My electric bill says I pay an energy charge of $0.04618 per KWH and a fuel charge of $0.02741 per KWH. How much does it cost me to run a 100 Watt light bulb for 24 hours?
100 W for 24h is 2.4 kWH, so that would be about 18 cents (17.6616)
Assuming fuel charge is a part of total electric cost,
Cost per KWH,
$0.04618 + $0.02741 = $0.07359 /KWH
Cost per watt hour.
(0.07359)/1000 = 0.00007359 /WH
Cost for 100 W for 24 hours,
0.00007359 x 100 x 24 = $0.017662 or approx 18 cents.
If the light isn’t needed don’t leave it on.
hmmm. Turning on th bulb presents the filiment with a thermal shock, which also results in physical stress. It is this that causes a bulb to expire(burn out). So, if I will need the light soon again, I just leave it on. I figure the shortening of the life by turning it off and on costs me more in new bulbs then it power used. Simillar with electronic equip. like computers and my TV.
100W bulbs can be purchased on the internet for about $.60. That is about 7 hours of electricity. Just how often do you think you will need to change this bulb. If you turn it off when you leave the room for 10 minutes every day you will have to change more often than every 42 days for it to be a savings to leave it on.
I am off by a factor of 10. That is 420 days of turning off the light bulb early.
If you leave your bulbs on continuously, or nearly so, skip past the “soft white” section, in the grocery store and look for the specialty bulb display.
Buy a garage door opener bulb. They cost nearly twice as much, but have twice the life. I use these exclusively in areas where I would otherwise be changing the bulbs frequently, like the back porch lights that we leave on all night.
They are also ruggedized to withstand vibration, so if you’re worried about frequent switching stress, these also may do better than normal bulbs, but I haven’t tested this feature.
The glass isn’t frosted or coated or anything, like table lamp bulbs, so the shadows are a little more harsh, but the lighting is still better than those horrid compact fluorescents.
Still waiting for a nice, warm, affordable LED home lamp…
Oh, here’s a link to one sold online.
And here’s am LED table lamp. For $170. They’re not being marketed to homes, but to restaurants and bars. Still looking…
gazpacho, how can u figure that with out knowing how much in burn time that each off/on takes away??
I used to change the hall light every couple of months. Since I have “taught” my wife not to turn it on and off 3-4 times per day, it lasts between 6 and 12 months. I can not imagine that the cost of electricty costs more then I save in bulbs.
Paul