What is a LED?
LED stands for Light Emitting Diode.
Originally invented in the 1960s, Light Emitting Diodes (LEDs) are solid-state lighting components.
Diodes are semiconductor devices which means that they:
• have no moving or fragile parts; and
• emit less heat because they consume significantly less energy.
Diodes are very rugged and do not fail when dropped or vibrated as can occur with incandescent or fluorescent lights.
LEDs can therefore last for decades.
Have there been technological advances?
Yes, in significant areas of performance.
The original LEDs only emitted light of one frequency or colour (blues, greens, yellows, oranges or reds) and were unsuitable for widespread use.
Technical advances have dramatically improved the reliability and the performance of LEDs since they were first used.
Recent innovations in materials, doping and die structure have developed high brightness LEDs that can provide the same output in light as incandescent or fluorescent light.
LEDs are now bright enough to be considered for applications that traditionally used incandescent bulbs.
Further, different materials and designs produce different coloured lights and intensities.
Can the use of LEDs cut energy consumption?
Most of the energy emitted from incandescent
bulbs is converted to heat instead of light hence you'll burn yourself
if you touch an incandescent bulb once it's turned on.
On the other hand, LEDs can be many times more energy-efficient than light bulbs, depending on the application. Savings can be in the vicinity of:
• up to 85 percent of the electricity used by incandescent bulbs*; and
• up to 50 percent of electricity used by fluorescents*.
LED lights are also designed to last around 50 times longer, which means less ladder-climbing maintenance and less waste.
LED = Less Energy + Longer Lifespan
Can LEDs be efficient in other ways?
Incandescent bulbs and fluorescent lights emit
light in all directions and much of the light produced by a lamp is
lost within the fixture or escapes from the fixture in a direction
that is not useful for the intended application. It is not uncommon
for 40-50% of the total light output of a lamp to be lost before it
exits the fixture.*
LEDs on the other hand do not produce harmful UV light and only emit light in a specific direction so that light can be delivered where it is needed. This "light source directionality" and intensity may result in higher application efficiency because it reduces the need for deflectors and diffusers that can trap light.
What is their lifespan?
Many manufacturers claim that their LEDs will
last 100,000 hours (35 years at 8 hours use per day) or even longer
before operating at half brightness; however, it is too early in the
LED industry lifecycle to properly validate this figure.
LED manufacturers have performed numerous accelerated degradation tests, during which they both overheat and overdrive the LEDs until they expire.
From these results, they then extrapolate the figures to find the expected life span under normal conditions which is where many manufacturers derived the 100,000 hour figure. Others specify an expected lifespan of anywhere from 60,000 to 80,000 hours.
A major factor in the longevity of LEDs is in the way that they are used, as different colours consume various amounts of energy, thus changing their total lifespan. Furthermore, the expected lifespan also assumes that the LEDs are operating at full brightness, which, depending on the application, may or may not be true.
Thus, it is difficult to validate the purported LED lifespan of 100,000 hours and they may last much longer or perhaps shorter than this. In any case, their lifespan is far longer than any other lighting technology currently available.
What are the possible applications for LEDs?
LED lights will assist in meeting BASIX standards
for efficiency in new homes and in obtaining 7 Star Home Energy Efficiency
LEDs possess a broad range of possible applications, including but not limited to the following:
Under or inside cabinets
Kitchen splash back lighting
Feature wall lighting
Home theatre/ media room
Interior and exterior special effect lighting (eg. Hotel, restaurant, casino, water feature, landmark)
Landscape lighting for gardens, parks, pools and spas
Small spot lighting
In-ground and underwater lights
Refrigerated display case lighting
General merchandise lighting, eg, creating effects and moods based on warm/ cold colours
Display case lighting
Concerts feature effect lighting
Concert hall and theatre lighting
TV Studios and stage lighting
Bars, clubs and restaurants
Safety and Security:
Exit and Entry Signs
Street and highway lights and signs
* Source: US Department of Energy's Office of Energy Efficiency and Renewable Energy