What's New in HID Ballasts

Written by Craig DiLouie

Published: Electrical Contractor Magazine, August 2011

As with other types of lighting, energy codes and legislation are influencing high-intensity discharge (HID) lighting—high-pressure sodium (HPS), metal halide (MH), and mercury vapor—in this era of regulated efficiency.


The Energy Policy Act of 2005 eliminated mercury-vapor ballasts—with specialty ballasts allowed by later legislation—encouraging a switch to HPS or white light. The Energy Independence and Security Act of 2007 eliminated probe-start magnetic ballasts in new 150–500W MH lighting fixtures, increasing demand for pulse-start quartz and ceramic metal halide (CMH) lighting. Pending energy legislation in Congress would eliminate general-purpose mercury-vapor lamps starting January 2016.
Meanwhile, commercial building energy codes continue to impose restrictions on outdoor lighting. California’s Title 24 energy code and the ASHRAE/IES 90.1 2010 energy standard go even further by requiring outdoor lighting to be capable of bilevel switching. And California Title 20 product regulations require 150–500W MH fixtures to achieve a certain level of ballast or fixture efficiency or feature automatic energy-saving lighting controls.


While many of these regulations affect the new construction market, the retrofit/replacement segment also offers opportunity. In 2010, this segment ­represented 46 percent of HID ballast sales, according to National Electrical Manufacturers Association (NEMA) sales data. Popular retrofit options include pulse-start electronic HID (eHID) replacements of existing large-wattage probe-start systems, and eHID/CMH replacement of halogen lamps.

As a result of this pressure, innovation is trending toward efficiency, controllability and smaller size. MH is the most popular HID light source with a massive installed base. As the market is shifting to white light options, most innovation is occurring in the MH category.
The big efficiency story is on the ballast side, where the trend is toward higher efficiency and controllability. The eHID ballast has been around for a long time, but its moment has arrived. Sales of eHID ballasts constituted 17 percent of the $231 million HID ballast market in 2010, up from 15 percent in 2009, according to NEMA. Most of this is in the wattages smaller than 150W segment, where the smaller than 39W pulse-start eHID ballast sales increased 338 percent over 2009 and 40–149W pulse-start eHID ballast sales increased 84 percent. Pulse-start eHID 150–250W ballast sales, however, also increased a healthy 108 percent, while those wattages larger than 250W, with fewer offerings, increased 21 percent.

In the larger than 150W segment, we’re seeing interesting innovations. A number of new ballasts feature digital construction, increasing their capabilities. Many eHID ballasts offer continuous dimming to satisfy energy codes, such as Title 24—usually with a range from 100 to 50 percent of lamp power per NEMA recommendations. Some of these products connect to 0–10V DC controls or DALI, enabling them to join a control network.

Another recent breakthrough in high-wattage eHID ballasts is the adoption of a low-frequency square wave shape, already popular in low-wattage CMH systems. The low-frequency square wave shape reduces wear and tear on the lamps, producing better performance.
Some ballasts can be used to operate both MH and HPS lamps, providing eHID options to HPS that were previously lacking and with fast HPS restrike. Finally, we’re starting to see more offerings for higher wattage lamps. Legislation and development has focused on 150–500W MH, but there are viable retrofit opportunities above 500W.
Some products worth a look include Sylvania Quicktronic MH, Sylvania Metalarc Powerball 200W system, GE UltraMax, Sylvania Quicktronic QHO (outdoor product), Universal Lighting Technologies 210W, Philips CosmoPolis programmable digital ballast, Metrolight SmartHID Plus and Empower digital ballasts.

In the smaller than 150W segment, the big story is 15W and 20W systems with eHID ballasts available in an extremely compact size, with the ultimate goal being to make the ballast “disappear.” This objective permits smaller fixture designs to open new track and other applications in both new and existing buildings. With extremely compact components, CMH lighting fixtures are approaching the factor and size of low-voltage MR16 halogen systems, offering an attractive alternative to traditional incandescent and halogen sources.
Let’s start with 20W, until recently the smallest MH system available. A 20W CMH system might replace a 75W halogen lamp, for example. To support CMH as a viable alternative, ballast manufacturers are producing extremely small electronic ballast designs. New ballasts from GE, Universal Lighting Technologies and Hatch Transformers measure about one-sixteenth the size of a standard eHID ballast, allowing for smaller products.

Even smaller than 20W is the recently introduced 15W system. An example is the Sylvania Metalarc Powerball 15W T4 CMH lamp and Super Mini ballast producing output comparable to a 12V, 50W MR16 and savings of up to 32W per lamp (25 percent energy savings compared to the 20W option). This system allows HID to be substituted for lower wattage lamps where the 20W system might be considered too bright.

Market pressure is driving an extraordinary level of innovation in HID ballasts, creating new opportunities in both new and existing buildings.