OLED), emitting light from easily attachable sheets, rather than from tube forms or small dies.
Heller foresees a market opportunity for LED retrofit kits that would enable upgrading existing older fixtures to newer technologies much more affordably. Currently, doing an LED retrofit requires taking out and scrapping old fixture, then rewiring and putting in entirely new ones.
In the new concept Heller describes, “existing two-by-four fixtures can be changed-out simply by replacing bulbs and ballasts, with minimal waste.” As of mid-2012, he says, “A number of companies are working on this.”
HID: A Renaissance?
Another major innovation these days, Warren continues, is solid-state technology being applied to control and improve lighting. For example, Philips, the electronics giant, recently won a huge award from the US Department of Energy (DOE) for developing the so-called L lamp; it replaces a 60-W incandescent, maintains a good color, and guarantees 25,000 hours, for a cost of about $50.
Greg Davis, founder of Lumetric, in Oak Ridge, TN, agrees with Warren that there’s huge opportunity for boosting light output efficiency by integrating solid-state drivers. This is particularly so for HID lamping. Davis’ firm is one of several emerging developers here.
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Photo: Lumetrics
The traditional magnetic ballast for high-intensity discharge lamps is being rendered obsolete by electronic circuitry, providing much better control of lamp illumination. |
HID lamps, he notes, are industry workhorses, giving intense light for large spaces like warehouses, big box stores, cold storage facilities, conference centers, and manufacturing sites. Overall, 71% of all such interior spaces still use decades-old HID lamps (mainly 400-W metal halide ones). Nationwide, between 4 and 7% of America’s total electricity output is consumed just for HID-lamped lighting.
Regarding the technology itself, HID electrodes in a gas-filled tube ignite the gas (of which there are many possible choices). This yields a charged plasma, and very bright light. Davis describes it as more or less the same process that the sun uses, that star being, in effect, “a big plasma ball,” he says.
HID lamps are still at par with the other efficient lighting for large areas, measured by LPW. For comparison, LEDs yield 45 to 50 LPW, and the best fluorescents top out at about 60 LPW. HIDs’ continuing dominance actually comes from the fact, in a lighting layout, it takes six to 10 fluorescent bulbs to equal one HID. Overall, the latter are much cheaper and easier to maintain. Their lighting color quality is also considered more pleasing.
Thus, Davis estimates, only about 5% of HID sites have ever been persuaded to switch to fluorescents.
However, one considerable drawback to HIDs is the antiquated ballast, based on an inefficient magnetic transformer. “That is the culprit that makes the whole system inefficient,” explains Davis, when compared to what it could potentially be.
To replace this weak link, in recent years several firms have developed solid-state circuit board controllers. These directly drive and control the arc. With such a refinement, LPW ratings jump to the mid 90s, with most HID lamp types, and over 100 LPW with ceramic metal halide ones—among the brightest lamps now commercially available. This LPW rate nearly doubles the efficiency of most fluorescents.
Thus, chip-powered HIDs are able to claim being “the highest efficiency of all,” says Davis. Typically, in any retrofit job, the newly re-ballasted HIDs yield a 40% to 60% energy savings.
Also, because the control is so precise and “easy on the lamp,” he says, bulb life nearly doubles. Lumen deterioration over time is also minimized. Color rendering dramatically improves, says Davis, noting, “It’s the closest to sunlight possible.”
His firm Lumetric launched its controller product in 2008; since then, it has faced resistance for its high initial cost, but payback periods are steadily declining, he says. HID relamping bids are always facing competition from cheap imported fluorescents. Davis also bemoans competitors’ spurious claims of producing equivalent lighting, and their under-stating maintenance.
Lastly, he notes, HID lamp-makers are R&D-ing and retooling for next-generation lamps that take advantage of these circuit-board controllers. New bulb lines, which will shatter the LPW record at somewhere around 150, are expected very soon.
Automated Controls: Real Power Economics
Probably even hotter as a topic than the hottest bulbs right now—several commentators agreed—is lighting controls.
Simply enabling dimming, adjusting, and easily turning off unneeded lumens will lop off a good 20% in energy waste—and probably more, in many cases. Controllability would thus seem to afford the best of all worlds for efficiency and personally controlled comfort.
