Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Community > MacNN Lounge > Cost of running a light bulb

Cost of running a light bulb
Thread Tools
Addicted to MacNN
Join Date: Feb 2001
Location: Your Anus
Status: Offline
Reply With Quote
Jun 21, 2006, 07:10 PM
 
Can someone help me settle an argument. How much, roughly, does it cost to run a normal household light bulb for 24 hours. What about those fluorescent energy saver ones?

What about other appliances? TVs? Fridges? Etc...

My sig is 1 pixel too big.
     
Addicted to MacNN
Join Date: Dec 1999
Location: Tampa, Florida
Status: Offline
Reply With Quote
Jun 21, 2006, 07:26 PM
 
Very roughly, a 100W lightbulb costs $4 to run for 24 hours. An equivalent fluorescent will cost $1 to run.
     
Admin Emeritus
Join Date: Oct 1999
Location: Zurich, Switzerland
Status: Offline
Reply With Quote
Jun 21, 2006, 07:39 PM
 
Find your cost per kilowatt-hour. 1 kilowatt is 1000 watts, so a 100W light bulb, for example, will use 0.1 kw, and for one hour, that means 0.1x1=0.1kw/h. Multiply that by 24 hours, and you have the number of kilowatt-hours used in 24 hours. Multiply that by your cost per kw/h and you'll know.

tooki
     
Addicted to MacNN
Join Date: Mar 2001
Location: USA
Status: Offline
Reply With Quote
Jun 21, 2006, 07:42 PM
 
100w bulb x 24 hours = 2400 watt hours, or 2.4 kWh. So using 2005's national avg for kWh, .0974, you get:

2.4 kWh * $0.0974 = $.234

THUS, a single 100w bulb running for 24 hours would average $.234, depending upon your cost per kWh.
( Last edited by RAILhead; Jun 21, 2006 at 07:50 PM. )
"Everything's so clear to me now: I'm the keeper of the cheese and you're the lemon merchant. Get it? And he knows it.
That's why he's gonna kill us. So we got to beat it. Yeah. Before he let's loose the marmosets on us."
my bandmy web sitemy guitar effectsmy photosfacebookbrightpoint
     
Addicted to MacNN
Join Date: Oct 2003
Location: Far above Cayuga's waters.
Status: Offline
Reply With Quote
Jun 21, 2006, 07:44 PM
 
Originally Posted by The Godfather
Very roughly, a 100W lightbulb costs $4 to run for 24 hours. An equivalent fluorescent will cost $1 to run.
you sure about that? is the rating on a lightbulb per hour? as in 100W bulb uses 100W/hr. meaning for 24 hours, 2.4kW/Hr and at $.14 a kW/Hr... i'm not sure how lightbulbs are rated, but the thought of having a 100W bulb on for a month and having to pay a $120 energy bill seems impossible to me. i've never paid more than $30-40 a month for a house with a fridge, computers, tvs and all that jazz.
     
Addicted to MacNN
Join Date: Oct 2003
Location: Far above Cayuga's waters.
Status: Offline
Reply With Quote
Jun 21, 2006, 07:46 PM
 
Originally Posted by RAILhead
100w bulb x 24 hours = 2400 watt hours, or 24 kWh. So using 2005's national avg for kWh, .0974, you get:

24 kWh * $0.0974 = $2.34

THUS, a single 100w bulb running for 24 hours would average $2.34, depending upon your cost per kWh.
you mean 23.4 cents.

2400 watt hours = 2.4 kWh
     
Addicted to MacNN
Join Date: Mar 2001
Location: USA
Status: Offline
Reply With Quote
Jun 21, 2006, 07:51 PM
 
Originally Posted by d4nth3m4n
you mean 23.4 cents.

2400 watt hours = 2.4 kWh
Heh, I fixinated myself and then saw this post. I was hoping to catch it before anyone read it!
"Everything's so clear to me now: I'm the keeper of the cheese and you're the lemon merchant. Get it? And he knows it.
That's why he's gonna kill us. So we got to beat it. Yeah. Before he let's loose the marmosets on us."
my bandmy web sitemy guitar effectsmy photosfacebookbrightpoint
     
Mac Elite
Join Date: Aug 2003
Location: Minnesota
Status: Offline
Reply With Quote
Jun 21, 2006, 08:07 PM
 
Wow, I pay only $0.069 per kw/h. You guys are getting robbed!
     
