However, there are also many differences that are important that can be easily seen by the naked eye. One example of this is the directional nature of the light that is produced by LED lights.  This enables the energy being produced to be emitted focused in a particular direction, rather than in all directions as with most traditional light sources. One side effect of the way traditional light sources emit light is that much of the light often is emitted in a (or many) direction(s) other than that which is desired.  This is extremely inefficient because much of the brightness of the light is lost in the process of redirecting the light back toward the desired direction.  

Another of the most obvious differences that occurs immediately when you turn on an LED light is the simple fact that the light turns on essentially immediately.  In contrast, many traditional lights can take several seconds up to many minutes to turn on, and even longer if they are turned on and off, then back on again.  
So, why is this?

A common (mis)perception associated with LED lighting is that it costs more than traditional incandescent lighting.  However, as you'll see in the post below, this might only be a matter of perception, depending in particular on what costs one focuses upon and the timeframe being examined...

I was speaking with a potential client recently, and it occurred to me that there really are an awful lot of questions out there about LED lighting and what makes it better than alternative lighting solutions.  Particularly because there are a lot of claims being made about terrific savings gained by using LED lights, which often use different terminology than has traditionally been associated with lighting, the whole situation can be confusing, frustrating and perhaps a little daunting as one tries to wade through the facts and hype, or perhaps even figure out where to start.  This often makes people very wary of the information being shared with them, and, as this gentlemen suggested, it can even feel like someone is trying to pull a fast one, so I thought I'd see if I can de-mystify why a seemingly straight forward question may not be so straight forward.

After a brief back and forth, he asked me "Why aren't you just giving me the number I'm asking for?"  I was a little shocked, as I was trying to answer his question, but, as I reflect back, I am better understanding why my accountant and lawyer so often answer "It depends."  This is because what seems like a straight forward question to the person asking the question can have a different answer depending on the circumstances and, because the asker might not be aware of what drives these differences, he/she might not even realize the answer they are receiving is being skewed because of the question asked.  Because there really are many variables that need to be considered before an accurate answer can be given, it is better if these are clarified before a factually correct, but potentially misleading answer is given.

So, what are some of these variables that can impact a seemingly simple question like "How much savings can I get by replacing my existing lights with LED lights?"  
Here are a few that I'll list, then review each one to explain a little about why this can impact the answer:
(1) What type of lights and what type of technology is being replaced?
(2) What is the area being lit, so we can understand what type of lighting needs to be provided?
(3) What is the height of the light, so we can tell what intensity is needed?
(4) What is the color of the current lighting, and is that the color that you want to light this space?
(5) Do you want to consider additional technology such as automatic dimming that can further increase your savings?
(6) What is the cost of the energy being used to power the light?

So let's review why each of these is potentially significant...
(1) What type of lights and what type of technology is being replaced?
In order to calculate with any sort of accuracy how much will be saved, one needs to consider what the characteristics are for the existing lighting.  For example, if you have a parking lot that currently has 400 watt metal halide lights being used to light it, the amount saved by replacing these with 75 watt LED lights will be at least 81.25%, all else being equal ([400-75]/400=81.25).  However, if the current lights are fluorescent lights that are drawing 136 watts and these are being replaced by LED Tubes drawing 68 watts, only 50% of the energy being used is saved ([136-68]/136=50).  As you can see, even though both are significant, even on a relative (%) basis, there is a wide difference that depends on the light being replaced.  
Further, each type of light has a different life expectancy, so the difference between the existing light's life expectancy and the LED's life expectancy can also make a big difference in terms of how much will be saved over the life of the LED light.  Therefore, how long the existing light is expected to last can also make a difference, both in terms of the number of times the light might need to be replaced, as well as the associated costs, including both parts and labor.

