It's Halftime for Solid-State Lighting

In the world of lighting, it's hard to dispute that in just a decade solid-state lighting (SSL) has "progressed beyond the limited world of traffic signals, exit signs and Christmas lights to become a player to be reckoned with in a growing number of general illumination applications".  We must however keep in mind that "the technology is still at a relatively early stage of its development" (Brodrick, 2013).

Through our collective efforts to determine where solid-state lighting resides on the technology life cycle, the Norlux team found an interesting perspective from a March 2013 Department of Energy article titled "It's Halftime for Solid-State Lighting". Author James Brodrick (Lighting Program Manager for the U.S. Dept. of Energy) offers a succinct view of where LEDs exist presently in commercial applications and what pitfalls must be negotiated for the technology to thrive well into the future.

Brodrick believes the forward momentum of SSL hasn't quite reached the level of persistence that sharks embody, but users of the technology must keep making consistent progress. "'Move forward or die' might be an overstatement, but as SSL reaches the mid-point of its potential, it must continue to make steady strides or risk becoming a novelty" (Brodrick, 3/13). James continues: "As tempting as it might be for SSL manufacturers to ease up a bit on the throttle that would be a big mistake, because the technology is at a turning point. Despite the dizzying acceleration in the sales of LED lighting products, they still only represent a drop in the bucket compared with the total universe of lighting installations—and, what’s more, increasingly find themselves in competition not only with CFLs and linear fluorescents, but also with earlier generations of LED products. So in order to turn the corner and achieve the widespread adoption necessary to make a significant dent in our energy consumption, SSL has to continue to improve" (Brodrick, 3/13).

To state it in sporting vernacular, James believes SSL technology has reached "half-time". James states "according to the best estimates, it’s roughly at the halfway point in terms of its potential. For example, checking the U.S. Department of Energy’s (DOE) LED Lighting Facts database of SSL products on the market, we find some good ones that have efficacies in the 90-100 lumens per watt range and are used in a number of different applications. While this represents a huge leap from even the best efficacies a few years back, DOE’s ultimate goal—which most people in the industry consider achievable—is to surpass luminaire efficacies of 200 lumens per watt" (Brodrick 3/2013).

One advantage of a maturing technology is the declining cost associated with that technology; and SSL is no different. "While efficacies are on the rise, prices are heading in the opposite direction. For many SSL luminaires, the LED package still comprises a significant portion of the cost, but those prices are dropping quickly, to as low as $5-$7/klm, which is on track with the projections in DOE’s SSL R&D Manufacturing Roadmap. In order to meet the needs of an increasing number of applications, LED packages are also becoming more and more diverse—though, fortunately, not at the expense of efficacy" (Brodrick, 3/13).

On the flip side, James explains some of the challenges facing SSL moving forward, stating "there’s a need for better greens and reds, and also for multichip monochromatic sources. It’s also essential to address such performance issues as dimming, flicker and reliability. The widespread claims that LED lighting products are fully dimmable often get contradicted by what happens in real-world installations—particularly with phase-cut dimmers, which are designed to work with incandescent lamps and thus can have compatibility problems with LED drivers. Those drivers are also the key to SSL flicker, with some drivers producing no visible flicker regardless of the light output, others causing noticeable flicker at all output levels, and others flickering only when dimmed" (Brodrick, 3/13).

We at Norlux agree with James that LEDs offer endless innovative possibilities in lighting because of the unique qualities of the technology. These attributes, if fine-tuned and constantly re-immagined will keep SSL on the fast-track to even greater adoption. "The keys to SSL’s market penetration are its unique attributes, which will function as value-added differentiators. One such attribute is SSL’s controllability, which makes it especially suited for use in smart lighting applications, where sensors can give a significant boost to energy savings. There’s also the potential to control SSL’s visible spectrum, which makes it possible to change chromaticity—not just for aesthetic reasons, but also to optimize our mood, productivity and health" (Brodrick, 3/13).

Norlux is the North American leader in high-brightness LED applications and complimentary technologies; contact us today!

Source: "LED Watch: It's Halftime for Solid-State Lighting" by James Brodrick; March 2013.
http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/led_watch_03-04-13.pdf

Advantages of LED Streetlights

Eco-friendly LED lights for outdoor applications are becoming quite a trend in today’s society, and the reasons to choose this method of illumination are many. Speaking specifically of streetlights, large municipalities and small towns alike are constantly looking for ways to keep energy costs down while limiting potentially adverse effects on the surrounding environment. Listed below are some ways in which street lights that utilize LED technology come out ahead of the competition.