Addicted to MacNN
Join Date: Oct 2003
Location: Far above Cayuga's waters.
Status: Offline
Reply With Quote
Jun 21, 2006, 08:09 PM
 
it's like 13.9¢ here. gotta love NY.
     
Addicted to MacNN
Join Date: Oct 2001
Location: BFE
Status: Offline
Reply With Quote
Jun 21, 2006, 08:38 PM
 
And you guys said you'd never need math outside of high school!

I'm a bird. I am the 1% (of pets).
     
Mac Elite
Join Date: Aug 2003
Location: Minnesota
Status: Offline
Reply With Quote
Jun 21, 2006, 09:14 PM
 
I used this and my Kill-A-Watt device to see how much power my Macs are using. I also set up a Windows laptop as a data logger for my weather station. My weather station computer only uses 9 watts when everything is disabled except the internet upload! That's very efficient.

I also try to use as little power as possible when using my computers. I sleep my Macs, which means each one is consuming less than 5 watts in this mode. I don't leave anything except my weather station laptop running full time. I even have my computer at work set up to automatically shut down after running some cleaning programs and then automatically start up each morning before I get to my office.

Saving energy can be fun!
     
Professional Poster
Join Date: Jan 2003
Location: Teaneck, NJ
Status: Offline
Reply With Quote
Jun 22, 2006, 11:18 AM
 
So this means that it is cheaper to run a laptop 65w (max draw) than a lightbulb? I see the numbers, but I never thought of it this way.
AT&T iPhone 5S and 6; 13" MBP; MDD G4.
     
Addicted to MacNN
Join Date: Sep 2000
Location: Isle of Manhattan
Status: Offline
Reply With Quote
Jun 22, 2006, 11:23 AM
 
Originally Posted by d4nth3m4n
it's like 13.9¢ here. gotta love NY.
NYC is 19¢
"Faster, faster! 'Till the thrill of speed overcomes the fear of death." - HST
     
Professional Poster
Join Date: Jun 2006
Location: "Working"
Status: Offline
Reply With Quote
Jun 22, 2006, 11:25 AM
 
Originally Posted by SSharon
So this means that it is cheaper to run a laptop 65w (max draw) than a lightbulb? I see the numbers, but I never thought of it this way.
So much of the lightbulb's energy is wasted in heat. Fluorescent and LED's are much more efficient.
     
ort888  (op)
Addicted to MacNN
Join Date: Feb 2001
Location: Your Anus
Status: Offline
Reply With Quote
Jun 22, 2006, 12:19 PM
 
Thanks guys, my wife was yelling at me for leaving the hallway and bathroom lights on almost everyday when I go to work.

The bottom line is that my bad habit is costing us about $1 a month. I told that I had reached a point in my income level where not worrying about it was more important to me then losing a few bucks a month. Not that I'm going to leave lights on intentionally, just that it's not worth even thinking about.

Thanks for the help!

My sig is 1 pixel too big.
     
Professional Poster
Join Date: Jun 2006
Location: "Working"
Status: Offline
Reply With Quote
Jun 22, 2006, 12:40 PM
 
We turned the central A/C on in our house (large, old 5 bedroom house w/ 6 college guys living in it) for about half of May and our elec bill doubled from April to May. Needless to say, we are putting up with 85 degree temps inside now.
     
Mac Elite
Join Date: Aug 2004
Location: Seattle, WA
Status: Offline
Reply With Quote
Jun 22, 2006, 12:43 PM
 
I read an interesting article that estimated 7% of the US's electricity usage is keeping off appliances on. The clock on your stove, your TV being in standby so the remote can turn it on, your computer being off but having a trickle to be able to turn it on, power adaptors not attatched to anything... etc.

We'd save a lot of electricity if things actually turned off like they used to.

ImpulseResponse
     
Professional Poster
Join Date: Jun 2006
Location: "Working"
Status: Offline
Reply With Quote
Jun 22, 2006, 12:52 PM
 
I suppose if you really wanted to you could put a powerstrip at each outlet and really shut them off when you wanted to.
     
