In February 2014, the U.S. Department of Energy (DOE) announced new energy-efficiency standards for ballasts sold as part of new metal-halide luminaires, which are commonly used for illumination in parking lots, roadways, warehouses, big-box retail and floodlighting. Compliance is required by Feb. 10, 2017, and will affect availability of 50–1,000-watt (W) luminaires.


Implemented under authority granted by the Energy Policy and Conservation Act of 1975, the new rules update existing energy-efficiency standards created by the Energy Independence and Security Act of 2007. The previous standards essentially eliminated probe-start lamps and ballasts from new 150–500W metal-halide luminaires.


The new standards establish minimum ballast efficiencies for luminaires based on luminaire location (outdoor or indoor), ballast type and rated lamp wattage (50–100, 101–149, 150–250, 251–500, 501–1,000). New efficiency standards were created for 50–149W and 501–1,000W; existing standards were amended for 150–500W. Probe-start ballasts were banned outright for luminaires with 501–1,000W rated lamp wattages.


The new rules only cover new luminaires, not replacement ballasts.


Regulated-lag ballasts—limited to heavy industrial, security, and street and tunnel lighting applications—remain exempt from the rules. The same is true with 480V electronic ballasts. Metal-halide luminaires rated only for 150W lamps and for use in wet locations and that contain a ballast rated to operate at ambient air temperatures higher than 50°C lost their exemption and are now covered.


As a result, all metal-halide ballasts in the low-wattage (50–149W) segment are pulse-start. The Energy Independence and Security Act of 2007 required probe-start ballasts in the medium-wattage (150–500W) segment to be at least 94 percent efficient, effectively banning this ballast type (aside from listed exemptions). The majority of metal-halide lamp shipments are in this segment. The new rules, meanwhile, effectively eliminate probe-start in the relatively small high-wattage (501–1,000W) segment. Note that 1,001–2,000W ballasts are not covered.


Within the pulse-start offering, there are magnetic and electronic ballasts. Depending on the lamp wattage, compliant magnetic and electronic ballasts are already available. Noncompliant products will be redesigned or discontinued on a case-by-case basis.


Magnetic ballasts currently make up more than 90 percent of the metal-halide ballast market. Pulse-start magnetic ballasts are more efficient and provide better lumen maintenance and color stability than probe-start magnetic ballasts.


Electronic metal-halide ballasts are available for indoor and outdoor applications. They are up to 95 percent efficient, producing about 10 percent energy savings compared with magnetic ballasts. These ballasts may also improve lumen maintenance and extend lamp life. End-of-life protection turns the lamp off to prevent cycling. Many ballasts also are dimmable and offer controllability. The ballast may be high-frequency or low-frequency square wave. Note that high-frequency electronic metal-halide ballasts are not compatible with all metal-halide lamps; matching an incorrect lamp with the ballast could result in early lamp and/or ballast failure.


With their high efficiency and other performance benefits, electronic ballasts would appear to be a good choice. However, switching from magnetic to electronic at the OEM level is problematic. Electronic ballasts are simply not as rugged as their magnetic counterparts, resulting in risks applying them in certain applications, particularly outdoor environments. For example, adopting an electronic ballast for an outdoor luminaire would require an internal or external surge-protection device to protect it against transient voltages. Electronic ballasts in indoor luminaires may require a 120V auxiliary tap to operate an emergency incandescent lamp. Electronic ballasts in outdoor and certain indoor applications may require thermal protection. Additionally, Florida Power and Light has expressed concerns that it operates a National Electrical Safety Code two-wire system and is having difficulties with electronic drivers.


In short, over the next three years, manufacturers will be evaluating their products to determine which already comply, which must be redesigned or which will be discontinued. In some cases, the luminaire will need to be redesigned then retested to accommodate a larger magnetic ballast size or an electronic ballast. This may create an aftermarket that mixes current designs with redesigns. Manufacturers may be reluctant to invest significant resources as the market for metal halide is declining due to the encroachment of light-emitting diodes. We may see a significant number of products removed from the market, with some gaps in availability in cases where the luminaire must be redesigned and tested.


The customer, meanwhile, will see energy savings but, potentially, a higher cost that could be lengthy to recoup. The DOE evaluated representative products and determined paybacks ranging from 4.5 to nearly 20 years (with the exception of 1,000W lamp ballasts, which would see a relatively quick payback of less than a year).


These DOE energy-efficiency standards will shake up the metal-halide category, promoting efficient pulse-start options, particularly electronic ballasts.