DOE Report on Energy Reporting Capability of PoE Connected Lighting Systems

DOE Publishes Report on the Energy Reporting Capability of PoE Connected Lighting Systems

DOE has published the first part of a study to explore the energy reporting capability of commercially marketed Power over Ethernet (PoE) connected lighting systems. The new report provides a brief background on the development of the various PoE technologies, ranging from standards-based to proprietary, and illustrates the convergence of PoE power sourcing capabilities and LED luminaire power requirements. It then classifies PoE system devices in relationship to how they’re used in systems — introducing clarifying terminology as needed — and briefly describes different PoE system architectures implemented by various lighting manufacturers. A discussion of existing standards and specifications that address energy reporting is provided, and existing test setups and methods germane to characterizing PoE system energy reporting performance are reviewed.

Connected lighting systems that can report their own energy consumption can deliver increased energy savings over conventional lighting solutions by facilitating data-driven energy management. PoE technology — in which a single Ethernet cable is used to both provide low-voltage DC power and enable network communication — has the potential to bring this capability to mainstream lighting applications, and has become increasingly viable for LED lighting.

For a closer look at the findings, download the full report.

Best regards,
Jim Brodrick

— Jim Brodrick

Atlanta Commits To 100 Percent Renewable Energy By 2035

Atlanta Commits To 100 Percent Renewable Energy By 2035
The city becomes the 27th in the U.S. to pledge to go totally green.
By Chris D’Angelo
WASHINGTON — Atlanta lawmakers approved a measure on Monday aimed at powering the city entirely on renewable energy sources, including solar and wind, by 2035.

A resolution introduced by city council member Kwanza Hall and unanimously approved commits city government to develop a plan for transitioning all of its buildings to clean electricity sources by 2025, and for the entire city to go green a decade later.

“We know that moving to clean energy will create good jobs, clean up our air and water and lower our residents’ utility bills,” Hall, who’s also a Democratic candidate for mayor, said in a statement. “We never thought we’d be away from landline phones or desktop computers, but today we carry our smart phones around and they’re more powerful than anything we used to have. We have to set an ambitious goal or we’re never going to get there.”

Atlanta becomes the 27th U.S. city and the first in Georgia to pledge a 100-percent renewable energy goal, according to the Sierra Club.

“Just days after hundreds of thousands marched for climate action across the globe, city leaders here in Atlanta are answering the call,” Terry said in a statement. “Today’s commitment will inspire bold, ambitious leadership from cities throughout the United States and pave the way for a healthier and stronger Atlanta.”

Monday’s vote comes less than a month after Hall came under fire for voicing skepticism about climate change.

“I got a question mark on the global warming thing,” he said at a forum last month, the Atlanta Journal-Constitution reported. “I do believe in sustainability. I’m a science-minded person and I have a science background. But stuff is in the media too much. … It’s hard for me to be convinced sometimes.”

One day after his controversial remark, Hall issued a press release spelling out his goal to make the city run on clean energy and clarifying his previous comment.

“I did not articulate where I am coming from clearly, at all,” he said. “I believe in science, and the overwhelming scientific consensus that tells us that our planet is warming and it is caused by humans burning fossil fuels. What I’m not sold on is the politicization of big issues like climate change. A lot of it is senseless propaganda, and it comes from both sides.”

Atlanta’s commitment follows a similar pledge by the city of South Lake Tahoe, California, last month.

From SSL Postings: All Fired Up About Down-Conversion

April 19, 2017
All Fired Up About Down-Conversion
As you probably know, the process of down-conversion by phosphors has been central to the development of white-emitting LEDs. That’s because, for most white-LED systems, the LED emits blue photons, most of which are converted to green-yellow and red by a layer of phosphors that typically rests on top of the LED, with the resulting color mix perceived as white by the human eye.

This process, by which photons are converted from more-energetic colors to less-energetic colors, is known as down-conversion. And while down-conversion phosphors have progressed considerably over the past decade, they still need significant improvements in order to meet the performance targets described in the DOE SSL R&D Plan. That’s especially true for red phosphors, which could benefit from being less thermally sensitive and having a narrower spectral width to better match the eye response. With DOE R&D support, GE has commercialized a promising narrow red phosphor, PFS, that’s making its way into GE lighting products with excellent color quality and efficacy. Another narrow red phosphor that has made it into LED products with similar benefits is the SLA phosphor developed by Lumileds.

