UM Wireless Lighting Control System To Save Energy, Money
The University of Michigan will test an energy-savings lighting technology that also enhances safety and visibility with a pilot project in the Hill Street parking structure adjacent to the Stephen M. Ross School of Business.
The new LimeLight system, developed by a Michigan company, makes use of a sophisticated computer management system that allows individual lights to be turned off and on by program settings, motion sensors and photocells.
"We are thrilled to introduce this new breed of lighting system to the campus community," said Steve Dolan, executive director of Parking & Transportation Services. "The LimeLight system automatically reacts to the lighting needs in any given location to enhance both the safety and energy efficiency of our structures."
The system works like it would for a homeowner, where a motion detector turns on an outside light as the homeowner's car approaches the garage.
In this case, the 231 lighting fixtures in the 473-space parking structure can be controlled in several ways.
Lights can be controlled through computer programming. Each lighting fixture is assigned to a lighting group and the typical schedule for those lights is set based on the facility's typical use patterns.
Motion sensors also control the lighting fixtures. When motion is detected, the sensors override the programming to activate groups of lights.
For example, once turned off for the night, the lights would turn on as an employee, working late, starts walking toward their vehicle. Lights would continue to light up the path of the vehicle as it exits the darkened parking structure. The lights would turn off after 15 minutes of inactivity.
Photocells sense ambient lighting levels and activate alternate programs that turn off individual lamps. This is known as light harvesting.
"The sensors will detect when natural light is available and activate other programming that selectively turns off lights," said Diane DeLaTorre, associate director for parking operations and maintenance at PTS. "When it becomes darker, normal programming resumes. This feature will save energy and the life expectancy of the lamps."
The Hill Street location was selected as the first test site because the lighting system was obsolete. The old lighting fixtures used 250 watts compared with the new technology, which uses a 102-watt fluorescent fixture.
"The old fixtures produced insufficient light levels by current standards, resulting in dark areas and were operationally inefficient," DeLaTorre said. "With Limelight we were able to achieve improved lighting and also gain significant operational efficiency."
The new pilot project is consistent with the university's overall efforts to reduce energy. Earlier this year, the university announced that its Planet Blue program decreased overall energy use by 14 percent -- avoiding $5.2 million in costs -- in 67 buildings on the Ann Arbor campus during the last year.
"Our Parking and Transportation team is very focused on finding ways to reduce operating costs in all aspects of our operation," Dolen said. "Depending on how aggressive we are with using the features of the Limelight system, we can expect energy savings associated with running the lights of up to 40 percent. It's a great example of how using technology can help PTS with its fiduciary and sustainable responsibilities."
The total cost of the project was $550,000. University officials say the energy-savings technology cost approximately $100,000, which should pay for itself in 2-3 years.
The university will review the success of the pilot in coming months to determine whether to convert other structures to the energy saving lighting system.
