The election of 2006 may have prompted a renewed interest in energy efficiency. It actually started with the Energy Policy Act of 2005, in which tax incentives were provided, and standards for a number of specific lighting technologies were set. The 110th Congress is expected to extend the period for these tax deductions as well as make other enhancements.
As usual, lighting ends up being an important target of these and other initiatives. Despite a whopping 75 percent reduction in lighting energy use for most new building types since 1973, many believe lighting innovations can continue to reduce the need for energy. Surprisingly, they’re right. In many situations, it is just as easy to achieve energy savings of 15 to 20 percent as it ever was. The key is to know which are the truly efficient products and practices and to use them in the right places. Here are some of the hottest lighting energy opportunities.
Don’t be fooled by the hype surrounding light-emitting diode (LED) lighting. The U.S. Department of Energy (DOE) tested a number of LED products in 2006 and found them much lower in light output and lamp life than advertised. In fact, there are very few LED products that provide significant energy efficiency compared to our other choices. The best spots for LED lamps include exit signs; step lights; traffic signals; and automobile, marine and aircraft applications where light weight and diminutive size are assets and small amounts of light are needed. But in 2007, we will see some of the first practical LED products that have been thoroughly tested and are using warm-toned LED lamps with great color. In other words, particularly with LEDs, a healthy dose of skepticism is necessary to make informed choices.
There is, however, no argument about the superiority of the “super” T-8 and T-5 fluorescent lamps. It is important to use both a high-efficiency lamp and the high-efficiency ballast for it. A current list of high-performance T-8 lamps and ballasts can be found at www.cee1.org/com/com-lt/com-lt-specs.pdf. Recently, high-efficiency dimming ballasts also have been introduced (more about that later). Keep in mind that low-mercury T-5 and T-8 lamps are standard and should be used everywhere.
Perhaps the most important new sources are ceramic metal halide lamps and electronic ballasts. At the low-power end, metal halide lamps at 20, 39, 50 and 70 watts can be used for a wide range of interior and exterior lighting applications, and the lamp size in turn allows small but efficient fixtures. However, also look at the 400-watt class of metal halide lamps (320-350-400 watt). Ceramic metal halide lamps provide outstanding color, and when used with electronic ballasts, power can be reduced by 25 percent compared to ordinary metal halide.
Among compact fluorescent lamps (CFL), the big improvements are in residential and light commercial lighting, where screw-based lamps can be used in a wide range of lighting fixtures. Some of the products are dimmable, too. Given the quality and low cost of CFL products, there is almost no excuse for not using them in table lamps, floor lamps, downlights and many other common uses in hotels, motels, family restaurants and casinos.
There are several recent developments in lighting fixtures. By far the most important has been the T-5 troffer. Using two 28-watt T-5 lamps and operating at 72 watts, its performance is similar to an ordinary three-lamp T-8 luminaire operating at 90 watts. A shallow fixture that can be used to reduce ceiling plenum depth, T-5 troffers can produce over 50 foot-candles at 0.7 watts per square foot.
Another important fixture type is the high bay fluorescent. Mostly using T-5HO lamps, high bay fluorescent lighting can provide great distribution and color while permitting dimming and frequent switching. In addition to factories and warehouses, fluorescent high bay fixtures can be used in gyms, big box stores and other spaces with mounting heights up to about 35 feet.
Another key development in the last few years has been the integrated classroom lighting system (ICLS). Developed as a research project for the California Energy Commission under the PIER program, the ICLS is a special type of suspended direct/indirect lighting system that is very energy-efficient (<.85 W/sf) while, at reasonable cost, provides separate lighting scenes for general classroom work and for the growing use of video projection. An added benefit is the use of plug-and-play controls that, in addition to reducing cost, ensure rapid and trouble-free installation and commissioning.