• Immediate switch-on: As soon as LED lights are turned on, they immediately begin to emit a high level of light. Contrarily, it takes time for the filaments inside of conventional types of streetlights to warm up before they begin to emit the correct level of light for viewing. 
• Requires less maintenance: The lifetime of LED streetlights is usually 10 to 15 years, many times the life of current technologies. LEDs are suitable for places where replacing light bulbs is expensive, inconvenient or otherwise difficult, such as roadways or around bridges and overpasses.
• Durable and efficient: As stated in the previous Norlux blog titled: "LEDs: Energy Efficiency Leaders", LEDs are leading the way in efficiency against other prevalent lighting technologies. LED-based streetlights are also very durable, with no fragile components, and are resistant to heat, cold, and shock and ingress protection.
• Environmentally friendly: LEDs are free from hazardous chemicals, such as mercury and lead. As a side note, LEDs don't produce ultraviolet light, which attracts bugs, so they can be left to their natural pursuits.
• Directional: Because they produce "directional" light (light emitted in one direction, rather than a diffused glow) LEDs can be used to direct light on specific areas. Utilizing LED streetlights reduces “light pollution” of our night skies, allowing for better stargazing opportunities.

Some cities have utilized motion sensor technology with their LED lights, so that the lights increase in brightness when a pedestrian walks by. They can also be made to alert officials to maintenance requirements or to blink rapidly to direct emergency responders to a specific location. By integrating solar panels, the LED street lights can become self-sufficient and virtually maintenance free for a decade.
 

As LED technology evolves even further, it will no doubt become the illumination technology of choice- and not only streetlights, but in all general lighting purposes in the future. For help in the design or manufacture of your LED-based lighting products, contact Norlux today!

 

References:

“Advantages of Having LED Street Lights”: 13 Nov. 2010, By Carol K L Oon http://EzineArticles.com/5375838
“How LED Streetlights Work” by Jacob Silverman

http://science.howstuffworks.com/environmental/green-tech/sustainable/led-streetlight1.htm/printable

LEDs: Energy Efficiency Leaders

When it comes to efficient lighting, LEDs are the solution. As Americans, we use from 10-15 kilowatt-hours of energy per day on lighting. How is this calculated? This is just another way of saying that we use the equivalent of twenty-five 60 watt incandescent lamps for an average of 6 hours throughout the day. Realistic estimates predict that introduction of LED lighting to replace incandescent lamps could cut this to one third of our current usage.

In order to understand how to reduce our consumption, we need to review some basic definitions:

• Lamp Life: The expected useful life of light source with end-of-life defined as failure or diminished light output (which is typically expressed in hours).
• Lumen (lm): The output (or relative “brightness”) of a light source normalized to correlate with human vision.
• Watt (W): Standard unit of energy.

With these definitions, we can now begin to evaluate logical buying choices. If we look at a standard 40 watt incandescent lamp, it typically delivers 450 Lumens of light. If we assume our energy cost is $.11 per kilowatt hour and the bulb is operated 3 hours a day for 365 days per year, the annual operating cost is: 3x365x40= 43,800 watt-hours per year. This is approximately 44 kilowatt-hours per year (we need to divide by 1000 to get kilowatts). At $.11 per kilowatt-hour, the bulb would cost us $4.82 per year just to operate.

Source: http://www.gelighting.com/LightingWeb/na/resources/tools/lighting-assistant-toolkit/simple-life-cycle-cost-estimator.jsp

Now let’s look at two other lamp sources LED (light emitting diode) and CFL (compact florescent lamp) that put out the same amount of light. Since they are more expensive, let’s look at the total cost of ownership over their respective lives using a cost calculator from General Electric.

Notice that the incandescent cost more not only from energy consumption, but due to the fact that you need 5 bulbs per year from short life! Even though the LED solution is the most expensive initially, it is the clear winner in the long run because of long life and low energy consumption.

LED’s have now become the leading choice for indoor lighting. Unlike fluorescent lamps, there is no Mercury content that can be harmful. Although our analysis is a residential example, Norlux stands ready to help you with an OEM solution for you architectural, medical or industrial products! Contact Norlux Today!

LED Lighting: At Home in the Hospitality Industry

Lighting is crucial to the hospitality industry, as it plays an important role in the overall customer experience.  Atmosphere, comfort and security all depend on properly lit banquet & conference rooms, lobbies, halls, restaurants and the guests’ quarters.  Hotel industry professionals considering alternative lighting sources from a cost and environmental impact standpoint are realizing more and more that LEDs are the answer.

