I keep hearing people talk about Compact Flourescent Lamps, and how they are so much more energy efficient than standard bulbs. Let’s do some math and find out..

If you are replacing a standard 150w bulb, the CFL replacement will use around 42 watts. According to my last energy bill, I’m paying $.0876/kwh. Assuming you are using your lights for 8 hours a day (which is on the high side), the 150w incandescent bulb will consume 1.2wh each day. The 42w cfl bulb will consume .336kwh each day. With 365 days in a year, the 150w bulb ends up costing you (1.2 * 365 * .0876) == $38.36 a year. The 42w bulb ends up costing you (.336 * 365 * .0876) == $10.74/yr.

Wow - that’s quite a difference. Of course, this is a high-powered bulb, and assuming lots of use — but still, WOW! And we are only considering the raw energy cost.. you also don’t have to replace these bulbs nearly as often, and they put out far less heat. Sounds like a win-win to me!