By Doug VerBockel

LED (Light Emitting Diode) lighting.  Is this the light of the future?  Will it replace the incandescent and fluorescent bulbs we now use?   LED’s are currently used in automobiles, digital clocks, traffic lights, televisions, flashlights, interior and exterior lighting and many other uses.

What do you think about LED lighting?  You may think the bulbs are too expensive or the light is too harsh with a white/blue cast.  In the past I would have agreed.  But you may want to look again.  The prices are coming down and there are new choices in color (temperature) and CRI (color renditioning index) all of the time.

First, let’s talk about why LED’s could be the potential bulb of the future.

The example below should help:

The advantages are apparent in the chart above.  The new LED light source uses dramatically less energy, lasts 50 times longer than incandescent lamps and produces the same amount of light.  Other advantages of LED’s compared to compact fluorescent are that they are dimmable, encourage plant growth, work well in cold temperatures and do not contain toxic mercury.

The disadvantages to LED lighting have been the initial cost, and the light color.  Both of these issues are getting better as technology advances.  LED’s are also vulnerable to high temperatures. If LED circuitry gets too hot, more current can pass through the junction and can cause LED meltdown. (more about this junction later)

In October, we (Forrer Business Interiors) replaced most of our exterior building lights with LED lights.  In one example, we replaced our 150 watt high pressure sodium ground lights with 13 watt LED.  Combining the initial fixture cost and installation costs, the payback is about 2.5 years due to the lower lamp wattage. We were also eligible for a Focus on Energy rebate which brings the payback time down even more.

So, what exactly is an LED light?  What is it that creates this magical light?  Basically, LED’s are tiny light bulbs that fit into an electrical circuit. They illuminate solely by the movement of electrons in a semiconductor material (typically aluminum-gallium-arsenide).  Free electrons on the negatively side of the semiconductor move to the positively charged area through a junction.  Photons are released as a result of the moving electrons.  Light is a form of energy that can be released by an atom.  It is made up of many particle-like packets that have energy and momentum but no mass.  These particles, called photons, are the most basic unit of light.  Depending on the materials used in LEDs, they can be built to shine in infrared, ultraviolet, and all colors of the spectrum in between.

LEDs are constructed to release a large number of photons outward.  They are often housed in a plastic bulb that concentrates the light in a particular direction.  They do not have a filament that can burn out so they last as long as an electronic circuit.  Their biggest advantage is their efficiency.  Since they do not waste energy in the form of heat as is done with a burning filament they are much more efficient per watt used.

The first practical visible spectrum LED was introduced in 1962 by Nick Holonyak with General electric.  As the LED technology advances, the uses will grow.  Today, you can purchase LED based task lighting for your office, exterior lights for your home or office and replacement lamps for your automobile.  There is new research on OLED technology (Organic LED) technology using thin films of polymer material that is capable of light ‘walls’.  Soon you may be able to light a room by turning on the polymeric wallpaper to light up the entire wall.

LED lighting is not currently the end all for all lighting solutions.  With a little research and investigation with your lighting professional you may find current solutions that make sense. Have fun with your research and stay tuned, the possibilities are endless.