@rplst8 posted:At 15c/kWh it costs about $10 to run a 100 watt bulb day and night for an entire month. Couple that with the fact that most bulbs sold are 60W or less, they rarely run for more than a few hours per day, (more in winter, but less in summer) and should be needed only in the room you are in, I can’t see how it would cost much more than $3-5/mo for a few bulbs to be on at a time.
Yes, they "should" only be needed in the room that you're in, however reality is some people (who shall remain nameless in my house) don't understand the two positions of a light switch! It's not unusual for me to see lights in many rooms that don't need to be on. With LED's, I don't have to be nearly as much of a PITA running around turning them all off. 
@rplst8 posted:Add that to the fact that during the months where the indoor temp is lower than the outdoor temp, the incandescent bulbs are lowering your heat bill.
So one of three things is possible, either the electric company is ripping people off, people have no windows and leave the lights on in their house all day long, or they don’t turn off the lights when they leave a room. Another possibility is that the people that notice the most difference live in southern states, use A/C year round, and use a lot of lights, as it costs about 1.5 times the energy to run a light bulb in A/C.
And all summer long you're paying that efficiency back by running the A/C more to get rid of that incandescent heat, so that's not a gain. Add to the fact that my heating costs using natural gas in PA are far lower than my A/C costs using expensive PECO electricity, I lose out.
@rplst8 posted:Refrigerators, dryers, A/C, and other electronics use far, far more energy than incandescent light bulbs.
However, driers don't run nearly as much as light bulbs. Also, my drier is gas heated, much cheaper.
My TV's are all LED models that use 50-60 watts when they're on, so that's not an issue. Even my computer and monitors use less than 100 watts. However, a single 60W bulb left on for 12 hours a day will cost me around $3.24/mo. Change that to an 8 watt LED, and it costs me 42 cents for that same month.
@rplst8 posted:If we wanted to reduce our energy use by a significant amount, they should design refrigeration that vents the heat outside in summer and uses outside air in an air-to-air intercooler in the winter.
I suspect there's a good reason that hasn't happened. The costs would be astronomical! The return on investment for the difference in price of the fridge would probably be around one hundred years. Of course, I won't be here, and the fridge wouldn't last that long, two major problems with that idea.
In addition, the fridge doesn't use as much as you think, this is one of many recent quotes on what a modern fridge costs to run.
ENERGY STAR Refrigerator (side by side) 21 cu. ft. 51 kWh per month $ 6.63 per month
In my case, probably more like $8/mo, that assumes 13 cents/KW. So, it's not much more than a couple of incandescent bulbs.
