Below is another of my contributions to the May 2018 issue of tED Magazine. Reprinted with permission.
OLED continues to develop as a complementary technology to LED. In 2016, the Department of Energy (DOE) published two reports about the technology: the first, a market assessment, and the second, a GATEWAY report evaluating Acuity Brands’ Trilia OLED lighting system installed in an office application.
More recently, accounting firm DeJoy, Knauf & Blood LLP (DKB) invited DOE to evaluate a diverse installation of OLED lighting at its Rochester, NY offices comprising about 14,000 sq.ft. One of DKB’s founding partners is a co-founder and CEO of OLEDWorks LLC, the only U.S.-based OLED manufacturer. DOE published the resulting GATEWAY report in 2017, reporting significant energy and quality improvements over the previous fluorescent T8 lighting while gaining insights into OLED’s effectiveness in a real-world setting.
The office lighting project features LED lighting with OLED in a supporting role, taking advantage of its strengths and distinctive aesthetic. Acuity Mark LED Slot 2 linear LED luminaires provide general lighting in open offices. Acuity Gotham EVO downlights provide general lighting in private offices, complemented by OLED task lights by OLED Devices. OLED pendants by Acuity, Birot, Designplan, OMLED, and Visa feature prominently in spaces such as break/copy/conference rooms, lounge, and reception desk.
All of the OLED luminaires use OLEDWorks panels and feature dedicated OLED drivers (mounted remotely except for two, which integrate the drivers). When Acuity introduced the Peerless hybrid LED/OLED Olessence luminaire in 2017, which promises an efficacy of 71-81 lumens/W, DKB replaced some of the LED linear products in the open offices. DOE did not test them in its evaluation.
Measured efficacy for the previously installed OLED luminaires ranges from 21 to 58 lumens/W, lower than the LED luminaires (80-90 lumens/W). They are warm in color appearance (around 3000K) and render colors at a measured 79-91 CRI. Nearly all connected to 0-10V dimming controls and dim without flicker. In the nine months of operation, no luminaire failures were reported. Overall, DOE found the OLED lighting to provide comfortable brightness, illumination on vertical surfaces as well as the workplane, and soft, diffuse lighting quality. The total connected load for the LED and OLED lighting is 0.6 W/sq.ft.
This project demonstrates OLED lighting has come a long way over the past five years, though demand continues to be inhibited by its cost premium and low efficacy relative to LED luminaires. Another issue is that as the OLED panels age, they draw more power, which requires compensation in electrical circuit sizing and lighting power calculations. (DOE recommends using an additional power draw of about 15 percent when performing lighting power density calculations.) Next-generation OLED products, however, promise efficacies that are competitive with LED, 90 CRI, and a lifetime of 30,000 to 50,000 hours. This may position OLED well as a complementary technology to LED for general lighting.
Download the DOE GATEWAY report at bit.ly/2ynRiC1.