You replace a 100 W incandescent lightbulb with a 22 W CFL bulb. If you leave your lights on 24 hours a day, how much energy are you saving each day by replacing this bulb?

100 watts = 100 joules per second

22 watts = 22 joules per second

Saving = 78 joules per second

1 hour = 3,600 seconds

24 hours = 86,400 seconds

(78 joules/sec) x (86,400 sec) = 6,739,200 joules