Quietly, digital lighting controls are evolving and becoming the next great revolution in our industry. They will replace line-voltage control gear almost completely—unswitched power goes directly to the ballast, and based on a digital signal, the ballast turns on and dims to the right level. While the primary benefit is dramatically improved energy management, the added costs of control wires and equipment will be more than offset by savings of conduit, line voltage No. 12 wire and the related labor. Digital systems, in turn, allow easy, building-wide control functions that include local motion sensing, daylighting controls and demand reduction.
Perhaps the most exciting tech product is wireless lighting control. New mesh network systems using the ZigBee protocol, for instance, now are being demonstrated. Imagine being able to install a state-of-the-art lighting control system without control wiring. In an older building, this is a dream come true.
The ICLS system is a unique case but possibly a forerunner of the future. Controls are hardwired using Category 5 cable, but the functions are analog logic. While digital controls’ versatility and broad function range are appealing, they also are overkill in many places. Remember, digital lighting controls must be programmed to operate; the ICLS system is truly plug-and-play. Expect to see some new control concepts using analog logic and various hybrids of analog and digital in the future.
In offices, the buzz is “task and low ambient.” Research from Southern California Edison’s oPod project shows that most workers in offices and other computer-intensive jobs prefer low ambient lighting systems. Ambient fluorescent lighting systems operating at 0.6 to 0.7 W/sf are combined with task lights using LED lamps and compact fluorescents to produce a computer-friendly work environment. One fixture manufacturer has introduced a T-5-based lighting system mounted directly to office furniture systems that provides both task light and ambient light with good results at well under 0.9 W/sf.
For lighting in stores, designers are using a similar approach, called layered design. As much lighting as possible is provided using high-efficiency lighting systems like T-5 troffers and T-5- or super T-8-based general lighting systems. Then, display lighting is added, and with the recent drop in electronic ballast costs, ceramic metal halide track lighting is really catching on. Other efficient choices include fluorescent or LED display case lighting, compact fluorescent or CMH wallwashing, and for grocery stores, LED lighting inside of refrigerated cases. Exciting new PAR38 screw-based compact fluorescent 23-watt flood and 25-watt CMH spot lamps allow older track lighting systems to operate at one-third of their original power.
The latest California Title 24 and ASHRAE/IESNA 90.1 energy codes place new restrictions on outdoor lighting power. If you are careful and use mostly metal halide, high-pressure sodium or compact fluorescent lamps, meeting the energy code will be fairly easy. But, there is a growing concern about light pollution, and soon there will be a national Model Outdoor Lighting Ordinance (MOLO) that communities throughout North America will be adopting.
To be prepared for these major changes in outdoor lighting, save both energy and dark skies by using modern, well-shielded and directed luminaires. Forget the term “full cut off”; the Illuminating Engineering Society of North America (IESNA) has dropped it. Instead, look for products that have less than 1 percent of uplight component and really good shielding in the high-angle glare zone of 80 to 90 degrees above horizontal. Products now are available from the basic shoebox style to contemporary and traditional suitable for just about any outdoor project. Likewise, use shielded wallpacks, step lights and decorative fixtures in all outdoor locations.
Making it worth your while
Here are at least five good reasons for concentrating on energy-efficient lighting:
1. Your client/customer will save money. Since most lighting adds to demand as well as energy charges, persisting midday lighting power savings generally have an accelerated payback rate.
2. Your client/customer might qualify for a tax deduction of up to 60 cents per square foot. This is in addition to the normal depreciation.
3. Your client/customer might qualify for a rebate or other incentive from the local utility. Typical rebates are for 20 to 30 percent of the incremental first cost of an efficient alternative, but some rebates can be much higher.
4. Your client/customer will increase his or her LEED point count. Many local, state and federal projects now require LEED certification, and an efficient, dark-sky-friendly lighting system can add two to five points.
5. Your installation will easily comply with any energy code.
When it comes to return on investment, lighting provides a more tangible return than almost any other expenditure one can make in a building. Given that electric energy rates will continue to increase and power will become more precious, the side benefits of a modern lighting system are enormous. The primary benefit, by the way, is still better lighting. EC
BENYA, P.E., is a lighting designer, an author, and a well-known speaker. Find him at www.benyalighting.com.