BoletĂn de noticias Led Diciembre 2008
Ledding the future
LOS LED EN USA
17 Dec 2008 │Pittsburgh councilman releases plan to convert city street lights to LEDs If the city approves the proposal, it would save taxpayers more than $2.5 M annually and allow manufacturers to submit test products. At a press conference Monday afternoon, Pittsburgh (Pennsylvania) City Councilman William Peduto released a plan to convert all 40,000 city street lights to LED lights. The plan would save taxpayers more than $2.5 million annually in energy and maintenance costs. In addition, the conversion would lead to the reduction of more than 984 lbs of carbon dioxide emissions each year. “This is a plan that saves taxpayers millions of dollars, while also protecting the environment,” said Councilman Peduto. “LED street lights use less energy, require less maintenance, provide a brighter light, reduce carbon dioxide emissions, and contain no mercury. This is a win-win situation.” A spokesperson for Peduto said the proposal’s approval timeline is not clear, as it may get held for a public hearing. He said it will come up for some form of action next week, but likely will be held for true action until January.
Over six months ago, Councilman Peduto launched a trial of LED lights along the Walnut Street business district. Today, he is submitting a proposal for Pittsburgh to replace all existing street lights with 200 W LED lights. The benefits listed in the Councilman’s report are: Pittsburgh currently spends $3.2 million each year in electricity costs for street lights. With the reduction of 137 W of energy used by each of the 40,000 lights, taxpayers will save $1.92 million per year in energy costs. Pittsburgh currently spends approximately $1 million each year maintaining our street lights. An HPS bulb has 2-4 year life span versus 10-15 years for an LED light. Additionally, an LED fixtures burns out one LED at a time, which is in contrast to the current lights HPS lights which completely blow out all at once. This is expected to save taxpayers approximately $700,000/year in maintenance costs. A 200W LED light only uses 93W of power. However, the existing 150 W high power sodium (HPS) bulbs use ~230 W (includes the ballast) of power. Therefore, over the year, the City of Pittsburgh will save 600 kWh of energy. This translates into 984 lbs of carbon dioxide emissions eliminated by switching all lights to LED. LED lights turn on and off instantly with no warm up time. The existing HPS bulbs have a slow warm up period that is a waste of energy. Additionally, the existing sodium bulbs contain mercury in the ballasts, LED lights have no mercury. LED lights produce a white light that stimulates the rods and the cones of our eyes. This creates a higher quality white light, while using less energy than the HPS lights that only stimulate the cones of our eyes and produce a yellow-orange light.
06 Nov 2008 │ Lansing, Michigan, utility expands trial of LED street lighting With the streetlight trial going smoothly and positive response from residents, the utility gave the go-ahead for 6 additional LED fixtures. The Lansing Board of Water and Light (LBWL), a municipally owned utility in Lansing, Michigan, recently expanded its trial of LED street lamps with the addition of six new fixtures.
The city now has 23 LED streetlights with neutral white LEDs, and LBWL officials are considering a significantly larger pilot to determine whether the 34,000 high pressure sodium and metal halide street lamps in the greater Lansing area will eventually be replaced with LED models. Public reaction to the initial LED streetlights has apparently been positive. In a recent survey, 85% of respondents said the new fixtures have a pleasant glow, sufficient brightness and safe light pattern. The vast majority also said they supported installation of solid-state street lamps in other neighborhoods. “The ‘green’ movement is making it important for us to implement environmentally friendly solutions wherever possible, and that includes street lighting,” said Roger Adsit, LBWL street lighting designer. “Everything is going well with the fixtures in this pilot so far, and we are continuing to pursue the possibility of transitioning to LED street lamps over the long term.” Lansing is among a growing number of municipalities around the world that are evaluating the use of solid-state illumination for street lights to take advantage of various LED cost, performance and technical benefits. These include an energy savings of up to 50%, long LED life, mercury-free construction, and better color rendering that can help improve safety and security by reproducing truer color and and sharper detail – particularly when compared to the yellow light cast by sodium lamps. The LED light engines used in the fixtures were designed by Midwest Circuits, a Ferndale, Michigan-based manufacturer of LED assemblies for outdoor lighting applications.
area roadways and sidewalks with LEDs to reduce energy and bulb replacement costs. After the LBWL received an American Public Power Association (APPA) Demonstration of Energy Efficient Development ("DEED") grant to experiment with LED lighting, the utility approached a number of vendors for proposals. When it learned about the LBWL project, Midwest approached the LBWL with a prototype board. Impressed, the LBWL provided Midwest with a few lamp heads so that the company could develop test fixtures. After thorough testing of products from all the major power LED manufacturers, Midwest chose L through Future Lighting Solutions, the exclusive worldwide distributor of LEDs.
