Energy-efficient lights are bright idea

Dave Cary
Tags: energy management

Want your workforce to let out a groaner chorus of “yeah, right”? Just announce that you’re going to implement a cost-saving improvement that they will welcome and appreciate. “Yeah, right.” Yes, really.

If the improvement is installing energy-efficient fluorescent lighting (T8s or T5s) to replace the high-intensity discharge (HID) variety in your plant, you’re likely to see a radically different reaction – surprise and delight – once your workers see the end result. Some of the delight will probably spill over to your company’s financial types as well, because energy-efficient lighting is as close to a win-all-the-way-around situation as you’re likely to see.

The reasons for upgrading plant lighting come under four main headings.

1) Economy through energy efficiency: Cost savings usually drive a lighting project. The approximate savings that you can expect are relatively simple to state. Replace HIDs with T8 or T5 fluorescents and you will receive about twice the light (and a better quality of light, at that) for about half the operating cost, with payback in the range of 18 to 36 months. Lighting typically accounts for 30 to 50 percent of a manufacturing facility’s total power bill, so the amounts involved are not trivial.
Further cost savings can come from several sources:

  • Fluorescents operate 1,000 degrees F cooler than HIDs. Typically, 10 percent of an air-conditioned facility’s power usage will be used to make up for HID heat production. If there is no air conditioning, warm-weather ventilation is more effective.

  • Fluorescent tubes cost quite a bit less and have much longer effective life than HIDs.

  • The better lighting of fluorescents makes it possible to eliminate much of your plant’s task lighting.

  • The fluorescents’ overall lower current draw will free space on electrical panels and/or delay installation of more panels.

The last item reflects the fact that most companies tend to add equipment over the years with power usage migrating upward. Lighting rarely keeps pace with the change, aside from jury-rigs and added task lighting, so a complete survey by a lighting professional or company task force is a good idea every so often.

Oddly, the cost of the new fixtures themselves is not terribly important in the overall cost calculations. In a typical installation, 86 percent of the total lighting cost over the fixture lifetime comes from the electric bill. Another 11 percent comes from replacement lamps and the labor of changing them. That means that just 3 percent is due to the cost of the fixtures.

At a Marquip manufacturing plant, the orange high-pressure
sodium (HPS) lighting was replaced by full-spectrum T8s which
operate 1,000 degrees F cooler and use less than half the power.

2) Productivity issues: A benefit does not have to be large to make a substantial difference to productivity. If improved lighting cuts the time needed for a production task by 36 seconds per hour – an amount probably imperceptible to the employees doing it – it translates to a 1 percent gain in productivity. Spread that over a work area that handles a million dollars’ worth of work a year and those 36 seconds are worth $10,000 annually.

In a documented and startling instance, an Oak Creek, Wis., die company spent $3,000 to upgrade its lighting to T8s, and experienced $45,000 in annual savings due to improved productivity and reduced downtime. They also saw a 45 percent drop in energy and maintenance costs.

Remember these points:

  • HID lights do not provide good color rendering to begin with and their color shifts with age, often within just a few months. They also lose about half their light-emitting power over their lifetimes.

  • T8s or T5s maintain their true, full-spectrum light (often compared to sunlight at noon) over their entire lifetimes. They lose less than 10 percent of their light-emitting power over that span.

  • Fluorescents do not cast harsh shadows or cause the sort of temporary blindness you get when looking directly at HIDs.

  • All of these – color rendering, light quantity and harsh shadowing – can be important on a production line, particularly if the work involves color-matching, product finishing or even inspection.

  • The T8s and T5s have instant off-on capability. There are no five- to 10-minute delays after power outages.

3) Safety issues: Most workplaces are pretty safe already, but increasing the level and quality of light in a professional manner is an obvious boost to safety.

4) Worker issues: A study by Steelcase Inc. found that 56 percent of the workers in one plant reported that poor workplace lighting triggered tired and watery eyes, with another 30 percent saying they had headaches as a result.

It’s not a stretch to say that this cuts across productivity and safety as well as being a worker-comfort issue. Who would want to have a workforce with tired eyes or even headaches?

Finally, there is a simple attractiveness to the full-spectrum lighting of T8s or T5s that must be experienced directly. Most people describe the light as “excellent,” “clean” or “crisp.” They like being in it.

So, take a close look at energy-efficient T8s or T5s. Your bean-counters, production workforce and maintenance crew will love it. “Yeah, right.” Yes, really.

Dave Cary is the communications specialist for Orion Energy Services, a Plymouth, Wis., company that manufactures and markets energy-efficient lighting solutions. To learn more, visit

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