On average, interior lighting accounts for 28% of a hotel’s energy bill. Switching to efficient lighting can help reduce the energy consumption and overall operating costs, while providing an opportunity to demonstrate tangible environmental responsibility to hotel guests. Compared with the general halogen lamps, fluorescent tubes and metal halide, LEDs have a long life (exceeding 5 years on average), resulting in lower overall maintenance costs.

High CRI (Color Rendering Index) LED lamps prove ideal for the hospitality industry.  CRI is defined as “a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source.”  By combining high CRI with warm or cool colors, interior designers are able to create a more natural, enticing atmosphere, or direct a customer's attention in a specific way.  In an industry where look, feel and comfort are vital, LEDs provide an ideal solution.

Changing over an entire hotel to LEDs is obviously a major investment, as the initial costs can be considerable.  To mitigate this, hotels often start retrofitting with LEDs or replacing outdated fixtures in areas where the lighting is in use 24/7 (lobbies, hallways and corridors). There, the impact on energy costs is greatest and the cost savings is felt almost immediately.  Energy savings can be one of the best ways to reduce cost while increasing guest satisfaction, which is ultimately the main industry goal.  Utilizing LED-based lights will substantially reduce electricity usage and costs, which is great for the environment and the bottom line. 

For help with the design and manufacture of your LED lighting products, contact Norlux today!

Reference:
http://ezinearticles.com/?LED-Lighting-For-Your-Hotel---Cut-Costs-And-Reduce-Your-Carbon-Footprint&id=6388655

How to Design Drivers for Long Life

In order to understand how to design LED drivers for long life, one first has to understand what factors can limit driver life span. The most basic potential cause for premature failure exists in the components that are used in the design of the driver. When do different components typically wear out and what is considered their “normal use”? 

Different types of components wear out in different ways. This concept seems simple, but it really needs to be understood. For example, semiconductors have a very long life when operated at a constant temperature within specifications. However, if the temperature is cycled, for example, by the driver being turned ON and OFF, then the thermal expansion and contraction of the semiconductor can cause mechanical failures in the connections between the semiconductor die and the outside world.  This failure mechanism can be mitigated by operating the semiconductors at temperatures significantly lower than their maximum rated temperature. For example, most MOSFET’s are rated to operate at a junction temperature of 150C. However, the maximum junction temperature is usually limited to 100-110C or lower at the maximum operating temperature, to limit the damaging effects of thermal cycling.

 Another “wear-out mechanism” for drivers is related to the limitations of electrolytic capacitors. These typically have a life rating of 5,000 to 10,000 hours for high grade capacitors at their rated maximum temperature. The life of an electrolytic capacitor increases by a factor of two for every ten degrees the operating temperature is lowered.  Since a year is about 8,000 hours, it is easy to see that the electrolytic capacitors must be operated at a lower temperature than their maximum rated temperature to achieve a “lifetime” that would exceed one year.  Other components such as film capacitors and magnetics also have maximum temperature ratings that must be observed to achieve long life.

One key life-span measurement addresses how long the driver will continue to function in a controlled laboratory environment with elevated temperature or with temperature cycling.  This type of test discounts other factors that can also limit the life or damage a driver in the field.  One such factor includes extreme voltages on the input, outside the normal specified input voltage operating range. Lightning strikes are very short, high voltage (several thousand volts) impulses applied to the input of the driver that can cause damage if input surge suppression components are not used in the design. The IEEE has recommended levels of lightning protection depending on the location that drivers are applied.  Europe has a general requirement for lightning immunity that is commonly met by U.S. products.  However, the levels and frequency of lightning that can happen in certain parts of the U.S. (such as the Southeast) are much higher than the European standards.  Moreover, normal power line voltage variations (due to load switching and power outages) can also produce voltages on the input that can damage components as well as limit the life of the driver. 

Designing drivers for long life can only be achieved by understanding the limitations of all the components that are used in creating them. Operating the components at levels well below their maximum ratings and understanding “real world” occurrences that could affect a driver’s longevity goes a long way in improving the long-term effectiveness of a driver design.

Norlux is the North American leader in high-brightness LED applications and complimentary technologies; contact us today!

Smart Shopping for LED Surgical Headlights

LEDs are rapidly becoming the most valued light source in medical illumination today, and surgical headlights are certainly no exception. Surgeons choose LED-based headlights for numerous reasons including their long lifespan, energy efficiency, ruggedness and the low-maintenance requirements. LED Technology has also opened many innovative pathways with its dynamic color mixing and color sequencing capabilities.

