in Electrical Systems
LEDs have been in widespread use for more than a decade, lighting everything from traffic signals and cell phones to computers and TVs, due to their extremely low energy use, long life span, and high-quality light. While not new, LEDs now offer unique and compelling characteristics for industrial applications. LEDs are more durable and reliable, and lack the maintenance requirements (e.g., re-lamping, re-ballasting) associated with traditional lighting. With properly designed fixtures, LEDs can operate well in all temperature environments, are inherently controllable due to instantaneous on/off and dimming, and are much more energy efficient than alternative lighting solutions.
Traditional industrial light sources share few, if any, of these characteristics. This is because, unlike high-intensity fluorescents (HIF), high-intensity discharge (HID), high-pressure sodium (HPS), and metal halides, LEDs are actually semiconductors, not light bulbs. This fundamental difference is the source of many of the misconceptions surrounding LEDs. So, let’s delve into those unsubstantiated myths and look at the underlying facts:
MYTH: LEDs are not a cost-effective replacement for fluorescents.
FACT: LEDs are excellent replacements for fluorescents, HIDs, and other industrial lighting.
While initial purchase costs for LEDs are higher than for fluorescents, the price difference is a fleeting issue, at best. Unlike in past decades, when lighting-related energy costs played a relatively small role in purchase decisions, a decade of rapidly escalating energy prices has transformed energy use into the major cost driver for industrial lighting.
Because intelligent LEDs are dramatically more energy efficient than fluorescents or even plain LEDs, not only are they more cost-effective in current terms, but an imperative in a rising energy cost environment. As a result, many industrial organizations are no longer willing to trade off marginally shorter initial payback periods—usually measured in months, not years—for a decade or more of substantially higher energy costs. From a purely financial perspective, purchasing non-LED lighting no longer makes sense. Factor in the elimination of maintenance and mercury disposal costs, and the advantages of LEDs are overwhelming.
For example, if you compare the annual energy costs of a 100-fixture installation of 6-lamp T8 HIF vs. a 13,000-lumen Intelligent Lighting System in a $0.10 kWh area with 20% occupancy, the results are as follows:
The 5-year energy costs for the LED-based Intelligent Lighting System are less than a single year’s energy costs for the HIF.
MYTH: LEDs are too new of a technology.
FACT: LEDs have been in widespread use for more than a decade, including critical safety-related applications.
Following more than a decade of widespread use, LEDs are a mature, reliable technology that has earned its place in the mainstream lighting market. The surging popularity of LEDs is based on their unique ability to provide dramatically more energy-efficient, sustainable, and cost-effective lighting. By combining much greater flexibility and control over how lighting is used within a facility, with higher quality light, LEDs are rapidly becoming the illumination technology of choice for industrial applications. Their customer-proven durability is well suited to high-intensity industrial applications, including manufacturing, warehousing, maintenance depots, hangars, and numerous others.
MYTH: LEDs have magnetic ballasts that require servicing and/or replacement.
FACT: LED lights use electronic drivers, which don't need replacement.
A magnetic ballast is an electrical circuit that regulates the amount of current that passes through a gas discharge light, controlling both the starting and operating voltages. Over time, magnetic ballasts used in traditional industrial lighting (HID, HIF, HPS, metal halide) wear out, requiring servicing and/or replacement. For large industrial facilities with hundreds of fluorescent or HID fixtures, servicing ballasts is an expensive proposition—in terms of manpower, workplace disruptions, and component replacements. LEDs are semiconductors that efficiently generate light, and require electronic drivers. In a well-designed fixture, the driver is a critical component, managing the power delivery and playing a vital role in overall energy efficiency of a fixture. It is a key element in fixture power consumption per lumen delivered, heat generation, and longer fixture lifetimes. Because LEDs use electronic drivers, they provide LED manufacturers with the opportunity to integrate control features (e.g., sensing, dimming, and instantaneous on/off) into lighting fixtures for maximum functionality and efficiency.
MYTH: LED prices will go down, so it pays to wait.
FACT: Waiting for LED fixture prices to drop will cost you money.
