LED based lighting systems offer the most promising change in lighting since Edison introduced a commercially practical light bulb over 130 years ago.

A lamp made with LED technology – which stands for Light Emitting Diode, also known as Solid State Technology – is essentially a semiconductor chip that glows when current runs through it. Originally it glowed enough to illuminate numbers on a control panel, and it was an attractive option since the LED lasted longer than the panel was likely to be used. Today, LEDs have evolved to where they can provide enough light intensity to illuminate an entire room.

The technology has a lot of advantages:

LEDs use at least 85% less energy than incandescent bulbs.
Further, because they are semiconductor chips, many people believe their performance will improve exponentially, and their cost will come down at a similar rate.

The projected improvement in LEDs is sometimes referred to as Haitz’s Law, something every marketing person wants to believe and no engineer wants to be held accountable to.

Haitz’s law is an observation and forecast about the steady improvement, over many years, of light-emitting diodes. It states that every decade, the cost per lumen (unit of useful light emitted) falls by a factor of 10, and the amount of light generated per LED package increases by a factor of 20, for a given wavelength (color) of light.

It is considered the LED counterpart to Moore’s law, which states that the number of transistors in a given integrated circuit doubles every 18 to 24 months. Both laws rely on the process optimization of the production of semiconductor devices. Just as Moore’s law has revolutionized personal computers; we believe Haitz’s law is revolutionizing lighting.

 

Lights using LEDs last a very long time

LED light bulbs are now being rated for 50,000 hours and many believe that 100,000 hour lamps are very close at hand. That would mean a bulb that was being used continuously would last over 11 years. That same bulb kept on twelve hours a day would last almost 23 years. If it were on three hours per day, the DOE standard, it would last over 91 years.

And these numbers may be conservative.

When your old light bulb was at the end of its life – POP!  It burned out. LEDs don’t burn out, they fade out. They gradually reduce their lumen output over 11, 23 or 91 years. They never really stop producing light – they only produce less light. The electronics and soldering around the LED chip will fail sooner than the light source itself (at least for now).

This created confusion about how to communicate the actual life of an LED lamp, so the industry and the government stepped in creating a new standard. When LED bulbs produce only 70% of their original lumen output, they are declared burned out, even though they still glow. This is called the L70 point.

Practically, few people will notice that day 23 years into the future when their lamp drops from 71% of its original lumen output to 70%.

LEDs will outlive us all.

This is why so many companies want to begin to experiment with LED lamps and fixtures in their workplaces … so they can have the first experience with this promising new technology … so they can help influence its development.

 

LEDs may be the environmental Holy Grail

Fluorescent technology offered benefits over incandescent. They use a lot less energy and last a long time.

But they have had draw backs.  The light they produced was often harsh and blue. The fixtures buzzed. They took awhile to warm up. The moderately priced fluorescents cannot be dimmed … and no matter how hard lamp makers tried, fluorescents all contain mercury, which is known to be toxic.

LEDs have all the advantages of traditional incandescent bulbs. They dim. They turn on instantly. They don’t make sounds. They don’t contain mercury, and because they last so long, they won’t be showing up in landfills anytime soon.

The obstacles holding LEDs back today are:

1. LED technology is still immature, and installation can be more of an art than a science. Hundreds of new companies that have never been in the lighting business are now making and selling light fixtures and lamps. The color of the light can be inconsistent, even from orders from the same manufacturer.  Color shifting is common, especially within the first six months of installation.

2. LEDs are more expensive than traditional technologies up front. Most everyone expects this upfront cost premium to come down.

• Large global semiconductor firms are lowering the cost of the chips themselves.
• Light designers are using the inherent directionality of LED lighting to reduce the lumen output needed from a lamp to light a specific space; still with the right light levels.
• Many common spaces will need fewer fixtures.
• Other spaces will utilize lots of very small fixtures.

3. Premature failures of LED fixtures, often due to poor design where the LED driver fails. LEDs do not like heat, and fixtures and LED lamps, if not properly designed to dissipate heat, can fail after 3-6 months, leading to an expensive warranty claim.