(2) What is the area being lit, so we can understand what type of lighting needs to be provided?
Another area that is critical is what you are trying to accomplish with the lighting.  Is the goal to provide maximum lighting for the space, so a replacement light should be as bright or brighter than what was previously installed, or does the area just need to be lit to safety standards, with maximizing energy efficiency being most important?  Depending on the answer to this question, using the parking lot example from above, it is possible that an LED retrofit could be installed that draws anywhere from 38 watts to 120 watts.  This again, would change the answer of how much savings was going to be provided, even if you keep the light being replaced constant.  ([400-38=362]/400 = 90.5% savings vs. [400-120=280]/400 = 70% savings)

(3) What is the height of the light, so we can tell what intensity is needed?
This may seem a little obvious, however, it is surprising how often the current light installed is not appropriate for the situation.  Even though the height is presumably constant between the old and new light, the amount of energy saved could vary depending on if a different light was chosen to more appropriately light the space.  This can also vary based on other characteristics, such as whether the directional characteristic of LED lighting can be leveraged to reduce the amount of overall brightness that is needed because the light is actually directed where it is needed rather than having more than half of it dispersed in other directions.

(4) What is the color of the current lighting, and is that the color that you want to light this space?
Another aspect of lighting that is important to its overall effectiveness is what color the light is perceived to be, and whether this is considered appropriate for the application.  When answering the question "How much will I save?," the color of the lights is not always a large factor, but can make a difference.  This is primarily for two reasons.  First, the efficiency of the light being produced does change somewhat depending on the light color being emitted.  Second, if a brighter light is desired, but this is primarily because the current light is actually just too yellow because of deterioration of the light quality, maybe a brighter light really isn't needed.  This could mean that the desired lighting might be able to be provided through a cleaner (less yellow) colored light that is actually drawing less energy.

(5)  Do you want to consider additional technology such as automatic dimming that can further increase your savings?
So far, we have been focused on simply replacing an older lighting technology with more efficient LED lighting.  However, there are other things that can be done which could significantly increase the amount of savings achieved, while only slightly increasing the cost.  For example, Leading Edge Designs has patented technology that, if chosen, enables all of our lights to be dimmed (smoothly - no flicker) down to 5% of their brightness, while also reducing energy consumption down the same amount.  This can be either manual or automated, and can sometimes also be combined with other technologies such as automated sensors that detect motion or ambient light.  The end result of this can drastically increase the amount of energy saved, particularly if a space is accessed infrequently, but needs bright lighting when it is accessed.

(6) What is the cost of the energy being used to power the light?
Finally, a last point, even though it doesn't change the % of savings, the absolute amount of money being saved can vary dramatically simply because of the cost of energy at a given location.  Another similar factor that would also impact the absolute dollar figure of savings would be how often and for what length of time a light is going to be used. 

So, these are just few of the questions that need to be addressed before an accurate answer can be given to the question "How much can I save?"  This is one of the reasons that Leading Edge Designs operates using a business model focused on educating potential customers and trying to understand their lighting needs, then helping them to choose the best solution.  This offers the opportunity to discuss factors like those above and gain a true understanding of what might impact the amount of savings realized and, hopefully, ending-up with a solution that provides exactly the light you need for years to come...  So next time a lighting professional begins an answer with "it depends," allow them an opportunity to explain - it really might depend...

So, what does all of this mean?  A rough rule of thumb to use is that, in order to compare an LED light source to a traditional light source, one must reduce the lumen results of the traditional light source by up to 50% or greater to account for brightness lost getting to the observer's eye.  I call this "Usable Lumens."  Who knows, maybe the industry will pick this term up to help better explain how two lights compare to each other.  Either way, it is in part because of this difference in "Usable Lumens," that a traditional light rated at 20,000 Lumens would be observed to be less bright that a 10,000 Lumen LED light under the same conditions.  

Another common way to measure light intensity that is often used in regulations such as OSHA (Occupational Safety and Health Administration) standards is the unit of measure foot-candle.  I'll discuss the difference between this and a Lumen in a future post.  In the meantime, you can learn more about the latest in LED light fixtures at our website, www.LED-ltd.us.  Please post a comment or question on the blog, and we'll get back to you as soon as possible.  

