Category Archives: Lighting
First green LED means a lighting revolution is fast approaching
First green LED means a lighting revolution is fast approaching
When scientists at the National Renewable Energy Laboratory (NREL) tried to apply their expertise in solar cell technology to build a green LED light from the ground up, they surprisingly centered the objective at their very first try. In doing so they solved a long-standing technological problem and paved the way for the large-scale employment of white LEDs for public and domestic illumination over the course of the next few years.
What’s wrong with your good ol’ tungsten bulbs, you may ask? The problem is that they produce light by incandescence, which is about the least efficient way to produce light — it wastes the majority of energy to produce useless heat, which inevitably ends up inflating your electrical bill. To a lesser extent, compact-fluorescent lights also share this inefficiency problem, which has led the U.S. Department of Energy to predict that both kinds will be phased out in the space of only four and ten years respectively, leaving LEDs virtually the only player in the market.
LED lights are unanimously regarded as a vast improvement over previous light bulbs because of their much longer lifespan and higher efficiency, which ends up saving us money in the long run, even when the higher initial cost is taken into account.
But to create a white LED, red, blue and green light need to be combined. While the first two colors have been relatively easy to manufacture, researchers have struggled to produce a green LED. The LED-based lights available today circumvent the problem by aiming the blue light at a phosphor, which then emits green light. This does produce white light, but it is still wasteful compared to a white light that makes use of three distinct, all-LED components.
NREL researcher Angelo Mascarenhas, who holds patents in solar cell technology, realized that a LED can be thought of as the reverse of a solar panel, since one takes electricity and turns it into light, while the other takes (sun)light and turns it into electricity.
Mascarenhas used the knowledge gathered by NREL when they created a world-record inverted metamorphic solar cell by combining layers of different lattice sizes to optimally capture solar energy across the visible spectrum. The researchers had already tackled the problem of how to absorb sunlight in the green spectral region, and Mascarenhas built on this knowledge to reverse the process in order to manufacture a green LED.
Absorbing green light is technically challenging because of the way the different layers of lattice that should absorb it are manufactured: if the layers don’t match up with the layer below, leaving too big a gap, the efficiency plummets to next to zero. NREL’s solution was essentially to insert extra layers of lattice that gradually bridge the gap, improving the cell’s efficiency.
Mascarenhas’s idea was to reverse the process — that is, making a current flow between appropriately spaced layers of lattice to obtain green light – and reportedly managed to produce a radiant deep green light on the very first try.
NREL is now trying to produce a fourth color to make the white light even whiter. They plan to arrange the four colors in a beehive structure, each cell being an LED of a specific color, so that the light will look white when seen from a distance.
The researchers also plan to make their LED light “intelligent,” dynamically matching the percentage of the four colors to the time of the day – for instance, increasing the blue component during daylight, or the reddish-yellow during the night.
Further predictions from the Department of Energy estimate that the move toward LEDs for both public and domestic lighting could save the U.S. as much as US$120 billion over the course of the next 20 years, as well as 246 million metric tons of carbon (approx. 5 percent of U.S. total emissions during the period 1850 through 2000) that would otherwise be released into the Earth’s atmosphere.
http://www.gizmag.com/first-green-led-light-manufactured/14761/
Smart Energy Glass controls light on demand
Smart Energy Glass has three modes – dark, privacy, and light
While the idea of using photovoltaic technology in windows to harvest sunlight for conversion to energy is not new, Smart Energy Glass (SEG) is taking a slightly different approach with a solar window that can be darkened or lightened for comfort and convenience.
The window’s opacity can be adjusted for three modes; dark, privacy, and light. Dark will harvest some light, while privacy will harvest the most. The energy is used to power the window itself and eventually lights and ventilation could be run from the energy harvested. Additionally clients can choose the color of glass and add logos if required.
SEG has obvious advantages for office cladding as in summer heat and light streaming through the window can make working conditions uncomfortable, while in winter much warmth is lost via the glass. But it could also have advantages on a smaller or domestic scale, for presentations, or in homes with sun-facing windows.
No details are yet available on the exact mechanics of the Smart Energy Glass. Peer+ says the patent pending technology is still under development and we can expect updates as pilot programs get underway this year in the Netherlands.
Peer+ via Red Ferret.
