DOE Publishes Report on LED Street Lighting's Impact on Sky Glow

DOE has published the results of a study of the expected contributions to sky glow from converting high-pressure sodium (HPS) street lighting to broader-spectrum (i.e., white light) sources, with specific focus on LEDs, and presents the contributions in a manner relative to HPS baseline conditions. These conditions represent typical conversions in the U.S. and include changes in spectral power distribution (SPD), percent uplight, and lumen output.
 
Drop-lens (left) and flat-lens (right) cobra head street light fixtures. (Image: DOE)
 
 
  • All of the LED product conversions reduce sky glow relative to an HPS baseline when the results are expressed as unweighted radiant power, for both near and distant observers.
  • When the results are scotopically weighted to evaluate the effects on human vision, some LED products reduce sky glow for the near observer compared to the baseline, and others increase it, depending on their relative content of shorter wavelengths. An important related finding, however, is that CCT is not a very reliable predictor of sky glow impacts, especially when scotopic weighting is not applied.
  • Overall, the results for LED conversions in this study ranged from a low of 0.2 to a high of 1.6 times the baseline HPS sky glow, depending on the combination of variables and factors studied.
  • For a distant observer under the scenarios modeled, even at only 40 kilometers from the city center, the elimination of uplight that occurs in typical conversions nearly removed (by 95% or more) the contribution to sky glow from the street lighting system, for both the unweighted and scotopically weighted results, for all SPDs and atmospheric conditions.  

 

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

Disclaimers of Warranties
1. The website does not warrant the following:
1.1 The services from the website meets your requirement;
1.2 The accuracy, completeness, or timeliness of the service;
1.3 The accuracy, reliability of conclusions drawn from using the service;
1.4 The accuracy, completeness, or timeliness, or security of any information that you download from the website
2. The services provided by the website is intended for your reference only. The website shall be not be responsible for investment decisions, damages, or other losses resulting from use of the website or the information contained therein<
Proprietary Rights
You may not reproduce, modify, create derivative works from, display, perform, publish, distribute, disseminate, broadcast or circulate to any third party, any materials contained on the services without the express prior written consent of the website or its legal owner.

The recent outbreak of COVID-19 has prompted the large-scale search for practical solutions that can prevent the spread of the deadly virus — from researchers and scientists committed to finding a solution, to the manufacturers and consu... READ MORE

Nichia’s Tunable 757 receives rave reviews from industry leaders, including the coveted LpS Best Sustainability Technology Award. Nichia, the leader in and inventor of the high-brightness LED, announced its game-changing single LES, tuna... READ MORE