Light-emitting diode : the (b)right light source?

San Diago Convention Center Exhibit Hall LED Retrofit overview

I would like to switch my “X” Watt lamp to a comparable LED solution.

Would it be “bright” enough for my application?

As a light-emitting diode (LED) Lighting manufacturer, we are asked this question innumerable times. And relevantly so. Traditionally, we are used to quantifying any light fixture in terms of its wattage, assuming the brightness to increase with power consumption. While this holds true for LEDs as well, the light output obtained per Watt ( referred to as the efficacy) is much higher than the legacy technologies. And not just that, the benefits of switching to an LED source are much more than that.

Energy Savings

With significantly higher efficacies (lumen/Watt) than the incumbent lighting technologies, there are a tremendous amount of energy savings which can be achieved by switching to LEDs from legacy light sources. 

Warm-up times

Traditional commercial lighting sources such as the HPS and the metal halides require a warm-up time of about 15 minutes for the source to reach its full brightness. This is because the emission of light is done by secondary means in a metal halide lamp and light is generated from a high voltage arc which vaporizes mercury within the lamp.  In case of the LEDs, however, the start is instant.

In addition, if a metal halide or HPS lamp loses power during start-up,it may not reignite immediately and a cool-down time is recommended before the lamp is restarted. The LED technology, on the other hand, promises an instant start.

Light quality

The beauty of the LED lies not just in the energy efficiency, but in the ability to customize it and make it “right” for your application. Research has shown that it is not only the LED intensity that counts, it is the “quality” of light which needs to be carefully evaluated before choosing a light source. Whether it is human circadian rhythms and alertness to blue wavelengths [1] or the response of plants to various lighting conditions [2], the spectral composition of the light is important to ensure that it serves its users well.

San Diago Convention Center Exhibit Hall LED Retrofit installation sky jack

Lower maintenance costs

Maintenance costs are manifested in various ways in a traditional lighting fixture, with the lamp replacement cost and the corresponding labor expenses being the primary components. With the LEDs however, the lifetimes are significantly higher than the traditional HPS or Metal Halides, minimizing the costs of maintenance for the facility owners.  In most cases, LED lifetimes are approximately 50,000 hrs, with no lamps to change for the entire lifetime!

LEDs emerge as true champions of color offering millions of hues and spectral combinations with continuous intensity control options. The spectrum tunability for LEDs makes it a unique light source with application in a variety of areas, from architectural lighting to horticultural, and from industrial lighting to interiors.  Ranging from “cool whites” to “blurples”, LEDs own the podium when it comes to achieving different form factors as well.

the optilux plants

Typically lighting color and quality is measured using the correlated color temperature (CCT) and the color rendition index (CRI). So, is an evaluation of these metrics enough to qualify  lighting for any application? The answer is “No”. While these metrics serve as an important tool to determine light quality in many applications, their usage is not even applicable for certain applications such as the horticultural lighting. To get an idea of how lighting can affect plants, take a look at our Horticultural lighting series here.


  1.  G C Brainard, J. Hanifin, (2005). Photons, Clocks, and Consciousness. Journal of biological rhythms, Volume 20, Pages 314-25.
  2. M.L Mortensen, E. Strømme (1987), Effects of light quality on some greenhouse crops,Scientia Horticulturae, Volume 33, Issues 1–2, Pages 27-36.
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