The U.S. Department of Energy (DOE) has published the final report from a demonstration of LED technology in ornamental post-top street lights, conducted in Sacramento, CA. This report provides an overview of the evaluation of four different LED replacement products using computer simulations, field measurements, and laboratory testing. The evaluation was conducted by DOE’s Municipal Solid-State Street Lighting Consortium in collaboration with the Sacramento Municipal Utility District and the City of Sacramento, with additional support from City consultant Mary Matteson Bryan.
In this pilot project, the study was restricted to lamp-ballast retrofit kits and complete luminaire replacements that would preserve the daytime appearance of the existing acorn-style luminaires. This challenge proved formidable, as the results indicate that none of the LED products evaluated could match the performance of the existing 100W HPS luminaires. To allow for apples-to-apples economic comparison, the pricing and input power of the LED products were scaled proportionately to represent hypothetical products which would match the HPS light levels.
Energy used by three of the “scaled-up” LED systems ranged from 63 to 90 percent of the baseline HPS—the fourth product would actually increase energy use by 15 percent—and none of the products would represent cost effective alternatives to HPS. In response to recent industry developments, the study also investigated the relative significance of mesopic multipliers offered in the new IES Lighting Handbook and the lumen maintenance extrapolation methodology offered in the new IES TM-21.
This pilot project is the first in a series conducted by the DOE Municipal Solid-State Street Lighting Consortium, which serves as an objective resource for LED product evaluation and a repository for valuable field experience and data. The report highlights some of the critical nuances involved in LED product selection, and data generated from this project may be useful to standards groups, manufacturers, and those considering retrofits to LED. For more details, view the full report.