GE bids to replace 40-watt bulbs with new LEDs
In just a few years, incandescent light bulbs have become a thing of the past — replaced by more energy efficient and affordable compact fluorescent bulbs. But now General Electric says it has a technology that could kill the standard light bulb altogether: A new light-emitting diode bulb that performs just like a 40-watt incandescent, but lasts more than 17 years.
Marketed as the Energy Smart LED Bulb, the product should hit shelves by the end of 2010, GE says. Not only does it last 25 times longer than the bulbs consumers are accustomed to, it also substantially cuts energy use (requiring only 9 watts to emit the same 450 lumens) — presumably saving homeowners cash off their energy bills for more than a decade.
The one catch? Its price tag exceeds $40. Who will be willing to pay that much when people are used to buying a four-pack of bulbs at the grocery store for under $10? GE says it has faith that consumers will weigh potential savings against upfront cost, but this has never been a strength of the mass market.
The GE bulb is revolutionary for several other reasons. One of the reasons LEDs haven’t been widely adopted for general home and workplace lighting is because their beams tend to be focused, rather than diffuse. One of the companies working on this problem is Bridgelux, which just came out with its own screw-in LED bulb, called the Heleion. The Energy Smart LED bulb uses plastic structures wrapped around the glass to more evenly distribute the light.
GE also plans to message the new product as safer than regular bulbs. It doesn’t contain mercury, making it easier to dispose of without worrying about toxic waste or watershed contamination. And it doesn’t need to heat up to cast off light, making it less of a fire hazard than its predecessors.
The competition in the LED market is now three-fold. First, who can come up with an LED bulb to rival 60-watt incandescents, giving consumers more options? Second, who can create a screw-in LED bulb that can literally replace the bulbs we’re using now in traditional lighting fixtures? And third, who can do it at the lowest cost? Bill Watkins, CEO of Bridgelux, predicts that his company will have its interchangeable LED bulbs available for below $10 in the next year or so.
Bridgelux is also pursuing a different marketing strategy that GE might want to consider. Instead of selling LED bulbs to consumers in stores like Home Depot and Safeway, the company plans to target the people who make lighting fixtures, including architects and contractors. On top of that, it is focusing on the commercial lighting industry.
Watkins argues that companies are much more likely to adopt general LED lighting than homeowners. Why? Because companies keep more precise tallies on how much they are spending on lighting versus how much they are saving in energy and on their energy bills. A simple cost-benefit analysis will show that the LED bulbs pay for themselves over time, he says. Homeowners don’t look that far ahead.
If GE, Bridgelux, Osram Sylvania, Panasonic and others successfully infiltrate commercial lighting, they could build up a nice cushion to bring down the cost of LED lighting for the residential market — maybe within the next two years.
http://green.venturebeat.com/2010/04/08/ge-bids-to-replace-40-watt-bulbs-with-new-leds/
Start-up develops snap-in LED light
Bridgelux worked with Molex to make a lighting fixture that can snap into a base, a system designed to make upgrading and installation easier. (Credit: Bridgelux)
LED lighting company Bridgelux says out with the Edison screw-in bulb and in with the snap-in lighting module.
The Livermore, Calif.-based start-up said Wednesday it has designed a lighting module called Helieon that combines Bridgelux’s LED lights and a snap-in interconnect system made by Molex, which is based in Lisle, Ill.
The interconnect system will make it easy to install LEDs and upgrade them when more efficient or brighter lights come out, the companies said.
The Helion system, which will be available in May for $20, is aimed at lighting manufacturers that build actual lighting fixtures. The Helion will be available with a light output between 500 and 1,500 lumens, the equivalent of between 40 watts and about 100 watts for incandescent bulbs but will use significantly less electricity.
Bridgelux says that the packaging and efficiency of its lighting system is a step toward making LED lighting more cost-effective when compared with other forms of lighting. “Solid state lighting is poised to displace conventional incandescent, fluorescent and other technologies in many high-volume general lighting applications,” Bridgelux CEO Bill Watkins, who joined the company earlier this year, said in a statement .
