# Energy calculator: Incandescent bulbs vs. CFLs

Everyone says that you'll save energy and money if you replace your incandescent bulbs with CFLs. But how much can you actually save? Excel Energy's Lighting: Energy Calculator can show you the answer.

Designed to help users determine the energy dollars they could save by replacing inefficient incandescent bulbs with new CFLs, the Lighting: Energy Calculator is both user friendly and eye opening. Simply move the sliders on the tool to indicate how many of each type of incandescent bulb will be replaced with a CFL, and the calculator does the rest.

It shows you the savings in terms of Kilowatt hours (kWh) not used, dollars saved, incandescent bulbs never made, tons of carbon never released, trees planted and cars taken off the road.

To arrive at these statiscics, Xcel Energy uses the following numbers for calculation:

• 1,000 Hours = Life span of an incandescent bulb
• 10,000 Hours = Life span of a CFL bulb
• \$0.10 = Price per kWh (Kilowatt Hour)
• 1.45 Pounds = CO2 (Carbon Dioxide) emissions per kWh
• 2,932 Pounds = CO2 absorbed by a tree over its lifetime
• 118,083 Pounds = CO2 released by a car over its lifetime

View the Xcel Energy Lighting: Energy Calculator