The beloved incandescent bulbs are gone now, victims of the drive to reduce energy consumption and lower carbon footprints. For years, the only replacement that looked viable was CFL (compact fluorescent lighting), but that comes with a number of problems – safety, disposal, longevity – that have made the general public uncomfortable. Fortunately, developments in LED technology have made it varied and flexible, suitable for everything from flashlights to floods. Breakthroughs in materials science have brought it to the point of widespread feasibility sooner than anticipated, a development that will make both the environment and consumer wallets happy.

Basics

LED is short for ‘light-emitting diodes’, a diode that exhibits electroluminescence and emits photons from the p-n junction between the semiconductor surfaces. The first LEDs (or LDs) discovered in the 1950s emitted infrared waves, but as scientists varied the semiconductor doping, different wavelengths were produced, including many in the visible range. The devices were swiftly patented and used for niche purposes – fiber optics communication, digital readouts, and indicator lamps, for example.

For years, cost and technical issues restricted LD illumination from general use. But as concern grew about energy consumption and the environment, researchers saw the potential in widespread use of durable and efficient LDs for general illumination. They used federal environmental research money to develop a host of improvements in light-emitting diodes, making them commercially viable: varied colors (warm and cool) suitable for differing indoor and outdoor needs, dimmanble lamps for variable illumination, shaped packaging for everything from point to diffuse spread. With acceptance issues plaguing CFLs, LD may swiftly take the lead in household use, despite a higher initial purchase price for lamps.

LD Advantages

Modern LDs are highly suitable for the varied needs of household illumination. Their advantages can outweigh the increased price, particularly over time.

1. Longevity

Individual diodes are packaged inside solid plastic casings. When massed together in a case for use in standard sockets, they are packaged with metal heat sinks and plastic lenses, reflectors and caps to form the body of the bulb. There is no glass globe to shatter and no filament to burn out, making them safer and more durable than CFLs.

LDs are naturally more long-lasting than CFLs, and tend to dim as they age instead of dying completely. Incandescent bulb life was between 1,000 and 2,000 hours. Fluorescent lamps easily top them with 10,000 to 15,000 hours. LD bulb life is expected to be 35,000 to 100,000 hours at full strength, with gradual dimming extending their life beyond that for applications that are not lumen-critical.

2. Safety

One major complaint about fluorescence is flicker. Known to trigger migraines and epilepsy in sensitive people (and to annoy most others), flicker creates resistance to CFL implementation and has caused people to delay the transition from the steady incandescent glow as long as possible. LD radiance is continuous and flicker-free. It comes on almost instantly, without the ramp-up time of CFLs. Solid devices, LDs do not leak hazardous materials if damaged and do not require special disposal. There is no mercury to pollute the environment as there is from CFLs.

Another issue with CFLs is the potential emission of ultraviolet radiation, the same cancer-causing wavelengths that sunscreen blocks. Unfortunately, most people do not wear sunscreen indoors, and CFLs, if not perfectly coated with a UV-absorbing lining, are very likely to leak hazardous UV waves. LDs emit very specific wavelengths and LDs used for lamps do not emit in the UV range at all.

3. Efficiency

Heat is a byproduct of the conversion of electricity to light. The more efficient a the conversion, the less electricity is wasted as heat. LDs used for illumination produce no hot infrared wavelengths, so there is much less electricity waste than from other technologies.

A simple measure of efficiency is total watts used for similar brightness, measured in lumens. For 400-500 lumens, incandescent lamps use 40 watts, CFL’s use 8-12, and LDs require 6-9. This edge over CFLs is slight, but adds up over time to significant electricity savings. Considering that lighting accounts for around 6% of US electricity use, switching to LDs will have a significant impact.

4. Flexibility

With varied color and brightness, LD fixtures are flexible and fun. LDs tend to be more directional in emission than other technologies, but can be massed in a way that disperses radiance in a more even manner. With clever use of packaging, LDs can be used for anything from pinpoint illumination to floods. They are also easily dimmanble, and the latest bulbs work with current household dimmer technology. For early adopters, LD lighting can be controlled via computer or smartphone programming to change color and intensity as needed for different moods or purposes. This has given the new technology an unparalleled breadth and flexibility of use.

LDs are proving to be for everything from outdoor floods to standard household illumination to specialized uses like automobile and traffic signals. Improvements in materials have increased brightness and color levels and driven prices down. With every reason to believe that trend will continue, it looks as though household fluorescent lamps may have a very short reign.

SUMMARY: New LD fixtures are efficient, environmentally friendly, long-lasting, healthier, safer and more flexible than CFL lamps, and prices are dropping rapidly as technology advances.