Bridgelux has signed on some lighting fixture manufacturers to use Helieon, including architectural lighting company Focal Point. But as it goes after the general lighting market, it faces competition from a number of LED start-ups and established lighting companies.
http://news.cnet.com/8301-11128_3-20001055-54.html?tag=newsEditorsPicksArea.0
Estasi Lamp immerses LED light in Technogel to glow in the dark
Reinterpreting the history of lighting, designer Federico Delrosso has come up with a simple yet innovative lamp that resembles the shape of a traditional light bulb to be used as indoor as well as outdoor lighting. The “Estasi Lamp,” as hailed by the designer, is made of Technogel immersed with the LED light to illuminate in the dark. Free from all typology, the portable lamp can be employed as both a floor lamp and table lamp. “The softness of the material is reflected not only on the physicality of the lamp but also the diffusion of the light and therefore the atmosphere it sheds in the surrounding ambiance.”
Via: Mocoloco
http://www.thedesignblog.org/entry/estasi-lamp-immerses-led-light-in-technogel-to-glow-in-the-dark/
To save power, Digital Lumens networks LEDs
Digital Lumens has created a fixture for commercial buildings that includes a light, sensors, and on-board computer to communicate with other lights.(Credit: Digital Lumens)
To create a more efficient light, you need to make it more like a computer, says Digital Lumens.
The LED lighting start-up disclosed on Tuesday details on its product, which it says dramatically reduces lighting costs. Tests with its first 16 industrial customers in warehouse-like spaces have cut costs by 90 percent over HID lights.
The Digital Lumens system creates a mesh network of fixtures which can be managed by software. Each lighting fixture is equipped with an on-board computer, Zigbee wireless networking chip, and sensors for detecting light levels and when a person enters a room.
The software lets building managers program lights for maximum efficiency. For example, a person can set up different zones within a building and direct light to a specific area within a warehouse aisle. The software also collects data on how much electricity individual fixtures consume.
About half of the energy savings come from the more efficient LED bulbs with the other half coming from the ability to network and control light settings, said Digital Lumens CEO Tom Pincince.
Employees at the Boston-based company came from the networking and software industries, as well as from Color Kinetics, an LED architectural lighting company acquired by Philips.
Digital Lumens chose to develop a lighting product specifically for commercial installations because lighting is a signficiant cost and because business buyers tend to look at the total cost of ownership. Businesses can get a two-year payback for a lighting retrofit, compared with 10 years or longer for solar, said Pincince.
The company plans to target customers through lighting retrofit companies or energy service companies, which do energy-efficiency projects.
Digital Lumens, which has been quiet since its founding a few years ago, has raised $11 million in venture funding in two rounds from Black Coral Capital, Flybridge Capital Partners, and Stata Venture Partners.
http://news.cnet.com/8301-11128_3-20000518-54.html?tag=newsEditorsPicksArea.0
Liquid Sunshine showers wavelength LEDs to ease Seasonal Affective Disorder
In this fast moving era, people usually fail to sustain the pressure created at the workplace, home or even by society and show the symptoms of Seasonal Affective Disorder (SAD), also known as winter depression or winter blues, affecting their behavior and thus lives. Addressing the issue, Seattle-based designer Joseph Henney has come up with a therapeutic showerhead that helps users reduce, or even cure, depression after each morning or evening shower. The “Liquid Sunshine,” as the designer hails his design, makes use of an internal turbine, which is driven by household water pressure to power blue wavelength LEDs, bathing users in a deluge of light and water to ease both mental as well as physical stress.
Via: Joseph Henney
Flow bamboo lighting works on the principle of vertical wind turbine
Transmitting electric grids to the far-flung places, especially sea shores, isn’t as easy and practical as in habited areas, for they are not only difficult to maintain but also disrupt the natural beauty of those areas. However, the “Flow” from IGenDesign is a public lighting with difference that harnesses sustainable materials and energy to light the bleak nights at secluded places. Featuring a structure finished in bamboo that supports LEDs, wires and the dynamo, the self-maintaining light works on the principle of vertical wind turbine and seizes the wind from all directions to power the lamp at night. Locating the light source at the ends of the wind blades, the sustainable light forms either continuous lighting surface or slow, waving movements, according to the speed of the rotation, playing with the light.