Mac Elite
Join Date: Apr 2003
Location: Southern, NJ (near Philly YO!)
Status: Offline
Reply With Quote
Jun 22, 2006, 01:03 PM
 
LED Light Bulbs...expensive but worth it in the long run

http://www.msnbc.msn.com/id/9399209/
MacBook Pro 15" i7 ~ Snow Leopard ~ iPhone 4 - 16Gb
     
Mac Elite
Join Date: Jun 2004
Location: Nashville
Status: Offline
Reply With Quote
Jun 22, 2006, 01:24 PM
 
Some people are really silly about what they think saves money. For instance, driving halfway across town to save 2 cents a gallon on gas, leaving one store to travel 5 miles to another store in order to save 25 cents on a loaf of bread, driving with their windows down instead of running the car ac, trucks driving around with their tailgates down not realizing do so creates more drag, etc.
     
Professional Poster
Join Date: Oct 2002
Location: Off the Tobakoff
Status: Offline
Reply With Quote
Jun 22, 2006, 01:36 PM
 
LED Light Bulbs sound interesting, but the guy also touts CFLs, which still aren't as pleasing, to me, as incandescent. They're not as bad as some fluorescents, but they're certainly not as warm as a good old-fashioned Edisonian bulb.
"You rise," he said, "like Aurora."
     
Admin Emeritus
Join Date: Oct 1999
Location: Zurich, Switzerland
Status: Offline
Reply With Quote
Jun 22, 2006, 02:26 PM
 
I've been replacing bulbs that tend to be left on (e.g. entryway, hallway, etc) with CFLs as they have burned out, but I've reverted my bathroom lights to incandescent: the CFLs take too long to turn on if I just want to go in and grab something real quick.

tooki
     
Addicted to MacNN
Join Date: Mar 2000
Location: Garden of Paradise Motel, Suite 3D
Status: Offline
Reply With Quote
Jun 22, 2006, 02:36 PM
 
Originally Posted by The Godfather
Very roughly, a 100W lightbulb costs $4 to run for 24 hours. An equivalent fluorescent will cost $1 to run.
That sounds a little high.
He can be fixed -- you can't.
     
Addicted to MacNN
Join Date: Mar 2001
Location: USA
Status: Offline
Reply With Quote
Jun 22, 2006, 02:50 PM
 
Originally Posted by finboy
That sounds a little high.
Finish reading threads very often?

/Couldn't resist
"Everything's so clear to me now: I'm the keeper of the cheese and you're the lemon merchant. Get it? And he knows it.
That's why he's gonna kill us. So we got to beat it. Yeah. Before he let's loose the marmosets on us."
my bandmy web sitemy guitar effectsmy photosfacebookbrightpoint
     
ort888  (op)
Addicted to MacNN
Join Date: Feb 2001
Location: Your Anus
Status: Offline
Reply With Quote
Jun 22, 2006, 02:57 PM
 
We're in the process of replacing all of our bulbs with fluorescents. Our main problem is that they stick out further and mess up some of our fixtures.

My sig is 1 pixel too big.
     
Professional Poster
Join Date: Jan 2003
Location: Teaneck, NJ
Status: Offline
Reply With Quote
Jun 22, 2006, 03:02 PM
 
Now I wonder what the halogen light in my room uses. It went out a few years ago in a flash of light that actually melted the glass bulb.
AT&T iPhone 5S and 6; 13" MBP; MDD G4.
     
Addicted to MacNN
Join Date: Mar 2000
Location: Garden of Paradise Motel, Suite 3D
Status: Offline
Reply With Quote
Jun 22, 2006, 07:04 PM
 
Originally Posted by RAILhead
Finish reading threads very often?

/Couldn't resist
Think about it -- why would you even bother to post something that sounds that incredibly wrong?
He can be fixed -- you can't.
     
Dedicated MacNNer
Join Date: Jun 2004
Status: Offline
Reply With Quote
Jun 22, 2006, 07:19 PM
 
Originally Posted by tooki
I've been replacing bulbs that tend to be left on (e.g. entryway, hallway, etc) with CFLs as they have burned out, but I've reverted my bathroom lights to incandescent: the CFLs take too long to turn on if I just want to go in and grab something real quick.

tooki
So have I. I use a tubular, or showcase, bulb in a cabinet fixture as a "night" light. It's on 24/7. But it doesn't last a month. I find GE lasts longer than Phillips, but they're hard to find around here. A note to Phillips results in them sending coupons for more of their crummy bulbs. I replaced bulbs in the utility area with CFLs, but they take a while to get to maximum brightness and are not as bright when they do get there. Not a good idea for a place you just pop in and out of.
     