Chip-enabled automation of controls also dovetails with the burgeoning smart meter infrastructure now underway. Lighting that interconnects with these boxes effectively turn the ceiling lights into a demand response resource. In this scenario, automated lighting (and other building systems), as Warren explains, “receives a gateway signal from the electric meter, which reports kilowatt-hour usage,” then adjusts power accordingly. These systems already exist; he cites those of Johnson Controls, Honeywell, and Siemens, among others. Now, though, they’re fairly pricey for current economics.
A wireless control technology specific to lighting has also emerged in the past half-dozen years. Developed at the University of California at Berkeley, newly arriving products have been spun-off and marketed in a startup called Adura Technologies, of San Francisco, CA.
Cofounder Charles Huizenga, a professor at Berkeley’s Center for the Built Environment, is Adura’s chief technology officer. Since the product-line’s introduction in 2008, nearly 100 projects have been installed with them, totaling 6 million square feet of commercial space. These consistently save 40 to 60% on electricity consumption, Huizenga reports.
In large commercial office buildings, lighting eats 30 to 40% of electricity usage, so the potential for large-scale conservation is high.
Huizenga describes wireless automated technology as “a paradigm shift.” This is because, firstly, automated control devices go into each lighting fixture or ballast. This enables individual on/off and dimming and “a much higher granularity of control for lighting,” than in previous-generation lighting, resulting in “a whole new level” of both energy efficiency and personal control.
Secondly, each device measures the energy consumption. This, too, provides unprecedented control and quantification. It enables “mapping where energy is being used, when, how, and by whom. . . .This fills a huge need,” he says. By tracking energy usage at the fixture level, this serves as “an important tool for facilities, to be able to manage it.”
Thirdly comes the controllers’ interface with sensors. These detect occupancy, motion, and ambient daylight.
Lastly comes manual personal control, via computers and smart phones. Huizenga comments: “In general, the user is the best sensor. They know what they want and should be allowed to select the light level at any given time,” with the exception of fire emergencies or demand-response events.
Low-power radios carry signals to a controller; it finally decides how the lighting should work. “We call it a ‘distributed intelligence’ model,” he says.
Costing around a dollar-and-a-half per square foot to put in, projects pay back in six months to six years, depending on electricity rates and rebates.
Good or Bad Lighting: It Can Heal or Harm
On a final note, McGowan reports on important paradigm-changing research that is shedding light on how the quality, timing, and strength of workplace illumination can profoundly impact mental and physical well-being.
A consensus has emerged on this, says McGowan, who, besides the affiliations noted above, has also held committee leadership roles in the American Lighting Association. Supportive data comes from hundreds of papers, spanning a decade or so, and is regularly explored at industry symposiums.
McGowan summarizes it this way: “Human beings need bright days and dark nights. And if they don’t get it, they get sick.”
This applies to all of us, but particularly to the elderly living in retirement centers and rest homes. Studies show, for example, that “if residents with Alzheimer’s receive bright light early in the day, it helps set their internal clock and makes for a much higher-quality day for the person,” he says. So far, lighting designers are not yet acting on such findings, “but the research suggests that we should be.”
Not only in old-age homes, but also in the workplace, the good or ill effects of lighting can heal or harm. He points out: “For some years, it’s been recognized that workers on night shifts are more vulnerable to cancers than others are.”
Third-shift workers—who’ve been studied for this “in the thousands around world”—are more prone to breast cancer or prostate cancer. The apparent reason: “Their internal clocks get out of whack,” because lighting or its absence triggers the circadian rhythm day and night.
In an ideal lighting design, bulbs should carry particular color characteristics at relatively fixed times in the day, in appropriate amounts.
“One color should be given at a one time and another color at another,” he says. A sort of customized recipe or prescription for healthy lighting should be formulated, specific to a facility—hospital, school, factory, or retirement home.
Again, ideally, all people in the morning tend to need “a good dose of daylight, rich in blue wavelength, because blue stimulates the circadian system the most,” he says. “Then, as the day goes on and especially in evening, those wavelengths need to be cut out. And if you get up at night, the last thing you want to do is turn on light that has a lot of blue in it—like a fluorescent. That is not good to do, because its sets off the circadian rhythm, reducing melatonin.”
The American Medical Association has endorsed the research conclusions, he notes. Eventually, OSHA may jump in and show regulatory interest. And, given the mounting evidence of health hazards, the legal system may also someday test employer liability for illnesses plausibly linked to “toxic” light.
“Why all this hasn’t hit headlines, I find remarkable,” concludes McGowan. “But it will. Sooner or later everybody will be talking about it.”
Author's bio: Writer David Engle specializes in energy-related topics.