30 Oct 2008 │ Aus/n, Texas, wants to replace the cobra with solid state lighting. The city, which has been experimenting with several green technologies and trying to encourage green companies to locate there, will evaluate the cost-effectiveness of replacing 250watt high pressure sodium "Cobra-head" street lights with LED street lights, which consume far less energy. The city estimates it could save up to $500,000 a year in utility bills by inserting LEDs in 5,000 street lights alone. Maintenance costs would also likely decline because LEDs last longer. Although LEDs cost more, advocates say that the total cost of ownership, particularly in public light figures, is lower.
History Lansing’s first 17 based street lamps were installed in 2007 to explore the possibility of illuminating
07 Dic 2009 │ Cree wins contract to light the Pentagon LED manufacturer Cree has been awarded a contract from the U.S. Department of Defense to supply over 4,200 recessed LED lights for the Pentagon, the company announced Tuesday. Financial details were not disclosed. Testing commissioned by the U.S. government determined that Cree's LR24 recessed LED lights would offer a 22 percent energy reduction compared with fluorescent lights, and save the Pentagon 140 tons of carbon dioxide emissions per year. The government also commissioned a cost analysis that showed the lights would yield a payback of less than four years once things like energy savings, maintenance, and the expense of properly disposing mercury-laden fluorescent bulbs were taken into account, according to Cree.
Before: A Pentagon room before LED lights were installed.
After: The same room at the Pentagon after LED lights were installed.
LOS LED EN EUROPA
May 15th 2008 | DUSSELDORF LED street lights From The Economist print edition Replacing gas lamps with LEDs DUSSELDORF is not well-endowed with nostalgic charm, and soon may be shorter of it still. The 17,000 or so gas lamps that still bathe the streets of the old centre in their glow are on their way out. The German city's municipal power utility plans to replace about 10,000 of them with a technology that is cheaper to operate but so modern that only a handful of cities have begun to use it: lightemitting diodes (LEDs). So far, only two dozen experimental LED street lamps have been put up in Dusseldorf. Although LEDs can initially be more expensive, they are a lot more reliable and they can last longer than conventional light bulbs. But LEDs do have drawbacks. The utility reckons that in terms of the total amount of light produced from a watt of electricity, LEDs still do not match fluorescent or sodium lamps. But that will change in coming years as LEDs improve. Anyway, the light from LEDs can be used more efficiently than that from conventional lamps, reckons Ulrich Kuipers, from the South Westfalia University of Applied Sciences, which developed the Dusseldorf lamps. “You can direct LED light very well,” he says. So instead of casting light all around—often over places that do not need to be illuminated, each LED is directed much like a spotlight. But not everyone is happy. Many people think the white light from the LEDs is too cold. “It's true, I made a mistake there,” admits Mr Kuipers. So he now plans to use another useful characteristic of LEDs—their ability to produce different colours and hues. That way he hopes to imitate the friendly glow of old gas lamps.
19 Dec 2008 | First test installation for LED street light in Vienna The actual assets of Streetlights in Austria originate from the Sixties and Seventies of this century. The consequentially high electric power consumption is evident. The modification of the exiting street lighting will come up to all municipalities sooner or later, not only because of the upcoming necessary restrictions of the European Union concerning this sector. Not only developers but also lighting professionals see the LED as a resort for the worldwide energy wastage. This is mainly important for the public lighting and especially for street lighting. Together with the Regional Management of the City of Vienna (4th District), the Austrian Federal Economic Chamber, the association FREIHAUSVIERTEL, the Municipal Department MA33, responsible for Public Lighting and Traffic Lights in Vienna installed at Kühnplatz in 1040 Vienna. The spirit of innovation and the commitment to energy efficiency and LEDTechnology of all parties concerned enabled this first test installation. Further installations will follow in 2009. The ambition of the project is not only the proof of the technical reliability and cost efficiency of LED Lightings, but also the feedback of the inhabitants of the district, to compare the conventional yellow/orange lighting of the NAV lamps to the bright and white lighting of theLEDStreetlights. "The LED-Streetlight is saving about 50% of the energy costs in comparison with conventional streetligths. The installation specialists were also convinced by the easy handling during the installation process, “With LED-Streetlighting, it is now possible to control the light emmitance exactly, and avoid unnecessary blending and light pollution. More over the bright white light of the LED and the high colour rendering index assures a tremendous advantage in traffic safety."
