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Universal ROI Calculator

An Estimating Tool to Compare
Payback of LED Lighting

Please read:

This calculator gives payback time, the annual and life-time power, CO2 AND maintenance savings when you upgrade your lighting to LEDs.  Enter the wattage and life for both the old and new fixture and the billing rate per kilowatt-hour.  Be sure to include all costs, i.e. labor, parts, inventory, fuel, equipment, etc. 


Start with the Tab key, fill in shaded cells and/or step forward with Tab; step backward with Shift Tab.

1. Compute kilowatts (kW) saved by upgrading to LED technology.
Original Fixture
Wattage + Ballast		   LED
Wattage		   Watts Saved
per Fixture		   # of Fixtures
to Replace		   Watts Saved
Watts -  Watts = Label Watts × =
Label W
Label  kW
 
2. Compute kilowatt hours (kWh) saved and tons of CO2 production saved annually.
Kilowatts
Saved		   Hours of Use
per Day		   Days of Use
per Week		   Weeks of Use
per Year		   Annual savings:
Label kW × × × = Label kWh
  = Label Tons
3. Compute power cost savings per year. of CO2 production *
kWh
Saved per Year		   Cost Per kWh
(typically $0.10)		      Annual
   Savings		  
Label × $ = $Label   
 
4. Compute power cost savings and saved CO2 production over life of the LEDs.
Replacement
LED Life (hours)		   Hours per Year
Usage		   LED Est. Life   Annual Power
Cost Savings		   Lifetime Power
Cost Savings
 Hr  ÷  Label hr/yr  =  Label Years  ×  $Label  =  $Label
LED lifetime CO2 savings *   = Label Tons
5. Compute payback from power cost savings.
NOTE:  LED Cost is the amount used to calculate payback.  It may be the direct cost if retrofit, or may be the cost
difference between the LED and the fixture it substitutes if a new installation.  This entry should include all installation costs.
    (Enter LED Cost)  
Payback From
Power Savings		 = LED Cost, or Diff. between LED & Original = $ × Label Lights = Label Years
Power Cost Savings per Year $Label
 
Return on
Investment  (ROI)
from power savings		 100% is based on
full repayment
in first year		 = 100 = 100 = Label % 
Simple Payback Label 
 
6. Compute maintenance savings during life of the LEDs.   Include labor, equipment, fuel, parts, inventory, etc.
LED
Life (hours)		   Original Fixture
Life (hours)		   # of
Fixtures		  Maint Labor
Original Fixture		   Maint. Parts
Original Fixture		   Lifetime
Savings
Label ÷ × Label × ( $  + $  ) = $Label
7. Compute the amortized changeout cost savings per year.
Total Lifetime Replacement Cost Savings Lifetime of Replacement Fixture Total Amortized
Savings per Year
$Label ÷ Label Years  = $Label
 
Simple Payback on
Power Consumption
And Maintenance Costs		 =

 Initial Cost of Upgrade =

 $ Label  × Label =

 Label  Years
Power + Maintenance
Cost Savings		 $ Label
 
ROI  =   100 = 100 =  Label %
Simple Payback  Label

*US national average CO2 emissions caused by various power generation capabilities, value provided by the US EPA.


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