The U.S. Department of Energy (DOE) recently shared the results of one of its solid-state lighting (SSL) GATEWAY demonstration projects on Franklin Roosevelt Drive in New York, where LED luminaires from four different manufacturers were compared to the incumbent high-pressure sodium (HPS) luminaires and evaluated for relative light output and performance. Energy savings ranged from 26 to 57 percent compared to the incumbent HPS, and there was a high potential for improvement in illumination quality. However, the report showed that life-cycle costs would need to improve to economically justify an investment in solid-state lighting for many similar roadway lighting applications and that payback for this project would take at least eight years.

The study's executive summary said, “The cost effectiveness of the FDR Drive installation depends on high electricity rates and deferred costly maintenance. The lighting system maintenance in limited-access installations like elevated roadways, tunnels and heavily traveled urban highways can be quite expensive because it generally requires lane closures and multiple staff charging overtime labor rates, and even then the work must be carried out in close proximity to moving traffic. Safety issues increase as the speed of travel and traffic volume increase, both of which are significant at this location.”

For more details on this and other DOE Gateway studies, check out www.eere.energy.gov.