Each 13-watt CFL, over the expected 10,000 hour life of the bulbs, will save 470 kilowatt-hours (kwh) of electricity as compared to 60-watt bulbs. This translates to a global warming fighting reduction of over 730 pounds of carbon dioxide. It also means a reduction of 1.6 pounds of nitrogen oxides (which contribute to ozone and acid rain) and 4.3 pounds of sulfur dioxide (which contributes to haze and acid rain), and makes significant reductions in other impacts of coal-produced power such as mercury pollution and destruction of forest and stream habitats in mining areas. ONLY 10% of the energy used by these standard bulbs contributes to light the remaining 90% is heat.

Here’s a comparison of costs based on 10,000 hours of light:

CFL Incandescent
Energy Input (watts) 13 60
Light Output (lumens) 810 830
Useful life (hours) 10,000 1,500
# Bulbs for 10,000 hours 1 6.7
Bulb Costs $ 2.25 each 6.7 x .32 = $2.14
Electricity Used (kilowatt hours) 130 600
Electricity Cost (@ $.10 per kwh) $13.00 $60.00
Total Cost (Electricity + Bulb) $15.25 $62.14


Lifetime cost savings by using a CFL – $46.89!

Average household uses 20-30 light bulbs

25 bulbs @ $46.89 savings each = $1172.25