Nearly There: Screw-In LEDs

The stakes are high. According to U.S. Department of Energy (DOE) estimates, nearly 1 billion 60W A19 lamps will be installed in the United States by 2010. America is calling for a super-efficient lamp and has pinned its hopes on solid-state lighting. Are light-emitting diode (LED) screw-in replacement lamps ready to take on that venerable workhorse: the 60W incandescent A-lamp? DOE CALiPER product testing research suggests they are not.

Between initial testing in 2006 and Round 6, the most recent testing, CALiPER tested 10 LED omnidirectional A-lamp replacement lamps and found a wide range of performance.

In terms of efficacy, the best performing product produced 62 lumens per watt, about 4–4.5 times more efficacious than incandescents and on par with compact fluorescent lamps (CFLs). However, the lamp produced less than 300 lumens, about one-third of the light output of a 60W incandescent. This level of light output puts the lamp somewhere between 25W and 40W incandescent A-lamps. The highest output in the test group was still less than 450 lumens. So if LED lamps aren’t ready to take on 60W or larger lamps, are they suitable replacements for lower-wattage lamps?

Again, the results suggest they aren’t.

“As replacements for lower-wattage incandescent replacement lamps from 4–40W, some LED replacement lamps appear to perform well and could provide energy savings,” said Mia Paget, senior research engineer for Pacific Northwest National Laboratory, lead for CALiPER. “However, even targeting these lower wattage levels, some LED products that have been tested clearly do not provide the light output levels or the omnidirectional light distribution that would traditionally be expected in these replacement lamps, and a number of products sold as ‘white’ do not actually meet ANSI chromaticity standards for white light.”

For example, one lamp producing nearly 300 lumens exhibited two problems, making it unacceptable for most applications. The color temperature was measured at 7,272K, which is a cold, bluish light, and the power factor was 0.48. Other lamps exhibited problems such as distorted light distribution, poor color quality, dimmer incompatibility, and forms that made them unable to fit lighting fixtures designed for incandescent A-lamps.

CFLs suffered a rocky introduction, too. The bad part for LEDs is that the DOE’s testing data often contradicted manufacturers’ sales claims, suggesting manufacturers are routinely overstating product performance.

“The testing of omnidirectional LED lamps, like all SSL products, reveals huge ranges of performance in products available today,” Paget said. “Manufacturer claims regarding performance of LED replacement lamps are usually inaccurate or misleading.”

For example, the highest output LED lamp in Round 6 testing produces the same light output as a 40W incandescent but is claimed to produce the same light output as a 100W incandescent. In other cases, products claiming to be replacements for 40W or 60W incandescents produce light output more in line with 15W or 25W lamps.

While the DOE is concerned that underperforming products could disappoint early adopters and threaten the technology’s future market potential, Paget remains optimistic.

“LED replacement lamps are likely to be competitive within the next couple of years, but they are likely to be expensive in the near term and will only be used where users are seeking energy savings but for some reason have rejected lower cost CFLs,” she said.

Examples include cold temperature applications, applications prone to vibration or breakage, and other spaces where LEDs deliver a unique required benefit.

The DOE also expects a successful replacement lamp to be developed in the next one to three years and, as an incentive, is offering a $10 million “L Prize” to whomever can produce a high-performing, 90-lumen-per-watt LED replacement for 60W incandescents. To further usher things along, the DOE also has released draft Energy Star criteria for LED replacement lamps and plans to have the final criteria take effect this summer. Products that meet these criteria will qualify for Energy Star labeling, which says each product provides a minimum level of performance and is represented by claims based on industry-accepted testing standards.

And just in time, too, as GE has announced that it has suspended development of the high-efficiency incandescent lamp, ceding the field to energy-saving halogen screw-in lamps, CFLs and LEDs, starting in 2012, when the Energy Independence and Security Act of 2007’s lamp regulations begin to kick in.

Until then, seek independent data to verify claims. Consider all aspects of the product’s performance, not just wattage. Check for compatibility with installed dimming controls. Try out lamps personally. Install a few lamps in the application before committing to larger volumes.

To view reports summarizing testing of LED replacement lamps, visit and search for LED testing. For more on the L Prize, visit

DILOUIE, a lighting industry journalist, analyst and marketing consultant, is principal of ZING Communications. He can be reached at

About the Author

Craig DiLouie

Lighting Columnist
Craig DiLouie, L.C., is a journalist and educator specializing in the lighting industry. Learn more at and .​

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