This article was originally published in the March/April 1993 issue of Home Energy Magazine. Some formatting inconsistencies may be evident in older archive content.
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Home Energy Magazine Online March/April 1993
TRENDS IN ENERGY
So Many Sockets, So Little Time
This year promises to see product standardization finally lending order to the diverse array of compact fluorescent lamps. That seemed to be the most significant point made at the third annual conference of the California Compact Fluorescent Consortium, a utility and industry partnership to promote energy-efficient lighting technologies. Participants at the conference, held November 4-6 in San Diego, debated issues ranging from lamp and fixture design to conservation program measurement and evaluation. One of the hottest topics concerned specifications for energy-efficient lighting that will soon be adopted by utilities. Their purchasing patterns will determine what kinds of compact fluorescent lamps manufacturers produce.
Compact fluorescents, popular in utility demand-side management conservation efforts, have the potential of changing the physical properties of the electricity they use. This alteration of power quality is measured by total harmonic distortion (THD) and power factor. The lower the THD and the higher the power factor, the less detrimental effect a lamp has on power quality. Experts have continued to argue whether a service grid filled with compact fluorescent lamps, particularly those outfitted with the first generation of electronic ballasts, may be poor power quality culprits. These lamps draw current in bursts which could wreak havoc both with performance of devices on the same electrical circuit and with power transmission services. Other devices may also contribute to the problem, especially computers and motors with variable speed controls. While an appeal of the magnetic ballasts in compacts is that they generally exhibit lower THD than electronic ballasts, their power factor may be lower too. Moreover, consumers complain that magnetically ballasted lamps are big and heavy, warm-up slowly, and contain trace amounts of radioactive materials.
Three researchers at the conference presented differing research results on power quality. Dave Pileggi of New England Electric System (NEES) designed a computer model which showed significant power quality degradation in a hypothetical system. Rudy Verderber of Lawrence Berkeley Laboratory presented measured data which showed only minor effects from a building totally outfitted with electronically ballasted fluorescent lamps (not only compact fluorescents). Jim Bemis of Sacramento Municipal Utility District saturated a residential neighborhood served by a single power feeder (through a 75 kilovolt transformer) with electronically ballasted compact fluorescents and found little measurable effect on power quality at that scale.
The jury is still out on the magnitude of the problem. According to Chris Granda of NEES, some at the conference challenged the SMUD study, maintaining that the 75 kilovolt transformer feeding the neighborhood in the study was large enough to absorb distortions, and thus capable of masking potential power quality problems. (Various feeders exhibit different levels of distortion in power quality.) Verderber expressed concern that specifications may be applied without sufficient research to determine what the actual requirements should be. Meanwhile, most agree that the effects on and by household electronics need further study, especially with myriad new devices reaching consumers annually.
In light of caveats like these and other uncertainties, utility representatives tend to agree that it is prudent to encourage manufacturers to improve power quality characteristics while enhancing the more tangible performance aspects. As high volume purchasers of compact fluorescents, utilities can influence how lamps are designed. Some have established their own benchmarks, typically a power factor of at least 0.9 and a THD of less than 33%--corresponding with Green Seal's Class A specifications. On the other hand, NEES, for one, is using an even more stringent THD level--25%. NEES fears that products designed only to Class A parameters will not exhibit sufficiently low THD to satisfy its needs. Presently NEES conservation programs are limited to magnetically ballasted lamps, reports Granda.
In response to utility demands for lamps that suit their hardware as well as their consumers, Green Seal finalized its long-anticipated specifications in cooperation with the California Compact in time for the conference. However, according to Granda, this may present a problem: If utilities jump on the bandwagon and adopt the Green Seal guidelines, NEES and others may find that manufacturers no longer produce the higher quality lamps they need.
The specter of lighting specifications propelled at least two manufacturers, Lights of America and Beacon, to design a compact fluorescent featuring integrated circuitry that eliminates power quality problems. Enertron is not far behind, promising a dimmable 27 W lamp with a power factor of nearly 1.0 and a THD less than 20%. When questioned in the manufacturers panel, most--but not all--companies reported they were developing compact fluorescent lamps with power quality characteristics that meet Green Seal's Class A specifications.
-- Judy Jennings
Judy Jennings is a senior research associate at Lawrence Berkeley Laboratory, and a consultant in the energy and environment consulting firm, CK and Associates in Albany, Calif.
Does this lamp lay power quality concerns to rest?
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