Building Management Hawaii - August/September 2012 - (Page 14)
Don’t be left in the dark on cost savings.
By Howard Wiig
The City of San Marcos has been testing two types of energy-efficient street lighting—LEDs and induction. The goal is to reduce energy costs, but other benefits include reducing crime and making streets safer for drivers and pedestrians.
usch Stadium, home of the World Series-winning St. Louis Cardinals, recently converted more than 1,000 lighting fixtures to LEDs, often achieving a 90 percent savings totaling more than $300,000 annually. Even though the stadium is only six years old and St. Louis only pays about one-third of Hawaii’s electricity costs, the retrofit still made economic sense. Hawaii’s property and facility managers can achieve similar dramatic savings while delivering higher quality light. Most facilities demand the most electricity between 5 p.m. and 9 p.m., exactly when most lights are on. Reducing lighting wattage with LEDs reduces peak demand charges.
LED streetlights can spread light in an ellipse to match the shape of streets, while conventional streetlights waste most of their light going up, sideways and into windows.
Dim & Motion
As you may know, traditional incandescent and compact fluorescent (CFL) lamps are “omnidirectional.” In a recessed can fixture, much of their light ricochets throughout the can and gets lost as it travels in all directions. In contrast, LED lights are “directional,” allowing a beam to spread with almost laser-like precision. This makes LED lights ideal downlights, a light designed to throw illumination downward. It is especially effective in places such as open parking lots, pathways, porte cocheres, lobbies and hallways. LED fixtures can be fine-tuned to distribute almost 100 percent of their light to the targeted area. For instance,
While precise LED beam spreads can result in energy savings as high as Busch Stadium’s 90 percent, even greater savings are possible through dimming and motion sensors. Unlike fluorescent, metal halide and highpressure sodium lights, LEDs can be dimmed and switched on and off as readily as incandescent lights. This opens up many possibilities: • Lights can be dimmed or turned off late at night, and reactivated by motion sensors. This has the side benefit of alerting security to late-night movement • Lights can be dimmed to a warmer
(orange-ish) color late at night to minimize hazards for birds or turtles in beachfront areas. • Lights can be dimmed to improve starlight visibility for evenings on the lanai or for others promoting “Dark Skies.” Honolulu is the primary source of light pollution for astronomers atop Mauna Kea. Eliminating light that goes up and sideways, instead beaming it down on its target, reduces light pollution. The Big Island is experimenting with 1,000 LED streetlights, specifically designed with astronomy in mind. Dark Skies legislation has been introduced in the Legislature for the past two years. It may be only a matter of time before laws are in place. Shifting to LED’s anticipates new laws and improves astronomers, residents and visitors’ ability to enjoy the starry heavens.
Do the Math
LEDs are especially attractive in Hawaii, given sky-high electricity costs.
If the price of replacing a 60-watt halogen light with a 12-watt LED downlight is $58, and if the lamps burn 4,000 hours a year: the 48-watt savings (60w – 12w) x 4,000 hours/year = 192,000 watts per hour or 192 kilowatt savings per year. 192 kWh x $.30 = $57.60 savings, yielding one-year a payback time and an ROI of 100 percent. Hawaii Energy’s rebates will further reduce the payback time. If owners resist converting, many vendors finance LED conversions, knowing that clients can pay back from the savings.
Table of Contents for the Digital Edition of Building Management Hawaii - August/September 2012
Cover August/September 2012
A New Way to Ride
Let There Be Light
Be LED, But Not Astray
Corrosion Clean Out
Raising The Bar for Security Guards
On Site: Empowering Employees
Ask An Expert: Shifting Soil
Movers & Shakers
Resource Guide: Plumbing & Wastewater Maintenance
Building Management Hawaii - August/September 2012