The U.S. Department of Energy (DOE) recently issued new energy efficiency standards for ballasts sold as part of new metal halide luminaires. (To be clear, replacement ballasts are not covered.) The new rules strengthen current standards while expanding their scope, and will affect availability of 50-1000W luminaires. The deadline for compliance is February 10, 2017.
The existing energy efficiency standards were created by Congress with the Energy Independence and Security Act of 2007. They eliminated a majority of probe-start lamps and ballasts from medium-wattage (150-500W) luminaires.
Acting under its authority granted by the Energy Policy and Conservation Act of 1975, DOE strengthened these standards while expanding coverage to include low-wattage (50-149W) and high-wattage (501-1000W) luminaires.
Regulated-lag ballasts, limited to applications such as heavy industrial, security and street and tunnel lighting, as well as 480V electronic ballasts remain exempted from the rules. Metal halide luminaires rated only for 150W lamps; rated for use in wet locations; and containing a ballast that is rated to operate at ambient air temperatures higher than 50 degrees Celsius, however, lost their exemption and are now covered.
Currently, all metal halide ballasts offered in the low-wattage segment are pulse-start. Under existing energy efficiency standards, a majority of medium-wattage ballasts are pulse-start. The new standards will result in a majority of high-wattage ballasts on the market being pulse-start. Pulse-start ballasts offer superior efficiency, lumen maintenance and color stability than probe-start.
About ninety percent of metal halide ballast shipments are magnetic ballasts and 10 percent are electronic. Electronic ballasts offer superior efficiency and potential performance advantages such as better lumen maintenance, longer lamp life and continuous dimming capability. The ballast may be high-frequency or low-frequency square wave; high-frequency electronic ballasts are not compatible with all metal halide lamps. Despite these advantages, electronic metal halide ballasts pose reliability concerns in rugged applications. To satisfy these applications, transient and thermal protection features are required. Additionally, some electronic ballasts in indoor luminaires would require a 120V auxiliary tap to operate an emergency incandescent lamp. A final concern is that during DOE’s meetings with industry prior to the ruling, Florida Power and Light expressed concern that it operates a National Electrical Safety Code two-wire system and is having difficulties with electronic drivers.
Ballast manufacturers will be reviewing their product lines and determining on a case by case basis whether the product already complies, must be redesigned, or will be discontinued. If the magnetic ballast must be redesigned, or if an electronic ballast will be put forward in place of a magnetic ballast, the luminaire may need to be redesigned and retested, which may result in some gaps in availability. In the case of magnetic, this may further result in an aftermarket mixing current designs and redesigns. Because ballast and luminaire manufacturers may be reluctant to invest significant resources as metal halide is a declining market due to LED competition, we may also see a significant number of products removed from the market.
The new DOE energy efficiency standards will shake up the metal halide category, promoting efficient pulse-start options, particularly electronic ballasts.