Simply put, the 50,000+ hour lifespan of high quality LED lights means that the initial cost of a light (bulb) is a smaller percentage of the Total Lighting Cost or "TLC" (the total cost of providing lighting to a space.)  But, there is actually more to it.

While most people would agree that "Going Green" is good for the environment and can even save money, many people don't realize just how much value can be created.  For example have you ever considered how much changing lights to efficient LED lighting can add to your bottom line?  Or, take it a step further.  If that bottom line is associated with a property, upgrading to energy efficiency lighting not only reduces energy costs and increases profits, but also has a direct impact on the value of the property.

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...