Parking lots and garages light up the night: Daytime users drive home and nighttime users are few, but for safety reasons, the lights stay on.
Michael Siminovitch, director of ºÙºÙÊÓƵ' California Lighting Technology Center and a professor in the Design Program, says seeing all that wasted light "makes you jump out of your seat and say 'Stop!' "
And that's what Siminovitch and his lighting-center team have done, in collaboration with ºÙºÙÊÓƵ facility managers, California energy regulators and providers, and a handful of key firms in the lighting industry.
The innovative result, unveiled today in a ºÙºÙÊÓƵ parking garage after two years of development and field testing, is a highly efficient and innovative package of technologies.
The system uses about 20 percent of the energy of conventional parking lighting systems, yet provides better safety, reduces light pollution and makes less toxic waste.
This bi-level lighting, part of ºÙºÙÊÓƵ' Smart Lighting Initiative, is already serving six ºÙºÙÊÓƵ sites (three parking areas, one pathway network and two building exteriors), as well as Sacramento State University and Arcade Creek Park in Sacramento.
It is also being exported to other users via a new effort called LED University. Early adopters include: UC Santa Barbara; Cal Poly San Luis Obispo; Tianjin Polytechnic University in China; University of Notre Dame; North Carolina State University; and University of Arkansas.
The new system includes:
- Light-emitting diode (LED) lights: LEDs give off bright white light but use little electricity. Each lighting fixture, called a luminaire, has three light bars containing 60 LEDs. Compared to conventional metal-halide lights, LED lights take less electricity (85 watts vs. 175 watts), last longer and contain no mercury.
- Motion sensors: Sensors detect the motion of a person or vehicle within about 35 feet. When no motion is detected for a designated period of time (30 seconds to 30 minutes), the sensor switches the LED light from its high level to a low level that uses half the energy. Even low level is bright enough to provide plenty of light for people entering the garage. And the switch from low brightness to high signals to people using the garage that there is another car or person moving nearby -- and gives that information to security personnel, too.
“Switching to LED lights and adding bi-level activity-sensing technology yields energy savings for the project of 50 percent when the lights are at full power and 80 percent when they are in low mode. As for maintenance savings, we project they will be 42 percent of what we spent on the fixtures that were replaced," Siminovitch said.
"Even at half power, the LED fixtures are delivering plenty of light to the space. We may be able to cut levels further, saving even more electricity and lengthening fixture lifetimes."
ºÙºÙÊÓƵ' external partners in the Smart Lighting Initiative are:
- PG&E, which offered incentives as part of a University of California systemwide energy initiative and supplied partial funding based on demonstrated energy savings.
- Ruud Lighting/BetaLED of Sturtevant, Wisc., which supplied the LED light fixtures; and
- Watt Stopper/Legrand of Santa Clara, Calif., which supplied the occupancy sensors.
About the California Lighting Technology Center
Part of the Design Program at ºÙºÙÊÓƵ, the center is a research and education facility that focuses on the application of energy-efficient lighting and daylighting technologies through research, development, demonstration, outreach, and education in partnership with utilities, manufacturers, end users, builders, designers and governmental agencies. The center was established through a collaborative effort of the California Energy Commission's Public Interest Energy Research (PIER) Program and ºÙºÙÊÓƵ, with support from the U.S. Department of Energy and the National Electrical Manufacturers Association.
About ºÙºÙÊÓƵ
For 100 years, ºÙºÙÊÓƵ has engaged in teaching, research and public service that matter to California and transform the world. Located close to Sacramento, ºÙºÙÊÓƵ has 31,000 students, an annual research budget that exceeds $500 million, a comprehensive health system, and 13 specialized research centers. The university offers interdisciplinary graduate study and more than 100 undergraduate majors in four colleges -- Agricultural and Environmental Sciences, Biological Sciences, Engineering, and Letters and Science -- and advanced degrees from five professional schools: Education, Law, Management, Medicine, and Veterinary Medicine. The ºÙºÙÊÓƵ School of Medicine and ºÙºÙÊÓƵ Medical Center are located at the Sacramento campus.