Chris Cioni, Associate Director of Facilities Management with the University of California, Davis, discusses the university's Smart Lighting initiative
Christopher Cioni
Associate Director, Facilities Management
University of California, Davis
Davis, Calif.
What are the key goals your department hoped to achieve with the university's Smart Lighting initiative?
Reduce energy consumption; improve lighting system reliability; reduce maintenance costs; address the perception that we waste energy or light during the night – midnight to dawn.
The university retrofitted one of its three parking garages with bi-level induction lamps and part of another with light-emitting-diode (LED) technology. How have these retrofits reduced both energy use and maintenance costs?
There are three components to the energy savings. First, the induction and LED fixtures have slightly lower baseline consumption compared to the existing sources, such as high-pressure sodium and metal halide. Second, the induction and LED lamps experience much lower lumen depreciation over their useful lives, so a lower wattage lamp can be installed. Third, adding a dimmable ballast and connected occupancy sensor allows energy use to drop significantly during non-occupied hours, particularly overnight.
In terms of maintenance costs, it is too early to quantify savings. The manufacturers of the induction and LED fixtures state that we can expect lamp life of up to 100,000 hours. Our experience with the high-pressure-sodium and metal-halide fixtures on campus tells us those lamps typically require replacement more frequently – roughly every two years. Based on these figures, our cost to relamp will drop significantly.
Here are the number of exterior fixtures on our campus: 1,400 in parking structures; 700 on roadways; 1,000 on pedestrian or bicycle paths; 900 in parking lots; and 3,000 mounted on building exteriors.
Your department also will retrofit bike paths, surface lots, and fixtures mounted on the exteriors of buildings. What technology will you specify for these retrofits? Why?
Our experience with certain induction and LED products has been very positive, so those are obvious choices as we move forward. We are particularly interested in dimmable – bi-level – technology and extended lamp life. Working with our campus partners at the California Lighting Technology Center, I’ve come to realize there is a great deal of research and development taking place in the lighting industry. High-performance metal-halide lamps are being introduced to the market, and these might be attractive in certain applications – or as an alternative to whole-fixture replacement. So while we remain focused on induction and LED, we will continue to explore new technology development.
It boils down to reliability and energy. The notion of 100,000-hour lamp life is very appealing. Reliability translates to safety and maintenance savings, which are extremely high priorities. Obviously, the energy savings are the financial engine driving the retrofits and make a great contribution to sustainability.
How have the lighting retrofits impacted security on campus?
So far, the retrofits have been well-received and considered an enhancement to campus security. I realized security issues would figure prominently, so the university’s chief of police was brought into the discussion to gain buy-in, as well as identify desirable features that might be incorporated into the new scheme.
The discussions were very constructive and actually helped turn a potential negative into a security enhancement – the bi-level occupancy feature. There was some concern that the lower lighting level – 50 percent – would detract from safety. But the first demonstration revealed the 50 percent light level provided surprisingly good luminance, both measured and perceived.
There is consensus that the jump in lighting level triggered by occupancy might serve to alert parking garage and parking lot patrons to the presence of others. The police chief also considers the improved color rendering to be a positive feature in visual identification by patrol officers and the campus community.
How has the Smart Lighting program contributed to the university's overall focus on sustainability?
Sustainability and energy conservation already are key elements of the university’s business practices. But the program has clearly demonstrated sustainability does not have to be a zero-sum game.
What began as an energy-saving project evolved into something much larger – improved lighting quality in terms of color rendering, lower maintenance costs due to extended lamp life, increased system reliability, reduced solid-waste disposal cost for used lamps, and reduced light pollution and dark-sky impact. Our campus views this first phase as a definite success and has launched a larger working group to address the prospect of reducing overall lighting energy use – interior and exterior – by 50 percent.
posted: 7/8/2009
