illumitex ROI Calculator

A few months ago I wrote an article on the return on investment (ROI) and total cost of ownership (TCO) between LED lighting systems and HPS legacy lighting systems.  Since then, I have had several requests for the excel file used to create the tables and graphs.  Due to popular demand, I am providing the excel file that I used to create these tables and graphs through the link below.

In the white paper, “A Short Payback Period for Illumitex LEDs vs. 1000 W HPS,” I presented the definition of payback period (or ROI) and its application in horticulture lighting.  The baseline model was the following:

  • 6 fixtures each for two LED systems (Neosol DS and Power Harvest 10) and an “average” HPS system – based on values found in the literature
  • Energy usage calculated by total wattage with cooling expenses as a 50% increase in wattage consumption
  • 10 hours for the photoperiod
  • $50 for HPS lamp cost
  • $7 for labor and disposal to replace the lamp
  • $0.11 per kilowatt cost of electricity

The report provided data for initial lighting system cost, energy cost, and maintenance cost.  In addition, it included figures showing the change in payback years due to differences in electricity rate and photoperiod.

Below you will find a link to the Excel model I used for these calculated values.  I have protected the cells but left the equations visible so the calculations can be understood.  The file is formatted to calculate the total cost of ownership and graph this by projecting annual expenses until the lifetime of the LEDs.  For this reason, there is a set of data below the dashboard which automatically adjusts based on changes to the model.


I hope you find this file and other resources on our website useful.  As always please feel free to leave us a comment, sign up for our newsletter below and check out all our posts on the social media link above!