LED lighting, as seen here in a Tokyo holiday display, has increased energy efficiency in homes and buildings around the world.
The 2014 Nobel Prize in physics went Tuesday to three scientists who gave lighting a makeover by inventing blue LED lights. The award recognizes a seemingly commonplace innovation, but one that has paved the way for a sea change in lighting efficiency that is under way around the world.
Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura developed the blue light-emitting diode (LED) in Japan in the early 1990s, triggering a "fundamental transformation of lighting technology," according to a press release from the Royal Swedish Academy of Sciences, which awarded the prize.
Red and green diodes had been around for several years, but adding blue diodes allowed a mix that could produce practical white-light LED bulbs.
LEDs use less energy than do other forms of lighting, including compact fluorescent (CFL) and incandescent bulbs. A typical LED bulb can produce around 83 lumens per watt—a measure of how much brightness you can get from a unit of electrical power—compared with 67 for a comparable CFL bulb and 16 for an incandescent.
LEDs produce light by passing electric current through a semiconductor, whereas incandescent bulbs pass current through a wire filament until it glows from the heat. The wasted heat energy is chiefly why incandescent bulbs are so much less efficient. Most varieties of the incandescent light bulb have been phased out in the United States. (Related: "U.S. Phase-Out of Incandescent Bulbs Continues in 2014.")
LEDs also last about 30 times longer than incandescent bulbs do, according to the Energy Information Administration, and many LED bulb products promise up to 25,000 hours of use—more than 17 years if you used one for about four hours a day.