Although LEDs have been dominating new product development, 99 percent of existing installations in the U.S. are serviced by traditional sources, according to the Department of Energy (DOE). The innovations having the most immediate impact in nonresidential buildings are in fluorescent and high-intensity discharge (HID). These technologies are seeing continual advances in efficiency, service life, and controllability. And all of this is being driven by energy codes, utility rebates, LEED, and regulation that is steadily removing the least-efficient, lowest-cost products from the market.
Fluorescents dominate linear lighting, and the past 10 years have seen a major shift from T12 to T8 lamps, with T5 lamps a small but rapidly growing segment. The efficacy of lighting in commercial buildings increased from an average of 50 lumens/W to 70 lumens/W, according to the DOE, and this is largely attributable to the shift in technology.
The biggest issue now is the phaseout of 4-, 8-, and 2-foot (U-shaped) T12 lamps. By 2014, even the exemptions will be eliminated. This has serious implications for existing building stock, as there are approximately 550 million 4- and 8-foot linear T12 lamps in the industrial and commercial building sectors, most of which will require replacement.
Recently, the DOE introduced even tougher standards that will go into effect in November 2014. These standards cover T8 and T5 ballasts, as well as T12 ballasts, including earlier T12 exceptions such as those for residential and sign ballasts. Ballast Luminous Efficiency (BLE) is a new metric that supersedes Ballast Efficacy Factor (BEF), and it removes the lamp load as a variable. Dimming ballasts and some others are exempted from the new rules. Many products already comply, such as a majority of high-efficiency ballasts (for example, NEMA Premium). Others will need to be reengineered or discontinued. At greatest risk are T12 electronic ballasts, outdoor sign ballasts, residential ballasts, and T8 and T5 programmed-start ballasts that lack a cathode cutout design.
In step with the next round of lighting regulations, manufacturers have already introduced T8 lamps in energy-saving wattages of 25W, 28W, and 30W (and 32W high-lumen) as well as 23W. A significant number of energy-saving T5 lamps are available, including 25W or 26W replacements for 4-foot 28W T5 lamps; 44W to 51W replacements for 4-foot 54W T5HO lamps; a 35W replacement for 3-foot 39W T5HO lamps; and a 21W replacement for 2-foot 24W T5HO lamps.
To maximize savings, all linear fluorescent lamps should be paired with a high-efficiency electronic ballast wherever possible. T8 high-efficiency electronic ballasts are easily identifiable via NEMA Premium on the label. The National Electrical Manufacturer Association (NEMA)'s Premium program does not cover T5s, but these are marketed as "high efficiency" if they have an efficiency of 90 percent or higher.
Some ballasts are available in nonstandard factors such as 0.50 and 0.70, which enables designers to satisfy precise load calculations for energy-sensitive projects by tuning the load and light output closer to required levels. Some programmed-start electronic T8 and T5HO ballasts also can operate lamps in parallel, ensuring that the other luminaires will work when a single lamp on the ballast has failed.
Advanced lighting controls have an impact on lamp and ballast design. Lamps are available that provide longer service life at frequent switching cycles and programmed-start ballasts that turn on lamps more quickly, which increases compatibility with occupancy sensors. Ballasts are available that offer step or continuous dimming, from lower-cost load-shedding and economy continuous-dimming models to digital ballasts that can act as the controller in a network. Of note, NEMA revised it's LL9 standard last year, and ballasts designed to LL9-2011 provide sufficient cathode heating down to about 10 percent of full output. (This is down from 35 percent in the previous version of LL9.) Although LL9-2011 will go into effect in 2015, some manufacturers are already in compliance.
Also of interest is the supply crisis in rare earth materials, which has shifted investment and demand from value-added products to basic products with a lower cost. Five rare earth elements are used in phosphors for energy-efficient and high-color-rendering fluorescents. China, the largest supplier of these metals, has restricted exports over the past few years. In response, lamp manufacturers announced steep price increases last year. Although new supplies are being developed outside of China, europium, terbium, and yttrium—which are used in fluorescent lamp phosphors—will continue to face uncertainty in supply and cost.