INFORMACION LED
Save energy with LED street lights and reduce light smog With the LED Street Light, in cooperation with the research institute, HarzOptics, Autev AG plans to bring a cost-effective, energy-saving and environmentally-friendly LED street light to the market this year. Not only are filament bulbs threatened with extinction in the near future, mercury vapor lights, which currently account for approximately one third of the lights on German streets, will no longer carry the CE symbol from 2015 (expected date). A study on the subject also reveals that German cities and local authorities consume more than 4 billion kilowatts of energy on lighting streets and public areas every year. This produces some 2.5 million tons of CO². So, quite evidently, it makes sense to think about energy-saving alternative lighting systems. A Germany-wide first pilot project with LED street lights was kicked off in Düsseldorf at the end of 2007. But of course work is also ongoing elsewhere on concepts for energy-saving LED street lights. They report that, when compared with a good sodium vapor light, the LED Street Lights consume 42% less energy – before dimming. With dimming more than 57% energy can be saved. With its maximum performance of between 100 and 110 lumen per watt, the LED Street Light can also compete with a sodium vapor light in absolutely every other respect. And with regard to light intensity, which is between 10 and 20 lux, this light equipped with LEDs is at least as good as any conventional street light. In terms of the color reproduction index, which is used to describe the influence of a light source on an object’s color effect, the LED even surpasses a sodium vapor light, which only achieves 30%, while the LED’s index is around75% The scientists also plan to meet the highest ecological requirements with their concept. The LED will therefore also contribute to a reduction in
light smog, which, for example, can result in the extinction of some insect species. The researchers say that a containment of light smog can in particular be achieved by focusing light logically, and neither radiating the lights upwards nor horizontally.
La ventaja en de los leds para la iluminación nocturna y la seguridad Safety-centered approach improves quality of light for petrochemical facilitiesAn understanding of the human visual system and how it relates to LEDs, coupled with an improved understanding of the industrial lighting environment, can have a huge impact on safety, according to Rizwan Ahmad and Boris Viner.New lighting technologies such as LEDs hold out the promise of significant improvements in hazardous area lighting. These improvements include a much wider range of lighting capabilities that can lead to direct improvements in facility lighting as well as significant improvements in maintenance and safety. Lighting is a critical element of industrial safety, and well-lighted facilities are key to safety and productivity. The petrochemical (oil and gas) industry spends millions of dollars on lighting. In contrast, in many large industrial facilities, lighting is seldom considered to be a key safety consideration, even though safety professionals are continually focused on keeping the workers safe. One of the reasons for this dilemma is that the conventional lighting has limitations in performance and therefore in its interpretation by the end user. This has potentially serious implications in industries where employees are exposed to hazardous chemicals and where accidents can be especially severe. This risk extends to employees working in food industries, or with cleaning solutions, and in manufacturing industries and service establishments.
Eyewash and safety shower facilities
Eyewashes and safety showers were developed, in response to the increased use of hazardous chemicals, as emergency systems to protect an employee from injury in case of contact with such chemicals, chemical compounds or fire.
