Improve Efficiency, Safety With LEDs
EP Editorial Staff | September 18, 2019
The revolution in light and control is leading to a range of unprecedented capabilities and benefits in industrial operations.
By Omar Rivera, LEDVANCE
Keeping the lights on in industry is, quite literally, an enormous undertaking. According to the “Manufacturing Energy Consumption Survey” from the U. S. Department of Energy, Washington (energy.gov), lighting the nation’s manufacturing facilities consumed 55 billion kWh in 2014, i.e., about 7% of overall electric-energy consumption. Yet, despite the high cost of that energy, less than a third of responding organizations reported having undergone some form of energy-efficient-lighting system upgrade, with the majority still relying on conventional light sources.
Today’s light-emitting diode (LED) lighting fixture and control technologies present a major opportunity to significantly reduce this cost and thereby increase enterprise efficiency, profitability, and competitiveness. In addition to reducing energy and maintenance costs, energy-efficient lighting systems can improve productivity and safety while enhancing operational efficiency by way of measuring, monitoring, and location-based services. Thus, the case for upgrading systems is an easy one to make.
An industrial facility that has not adopted new lighting technology in the past few decades is likely illuminated by fluorescent strip-lights and high-bay, high-intensity-discharge (HID) fixtures, the latter installed at high mounting heights. In the past decade, white-light LED technology rapidly evolved to the point where it dominates new-product development in the lighting industry, and the majority of new buildings strongly favor it as a light source.
Increasing efficacy (quantity of light output per watt of electrical input) has driven the development of more compact fixtures and a steady decline in cost, in addition to lower operating temperatures and, in turn, longer service life. Today’s LED fixtures are highly efficient, reliable, compact, and have a long life. With a wide variety of lumen packages and wattages, they now provide a reliable energy-efficient alternative to virtually any fixture that might be found in an industrial environment.
In an existing industrial plant, upgrade options include doing nothing, doing a little, or maximizing benefits. Doing nothing presents the highest long-term cost, as operating-cost savings are left unclaimed. Doing a little involves replacing incandescent, halogen, compact-fluorescent, and linear-fluorescent lamps with LED retrofit lamps. While a simple upgrade, it doesn’t realize full energy savings, and, in the case of replacing linear-fluorescent lamps, it risks poor lighting if LED technology is misapplied to conventional fixtures.
The biggest benefits are available when fixtures are replaced in the general lighting system. Here, the owner/operators have one of two options:
• Replace HID and fluorescent fixtures with LED fixtures on a one-for-one basis. New LED light fixtures can produce satisfactory light levels while typically consuming 50% to 60% less energy than HID and 30% to 40% less than fluorescent. The wattage savings add up to significant energy (kilowatt-hour) savings due to the long daily operating hours in typical industrial applications.
• Redesign the existing lighting system with the idea of leveraging the superior optical (how much light exits the fixture and where it is emitted) qualities of premium LED fixtures to reduce the total number of fixtures required. LED fixtures are available with a range of optics and optical efficiencies. Because the light is emitted in a single direction, the emission is easier to control using optics. As LEDs are very small and produce little radiated heat, the optics can be placed on or close to the light source. TIR (total internal reflection) optics, for example, allow greater optical control that minimizes glare while making fewer fixtures possible.
The simplest case for investing in new lighting, therefore, is energy-cost savings that can produce a satisfactory return and positive cash flow.
Return on investment can be improved based on the availability of lighting-technology rebates from utilities and energy-efficiency organizations. Utilities offer these rebates because it is generally cheaper to incentivize customers to reduce energy consumption than to build expensive new power plants.
Another source of operating-cost savings can be found in maintenance. A well-designed LED fixture can produce light for as much as four times longer than an HID fixture. With LED technology, service life is typically rated not on the average number of hours before a lamp fails to light, but rather on lumen maintenance, the point at which the fixture emits a percentage of its original light output, such as L70 (70%). Today, LED products are available with rated life of 50,000 to 100,000 hours. Moreover, as solid-state sources, LEDs are far more resistant to shock and vibration than traditional lamps. All of this equals potential dramatic reductions in maintenance costs while enhancing workplace safety and productivity due to fewer outages and lamp-replacement activities.
The result of an upgrade is not just energy and maintenance cost savings, though. It can potentially offer a better quality of light in a facility. Well-designed LED fixtures produce satisfactory light levels, minimize direct glare, and provide superior color rendering than high-pressure sodium (HPS) HID lamps, known for their orange glow. Workers are likely to be more satisfied and experience better mood and energy levels working under well-designed LED lighting than HPS. Increased alertness, improved color rendering, and instant-on operation all contribute to worker safety.
