Last year, public works draped the 40-foot Christmas tree in downtown Webster, Mass., with strand upon strand of LED lights that Director Michael Suprenant estimates used one-fifth the electricity of the old incandescent bulbs.

If only all cost/benefit analyses regarding the rapidly evolving technology of solid-state lighting were as straightforward.

Jim Terry, a regional sales manager for Ameron Pole Products and self-professed "lighting geek" who's has been studying the industry for 15 years, cautions street managers to weigh several factors before upgrading their community's street-lighting equipment:

  • While LEDs are not always the most cost-effective option, a 40w LED is four to five more efficient than a 175w mercury vapor lamp. A 100w or 120w LED can easily take the place of a 150w high-pressure sodium (HPS) lamp.
  • The industry is largely unregulated, though the Roadway Lighting Committee of the Illuminating Engineering Society is developing standards. In the meantime, use a Kill A Watt to verify manufacturer claims.
  • Start slowly, and get public input. When Salt Lake City began using 150w LEDs for spot replacements of 250w HPS lamps, residents noticed the difference between the lights' white and amber hues. The city's since switched to 250w metal halide for replacements - still different, but not as dramatic.
  • LEDs are essentially computer circuit boards. Though their lifespan is up to 20 years in nighttime applications, when they do finally fail the entire unit - not just a lamp - must be replaced.
  • Make sure LEDs in unmetered applications qualify for decreased rates by your local utility.
  • Many cities are using funding available through the stimulus package to roll out large-scale retrofit programs, but some products are made overseas. According to Terry, Seattle has determined that the legislation's Buy American provision does not apply.

The good news is the U.S. Department of Energy is helping consumers sort through their confusion by launching an online consortium specifically so public works and utilities can share information and experiences regarding solid-state lighting. The community was created to help for the vast number of cities that applied but weren't accepted as host sites for the department's Gateway demonstration program.

American Public Works Association Congress & Exposition
Session: Solid State Lighting/A Solid Investment?
Mon., Sept. 14, 2009
James Terry, Northwest Regional Sales Manager
Ameron Pole Products Division
Snohomish, Wash.