Let there be LED
LEDs are semiconductors, and like all solid-state technology, they are getting better and cheaper on a predictable curve. In 1999, a researcher named Roland Haitz, then heading up semiconductor R&D at Hewlett-Packard, coauthored a paper that became the lighting industry’s manifesto. By charting the historical prices of LEDs and projecting forward, Haitz estimated that the amount of light they produced would increase by a factor of 20 per decade, while the cost would correspondingly drop by a factor of 10. Haitz’s law has proven remarkably accurate. Fluorescent lightening has been around since the 1930s, GE physicist Ed Hammer was the first, in 197, to figure out how to twirl that long gas-filled tube so it would screw into a standard socket. The GE CFL produced as much light as an incandescent, while drawing just 20 percent as much electricity. In 1980, Philips became the first company to market a CFL, with a design based on a series of bends rather than GE’s spiral. But problems of dimming, flicker, and light colour remained. And manufacturer claims of bulb lifetime and quality were wildly exaggerated. Consumers didn’t understand that CFLs burn out rapidly when they’re not allowed to rest at least 15 minutes between being cycled off and on. Though industry claims that some of the problems resulted from an early influx of cheap imported bulbs are true- as in the fact that CFLs have improved- many issues remain. No-name commodity bulbs still perform poorly, and even the big brands continue to poison the well by selling for example, CFL floodlights, which often wind up in outdoor motion-sensor systems. This is an absolutely inappropriate use, given how fast the bulbs expire when they have to flick on and off so quickly. The final blow came when consumers learned the CFLs contain mercury, enough that the Environmental Protection Agency’s cleanup instructions for a broken bulb run three pages and start with a warning to open windows and evacuate people and pets. However, Philips is the only company that has entered the competition so far, and the Department of Energy still hasn’t handed down a decision. GE invented the light-emitting diode in 1962. The first ones to come into wide use- glowing a space-age red- turned up in the clock radios, pocket calculators, and digital watches of the 1970s. Additional colors came along over the next couple of decades. LEDs are manufactured more or less like any other semiconductor. Each diode is cut from a wafer of crystals layered over a base of silicon or sapphire. The crystal color on early LEDs was gallium arsenide or gallium phosphide, which lent that reddish color. There are two ways LED makers create a more pleasant white. In the 1990s, the favored technique was to combine red, green and blue LEDs. Though still rather expensive to produce, LEDs are getting cheaper, just as Haitz’s law predicted, due to both technical advances and economies of scale. In February 2009, David Horn, a physicist and engineer who’d trained at California’s Lawrence Livermore National Laboratory, joined SuperBulbs as CTO. Part of the reason there’s still no L Prize winner is that LED bulbs are so new. Though the performance standards are clear, they’re also incredibly high, and devising ways to test them remains elusive. “Those bulbs will change the world,” Sharenow says.
MY OPINION
The light bulb landscape is rapidly evolving: incandescent are on the decline, compact fluorescents have become increasingly standard, and LED bulbs are becoming more affordable. In my opinion, LED bulbs are commonly used in enhancing our daily lives, such as, in our TV remotes, car bulbs, cellphones, and even housing lights (Christmas trees, etc). LED bulbs are cheaper, durable and consistent. Benefits of LEDs, compared with incandescent and fluorescent illuminating devices are that LED bulbs require less energy to work, which means that they can be operated with battery operated supplies. Moreover, LEDs have high efficiency, which means when power supplied it is converted into radiation in the desired form, with minimal heat production. Last but not least, LEDs have a long life and they can function for decades. Overall, LEDs are a great eco-friendly way to save energy and are durable in all ways.