Efficient concept comes to light
Apr 27, 2012 8:18 AM
Refrigerated facilities: Don’t just pay
the utility bill—manage it intelligently
By Tom Pincince
Chief Executive Officer
Lighting makes up a significant percentage of a refrigerated industrial facility’s utility bill—typically 20%. Yet many facility managers do not think of lighting as a resource where increased management can improve efficiency and lower costs.
While lighting energy consumption may not seem complex, numerous factors—even issues such as “timeouts” that manage the time difference between active and inactive states—can double the amount of energy used. Lacking the ability to control lighting as a managed asset, track usage, or implement strategies for more energy-efficient deployment, most facility managers simply pay the bill, and move on to the next thing: putting money in their utility’s pockets better invested in their own operations.
The underlying causes are twofold: a historical lack of intelligence built into industrial lighting systems, many of which only have switches at the circuit level, necessitating leaving some or all lights on constantly; and underlying technology that is not suited to controls due to warmup issues or shortened lifetimes. As a result, site staff lack the ability to match lighting to the facility’s actual use and have been tethered to legacy lighting technologies which drive lighting costs of about $1 per square foot per year.
This need not be the case, however. A new generation of LEDs suitable for high-intensity applications, deployed as part as an overall intelligent lighting system, offer refrigerated facility managers new levels of efficiency and control, enabling them to reduce costs substantially. These systems incorporate sensors and intelligence as core design elements, sensing when people are in the area and providing the appropriate right levels of illumination, as well as turning lights off when operators are not in a particular area.
Intelligent lighting systems gather data from every fixture on kilowatt-hour (kWh) use and sensor events, and provide the ability to reconfigure settings, as well. The system then provides the data to facility staff and management in accessible, web-based reports and charts.
That information can be used to further optimize system settings and sensor delays, for benchmarking, and for measurement and verification with a utility partner. The reports make it quick and easy to see how much energy is being used facilitywide, by room, by zone, and where savings opportunities are. How are light levels? Schedules? Sensor behaviors? The system can also provide notification if lights are no longer working properly.
Besides the kWh savings, which contribute to project payback and total cost of ownership (TCO), intelligent lighting systems also provide valuable capabilities for seamless documentation of savings and lighting energy use via the software and reports. The higher kWh savings driven by the intelligent lighting system typically command higher utility rebates, which can also enhance TCO and payback equations.
The systems also incorporate LEDs that run at a lower wattage and generate much less heat than high-intensity discharge (HID) lamps—important in climate-controlled or chilled environments.
Finally, these systems also enable lights to respond dynamically and efficiently to how a facility is actually being used at any given point in time, including dimming or turning off entirely without compromising use of the facility or causing safety risks. Lights then turn back on instantly when needed. With no warmup time required, these systems give facility staff confidence that the system will provide lighting when and where required.
This systems-based approach is turning lighting from a fixed element of a utility bill into a strategic managed asset. The new view is built on the idea that lighting can be managed and controlled to maximize efficiency, while providing safe, useful illumination levels.
Here are some common questions refrigerated industrial facility managers and other site staff often ask when investigating intelligent lighting systems, as well as some insights based on our interaction with customers.
•Are LEDs suitable for highbay, high-intensity applications? LEDs have, without a doubt, reached performance levels that make them ideal for highbay use without tradeoffs in light quality or levels. The notion that LEDs are not suitable for certain applications, including highbay, is a fallacy, often traceable to vendors that provide fluorescent lighting that LED lighting replaces. It is important to evaluate delivered light—foot candles at the target surface to ensure that the light generated by the system is actually going where it is supposed to go. This is a function of both the light and fixture optics, which manage where light goes. Certifications are also critical (see below.)
•Do I have to sacrifice light levels or quality to leverage LED lighting? Intelligent lighting systems deliver maximum efficiency, reducing lighting energy use by up to 90% over HID fixtures, and increasing light levels. Efficiencies result from integration of LEDs and intelligence. Simple LEDs without intelligence offer some savings—but not 90%. Adding intelligence to a well-designed, complete system designed around a solid-state (LED) light source generates far more savings.
•What is the thermal load difference between intelligent LED lighting systems and traditional high-intensity discharge (HID) or high-pressure sodium (HPS) fixtures? There is a drastic difference in thermal load in traditional lighting and LED lighting—and an even greater difference when considering intelligent LED lighting. For starters, LEDs typically operate at much lower wattage than other light sources. So if you replace a 400-watt HID (which actually draws 465 watts) and replace it with a 160-watt alternative, you have a major heat reduction in your facility—especially when you multiply the number of fixtures. However, intelligent lighting systems only turn lights on when there is activity in the area of a given light, which, for most facilities, means the lights are only on 20% of the time and that further reduces the thermal load.
•Is deployment of these types of systems common? Numerous industrial facilities, including some of the largest US warehouses and broadline distributors, have adopted intelligent lighting systems and are reaping the benefits to the tune of millions of kWh per year saved—both in direct lighting energy savings and from chiller load reduction.
•What industry guidelines are there to help me decide how to select an LED-based intelligent lighting system? Certifications are absolutely critical when considering LED products in industrial applications. The Energy Star program does not cover these products, but has partnered with the DesignLights Consortium for evaluations and listings. When considering an upgrade to LED lighting, be sure to choose a product that is on the DesignLights Consortium’s Qualified Products List (QPL). Many utilities require QPL listing for rebates. UL listing is also an important standard, but it’s important that the entire fixture be listed. Some vendors will claim UL listing when only a subsection of the system or product has been listed. The US Department of Energy-sponsored Lighting Facts label is also essential. Also, LM-79 and in-situ testing data should also be provided. Any reputable vendor will want to make sure you have access to that information. If it is not forthcoming, you may want to reconsider working with that vendor.
•What type of information should I have as I begin to investigate upgrading to a LED-based intelligent lighting system? Key data to gather before making a purchase decision includes current energy bill(s), your kWh consumption rate (current and projected), the number of fixtures in the facility, maintenance schedules, and any other expenses (eg, re-lamping schedules).
•How should I determine whether my investment will be worth it? TCO over a five- or 10-year period is the right framework for evaluating any energy efficiency initiative. TCO takes into account all variables for a purchase: initial costs, ongoing energy costs, maintenance, while factoring in any incentives or rebates. Payback period is also vital, but it is not an “either/or” proposition. You need to perform both analyses to see the complete picture. While a legacy technology like high-intensity fluorescent (HIF) may have a shorter payback period than an LED-based intelligent lighting system, the intelligent lighting system’s energy reductions are so dramatic and the maintenance costs so minimal that while the TCO payback is incrementally longer, the savings over a five- or 10-year period are compelling. Focusing on simple payback only would ignore these massive long-term savings.
•I just want lights; why do I need all these bells and whistles? The reality is that while intelligent lighting systems sound more complex, they operate like traditional lighting—just with more smarts baked in to intelligently increase energy efficiency. With lighting representing approximately 20% of the average facility’s monthly electricity bill, the expense is too large not to manage carefully. Facility managers look to chiller systems, variable-frequency drives, and other parts of the facility to eke out savings. Why not lighting?
Access www.digitallumens.com for more information.
© 2013 Penton Media Inc.