Mac Elite
Join Date: Jan 2003
Location: NYC
Status: Offline
Reply With Quote
Jun 22, 2006, 09:08 PM
 
Originally Posted by SSharon
Now I wonder what the halogen light in my room uses. It went out a few years ago in a flash of light that actually melted the glass bulb.
you probably touched the front of the bulb while installing it. the bulbs get hot enough that fingerprints on the front can heat up and cause soft spots in the glass, eventually melting and burning out the bulb much sooner than it should.

"I start fires!"
     
Dedicated MacNNer
Join Date: Mar 2003
Status: Offline
Reply With Quote
Jun 22, 2006, 11:57 PM
 
It's important to not only look at the financial costs of running a bulb constantly when not needed, but also the environmental costs.

-Chris
This signature is obsolete.
     
Addicted to MacNN
Join Date: Mar 2001
Location: USA
Status: Offline
Reply With Quote
Jun 23, 2006, 07:08 AM
 
Originally Posted by Chris Gilpin
It's important to not only look at the financial costs of running a bulb constantly when not needed, but also the environmental costs.

-Chris
"Everything's so clear to me now: I'm the keeper of the cheese and you're the lemon merchant. Get it? And he knows it.
That's why he's gonna kill us. So we got to beat it. Yeah. Before he let's loose the marmosets on us."
my bandmy web sitemy guitar effectsmy photosfacebookbrightpoint
     
Addicted to MacNN
Join Date: Oct 2003
Location: Far above Cayuga's waters.
Status: Offline
Reply With Quote
Jun 23, 2006, 12:15 PM
 
Originally Posted by greenamp
driving with their windows down instead of running the car ac
wasn't there a mythbusters on this one? i think the overall consensus was around town window open was actually more economical, but at higher speeds, the ac would become more economical because of less drag on the car.
     
Professional Poster
Join Date: Mar 2004
Location: Pretentiously Retired.
Status: Offline
Reply With Quote
Jun 23, 2006, 12:18 PM
 
Originally Posted by d4nth3m4n
wasn't there a mythbusters on this one? i think the overall consensus was around town window open was actually more economical, but at higher speeds, the ac would become more economical because of less drag on the car.
That's correct.
     
Mac Elite
Join Date: Sep 2000
Status: Offline
Reply With Quote
Jun 23, 2006, 12:28 PM
 
Originally Posted by Chris Gilpin
It's important to not only look at the financial costs of running a bulb constantly when not needed, but also the environmental costs.
It's true. A little waste here and there multiplied by every household sums up to a rather significant amount of energy being needlessly wasted. Still, arguing over a single light bulb left on is probably not worthwhile stress-wise, either. At least Apple is emphasizing efficiency, or "performance per watt" now.
     
Professional Poster
Join Date: Jun 2006
Location: "Working"
Status: Offline
Reply With Quote
Jun 23, 2006, 01:53 PM
 
Originally Posted by d4nth3m4n
wasn't there a mythbusters on this one? i think the overall consensus was around town window open was actually more economical, but at higher speeds, the ac would become more economical because of less drag on the car.
If I remember correctly, I think the cutoff was somewhere near 45mph.
     
Professional Poster
Join Date: Jan 2003
Location: Teaneck, NJ
Status: Offline
Reply With Quote
Jun 23, 2006, 02:15 PM
 
Originally Posted by MaxPower2k3
you probably touched the front of the bulb while installing it. the bulbs get hot enough that fingerprints on the front can heat up and cause soft spots in the glass, eventually melting and burning out the bulb much sooner than it should.
The bulb was operating fine for years. I have an X10 switch and tehy seem to have a rather short life sometimes. The switch was unresponsive so that you would have to hit the button a few times for the light to respond. Well I hit it one too many and then there was a bright white light. The filament was stuck in the glass and it had started to drip, but must have cooled rather quickly.

I don't touch halogen bulbs with my hands when I put them in, we have lots of them in my house and I am careful about getting oils on them.
AT&T iPhone 5S and 6; 13" MBP; MDD G4.
     
Baninated
Join Date: May 2005
Location: England
Status: Offline
Reply With Quote
Jun 23, 2006, 05:31 PM
 
screw lightbulbs, what does it cost for my pm sawtooth to be in deep sleep for 24 hours?
     
   
Thread Tools
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On
Top
Privacy Policy
All times are GMT -4. The time now is 02:40 AM.
All contents of these forums © 1995-2015 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2015, Jelsoft Enterprises Ltd., Content Relevant URLs by vBSEO 3.3.2