Lighting ROI Calculator

Find Payback
from costs & interest
with LED Lighting

Please read: This calculator gives payback time, and both the annual and life-time cost & savings figures for energy, maintenance, and CO2 production.  It calculates Lighting Power Density from area of at least 500 square feet per fixture, and provides the maximum fixtures allowed from a target LPD.  Check the DOE for your requirement.  Non-residential electric usually has additional cost for lower than 90% Power Factor.
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        Comparisons        Show LPD        Compare CO2        Cookies
      If residential lighting, enter 95 for PF (Power Factor).
Simple Comparison Options
(Not photometric)         


  Cookie Jar  

Parameters for energy statistics:  
Enter: Power Consumption, Power Factor, & No. of Fixtures
Orig. W  & PF % LED W Quantity 
 Totals:          Cost  $/ kWhr  
Hours/Day  ×   Days/Wk  ×   Weeks/Yr 
Annual Energy Cost: Original
Savings:    Annual = $     Monthly = $      %
LPD (Lighting Power Density) = Watts÷SqFt
 SqFt per Fixture =  Total
Target LED LPD =  fixtures  
LPD Statistics      W/SqFt
Original LPD      
new  LED LPD      
=  Saved      
Click for suggested LPD (see that Table 1)
Fuel:   Coal    Gas    Petrol    Hydro    Nuclear 
Results:  Payback time, ROI, Savings, Cost & Interest
CO2 reductions
 Tons Less / year
 Tons Less / lifetime
    Annual Savings:
  Investment ÷ (Energy + Maint. Savings)
                 $ ÷ $  =  Year Payback 
Simple ROI(saved energy & maint. −Investment)÷Investment = % 
           Annual ROI:            LED to Original cost:  
   Payment Count Choice:  by savings, or,      by selection.
 (define Lease or Finance program)      $
  LED Investment: (LED maintenance is cleaning, inspection, etc. as should be done with all lighting.)  
  LED Life  Hours ÷   Hours/Year  =  Years Lifetime     Saves $ Energy  
 Full Installed Cost Discounts for  1 Fixture = $ Interest 
LED Maintenance Interval:  Years @ $  per Visit.  [ Lifetime ÷ Interval × Cost × Quan.= $ ]
($ × ) + $ = $  + FIXED JOB COSTS $  = $ Investment
  Subtract a rebate from FIXED JOB COSTS, or, enter negative (-)JOB COSTS if rebate only.   
  Original fixture with lifetime maintenance and energy costs:  
  Original fixture life  Hours ÷  Hrs/Year =  Yrs Lifetime     $  One Fixture Installed Cost  
Years × $ annual energy = $  Relamp $(relamping, disposal, cleaning, etc. every  years)
 $  + $ energy = $  Orig. Cost during LED Lifetime, repaired  times.  
 *US national average CO2 emissions caused by various power generation capabilities, value provided by the US EPA. 
            Home             ©2011-2014 Patrick Mullins     Please Contact me with any comments regarding this calculator.