Trend: Incandescent bulbs will go the way of giant, gas-guzzling vehicles as the benefits of LED lighting become known.
Economist.com says that about 20% of all electricity generated is used for lighting. LEDs could eventually cut that amount in half. That would not only save billions of dollars in electricity bills, but also significantly reduce energy demand, environmental pollution and greenhouse-gas emissions.
Link: An even brighter idea | Economist.com.
Since LEDs were first invented over four decades ago, they have mostly been used in niche applications, first as simple indicator lights on calculators or watches and then, as their brightness improved, in displays, signs and traffic signals. More recently, some companies have begun to sell LED fixtures for residential use. “We're on the brink of a new lighting revolution,” says Jerry Simmons, head of the solid-state lighting programme at America's Sandia National Laboratory.
LEDs have become popular because they have numerous advantages over conventional light bulbs. For one thing, they last much longer: they can endure up to a decade of non-stop use compared with a few months or less for incandescent bulbs. They also take up much less space (a typical LED is about the size of the rubber on the end of a pencil), are shock resistant and, perhaps most important of all, are extremely energy-efficient.
An incandescent bulb, made of a wire filament encased in glass, emits only 5% of the energy it consumes as light; the rest is wasted as heat. Fluorescent lights, which consist of tubes filled with mercury vapour, are roughly four times more efficient. LEDs, however, contain no mercury and already rival fluorescents in efficiency. Upfront costs make them too expensive for most general lighting applications, but experts expect that to change over the next five years as prices come down and efficiencies go up.
Besides being environmentally friendly, LEDs allow unprecedented control over lighting. Unlike incandescent or fluorescent lamps, which spew light in all directions, LEDs generate directional light, making them ideal for selectively illuminating areas. Moreover, the ability to mix and match the output of red, green and blue LEDs makes it possible to “tune” the emitted light to produce any desired colour. Lighting designers are already using LEDs to illuminate monuments, restaurants and even famous paintings, such as Leonardo da Vinci's “Mona Lisa”. Because LEDs emit monochromatic light, any potentially harmful or unwanted radiation, such as ultraviolet or infra-red light, can be eliminated.
Disclosure: I own shares in CREE.
via Emergic.org
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