That is to say, they’re inside the heated space in my home and it’s heating season. I can therefore use them all I want, or leave them on when I’m not using them, and it costs me nothing in energy use. I wrote about this a while back, and Say Uncle has a post that touches on the subject.
There are some qualifiers though. A dishwasher dumps warm water outside the heated space, as does a clothes washer. A dryer dumps hot air outside the heated space too, but you can leave your television or oven on all day and it costs you no extra energy useage. If the appliances or the incandescent lights aren’t heating your home, the furnace takes over and uses that same amount of energy anyway. I submit that using the appliances more may actually save energy. Here’s how I got there; at least in my case, the furnace ducts are under the house, outside the heated space. Some of the losses from that extra-hot air running through the ducts under the house might be avoided by keeping the heat generation all inside the house. There was also a chapter in my college physics book that explained how inductive loads may be getting you some free energy, because of the way the metering works. I forget how that happens, but if it’s true then over-use of motors and transformers (florescent lights or anything that uses a power supply transformer) as opposed to relying more on the resistive loads in your electric furnace may be saving on your energy bill. Though that particular difference would be very small for a single home, IIRC the physics book says that this difference, this un-billed energy, is significant on a large scale.
If you want to save energy this heating season, using CF bulbs, turning off your lights, and using super efficient appliances (with the above caveats) isn’t the way to do it. Not during the heating season. Tightening up the house, adding insulation, using a heat recovery system on your dryer vent, etc., using less hot water (assuming that water’s being dumped outside the heated space) or turning down the thermostat, will save energy. Otherwise, don’t let ignorance and simplistic thinking influence your lifestyle.
Someone mentioned last time that some of the light from your evil incandescents (or any other lights) is being lost through your windows. True, but the visible light is a small fraction of the total output unless you’re using LEDs. In any case it’s the energy you don’t see that’s being lost in far greater quantity through your windows, and that loss takes place whether or not your lights are on. Use double or triple panes, and close your blinds at night. We use opaque (to visible and IR) venetian blinds. My friend, who I helped build a house on the Yukon/Kuskokwim delta, had a large, triple pane picture window with an insulated door that swung down from the ceiling and had magnetic seals like a refrigerator door. The house also has 18″ to 24″ of insulation in the walls and floor (double framed) and more in the ceiling. We had to insulate the house from the tundra underneath too, to keep the tundra from thawing in summer. That was an interesting project, but now I have digressed.