However, phosphors aren’t the only materials that can be used as down-converters. For quite some time now, scientists — some of them funded by DOE — have been working on developing alternative down-conversion materials called quantum dots (QDs), which are more tunable than phosphors in terms of emitted wavelength, and can be spectrally purer (that is, they have a narrower spectral width). In addition, QDs have demonstrated very high conversion efficiencies that match or exceed those of existing phosphors.

QDs are engineered materials that convert light through a different process than do phosphors, which are limited by their own material emission and absorption properties, whereas QDs re-emit light as a function of their size. What’s more, the ability to develop specific sizes of QDs gives them the potential for greater spectral control. For the past few years, QDs have been used in TV displays, because their narrow emission expands the color gamut, resulting in a more vivid image. However, the rapid degradation of QDs under on-chip LED operating conditions — notably, high temperature, humidity, and blue-flux intensities — has been the biggest barrier to their use as a narrow-band red solution for white LEDs in general illumination applications.

That barrier appears to have been overcome — or, at least, to be toppling. Scientists at Lumileds, reporting in the journal Photonics Research, say they’ve used red QDs with tunable peak emission and narrow spectral width to demonstrate the first commercial production-ready white QD LEDs for the general illumination market. This has resulted, they say, in LED efficacy improvements of 5-15% over commercial phosphor-based LEDs, at CCTs that range from 2700K to 5000K — and without the degradation that plagued previous attempts.

In other words, up until now, no one had been able to successfully deploy QDs on chips, because of the degradation from the flux, temperature, and moisture. Lumileds has succeeded by using QDs that are developed by Pacific Light Technologies and are able to withstand the extreme environment of a conventional LED package, while showing similar stability as the phosphors that they’re displacing.

This is an important breakthrough, because it puts a whole new technology in the LED lighting toolbox, enabling higher luminous efficacy and even more-refined control of the emission spectrum for down-converted LEDs. DOE is currently funding an R&D project at Columbia University that aims to further improve the manufacturability of the QDs that were used to get this result, and Lumileds is planning to commercialize the breakthrough.

The development of quantum dots illustrates the importance not only of taking an integrated approach that considers all elements and requirements of the system, but also of casting a wide net for R&D that takes into account alternative approaches that can help improve SSL performance.

Best regards,
Jim Brodrick

As always, if you have questions or comments, you can reach us at

— Jim Brodrick

LED Light Technology’s LED Plug N Play Plus™ tube is ballast and line voltage compatible!

LED Light Technology’s LED Plug N Play Plus™ tube is an innovative approach to the standard LED tube replacement. Our tube works in conjunction with the existing ballast and direct line voltage. The tube allows for a simple bulb change when using the current ballast or a quick rewire for direct line voltage, which generates even more energy savings. The tube is guaranteed to lower operating costs and reduce energy usage. Customers have seen a drastic reduction in upfront cost when upgrading to our LED tube that works off the ballast and then switching to direct line voltage at the ballasts end of life. Please contact to receive a promotional quote for this product.   Click here for Product Specification Sheet




Del Monte Fresh Produce, N.A. Inc. Installs Intelligent Energy Efficient LED Lighting

LED Light Technology provided Del Monte an innovative and intelligent LED lighting system at their Galveston Port Facility. 

Similar facilities that install LED Light Technology’s Intelligent LED Lighting System will obtain an estimated $132,225.00 in annual energy savings, which equates to removing 68 cars from the road and planting 9,213 trees every year.  Candidates for this system will recoup their investment within one to two years and will benefit from years of maintenance-free use and measureable validation of their investment.

Intelligent 80 Watt LED High Bay complete with wireless controllable software management system. This 80W fixture replaced a traditional 400W HID High Bay.
We want to thank you for all yours and Amy’s efforts on this project and we are very happy with the performance of the product. Being able to monitor the performance and cost savings using the software system is truly amazing and takes facility lighting to a completely differently level. We look forward to the higher performance and lower costs that LED’s provide and believe we made the right decision when we chose your company to make the conversion.
— Joe Wiley, Port Manager, Galveston, TX

New CALiPER Snapshot on TLEDs

Linear fluorescent lamps — energy-efficient, long-lived, and relatively inexpensive — have been a staple of ambient lighting in offices, classrooms, and other commercial spaces, where they’re usually housed in troffers. Linear LED lamps, commonly known as TLEDs, typically draw about 60% of the power of linear fluorescents and have become a viable alternative, used mainly in retrofit situations. DOE’s CALiPER program has released a new Snapshot report on TLEDs that’s based on LED Lighting Facts® data.

