Economical Analysis of Using Light-emitting Diode Technology for AK Street Lights

AIDC project number: 207099


Hsueh Ming Wang (UAA)

  • Alaska Department of Transportation & Public Facilities
  • UAF College of Engineering and Mines
  • Start Date: Oct 1, 2008
  • End Date: Sep 30, 2009

Project Summary

During winter nights in Alaska, streetlights often remain lit more than half the day, using energy all the while. Around the nation, communities are exploring the use of light-emitting diode technology for lighting streets and reducing energy use. Already, LED technology is successfully used in flashlights and electronic billboards. Some researchers suggest that, under ideal conditions, an LED streetlight system might use 50% to 75% less energy than a traditional streetlight system, with a longer performance life, too. In general, LED devices tend to be less fragile, switching on and off quickly, without flickering. LED technology, which may be the next step in efficient indoor lighting after fluorescents, is moving into the municipal streetlight market as a possible alternative to high-pressure sodium lamps. For this reason, AUTC researchers at UAA are exploring the use of LED streetlight technology for the Municipality of Anchorage. Converting an existing streetlight system to LEDs is not as simple as switching out a bulb. LEDs require entirely different circuitry and power supply designs, and the systems are more sensitive to changes in power supply. Installation alone of an LED streetlight system can cost a city several million dollars in immediate capital costs. However, while LED light systems can overheat in temperate climates, burning out circuitry and requiring frequent, expensive repairs, Alaska's lower environmental temperatures may provide an advantage for LED use. Some companies suggest that LED systems can last five to ten times longer than fluorescents in colder climates. This joint effort between UAA and UAF explores replacing traditional HPS streetlights with LEDs in urban areas of Alaska. The UAA team, led by Hsueh-Ming Wang, is developing an economic model to help the Municipality of Anchorage and DOT&PF form a replacement plan for urban lighting systems. The team is also exploring the possibility of equipping each LED streetlamp with an individual power source driven by solar or wind energy. The plan is ultimately to design, install, and monitor the performance of a prototype streetlight powered by a solar cell on the UAA campus. The UAF team, led by Richard Wies, addresses LED power use in a large-scale system, as well as whether an LED system can meet the national highway visibility standards set by the American Association of State Highway Transportation Officials. Thus far, a pilot experiment verified the performance of the LED light in arctic conditions (the light actually becomes brighter as the temperature gets colder). Another pilot project will test the system on the ground over the winter.