Lighting: The Need to Be Green
A new federal law is forcing the 50-cent light bulb into an uneasy retirement.
Penny Bonda -- Interior Design, 2/20/2008 12:00:00 AM
It used to be so easy. Pop in the right mixture of lamp types, switching devices and dimmers to suit the project's functional and aesthetic needs, and—voila!—you've got a lighting plan. The variables were manageable, if not by us, then certainly by the lighting designer, who we would increasingly turn to as new technologies became available.
We still do, but we require more from our consultants now, and from ourselves. The need to be green in lighting, as in all facets of design, means an understanding of the environmental impacts of our decisions. How much energy does each light source use, how much is wasted as heat, what is the lamp life and how do we dispose of them once they burn out? These are basic green lighting questions without easy answers, further complicated by the Energy Independence and Security Act of 2007, signed into law last December. (Read it if you must—I prefer the Wikipedia summary.)
Yes, it's true what you've heard. The law starts phasing out "general service lamps" in 2012 but only the inefficient ones—our beloved "A" lamps, sold in 4-packs for $2.69 that provide the just the right brightness, color temperature and dimmability. "R" lamps, also gone—as are most halogens as we know them. By 2014, all lamps must be 30% more efficient than today's products. Since a huge percentage of all lamps currently sold are on the banned list, the lighting industry and its customers, including designers and all consumers, will have to make changes. The residential sector will take a bigger hit than commercial, which has always been more likely to depend on fluorescent lamps.
Compliance with the phase-out requires an understanding of lamp efficiency—or efficacy—since it's the inefficient models that will have to go. Efficacy compares light output to energy consumption and is measured in lumens (the light output from a lamp) per watt (the electric power used to produce light) abbreviated as lm/W. In other words, how much light output do we get from watts consumed? A typical 100-watt incandescent lamp converts about 10% of the electric current into visible light; the rest—about 90%—is released as heat, yielding an efficacy of 10 lm/W. Not good, especially when compared to a compact fluorescent lamp (CFL) with an efficacy of 60–80 lm/W. Linear fluorescent tubes are rated about the same.
CFLs meet the new standards—they use 70% less energy and last eight times longer. Though they cost more to buy they will save money over time and are available in many shapes and sizes including the familiar incandescent, reflector, and globe. For more information, ENERGY STAR publishes a complete guide (pdf) of its qualified CFL light bulbs.
"Well and good," you say, "but I don't like CFLs." A recent and very good article in the New York Times sums up the feelings of those "who fear compact fluorescents would turn their home into a place with all the charm and warmth of a gas station restroom." Most lighting experts would not agree with that analogy. Neither do I—the CFLs in my home have a pleasing color temperature, no flicker or buzz and are bright enough after a short and tolerable warm-up period.
There is an environmental downside—all fluorescent lamps contain a small amount of mercury and most are not recycled, which means they will inevitably end up in landfills. Even so, EPA suggests that fluorescents are responsible for less mercury being released into the environment because "a power plant will emit 10 mg of mercury to produce the electricity to run an incandescent bulb compared to only 2.4 mg of mercury to run a fluorescent for the same time." Also, 90 percent of all CFLs are manufactured in China, which adds embodied energy to the product.
There is obviously frustration in the marketplace, not only with CFLs but also with other energy efficient alternatives such as halogens and LEDs. The challenges are daunting for those who want to make the best environmental choices without compromising lighting quality. "The first thing to understand," says lighting designer David Nelson, "is that with any of the lighting technologies, there's no silver bullet—no one solution that will answer all the design and green design issues." He advises choosing light sources that are appropriate for the task based on a balance of the desired performance and environmental characteristics.
Nelson is a huge fan of CFLs as a diffuse light source to replace the low efficacy incandescents but warns against trying to force the lamp to be what it's not. Though its color rendering continues to improve, it will not provide sparkle (see LEDs below) and can't be made to be directional. In retrofit installations, dimming is difficult especially with residential products. "I use commercial technologies no matter how small the project," says Nelson. "The standard incandescent wallbox dimmer doesn't produce good results because the dimming mechanism is in the integral ballast of the lamp, which is inexpensive and disposable." He is encouraged by the commercial grade products now being offered through consumer outlets like Home Depot.
Another candidate for replacing low efficiency lamps are light emitting diodes (LEDs), but the technology isn't there yet. Like all light sources LEDs do some things better than others. On the plus side they're super-directional so light can be placed exactly where it's needed. They're also very small, don't generate much heat and have a long (80,000+ hours) life. Though LEDs use very low wattage—it takes three 3-watt lamps to replace a 40-watt halogen lamp—they don't produce enough light in most retrofit situations. Nelson says he uses LEDs in a selective way for punch or sparkle when he also has a good diffuse light source such as fluorescents (see CFLs above). All the little decorative pendants over the bar, for example, are all going to LED.
The light manufacturing industry is not sitting quietly by watching an entire 125-year old technology disappear. Something is going to replace the billions of incandescent lamps that are sold each year. General Electric, the largest U.S. bulb maker, is hoping to introduce by 2010 an incandescent lamp projected to be twice as efficient as its traditional lamp, and another as efficient as CFLs by 2012.
LED Lighting Fixtures Inc. has already introduced, to great commercial success, its LR6 downlight with an efficacy of 60 lm/W, which is better than many CFLs. It is dimmable, has color rendering close to that of an incandescent and fits into standard 6-inch recessed cans. A smaller LR4 version should be available by March. The company has also developed a prototype PAR-38 lamp using LED technology with an efficacy of 113.6 lm/W, higher than any reflector style CFL on the market. Although not commercially available, the lamp is an example of exciting innovations to come.
Do we have to start to recognize that we can't have it all—that we can't keep burning 50-cent light bulbs without doing damage to our planet? Will science save us through the development of exciting new technologies? Dave Nelson poses another interesting question: if we are able to perfect renewable energy, will it matter how efficacious the equipment is? Think about it.
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