Most of the modern light sources today are still represented by incandescent light bulbs, which haven't evolved a great deal ever since they were first invented. Basically, typical incandescent light bulbs have a less than 10 percent efficiency, the remaining 90 percent of energy being dissipated in the surrounding medium in the form of heat. Speaking about inefficiency, the light bulb might just as well be the longest living inefficient device used in the history of mankind.
Fluorescent tubes and LEDs on the other hand, can score an efficiency rate at least twice higher than the incandescent light bulbs, which immediately translates into less expenses and lower carbon dioxide emissions during electric energy production. Currently, it is estimated that in the Unites States about 22 percent of all electric energy produced is used for lighting, representing 8 percent of the overall energy consumption throughout the country.
A reduction in energy consumption would most certainly have an immediate impact, not only on the economy of the US but on that of the entire world as well, says Yoshi Ohno of the National Institute of Standards and Technology. The problem of the fluorescent tubes has been pretty much settled. They are more than three times more efficient than incandescent light bulbs, a life span a couple of times longer, but they are dangerous because they need mercury to operate correctly.
Alternatively, solid-state devices such as light emitting diodes have efficiency rates 10 times greater than incandescent light bulbs, a life span a couple of times longer than that of fluorescent tubes and can be easily recycled. The sole obstacle standing between them and their implementation as general light sources is that they don't behave well while scaled up. Technology is about to solve this problem as well, but until then several other steps must be taken in order to ensure the implementation of said technology.
Standardization is just one of them. Which is exactly what NIST has done recently in the US. Two standards have been chosen as far, involving quality, performance, color specifications, fixtures, testing methods, efficiency and color quality.
The US Department of Energy is planning to reduce the energy consumption for lighting by 50 percent by 2025, which could save up to 280 billion US dollars in the next two decades. "More standards are needed, and this will be the foundation for all solid-state lighting standards," Ohno says while referring to the standard LM-79 recently issued by the Illuminating Engineering Society of North America.
And to make things even more interesting, the DOE is also expected to launch an Energy Star program for solid-state lighting devices by the end of this fall, which will ensure that the product is up to standard and provide an energy saving alternative for the costumers.