Do you think you have it in you to create a message or board with a detailed way to analyze for those of us who like the math?
...
And, all that data has to be filtered through the intended use.
I'll do it if you pay me enough for my time. Your requirements are... complex... but I'll at least try to help.
I'd like to be able to figure out, mathematically, what I should do, but I don't know how to. I don't know how to calculate the actual electricity use of an LED at different watts compared to an incandescent, especially with regard to dimming. And I don't know whether to trust the hours ratings given on the packages.
Have an
electricity usage calculator. A
Kill-A-Watt would be a good investment as well if your local library doesn't have 'em so you can find usage on dimmers. Keep in mind that the human eye can read with as little as 100 lumen after you let your eyes adjust to darkness. And no, you can't trust the lifetime hour ratings given on the packages. Dimmers are great with incandescents so long as your target wattages are within 50% of the bulb rating, otherwise the bulb will be too dim. (Read: a 40W incandescent pulling 30W will be brighter than a 65W incandescent pulling 30W.) You want to find out if it's worth the investment? Use the calculator. I'll give you an example for number crunching:
Your major factors are cost of bulb maintenance (M), life expectancy of bulb in years (L), wattage of bulb (W), electrical cost per hour (K), average hours per day (H).
We'll start with a formula: (M/L)+365(W/1000)KH
Daley has a 60¢ 40W incandescent bulb (~450 lumen) that he runs at 30W with a dimmer five hours a day with a cost of 10¢/KWH, and has to replace roughly every 18 months.
What is his cost per year with this bulb: (0.60/1.5)+(365*(30/1000)*0.10*5) = approximately $5.88 a year to operate
He takes a look at the Philips 6 year warranty LED bulbs that Chuckles recommended (yes, it's six, not seven), assuming that given the quality of electronics that there's only six years of guaranteed life (and especially if you consider that they may have offered a seven year warranty and peeled back a year due to failure rates). This is deemed okay given they just cut checks for failed bulbs. Given the lumen rating of the 40W bulb is about 450 lumen, he settles for the
Philips 417048 Dimmable AmbientLED as it produces about 470 lumen fully lit. Unfortunately, the incandescent dim switch won't work with the LED, so it either needs replaced or can run full bright. He opts to just run it fully lit.
So, Daley's projected replacement bulb costs $21.69 + $4.99 shipping and 9% sales tax, or $28.63 if he wants Amazon to keep the receipt for him, or $20.47+ tax down at
Home Depot. Choosing Home Depot as the practical solution, the cost is $22.31 and he expects the bulb to only last 6 years given electronics manufacturers frequently guaranteeing devices only to their average failure point.
All this info finally gives us a $22.31 LED bulb running 8W for 5 hours a day with the same cost per KWH, and is expected to have to replace at least once every six years.
What is his cost per year with this bulb: (22.31/6)+(365*(8/1000)*0.10*5) = approximately $5.18 a year
The ROI for the LED is shorter than the warranty in this scenario, but not by much... and gets blown out of the water if a new dimmer switch is installed to replicate functionality lost with the incandescent. This also doesn't factor the electronic waste and environmental impact of the LED bulb when it dies over the incandescent which is easily recycled, or the loss of brightness that will occur to the LED bulb over its lifetime. Granted, more expensive KWH rates would lopside this, as would electrical charges skewed for PF correction... but personally, I prefer full-spectrum light, not a mix of RGB replicating the visible color temperature of tungsten. I'll pay the extra as long as I can, the usage isn't much in a household that only has 2-3 bulbs burning in the entire house at any one time during a rough 5-7 hour window, so you can see why CFL or LED aren't worth it in Casa de Daley. YMMV.