LEDs (light emitting diodes) are becoming a fantastic green solution in lighting. The LED was first invented in Russia in the 1920s, and introduced in America as a practical electronic component in 1962. Since then, LEDs have been a major part of low-energy lighting.
LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved toughness, smaller size and faster switching. LED applications are diverse. They are used as low-energy indicators, but also for replacements for traditional light sources in general lighting and automotive lighting. The compact size of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are useful in communications technology.
Efficient lighting is needed for sustainable living. A 13 watt LED lamp produces 450 to 650 lumens, which is equivalent to a standard 40 watt incandescent bulb. A standard 40W incandescent bulb has an expected lifespan of 1,000 hours while an LED can continue to operate with reduced efficiency for more than 50,000 hours, 50 times longer than the incandescent bulb.
A single kilowatt-hour of electricity will generate 1.34 pounds carbon dioxide. Assuming the average light bulb is on for 10 hours a day, a single 40 watt incandescent bulb will generate 196 pounds every year. The 13 watt LED equivalent will only be responsible for 63 pounds carbon dioxide over the same time span. A building’s carbon footprint from lighting can be reduced by 68% by exchanging all incandescent bulbs for new LEDs.
LEDs are also nontoxic unlike the more popular Compact Fluorescent Light (CFL), which contains traces of harmful mercury. While the amount of mercury in a CFL is small, introducing less into the environment is preferable. LED light bulbs could be a cost effective option for lighting a home or office space because of their very long lifetimes, even though they have a much higher purchase price. The high initial cost of the commercial LED bulb is due to the expensive sapphire substrate which is important to the production process. The sapphire apparatus must be used with a mirror-like collector to reflect light that would otherwise be wasted. In 2008, a materials science research team at Purdue University succeeded in producing LED bulbs with a substitute for the sapphire components. The team used metal-coated silicon wafers with a built-in reflective layer of zirconium nitride to lessen the overall production cost of the LED. They predict that within a few years, LEDs produced with their revolutionary, new technique will be competitively priced with CFLs. The less expensive LED would not only be the best energy saver, but also a very economical bulb.
LEDs are on their way to becoming a revolutionary new alternative for sustainable lighting. We may be seeing more of them in our homes and workplaces fairly soon.