A “Dim” System is a Smart Solution for Costco

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by
Zach Abrams, ICF International, Michael Meyer, Pacific Northwest National Laboratory
on
Jan 08, 2016

Better Buildings Alliance member Costco, a membership warehouse retailer based in the Pacific Northwest, implemented a low-cost lighting technique in its office space that reduced the average wattage per fixture by 80%, and increased staff comfort. Costco buildings have been acquired and modified over time, and staff tend to change locations regularly. The standard 100 watt troffer lighting was too bright for many employees, leading to discomfort and, on occasion, independent adjustments like taping over fixtures.

Costco considered a variety of lighting controls to go with a transition to LEDs, but found that in their case the controls cost even more than the LED kits. Because of the relatively low cost of energy for Costco in the Northwest (different case in Southern California), the economics of the controls did not make sense because the controls only reduced the energy of the already efficient LED kits somewhat and could not offset the cost of the controls which in some cases cost more than the kits. The solution was an LED retrokfit including a lens that reduced the lighting power usage from to 35 watts from 100, and included a manual dimmer to allow light levels below 35 watts to be dialed into the space.

Costco selected an option by Orion Lighting, and Costco electricians converted the fixtures from fluorescent technology to LED technology with the dimming lens and manual dimmer. Electricians disconnected the ballast (power supply that operates the lamps), fluorescent lamps, and sockets and installed the new LED kits along with a new optical system for the LEDs, all in a remarkably short 15 minutes.

Newly empowered to set their own fixture levels at 35 watts or below, how would Costco staff respond?

The answer came in a surprise audit conducted by Costco’s utility, Puget Sound Energy. Costco and Puget Sound Energy agreed to initially set an energy reduction incentive package based on 35 watts, and for the utility to audit an initial building to gauge if usage was actually below 35 watts. When the utility found that the fixtures were running at half-power, about 18 watts, the incentive package was adjusted to provide even greater savings for Costco.

Currently, Costco is seeing at 3-year payback for this approach in the Northwest, and about a year payback in its Southern California properties where energy is more expensive. Assistant Vice President of Energy and Building Controls, Craig Peal, characterizes the lighting controls as a “dumb” dimming system. However, by coupling manual dimmers with LED kits Costco has implemented a very smart solution.