Step 1.
Calculate the total kilowatts saved by replacing the inefficient lamps with more efficient lamps
(1) Original Lamp Wattage

(2) Replacement Lamp Wattage
=
(3) Watts Saved per Lamp
x
(4) # of lamps to replace
=
(5) Total Watts Saved
=
(6) Total Kilowatts Saved
Step 2.
Calculate the total kWh per year saved by this upgrade
(7) Hours Used per Day
x
(8) Days Used per Week
x
(9) Weeks Used per Year
=
(10) Total kWh Saved per Year
Step 3.
Calculate the total energy costs saved per year by this upgrade
x
(11) Your Energy Cost per kWh (typically $0.10)
$
=
(12) Total Energy Cost Savings per Year
Step 4.
Compute the payback of the upgrade
(13) Initial Cost of Upgrade
$
/
(14) Total Savings per Year
$
=
(15) # of Years for Payback
Note:
Calculations on this page represent estimated values.