 

Daniel Cook, author of the “Surgeon’s Advice” column in Outpatient Surgery Magazine (October 2012,) interviewed Mark Drzala, M.D. and Assistant Professor at New Jersey’s University of Medicine and Dentistry. Dr. Drzala is a big fan of LED headlights and uses them often in his work. The following are a list of reasons for Mark’s Dr. Drzala’s affinity for LED-based headlights, along with the features consumers should consider when purchasing the portable headlights for their specific medical application.

• Freedom of movement. Most LED headlights are battery-operated — as opposed to xenon headlights that connect to light sources through fiber-optic cables — so you can work untethered around the surgical field, says an orthopedic spine surgeon with New Jersey Spine Specialists in Summit, N.J. "Surgeons like to move freely around the OR," he says. "They don't want to waste time asking someone to constantly disconnect and reconnect the headlight. That's a real nuisance.
• Battery life and weight. Consider the size and weight of a headlight's battery pack, suggests Dr. Drzala, because some physicians with back issues might find it difficult to operate with packs belted around their waists. "At the same time, some of the battery pack belts are robust and might actually provide some back support," he points out.
  
  LED headlights are powered by rechargeable batteries ensuring considerable duration on a single charge. Some LED headlights boast lifespans of 50,000 hours as well.
• Bright illumination. Can you narrow the headlight's aperture? And if so, does the illumination diminish when you do? Also look for uniform illumination, suggests Dr. Drzala, meaning hot spots don't appear in the center of the surgical field along with dimming along its perimeter.
  
  Some yellow-based lights sources have an incandescent look to them, while others have a cooler, higher Kelvin rating, which renders tissue with better coloration. "Surgeons must conduct their own head-to-head trials and see which ones they like best, because no 2 LED headlights are alike," says Dr. Drzala.
• Comfort. Look for lightweight, comfortable headsets, although comfort is very much subjective. Surgeons might take time to adjust to the feel of a headlight, and initially think the device puts them off-balance as they lean into the surgical field. "The weight of a headset can take some getting used to," says Dr. Drzala. "But with time, you get a sense of how you have to move your head in order to effectively shine the light source onto the field."
• Longevity. The lifespan of a xenon headlight is impacted by dimming bulbs and delicate fiber-optic cables that connect to light sources. "Every time a fiber-optic strand breaks through normal wear and tear, you lose a little bit of illumination," says Dr. Drzala. So, he says, xenon bulbs dim over time, while LEDs remain as bright as new even after repeated use. “A new xenon headlight and a new, high-quality LED model are equivalent," says Dr. Drzala. "But as time passes, LED headlights will better maintain their illumination and brightness."

Contact Norlux today for a consultation on your next LED lighting project for medical applications. We’re fast, highly automated, and we manufacture entirely in the U.S.A. 

 

Sources:  “Smart Shopping for Surgical Headlights” by Daniel Cook

Outpatient Surgery Magazine; “Surgeon’s Advice” column. October 2012.

http://www.outpatientsurgery.net/issues/2012/10/who-doesnt-like-leds&pg=3

LEDs Illuminate San Antonio’s River Walk for the Holidays

For the second consecutive year, San Antonio's River Walk will be aglow this holiday season with more than 1.76 million multi-colored light-emitting diode (LED) lights wrapping the trees and lining the street bridges along its banks. The new energy efficient lighting not only enhances the experience to all who visit the River Walk, but it also adds 20 times more lights, utilizes less than half the energy of traditional incandescent lighting and supports long-term sustainability efforts.

Earlier this year, the City of San Antonio converted 85,000 incandescent lights to 100 percent LED lights for this year’s River Walk Holiday Lights experience. Using more than 1.76 million LED mini-bulbs will save the equivalent of approximately 33,000 kilowatt-hours of energy. The LED lighting is durable and is expected to last 10 years in comparison to incandescent bulbs, which were replaced annually.

Local lighting consultant and renowned artist Bill FitzGibbons, who has created LED lighting displays across the world, developed the LED lighting plan for the City of San Antonio. In addition to the minibulbs, the eco-friendly lights incorporate the addition of multi-color programmable holiday accent lighting on all 22 street bridges at the River Walk. The lights will be wrapped on 170 trees lining the river, as high as 60 feet. To further enhance the Holiday experience, 26 heritage or iconic trees will feature up-lighting.

The enhanced LED lighting plan compliments Mayor Julián Castro’s inaugural Light Up Downtown Holiday Lighting Contest, which showcases creative holiday LED lighting displays at participating businesses on the street level. Both initiatives aim to bring visitors to downtown San Antonio this Holiday season while encouraging sustainability and energy conservation.

Norlux's team of engineers understand LEDs and related technologies like no other manufacturer in the world today. Contact us today to discuss your LED based lighting projects.

Source:
http://www.sanantonio.gov/riverwalklights.aspx