Because the first few seconds after exposure to a chemical are critical, eyewash and safety shower facilities must be within ten or fewer seconds of an employee’s reach. If the chemical is left in the eye or on the body for even seconds too long, permanent scarring may result, so the affected area(s) must be washed thoroughly before the chemical can cause further damage. In the course of an accident it is highly likely that the victim will experience decreased vision and mobility, so it is absolutely essential that the safety shower location is clearly indicated and easily identified during day or night conditions. Traditional safety shower location lights (incandescent or fluorescent) are limited in providing useful lighting for identification of safety eye wash stations at night, and provide practically no useful signalling during the day, as the safety lighting blends into natural daylight. This is just one usage example where it will be seen that LED lighting could deliver an immediate and valuable benefit during the precious seconds needed to locate the safety shower. Seven-point lighting profile
The performance of safety lighting can be vastly improved by utilising new lighting technologies that are capable of taking into account the human visual system, providing high-quality area illumination both at night and day, as well as optimum night identification of safety showers and other critical safety equipment. We have developed a revolutionary 7-point lighting profile (Fig. 1) and offer the following unique overview of the complex process of integrating the human visual system with artificial industrial illumination and signal lighting. The Quality of Light Profile shown in Fig. 1 consists of seven measurable points: 1) Color, 2) Candela, 3) Coverage, 4)Configuration, 5) Longevity, 6) Integrity and 7) Human Factor. Human Factor is the biggest part of the “puzzle” because all of the answers for “physiologically” developed lighting are in the eye itself. A. Human factor It is important to realise that light is not simply light, as it is being interpreted by a very complex human visual system. The retina, a light-sensitive
Figura 1
Figura 2
screen at the back of the eye, has many light receptors that convert light into electrified signals sent to the vision centres of the brain. Because of their shapes the two major categories of light receptors are called cones and rods. The sensitivity of the human eye varies at different light levels and, while cones are responsible for day vision, rods play an important role in night-time vision. The very central part of the retina, the fovea, contains only cones while the rest of the retina contains both rods and cones. Cones are active at high light levels and are most densely situated in the central part of the field of view, so when we look directly at an object, we are using our cone receptors. The rods are responsible for human vision at low light levels, and are prevalent in the peripheral field of view, away from our direct line of sight. As shown in Fig. 2 the spectral response of the cones corresponds to the photopic V(λ) sensitivity curve. As the light levels decrease, the cones become less active, the rods become active and spectral sensitivity gradually switches towards the scotopic response curve. The spectral sensitivity of the human eye at photopic light levels (day vision) has a maximum wavelength of 555nm as described by the International Commission on Illumination (CIE). At scotopic light levels this value is located at a lower wavelength of 507nm. Both in theory and in practice, the determination of lamp lumens involves knowing the spectral power distribution (SPD) of the lamp and the visual response of the eye. Vision scientists have known for most of the twentieth century that in fact the way the eye responds to color is dependent upon the lighting conditions. While it’s widely accepted that cones handle day vision and rods are designed for night vision, up until now lighting manufacturers measuring a lamp’s lumen output have continued -
to utilise light meters that are calibrated to the eye’s sensitivity to only cone-activated vision (photopic), completely ignoring the effect of rodactivated vision (scotopic). Unfortunately this represents a gross oversimplification of human vision. This problem is further compounded by the realisation that the V(λ) curve was established from research conducted using the fovea, the central ±1°of the eye’s field of view, while central human vision is at least ±10°. So, if the visual task is offcentre and at a low level of luminance, the fundamental definition of the lumen would not be accurate. B .- Color In the past it has been widely accepted that under virtually all circumstances where artificial light is used, lighting level calculations could ignore light source color. When calculating such levels in practical design situations, results are based on the lamp’s lumen rating, usually provided by the manufacturer. Calculated values of candelas, lumens, lux or cd/m2 are not dependent upon whether the light source is white, bluish white, yellow or pink.
peaks (or even with peaks predominantly in the blue/green regions) it will be seen that the energy output aligns more closely with the peak of the scotopic eye sensitivity curve. The net result is that the effective lumens increase as the light level reduces at night and the eye shifts to a blue/green peak sensitivity. In summary, under mesopic viewing conditions, yellow sources have reduced effectiveness while blue/green sources have increased effectiveness. We therefore propose the concept of a ratio for determining the true rating of a fixture’s illumination in relation to lumens utilised by the human eye. This could provide a mechanism to determine the true “quality of light,” hence the term quality of light factor (QLF). From the above discussion it is clear that the strength of the scotopic eye sensitivity of an LED is a number of times higher than that of an HPS source. Therefore the QLF of an LED source should be greater than the QLF of an HPS source and this factor should be rated high while purchasing Safety Lights.
