Department of Energy conducted a pilot project to assess the performance of Ballasted Lights and LED
technology in place of ornamental post-top street lights. A pilot project,
which was conducted in Sacramento, California attempted to characterize best-inclass
performance, as of March 2011, for two types of LED products relative to the existing
100 W high-pressure sodium (HPS) luminaires: lamp-ballast retrofits and complete
luminaire replacements. The LED option for ornamental post-top lighting
was not comparable to the 100W HPS lighting it would replace.
replacements were initially selected by the City of Sacramento, in coordination
with manufacturers and their sales representatives. An LED luminaire was subsequently
selected by PNNL to represent best-in-class LED performance for this particular
Even before Before measurements were taken in the field and at
a photometric testing laboratory, PNNL created a computer model using manufacturer-provided
photometry and predicted that the LED product would not match the photopic
performance of the existing HPS luminaires.
The measurements not only verified
none of these products matched the initial light levels produced by the existing
HPS luminaires, but also confirmed two of the products greatly reduced the uniformity
of illumination. Therefore the DOE says that any energy savings from the LED products
examined were directly attributable to reduced photopic light levels.