Among the key findings:
• TLEDs now comprise more than 50% of all lamps listed with LED Lighting Facts, and more than 10% of all listed products.
• TLEDs offer the highest mean efficacy of any lamp type, and also include the listed product with the highest efficacy (190 lm/W).
• In aggregate, TLED efficacy decreases by 3 lm/W for every 1000K decrease in CCT.
• While the raw efficacy of TLEDs exceeds that of dedicated LED troffers, the reverse is true if TLED efficacy is adjusted to account for luminaire efficiency. In other words, dedicated LED troffers tend to exceed the efficacy of troffers fitted with TLEDs.
• Almost all (98%) of the listed TLEDs have a CRI in the 80s, with most between 80 and 85.
• A vast majority (97%) of TLEDs that are currently listed by LED Lighting Facts (and that report this optional metric) have a power factor of 0.90 or greater.
• Nearly 90% of the currently listed TLEDs (which include 2’- and 4’-long products) emit between 1,000 and 3,000 lumens. This is generally less than the emission of a typical 4’ linear fluorescent lamp. Of the more than two-thirds of TLED products that are identified as having a 4’ length, the mean output is 2,094 lumens.
As the numbers from LED Lighting Facts attest, TLEDs seem to be everywhere, and their numbers are growing rapidly. But while their rise to prominence is indisputable, they’re not necessarily a clear favorite when evaluating performance.

LED Lighting Facts data show that TLEDs consistently draw less power and emit fewer lumens than the linear fluorescent lamps they’re intended to replace. On balance, they have somewhat higher efficacies, but the energy savings achieved are in large part due to the lower power draw. Importantly, TLEDs offer more of a directional emission than linear fluorescent lamps, meaning they can make troffers or other luminaires more efficient, delivering equal illuminance to the work plane, with fewer lamp lumens. However, sometimes the increased luminaire efficiency can’t compensate for the reduced lamp lumens. In such cases, energy savings are derived from reducing the light levels, which may or may not be acceptable. The change in distribution, something that’s not obvious from the LED Lighting Facts data, presents yet another issue, as it can change both the appearance of the luminaire and the distribution of light within a space.

TLEDs are often compared to other LED options for replacing a fluorescent lighting system — such as using retrofit kits or dedicated LED fixtures. At first glance, TLEDs may appear to be superior, with higher efficacy and likely lower product and installation costs. But accounting for factors such as luminaire efficiency may tip the balance against TLEDs in some scenarios, and their long-term costs may be increased by factoring in the remaining life of existing fluorescent ballasts, if they’re to be reused.

Nevertheless, viable TLED options are increasingly available, which was not the case a few years ago. And as they push the efficacy limits for LED products, TLEDs can be compelling replacements for fluorescent tubes, as long as other tradeoffs are appropriately accounted for. But there are thousands of choices when specifying TLEDs. And as the new Snapshot report shows, there’s considerable diversity in performance, even when examining only basic attributes. The Snapshot doesn’t address the electrical and safety considerations when changing from fluorescent to LED lamps, nor does it examine features such as distribution of light or lifetime. It also doesn’t distinguish between the different types of TLEDs (UL Type A, those that can operate directly on a fluorescent ballast; UL Type B, those with an integrated driver; UL Type C, those with an external driver; and hybrids), because they don’t differ appreciably in photometric performance. Their distinguishing features, however, are very important considerations during specification and installation.

When evaluating TLEDs, it’s critical to examine the expected performance of the complete lamp and luminaire system, understand the complexities of installation, and be cautious in considering long-term performance.

For a closer look at the findings, download the full report. For additional guidance, see the DOE Fact Sheet Upgrading Troffer Luminaires to LED.

Best regards,
Jim Brodrick

— SSL Postings, US Department of Energy