This issue has had an impact on 700 Series T8 lamps, which are scheduled to be phased out in favor of 800 Series T8s. The 800 Series, however, use 30 percent more rare earth content. Several lamp manufacturers—Philips, Osram Sylvania, GE Lighting, and Halco Lighting Technologies—requested, and were granted, a two-year reprieve from this transition.
Another option is to replace lamps less frequently, which would increase demand for long-life lamps and LEDs. Extended-life T8 and T5HO lamps offer up to 60,000 hours of rated service life. One lamp, the Sequoia T8, which was recently introduced by Kumho Electric, is rated at 75,000 hours when operated at three hours per start on a programmed-start ballast.
Over the past decade, there has been a major shift from mercury vapor to metal halide. Innovation in this sector has focused on energy efficiency, longer life, and controllability among higher-wattage lamps, as well as miniaturization and improved color performance among lower-wattage lamps that compete with halogen.
Legislation has banned mercury vapor ballasts (except specialty ballasts) and regulated ballasts sold as part of 150W to 500W metal halide luminaires. The latter requires luminaires in these wattages to have pulse-start ballasts. California tightened these rules, requiring an electronic ballast or either an occupancy or photosensor control. The DOE is working on new regulations that appear to be aimed at eliminating probe-start lamps (expected to become effective in 2016), and for ballasts sold in metal halide luminaires, which may expand wattages beyond 150W to 500W while nudging current efficiency levels even higher (expected to become effective in 2015). Since ballasts below 150W are already pulse-start, if the DOE covers these wattages, it is possible that it will establish standards at a level where only electronic ballasts can comply.
Congress is also considering regulating outdoor lighting through bills such as the Outdoor Lighting Efficiency Act. This bill would cover outdoor luminaires such as area, roadway, high-mast, dusk-to-dawn, and decorative post top, requiring that these types of lighting achieve certain levels of efficiency, provide bilevel control (except for roadway luminaires), and satisfy certain ratings for backlight, uplight, and glare. It would also set efficacy standards for high-output, double-ended halogen lamps and ban the manufacture of mercury vapor lamps starting in 2016.
Meanwhile, codes have had a meaningful, if not greater, impact on HID lighting. California's Title 24, in particular, requires bilevel outdoor lighting. ASHRAE/IES 90.1-2010 has a similar requirement.
For metal halide, strides have been made in pulse-start lamps, ceramic arc-tube lamps, and HID electronic ballasts. Pulse-start lamps offer longer lamp life, faster lamp start and restrike, and improved lumen maintenance.
With ceramic pulse-start lamps, there are two more trends: miniaturization and improved rendering of red. Ceramic metal halide systems are now offered in wattages as low as 15W, which can replace a 12V 50W MR16 for a savings of up to 32W per lamp. These lamps also have an improved ability to render reds with an R9 greater than 40, commonly used in retail.
On the ballast side, most innovation is occurring in electronic ballasts. Besides generating some energy savings, these offer lighter weight, a smaller size, improved lumen maintenance and life, and better power regulation which results in better color consistency. They are available for 15W to 750W lamps, both metal halide and high-pressure sodium systems, and have the ability to join zero-to-10V DC, DALI-based, and proprietary controls. Most products offer dimming to satisfy codes such as Title 24, usually down to about 50 percent. Others connect to zero-to-10V DC or DALI-based controls. A significant breakthrough is having the low-frequency, square-wave shape for higher wattages. This produces less wear and tear on the lamps and improves performance.
Although there is a great deal of innovation occurring in fluorescent and HID lamps and ballasts, these are mature technologies that in the long term will face a general slowdown in development. LED technology, meanwhile, is expected to become the dominant light source in nonresidential applications by 2030. As technologies evolve and LEDs make a run at fluorescent and HID market share, one thing is certain: Fluorescent and HID will not go down without a fight, and we should see many years of innovation in this segment.