Incandescent Bulb   Equivalent CFL Savings  
100 Watt Bulb = 23 Watt CFL $92 X  
Money: $0
CO2 (lbs): 0
Cars: 0
Trees: 0
75 Watt Bulb = 19 Watt CFL $67 X  
60 Watt Bulb = 14 Watt CFL $55 X  
40 Watt Bulb = 9 Watt CFL $37 X  

 

How are the savings calculated?

 

Energy Savings Formula:

 

life expectancy of bulb x energy costs per Kwh x wattage + cost of bulb(s) = total cost of ownership
1000

 
Examples:
Traditional Bulb:
10,000 hours x $0.12 per Kwh x 100W + $0.75 x 13-1/3 bulbs = $130
1000
Compact Fluorescent Bulb:
10,000 hours x $0.12 per Kwh x 23W + $5.00 x 1 bulb = $33
1000
Difference:
$97 in savings over the life of the bulb

 

CO2 Savings Formula:
(Incandescent Watts – CFL Watts) x life of CFL bulb x 1.45 lbs
1000

*1.45 LBS is the amount of CO2 generated by 1 kWh of electricity (from US Energy Information Administration).
*You must divide by 1,000 to convert watts into a kilowatts.

 

Equivalent of CARS taken off of the road Formula:

CO2 Savings x  number of bulbs
118,083

*118,083 are the average CO2 emissions over the life of a car that would be generated (from US Department of Transportation).

 

Equivalent of TREES planted Formula:

CO2 Savings x number of bulbs
2932

*2932 is the amount of CO2 absorbed by trees over the 100 year life in pounds.

 

Assumptions:*
10,000 hours - the typical life expectancy of a CFL bulb.
$5.00 - the average price of a single CFL bulb.
750 hours - the typical life expectancy of an incandescent bulb.
$0.75 - the average price of a single incandescent bulb.
$0.12 - the average cost of energy per kilowatt hour (Kwh).

*can vary depending on region and type of bulb used