LEDs technology is radically different from existing light sources and opens new directions in lighting design although market acceptance will require that it be trusted as healthful and safe, and that its features be valued by users.
The first known report of a light-emitting solid-state diode was made in 1907 by the British experimenter H. J. Round.
The first practical LED was invented by Nick Holonyak, Jr., in 1962 while he was at General Electric Company. The first LEDs became commercially available in late 1960s.
LEDs offer substantial benefits beyond energy efficiency.
LEDs: have no moving parts and are much more robust and resistant to vibration than other light bulbs available on the market.
It has a much longer life span than regular bulbs. Some LEDs can operate for up to 100 000 hours, depending on the quality of the diode and the application.
LEDs produce a highly visible light and are compact in size thus facilitating their use in a variety of capacities.
It also produces coloured light, eliminating the need for a tinted lens to produce the desired colour.
In outdoors applications, this prevents a phenomenon known as “phantom light,” which occurs when the sun (or other light) reflects off a tinted lens or traditional light source and makes a light appear to be on when it is off.
LEDs do not generally suffer catastrophic failure after initial energizing. If individual diodes do fail, the overall light output will not be noticeably affected, thus strengthening product reliability.
LEDs also can deliver additional savings through reduced maintenance costs as they can avoid the material and labour costs involved with continually replacing conventional bulbs.
The voltage and current required to operate LEDs lights are so low that small batteries or solar panels can be used as a back-up power source, improving safety in traffic signal applications.
In some cases, solar panels can act as the primary power source, avoiding the costly construction of power lines to remote locations.
Although the initial cost of LEDs remains higher than the conventional lightings but with the lower lifecycle and maintenance costs, LEDs technology will make it more attractive, especially as manufacturers continue to economize and increase efficiency.
Source : Construction Innovation, Vol 17, No. 2, June 2012, Dou Bulb and Evolving Technologies limited
(this article written for 1BINA.my)