The energy savings from upgrading a facility's lighting to LEDs far exceeds any incremental price declines in LED-based fixtures.
The major factors associated with industrial lighting are up-front costs and energy use, making the frequently cited comparison between computer processing chips and LEDs inappropriate. Yes, LED chips are declining in price, but much of the cost of LED lighting is in the system that is built around that chip, so the potential chip price decline affects only about a third of the fixture.
A quick glimpse at a typical facility's operating budget shows that lighting is one of the largest energy loads. By reducing that energy usage 50% to 90% (depending on the application and manufacturer), LEDs pay back in energy savings much more than could ever be accrued through incremental LED price declines. If anything, energy's upward price trend makes waiting even more costly. It does not pay to wait. It does pay to act.
Using the same $0.10/kWh rate, for example, a single 6-lamp T8 fixture typically consumes $174 in lighting-related energy costs per year while an intelligent LED fixture consumes just $27. This results in a net savings of $147 per year (not including the additional daylight harvesting, maintenance, and/or refrigeration savings associated with intelligent LEDs), meaning the cost of an LED fixture would have to drop dramatically in a single year to make waiting worthwhile.
MYTH: LEDs don't work well in high-temperature environments.
FACT: Well-designed LEDs work well in a broad range of environments.
During temperature tests conducted by independent labs, LEDs performed at least equally as well as fluorescents and HID (see note below on testing parameters). Quality matters and a well-designed lighting system that carefully manages heat dissipation are prerequisites for lighting operating at any temperature—hot, cold, or anywhere in-between.
At the same time, it is important to note that LEDs do perform extraordinarily well in cold environments, an area that has been particularly challenging for other types of lighting, such as fluorescent and HID.
Note: An good indicator of the quality of an LED solution's heat/thermal management is junction temperature, which measures the internal temperature of the LED chip within the lighting fixture. For specified operating intervals—usually 6,000 and 10,000 hours—these values are commonly available as part of industry standard tests performed by independent testing labs. Be sure to request all testing data documents from your LED supplier, including LM-80 and TM-21.
LEDs can also withstand 60 mph slap shots as demonstrated in this video.
MYTH: The extra investment for intelligent LEDs doesn’t result in payback.
FACT: Sensors embedded in intelligent LED lights provide opportunities for massive savings.
With lighting rapidly becoming an intelligent platform, deploying LEDs without intelligence is a missed opportunity that will be in place for many years. Intelligent LED lighting systems offer far greater energy efficiency (up to 50% more than plain LEDs) as a result of their sensors, which offer detailed insight into building operations and the ability to manage and fine-tune lighting to achieve further savings. Due to the sensors in intelligent LEDs, massive savings can result from fully integrated occupancy sensors, daylighting sensors, and power metering that eliminates light, and its associated costs, at times when lighting is not required.
Data collected from sensors wirelessly networked into intelligent lighting systems gives customers the ability to view detailed reports and interactive facility maps, which helps determine when, how, and where lighting is used. This essential operational data allows organizations to analyze everything from how effectively space is being utilized in highly trafficked areas to how successful a retail display is based on the “stop and dwell” time of passersby.
Massive energy savings from intelligent LED lighting systems combined with both federal and state rebates for energy-efficient technology allow for payback of a few years or less, and a substantial ROI for years to come.
Interest in LED lighting is at an all-time high as industrial facilities increasingly zero-in on energy efficiency, sustainability, and cost containment as key metrics for capital investment decisions. Given the importance of these metrics to a facility’s bottom line and long-term competitiveness, few question that LEDs will soon become the lighting technology of choice in the industrial sector. The key is for customers to become knowledgeable about LEDs—with accurate information, independent test data, and feedback from the growing base of real-world installations willing to talk about their successes. Be sure to ask any industrial LED lighting company you speak with for full test results (LM-79, LM-80, and TM-21), and relevant listings (UL, cUL, NOM, or CE, for example). For customers in the United States, check that any products you are considering are included on the DesignLights Consortium’s (DLC) Qualified Products List, which includes products that have met the DLC standards and qualify for rebates among participating utilities.
Article courtesy of Plant Engineering.