As a relatively new technology compared to the 130+ year old lighting industry, some people reasonably have questions about LED lights (or solid state lighting, as it is sometimes called), and even question if there are health concerns with this technology.  

As always, there are appropriate prudent, ongoing studies to ensure that LED lights are safe.  However, the good news is that evidence to date is indicating that LED lights are not only safe, but also that, because of characteristics that are unique to LED lighting, that they are closer to natural sunlight.  An early 2011 study that suggests a possibility of health concerns is associated with low intensity red Christmas tree lights that were crushed to dust, exposing lead in solder that was used to construct the light, not dedicated interior or exterior lights.  A review of the paper, including comments with the study's abstract can be found here: http://ledsmagazine.com/news/8/2/13. 

Below are just a few of the characteristics of LED lights that make them a healthy alternative both for humans and for our environment:  

1.  LEDs do not emit infrared or ultraviolet emissions
2.  Fewer or no toxic materials
3.  Low power consumption
4.  Tunable light color
5.  Vibration resistant
6.  Dimming capability
7.  Instant on / rapid cycle immunity
8.  Ultra-long source life and low maintenance
9. Directional light emission

1.  LEDs do not emit infrared or ultraviolet emissions
These radiation types can cause damage to sensitive artwork and other materials, as well as causing eye and skin burns with prolonged exposure.

2.  Fewer or no toxic materials
Many lighting sources such as Fluorescent tubes include Mercury and other harmful substances.  LEDs contain no Mercury. 

3.  Low power consumption
Reduces the carbon emissions required to generate electrical energy and produce the light.

4.  Tunable light color
By tuning the color of light emitted to match lighting needs, LEDs can reduce eye strain due to improper lighting or color shifting.

5.  Vibration resistant
Because of no need for filaments or glass enclosures, LEDs are much more resistant to breakage and reduce any risk of being injured by shattered glass.

6.  Dimming capability
When properly installed and combined with a compatible dimmer, LEDs enable dimming to lower lighting conditions, which can be more similar to natural light patterns

7.  Instant on / rapid cycle immunity
When lighting is needed for emergency situations, the instant on (to full brightness) characteristics is safer because critical light is immediately available. Further, lifetime not shortened by rapid on/off.

8.  Ultra-long source life and low maintenance
Because LED lights last significantly longer than traditional lighting, much less maintenance is required, reducing the risk of any injuries related to that maintenance.

9. Directional light emission
Light can be focused where desired, potentially eliminating light bleeding to areas where it is not desirable. (Dark Sky compatible)

As this industry matures and is better understood, it is very likely that we will find that it gets even healthier for us because the technology allows us to more precisely control the color and other characteristics of the light that is emitted, unlike its predecessors.

If you have questions or comments, please comment on this post or let us know by reaching out to us at Leading Edge Designs, so we can help you solve your lighting needs.  

     Light Emitting Diodes, or LEDs as they are commonly referred to, use a different technology than traditional, incandescent light bulbs.  LEDs, as their name would suggest, emit light.  But instead of this happening through the heating of a lighting element such as Tungsten that occurs in an incandescent light, LEDs emit light through the movement of electrons and the resulting release of photons.  To learn more, see this Wikipedia entry.  What is important about this is that it occurs at an atomic level and requires much less energy for the light to be emitted.
     As referenced earlier, another key characteristic of LEDs that contributes to their reduced energy usage is the fact that they do not radiate heat in the same way that incandescent light bulbs do.  This not only is more efficient in the production of light, but also, the lack of heat being generated in producing the light means that very little or no energy needs to be consumed to cool the light or the surrounding area when the light is being used.  This calculation is typically not included when overall energy savings achieved by an LED is considered, but could be significant if many lights that produce a lot of heat are replaced by LEDs producing relatively very little heat.
     Increasingly, LEDs are also being referred to as Solid State Lights or Solid State Lighting, which refers to the type of computer technology that is used to drive the lights.  Also, it alludes to the durable nature of the technologies used in these lights.
     To learn more about LED terminology, see our terminology page.