Help with T8 to LED lighting conversion analysis

Hi all,


I recently spoke with an LED sales rep and I am trying to do an independent analysis of the payback period of changing out T8 bulbs for the equivalent LED bulbs. I am coming up with the following assumptions and results. The challenge is that I am a commercial real estate broker and not a facilities or lighting pro, so I don't know if there are other issues I should be taking into consideration or if the assumptions I am using are right. If the numbers work I would like to promote the conversion to my office building clients, and if not then I would like to show them why not.



100,000 square foot office building

One fixture per 110 square feet

Three 32w, T8 bulbs per fixture

Total of 2,727 bulbs


49 hours per week of use

2,548 hours per year of use


Fluorescent bulb life: 28,000 hours

LED bulb life: 50,000 hours


4 foot, T8 fluorescent bulb price: $2.33 each

LED equivalent, in quantity: $61 each


With these assumptions I am getting a payback of 7.28 years. Apparently there is also a utility rebate (I’m in California), which I have not factored into the payback. The salesman is claiming an additional annual savings of $7,500 for maintenance/bulb change, but if the T8 life is really 28,000 hours that would not be the case. If there were that much in maintenance savings the payback is 3.44 years, which makes the change a much better deal.


Any thoughts would be appreciated. I am looking for confirmation or rebuttal of any of the assumptions, and especially if there are any real-world issues I am missing.


Thanks in advance.




  • Mike,

      We have been talking about looking into going LED on some of our light fixtures and, realistically, been looking towards the California standards for guidance on what they are doing.  I know that there is a website that was well written on the LED advantages and drawbacks to doing so - but I must not have tagged the site as a favorite when I was reading it.  I would suggest doing a search and you should be able to come up with it fairly quickly.

      That said, here are a couple of things that we have run into.  The first is that the color spectrum for LED is not quite there yet.  They do not have the color range that T-8's have - many still have that blue "tint" to them.  This is continuing to improve, so the longer you wait, the better the light quality is.  Since it appears to be in an office type environment, the lighting will have an impact on the productivity of the company and needs to be considered.

      The other issue I have seen and the main reason for us not to move forward on our end is that the ROI is really not there.  While LED's are in the front pages of the news and people are really trying to make headway, I usually find that there are other "low lying" fruits that can have a bigger impact on the bottom line than upgrading to LED's at this time. 

      There is one other item that you need to consider.  Right now, there are no standards for LEDs.  Each manufacturer has product made to their specs.  From what I have been seeing, as things change - so do the manufacturers and their equipment.  One thing we watch out for is that you end up buying a system and then are stuck with their product because you cannot find anyone else that is compatible with what you have.

    Hope that helps a little.



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