When I was growing up, not turning out the lights when you left a room was considered a sin in my house. Although it may not have been included in the original Ten Commandments, I think “Thou shalt turn off the lights” should be included in Version 2.0. If Moses were alive today, he no doubt would be inclined to agree, especially considering the enormous amount of energy we waste every time we leave the lights on unnecessarily.
But listen up, sinners. Thanks to advancements in LED lighting, the energy currently wasted every evening to, say, light our parking lots, can be dramatically reduced. A recent study by PG&E demonstrates why.
The investor-owned utility tested LED lights in a West Sacramento Raley’s parking lot, and the results are enlightening, to say the least. On high power, LED lights used more than 50 percent less energy than standard metal halide lights, 149 watts compared to 346 watts. Moreover, LEDs can be used in conjunction with bi-level motion sensors that reduce light levels when the parking lot is not in use. At the low level, lighting dropped to 52 watts, which represents a savings of more than 1,000 kilowatt-hours per fixture per year.
On average, PG&E’s study showed that the LED lights in Raley’s parking lot were on high power for 55 percent of the time and on low power for 45 percent of the time. This results in a “time-averaged demand” of 105 watts, or a 70 percent reduction compared to standard MH lights.
Sure, LED lights cost more upfront. On new construction, LED light fixtures cost about $1,300 per unit, while standard MH lights cost around $374 per unit. But with an annual energy savings of nearly $300 per light fixture, the initial cost is soon paid for by the reduced energy bill.
Increased safety is another benefit of LEDs, especially when they’re used with motion detectors. When the detector senses movement, the light turns on, making it easier to spot suspicious activity and scaring off the bad guys.
While PG&E’s report doesn’t mention it, reduction of light pollution is another huge advantage of bi-level motion sensor LED lights. There is something jarring about going by a brightly lit, empty parking lot at 3 in the morning, when things should normally be dark. The benefit of seeing more stars is to my mind priceless, even though it’s not considered in the study.
Here at SN&R, we’re are excited about using LED lighting in the parking lot of our new building on Del Paso Boulevard, and we are currently working with SMUD to make this vision a reality.
In a sense, I’m making up for the sins of my youth. The amount of energy we’ll be saving in our new parking lot will far exceed the energy I wasted when I left the lights on at home, even though I doubt that this good deed will fully satisfy Moses … or my parents.
