Back to Home Page
College Home
University Home
Past Issues
Contact the Editor
 
Signatures Cover
Download PDF of this Issue
 
 
Seeing the Big Picture
Talking Points
Taking Note
Making the Grade
Sharing Perspectives
Reaching Out
Staying in Touch
 
Reaching Out
Energy Week Battery Drain Home Bodies
We’ve Got it Covered That’s So High School Pretty in Pink
The Benefits of Collaboration Another Bright Idea  

Having a university in your backyard has its benefits. Over the last eight semesters, Douglas C. Hall, associate professor of electrical engineering, and several teams of undergraduates have been working with the South Bend Public Works and Division of Engineering to quantify the benefits of replacing all of the incandescent bulbs in the city’s traffic lights with light-emitting diode

(LED) units. The students studied the cost savings (incandescent bulbs must be replaced annually, even if the bulbs are still functioning, and they use more energy) and time savings (when work crews don’t have to change bulbs, they can focus on other needs). Another consideration was safety. When an incandescent signal burns out, the whole light is gone. In contrast, LEDs do not suddenly burn out. They can operate for years with slowly decreasing brightness, which eliminates driver confusion and the ensuing chaos that occurs when a signal suddenly fails. Incandescent bulbs typically last 18 months, while LED signals can continue to meet brightness regulations for up to 10 years

Most recently, Hall and senior Patrick Cash were involved in the months-long process as the city reviewed responses to its Request for Quotation to replace the incandescent lights. After in-depth interviews and selection discussions, South Bend chose to pursue a guaranteed energy savings performance contract with Johnson Controls. The company will switch out the city’s traffic signals with LEDs, and the city will receive annual audits showing the energy and cost savings, which is projected at $1.97 million over a 10-year period. Under the terms of the contract, if the energy savings are not as projected, Johnson Controls has to pay the city the difference. As part of the project, students’ calculations encompassed all of the bulbs in South Bend: 1,600 red, 1,241 yellow, and 1,586 green bulbs in traffic lights; 99 red, 146 yellow, and 154 green left-turn bulbs; and 1,100 pedestrian signals.

For more information about the students’ study and LED technology, visit www.nd.edu/~leds.