Determining the Most Cost Effective Lighting Source

Fluorescent bulbs are better than incandescent bulbs and candles are just plain dangerous.
The better question to ask is how long a F. bulb should be left burning before you've maxed out the thriftiness part. Let me explain: I. bulbs don't take much energy to turn on and off - they are great if you walk out of a room, turn off the light, then turn it back on to pop back in and get something you forgot, then turn the light off. A F. bulb uses most of it's energy being turned on, so they're not so great for the quick in and out.

I've heard that it's better to leave a F. bulb on when you walk out of the room if you are intending to come back in shortly - but the crux of the matter is how long leaving it turned on = a savings over turning it off and then back on again. That I do not know and this is what you need to research.

I'd also like to point out that you need to respect the wattage limits listed on the inside of a lamp shade. If it says, "Use X wattage," then don't go over that number because it may cause a fire. Don't think that F bulbs burn cooler so you can increase the wattage - absolutely need to respect the stated limits for both F and I bulbs.

This web site has a light bulb wattage conversion chart: http://www.ablamp.com/CFL_Equivalent_LED_incandescent_bulb.html

Please notice it is not stated as equals, but as equivalencies because they don't exactly equal each other. You need to look at Incandescent (regular bulbs) and CFL (the new type) comparisons. The Lumens are an indication of light output.

Electricity is the cheapest and safest. Low energy light bulbs and energy efficient appliances will save you even more. Lamp oil and candles not only cost more to light a room but they put residue into the air you and your family breathe which is unhealthy. Scented candles as air fresheners do the same.

You should be much more concerned with safety before thriftiness. In this modern age I'll use electricity before I will resort to a kerosene lamp or candles. It just takes one mistake and you could burn your house down or lose your own life or family in a house fire.

I don't know about cost effectiveness, but I do know electricity puts out more light, plus you can determine which wattage bulbs to use for given tasks. There was a couple years when I was a young kid, that all we had for lights were kerosene lamps. When we wanted to read at night, those of us that were reading sat around the kitchen table with one lamp in the middle of the table. Back then people got by but it wasn't real good light for reading. Candles wouldn't be any better.