Via: IGenDesign
Energy-Efficient Lighting Made Without Mercury
RTI International has developed a revolutionary lighting technology that is more energy efficient than the common incandescent light bulb and does not contain mercury, making it environmentally safer than the compact fluorescent light (CFL) bulb. (Credit: Image courtesy of RTI International)
RTI International has developed a revolutionary lighting technology that is more energy efficient than the common incandescent light bulb and does not contain mercury, making it environmentally safer than the compact fluorescent light (CFL) bulb.
At the core of RTI’s breakthrough is an advanced nanofiber structure that provides exceptional lighting management. Nanofibers are materials with diameters and surface features much smaller than the human hair but with comparable lengths.
RTI’s technology, which was funded in part by the Department of Energy’s Solid-State Lighting program, centers around advancements in the nanoscale properties of materials to create high-performance, nanofiber-based reflectors and photoluminescent nanofibers (PLN). When the two nanoscale technologies are combined, a high-efficiency lighting device is produced that is capable of generating in excess of 55 lumens of light output per electrical watt consumed. This efficiency is more than five times greater than that of traditional incandescent bulbs.
“By using flexible photoluminescent nanofiber technologies for light management, RTI has opened the door to the creation of new designs for solid-state lighting applications,” says Lynn Davis, Ph.D., director of RTI’s Nanoscale Materials Program. “This new class of materials can provide cost-effective, safe and efficient lighting solutions.”
Additionally, RTI’s technology produces an aesthetically pleasing light with better color rendering properties than is typically found in CFLs. The technology has demonstrated color rendering indices in excess of 90 for warm white, neutral white, and cool white illumination sources.
“Because lighting consumes almost one-fourth of all electricity generated in the United States, our technology could have a significant impact in reducing energy consumption and carbon dioxide emissions,” Davis said. “The technology also does not contain mercury, which makes it more environmentally friendly and safer to handle than CFLs and other fluorescent lamps.”
RTI is continuing development of this technology and is actively pursuing commercialization opportunities in the marketplace. It is anticipated that commercial products containing this breakthrough will be available in three to five years.
Story Source:
Adapted from materials provided by RTI International.
http://www.sciencedaily.com/releases/2010/02/100211140629.htm
Researchers Build OLED Light that Mimics Natural Phases of the Sun
Shane McGlaun (Blog)
Breakthrough may lead to brighter and more natural OLED lighting
OLED is a known technology for many technology enthusiasts and is most common in displays. OLED tech also has other uses, one of which is for lighting indoors that is more energy efficient than the current light sources in wide use today.
Researchers at the National Tsing-Hua University in Taiwan — J.H. Jou and his graduate students — have made a significant breakthrough in the design of indoor lighting using OLED panels. The researchers have been able to devise OLED panels that can accurately mimic sunlight and can simulate the phases of the sun from dusk until dawn.
The OLED panels may one day be useful for indoor lighting that is easier on the human eye and saves energy; thereby reducing greenhouse gasses produced from making electricity. The development by the team of researchers enables a white-light OLED panel to emit the same light wavelengths
as natural sunlight. This is accomplished by varying the voltage to the panel.
Jou said, “By varying the voltage through the OLED panel from three to nine volts can produce ambient light simulating natural light that changes from dawn to dusk. Truly there is genius in simplicity as this plain driver-IC can automatically modulate the voltage to render any desired color temperature between 2200 and 8000 K anytime.”
The OLED panel emits light via electroluminescence. The panel has a voltage applied across the electrodes to motivate the electrons in the semiconducting layer near the panels cathode. The electrons are then released near the anode and leave behind positively charged holes and the electrons can then fill these holes and emit photos that produce light.
LEDs are currently being used for indoor lighting, but the OLED technology promises to be thinner and consume less power. OLED lighting is already available from Lumiotech. The company is the only global supplier of OLED lighting, but its lights produce only one wavelength of light that is akin to sunlight on a cloudy day.
According to the researchers, OLED lighting may be ten times more energy efficient than current incandescent lights and as much as three times more efficient than currently used CCFL lighting. Research on OLEDs for lighting has been underway for years and the lumens of light produced per watt have increased significantly over the years. OLED light panels are expected to produce 50 lumens per watt in 2011. Much research is going into OLED panels for lighting and other uses.
In July of 2008, researchers made a breakthrough that led to brighter OLED panels producing 70 lumens per watt.
