We traded out all the incandescent bulbs in our house the weekend we moved in. Except for two: a recalcitrant half-globe fixture above the stairs that, despite four increasingly violent attempts, I can’t open, and a 4-way fixture in the foyer that uses torpedo bulbs with the candelabra screw base — smaller than the standard 1-1/16'' base you’re used to.
There’s not a big market for Compact Fluorescent bulbs with candelabra bases, so they’re expensive — something like $20 apiece when I called around, a couple years ago. Despite the tree-hugging appeal of having no incandescent bulbs in the house (except for that bastard above the stairs that I’m pretending doesn’t exist), I couldn’t justify the cost. We use the light in the foyer about three minutes every month, as dinner guests are putting their shoes back on on their way out the door. In a typical year, the electricity consumed by this fixture costs us … well, 160 watts (4 bulbs x 40 watts) times 36 minutes = 0.096 kWh; at 8.7¢/kWh (averaging the summer and winter off-peak, schedule E-7 TOU rates) … about 83/100 of a cent.
The break-even point for $80 worth of CF bulbs, at ~80% of .83¢/year, is 120 years. Compact Fluorescent bulbs may last a long time, but probably not that long.
On the other hand, my great-great-great-great-grandkids might be really impressed by my forward thinking. So I picked up a 4-pack of candelabla-base CFs at Ikea last month. CF prices have fallen, and Ikea has mastered the art of selling for cheap, e.g. by manufacturing furniture out of cardboard. The four bulbs cost about $18 total if I remember correctly, so it’s at least somewhat likely I’ll live to see breakeven, 21.6 years from now.
The only problem is, these bulbs suck. They’re so dim, it takes 10 seconds to know whether they’re working. When they’re fully warmed up, they do a real nice job of illuminating the inside of the frosted glass fixture.
But hey! I’m saving well over a half-cent a year! Rawk!