Renewable Energy Magazine: LED lighting expert Rob Lobitz takes a look at the past, present and future of light emitting diodes: one form of energy efficient lighting that thanks to its wide range of applications is quietly and consistently becoming ubiquitous in many sectors. “They're sweeping across the globe as a replacement
for all sorts of lighting uses. LEDs are being used in everything from signs to cars to flashlights and even more as the technology behind them grows,” explains Lobitz. Since the dawn of time, Man has been fascinated with light. Everything from the stars in the sky to the concept of the first fire has shaped the way we live and act in our daily lives. So it's no wonder that any time new technology in lighting is available, it's a pretty big thing to come across. Since the invention of the traditional incandescent light bulb, lighting technology hasn't changed much with the exception of the efficiency with which the bulbs are made, resulting in the low prices we see today on our store shelves. The only problem with this is that while the incandescent bulbs are cheap and accessible, they are incredibly inefficient with energy usage and their short lifespans often result in replacing them after months and not years of life.When CFL bulbs first appeared widely to the public in the 70s, people were at first relatively sceptical about this new helix-shaped bulb but the merits in its favour were hard to ignore. First of all the bright white light put off by CFL bulbs easily outshined their yellow light incandescent cousins while at the same time using much less power to output the same level of light. In recent years, CFL bulbs have widely replaced standard incandescent bulbs in most homes as traditional lighting due to their “green” status and lower cost in addition to boasting a significantly longer life span. The Light Emitting Diode (in case you were wondering what LED stands for) was created in 1927 for experiments in electroluminescence, but the first viable LED light wouldn't be developed until 1962 by Nick Holonyak Junior, now known as the “father of the light emitting diode”. After the first red diode was created, the technology was expanded on in 1972 by a graduate student of Holonyak who created yellow diodes and increased the brightness of red and red-orange diodes. In 1968, LEDs were far too costly to produce and use commercially (at about $200 per LED unit) until a company called Monsanto developed a technology to mass produce them for indicators, at which point HP began using them for lights in their calculators. Finally in 1970, the technology for LEDs was perfected, reducing the cost per light to about five cents which was enough to consider them for mass commercial use. Early LEDs were used solely in indicators for high powered lab equipment but as technology grew it saw expansion into TVs, telephones, radios, and other appliances as well. It wasn't long before the first beginnings of the kind of LED lighting we see today began to take shape. More and more colors became available and as light output from newer LEDs rose, the white light LEDs used in standard lighting we see now started to appear. Recently, LED lights and bulbs have vastly begun to replace even the CFL bulbs that had once replaced earlier incandescent bulb types. Now you know what LED bulbs are, but the question remains, why are they better for us than regular lighting? For starters, they're much more energy efficient than any kind of standard lighting today. In addition, you see LED bulbs lasting over ten times as long as a traditional incandescent bulb and even three times longer than CFLs. Breaking down the numbers themselves, studies have shown that incandescent bulbs cost about $2 and use 60 watts of electricity to put out about 660 lumens of light over an average of 2000 hours. This costs you, roughly, $197 per year at the use of 6 hours a day for how much light they generate. CFL bulbs only utilize 13 watts of electricity to output 825 lumens for roughly 8000 hours at twice the initial cost. You really see your savings in the yearly cost, much lower at only about $42 per year. LED bulbs, however, have a much higher purchase price of about $20 apiece. The difference, though, is that they only use 9 watts of electricity to produce 900 lumens of light. Over a year of use, costs only rise to about $29 and when you factor in the absolutely massive 25,000 hours of total light you get from an LED bulb, the choice for lighting should be clear. Not only do LED light bulbs use less energy to put out more light, they do it for much longer than all their competition. LEDs aren't just useful for standard lighting in lamps or housing. They're sweeping across the globe as a replacement for all sorts of lighting uses. LEDs are being used in everything from signs to cars to flashlights and even more as the technology behind them grows. Entertainment electronics have come a long way with the use of LEDs, particularly televisions. LED televisions are the TV of the future, putting older LCS and even top-grade plasma televisions to shame. They boast higher contrast ratios, refresh rates and resolutions in lower sizes compared to other kinds of televisions of the same size. They also have much brighter screens and are often only a fraction of the width of traditional LCD and plasma TVs, leaving them with a sleek, refined slim look. The low energy use benefit of LEDs is also passed on, reducing power usage by up to 60% over LCD and plasma models. Even now the technology behind the LED is growing and expanding, bringing new innovations to the world at each turn. For example, scientists are working with Organic LEDs or OLED technology as a new way to create unique, flexible displays. That's right, OLEDs can create a printable and bendable surface with unique properties. OLEDs are currently being used in a multitude of display technologies like for MP3 players, cell phones and cameras with expansive potential for use in lighting and entertainment. Another breakthrough use for LEDs is in the field of agriculture. Advancements in LED lighting have been used to substitute LED lighting for the indoor growth of plants and vegetables. Many indoor plant growers are flocking to new LED technology due to low long term costs as well as its high energy efficiency. The low heat emissions of LEDs also cause plants less damage and increases the time required between watering cycles. Such technology could potentially be harnessed for use in space for growing food over long periods of time for astronauts. UV emitting LEDs don't stop at just helping plants with photosynthesis, they can also be used to sterilize water and other substances by killing bacteria and other harmful organisms. A growing use for LED lights is in the use of machine vision. Machine vision is the process that allows for automated inspection and robot guidance for machine parts in industrial factories. The use of LED technologies allows machines to recognize the things they “see” in order to work efficiently. This is used for any kind of automated assembly line work such as the assembly and inspection of vehicles as well as systems that judge whether an item passes or fails safety requirements as it moves through a system. Even with its wide range of uses, machine vision via LEDs is only being used in about 20% of the fields it could be applied to. LED lights aren't just in high powered technology or far away factories, you can probably find them in things you have in your own home or are using right now. If you're using an optical mouse, the red light on bottom for the sensor is an LED. Many new flat screen monitors are also lit by LEDs as well. LED flashlights are becoming incredibly popular for home or emergency use as they put out so much light and can last for a long time on the same battery. That way you don't have to worry about a flashlight now working during an emergency power outage or if you should need to go out into the dark for any reason. Not to mention that most LED flashlights are waterproof so they'll work well even in some of the most adverse weather conditions. It's easy to see that with the expansion and growth of new LED technology, the world will see LEDs integrated into all facets of life. The technology is for manufacture and use of LEDs is constantly improving which just goes to show how important the use of LEDs will become. From the bar code scanner at your local grocery store to the lighting and technology in your home computer or vehicle or even to the lights above your head, LED technology is everywhere and spreading like wildfire. With the energy efficiency, low maintenance cost and overall “green” nature of LED lighting, there are very few reasons to continue with the use of outdated and costly forms of lighting previously available. Even if you're just taking a first few steps towards the future, you're doing good for yourself, the planet and for your wallet by converting to the new, highly efficient forms of LED lighting available to you right away. Source: Renewable Energy Magazine
