A photo of a man taking a photo of white and blue LED lights. Blue LED lights won the Nobel Prize in Physics.
LED , as seen here in a Tokyo holiday display, has increased energy efficiency in homes and buildings around the world.

 

Excerpt from news.nationalgeographic.co

 

Blue- innovation paved the way for a transformation in lighting efficiency.

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 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.
One of the main barriers to adoption of LEDs has been price: A typical bulb can cost more than twice as much as a comparable CFL. But LED prices are coming down, and use is growing.
The lighting transformation is not only in residences. LEDs are also being used for street lights, public holiday and decorative displays, commercial buildings, and other large energy users.
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LEDs also hold promise for bringing light to the more than 1.5 billion people around the world without access to an electricity grid, the Royal Swedish Academy of Sciences noted.