Despite their long history of reliability and low cost, the incandescents are hugely inefficient. About 90 percent of the energy they consume is given off as heat and only 10 percent as light. Production of 100-watt bulbs ended last October; production of 75-watt bulbs is slated to end in this year, and production of the most widely sold incandescents, the 40- and 60-watt bulbs, will cease in 2014.
The differences in the newer bulbs that matter to most people are the color and quality of the light the bulbs produce, the amount of energy they consume and how long they will last.
Halogen bulbs produce light that is very similar to that of incandescents and they last about the same length of time (about 11 months if used three hours a day), but halogen bulbs consume about 30 percent less energy. Compact fluorescent bulbs, commonly called CFLs, produce light in a broad range of colors that can be close to that of an incandescent bulb or literally as bright as daylight. Compared with incandescents, CFLs consume about 75 percent less energy and last about 10 times as long.
Light-emitting diode bulbs, commonly called LEDs, are the latest entry in the home-lighting arena. The choice in color of the light that LED bulbs emit is limited. In most cases, it is either close to that of incandescent bulbs (2700K) or close to that of halogen bulbs (3000K). LEDs use about the same amount of energy as CFLs, but they last forever — on average about 22 years, far longer than most people plan to live in the place where they will be installing them.
Three other pluses with LEDs: They can be used with dimmers (some CFLs can be used with dimmers but not all of them), the light reaches full brightness instantly (many CFLs take 30 seconds to several minutes to reach full brightness) and LEDs do not contain mercury (each CFL bulb contains only a minuscule amount of this hazardous mineral, but collectively many CFL bulbs in a municipal landfill is a very serious problem).
To get a sense of how the LEDs work in real time, I field-tested four types of LEDs from three manufacturers in my home (the manufacturers were GE, Sylvania and Lighting Science). I tried them at night, studying the quality of the light in different applications (reading and desk work, general room lighting, spotlighting art work). For me, the winners were the LEDs with brighter, whiter light in the halogen spectrum (3000K).
My husband, on the other hand, preferred the more subdued LEDs in the incandescent range (2700K). But in all cases, the light of these LEDs is more than acceptable and far superior to the first generation of CFLs. I think most homeowners will find the transition to LEDs fairly seamless.