Research and publications indicating the importance of lamp spectral distribution have been available for many years. Recently, some lighting experts have started to use the term “effective lumens” to define the modified lumen output of a lamp, taking into account the shifting color sensitivity of the eye at low light levels. For example, HPS lamps have high lumen ratings based on the definition that the lumen is the amount of light as perceived by the eye under photopic conditions. It is not so much that the sodium lamp produces a high output of energy, but rather that its energy peak is near the maximum photopic sensitivity wavelength of the eye (see yellow region in Figure 3). However, because very little energy output of the HPS lamp occurs at wavelengths shorter than the peak, so the effective lumens for scotopic conditions (the V'(λ) curve in Fig. 2) is greatly reduced. Sodium produces very little blue and green light, and therefore its effectiveness under low light levels is drastically reduced. In other words at night, when the light has a true purpose in providing area illumination, the quality of HPS source is rather poor due to very low “effective lumens”. In contrast if we consider a white light source (for example white LED) with some balanced energy
Fig. 3 Another practical application of the color chart, shown in Fig. 3, would be for solving the problem for safety shower green location lights by considering the optimum wavelength that is in the mesopic range, roughly between 507nm (peak sensitivity of the human eye night vision) and 555nm (peak sensitivity of the human eye day vision). Due to the safety requirements in the Oil and Gas Industry, the safety showers indication lights must be visible not only at night time, but it is also very critical to have these type of lights visible during the day time for the reasons explained earlier (as shown in Fig. 4).
G.Integrity Integrity relates to optimised fixture mechanical (see Fig.6) and electrical design that can be achieved by utilising new LED lighting technologies for developing fixtures with universal input voltage capabilities and much cooler identification temperature ratings. Best installation practices
Fig. 7 addresses by a way of an example the importance of using the most effective lighting practices for safety lights in hazardous environments.
Fig. 4 C.-Candela Candela defines the intensity of the light sources, so it relates to fixture optical design that addresses “light focusing” for optimum performance of industrial white lighting and intended application of LED visual signal lights.
Some of Dialight’s key principles for applying LEDbased fixtures are described using a gas recovery unit as an installation example. Firstly, LED technology gives better directional control of light than is possible with conventional lighting technology. This is important in areas where many railings and straight walkways need to be lit.
D.-Coverage Coverage is the amount of “effective” light that is spread out for the intended application. This is achieved through optical design of the LED fixture to ensure optimum light distribution (Fig. 5).
Fig. 7
Fig. 5 E.Configuration Configuration, in terms of balanced lighting layout with exact positioning of the fixtures (see Fig. 7), is especially important as it results in proper spacing between the stanchion mounts of industrial lights for optimum area illumination; this usually contributes to safety. F.Longevity Longevity of the light sources is a direct contributing factor to overall facility safety, because it minimises the need for maintenance personnel to climb the structures for relamping
Unlike conventional lights, LED fixtures contain several reflectors in Dialight’s patented optimised designs to achieve specific light distribution. They also use lower wattage than conventional lighting to address the same job. The result is that fewer fixtures are needed to light a given area, more light is focused on straight lines where it is needed and spillage is limited to just a few feet. Secondly, efficient operation and low installation costs can be achieved with LEDs by spacing the fixtures more widely than with conventional light fixtures. Using this approach, fewer lights are needed to cover a space laterally, thereby reducing energy needs. This also reduces installation time and costs while the LEDs’ long lifespan cuts maintenance to zero.
Also, unlike conventional lights, LED fixtures are designed to retro-fit to multiple alternative fixings like walls or stanchions and can often be used as side-by-side modules to expand an application. Some large users will carry a range of a few dozen types of fixtures to fit different locations, so using such multi-purpose LED fixtures can drastically reduce the amount of inventory to be carried in order to maintain lighting in different situations. Conclusions
With the introduction of new LED lighting technologies it is now possible to provide an ideal light source designed specially for maximum retinal efficiency of the human eye. For the first time in the Oil and Gas industry a recommendation is made to employ an optimum color and light source that would be compatible with the physiology of the human eye. By understanding the importance of color for the effective functioning of visual signal lights – for example to ensure day and night identification of eyewash stations and other critical safety equipment – and the importance of CRI for optimum performance of industrial white lighting, perhaps we are opening the door to increased safety at Oil and Gas facilities. There is no doubt that lighting is a critical element of industrial safety. The practical examples mentioned demonstrate how utilisation of new LED lighting technologies in conjunction with the Quality of Light Factor can contribute to safety improvement as well as energy savings. About the Author Rizwan Ahmad is responsible for global market development for hazardous area lighting at Dialigh, and Boris Viner is a Consultant with Dialight for hazardous area lighting.
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