In the simplest of terms, with LED technology, it really is possible to have it all: better lighting, lower energy costs, and less maintenance. Another benefit of LED technology is this light source is far more easily controlled than traditional lamps, resulting in additional energy cost savings and new capabilities found in measuring, monitoring, and location-based services.
Lighting controls are devices that control lighting operation by turning them on/off and raising and lowering light output (dimming). Automating these functions based on occupancy or available daylight is the key to harvesting ongoing energy savings by making sure lighting is turned off or reduced when it’s not needed.
Consider a warehouse, for example. The aisle lighting could be individually controlled by one or more occupancy sensors installed as part of the light fixture or remote from the fixture. If the lights must remain on, even when a space is unoccupied, they can be dimmed.
With traditional fluorescents, automatic switching was possible, but dimming required a premium dimmable ballast. With HID, occupancy-sensing-based automatic switching was typically impractical due to the long warmup and hot re-strike times, and dimming was difficult to implement.
In contrast, LED technology works well with controls. The light source is instant-on, frequent switching has a negligible effect on light-source life, efficacy (lumens per watt) is linear across the majority of the dimming range which ensures good savings, and dimming is available with negligible additional cost.
As a result, LED technology is ideally paired with lighting controls, which provides new opportunities to maximize energy savings and achieve additional benefits that can deliver dollars far exceeding the cost savings. A lighting upgrade is the ideal time to install controls, as all retrofit labor will be in place.
Just as the lighting industry underwent a major transformation due to the LED revolution, so did its control segment due to another, quieter revolution in intelligent lighting control. For a lighting upgrade, the first place to start is simple automatic switching through panel-based scheduling and occupancy sensors. Dimming can enrich energy savings where lighting must remain on but can be reduced in response to occupancy. Average energy savings for implementing aggressive, layered control strategies is about 50%. Due to their high energy savings, utilities offer substantial rebates for installing controls to help defray the initial cost.
A major trend in lighting is to connect all control points and enable them to communicate wirelessly with each other and a central command station using radio waves. This integrated approach to lighting control provides remarkable benefits:
Centralized control. The operator is put in full command of the facility’s lighting system. Connecting light fixtures in a wireless network enables easy configuration of settings and control zones and reconfiguration as space needs change. Commissioning (startup and testing) is simplified as it is done remotely.
Building-system integration. Unifying all control points into a single system permits connection to other building systems such as the energy-management system for increased energy savings and capabilities.
Demand response. Centralizing control of switching and dimming enables lighting to participate in a utility-demand-response program, if available. In such programs, the utility offers favorable rates to large industrial customers in exchange for agreeing to reduce electrical loads during emergency grid events.
Internet of Things (IoT). Integrating control points in a network permits data to be sent to a central server or a cloud system for retrieval and analysis by vendor software or third-party apps. This basic capability is another revolution in the making that will transform plant buildings.
Basic capabilities include energy measurement, which can be used to optimize energy efficiency, and power monitoring, which can be used for lighting maintenance. Additional capabilities can be gained by using occupancy data. From this starting point, additional sensors can be installed with the light fixtures to collect data theoretically about anything that is measurable, which would be fed to a central point for analysis using third-party software.
Indoor positioning. RFID (radio-frequency identification) tags on items such as warehouse forklifts can transmit signals through local light fixtures to apps on mobile devices, which allows easy tracking of equipment.
Overall, installing lighting controls as part of an LED upgrade provides a path to maximizing energy cost savings and leveraging the lighting system to generate actionable data with a substantial potential impact on operations.
MAKING IT WORK
The key to gaining the benefits of LED lighting is to prioritize quality of light and be discerning about product quality. First, be aware that today’s marketplace offers a wide range of product quality, with differences that can have a big effect on performance.
For example, LEDs emit little radiated heat, but generate heat internally. The fixture must be able to manage this heat or risk shorter product life with failure modes expressed as low light output, color shift, and driver (a device that regulates the LEDs’ operation similar to a ballast) failure. The driver should be of high quality, feature all the required ratings for the application, and be serviceable. The optics should deliver light where it is needed and without direct glare.
It’s important for industrial facilities to work with suppliers who can deliver rugged products that perform reliably in a wide range of demanding environments, and with consultants/contractors who are comfortable and familiar with those technologies. EP
Omar Rivera is head of luminaires for LEDVANCE, Wilmington, MA, maker of SYLVANIA general lighting in the U. S. and Canada. For more information, visit sylvania.com.