• Please review our updated Terms and Rules here

Power Consumption

Lorne

Veteran Member
Joined
Jul 27, 2008
Messages
1,164
Location
Chandler, AZ, USA
Our local utility company made some kW meters available (just like borrowing a book) through the local library branches.

With my electical bills ranging from a low of $ 70 in March to a high of $ 532 in August (for a 2650 sf house), and with all the talk of CFL bulbs and the like, I thought I'd see if I could save a dollar or two, and help the environment while I was at it.

In the process, I found out something interesting about running my computer.
I've always been one to leave the computer on and never turn it off. Back in the 80's I remember someone saying that turning the computer on and off does more damage than leaving it on (due to the heating and cooling of the PCBs, solder joints, etc). That made sense to me at the time - whether or not it's still true with modern computers and modern manufacturing techniques, I don't know.

Anyway, I got one of these "Kill A Watt EZ" meters. You can enter your cost/kW which is 10.64 cents per kWh (incl all taxes) in my case, and then select the time period (hr/day/week/month/year) that you want to see the cost for.

I checked the cost of running my desktop computer, two flat panel monitors, a cable modem, a router, and a powered USB hub.

Here's what I found:
- With everything turned on and running, the cost fluctuates depending on what you're doing.
- Not using the computer itself, as if you had walked away from it or left it on all night, and with the monitors on but in powersave mode, it's costing me $ 9.38/month.
- With the same equipment turned on but with the monitors turned off (instead of in powersave mode) it's costing me $ 7.12/month.

So much for that powersave mode.

I was actually surprised that running the computer and a couple flat panels costs as much as it does (IE: $ 10 + per month). That doesn't even take into account, the three printers that are always powered on as well.

I'm not going to be saving much - it's pretty clear that it's the air conditioning driving the size of the electrical bills, but essentially, I can reduce my electrical bill by up to $ 2.26 per month if I simply push the power button on the front of the monitors when I'm not using them.

Now I'm off to test what that freezer in the garage is costing me - it very nicely rejects heat to the garage in the winter, but also rejects heat to it in the summer, and the garage has it's own A/C system = not good for energy use.
That freezer may need to go - it's stuck in kind of an endless loop - energy wise.

Am I the only one that leaves their computer on, and is it still better to keep them running rather than turning them off?
 
No - you're not. My apartment is a 24x7 shop computer-wise; I have far too many computers as "servers".
 
I power off my computers after using them. Sometimes I let them stay on while on a short errand like checking the laundry room or cooking.

Yesterday I bought a couple of energy saving bulbs. Those are 9W and should correspond to a 40W light bulb. I installed one into my desktop lamp, but unfortunately found this particular bulb produces far less and not as bright light as the traditional bulb did. Perhaps it was a poor choice of model. Otherwise I expect the sales of painkillers will increase in the next couple of years as people get more headache from not having sufficient light sources where required. But hey, if you save a few dollars per month by switching to energy saving bulbs, you can afford to spend that on pills.
 
I'm with tingo in having lots of computers on all the time. Right now there are 6 running. Of course it's minus 18 and dropping right now so I get it all back.

I did some measurements last year and I seem to recall my DOS box took about 36 watts. I turn the HDD off for the noise, but it hardly makes a ripple on the meter one way or the other. My main computer is scheduled for a reboot sometimes in the next few weeks so I'll try to remember to measure it then.

@Lorne
Of course you will be concerned with your particular costs, but I pay about 7 cents /kwh here so the numbers will be different. Does that thing measure in watts as well? That way we could all compare more easily.

I don't have a suitable watt meter. I made a short extension cable with the wires separately exposed in the middle. Then I can use a clamp-on ammeter. Those are really cheap now and I couldn't resist. :)
 
Am I the only one that leaves their computer on, and is it still better to keep them running rather than turning them off?

Although I turn off my computers when I am done playing with them (since I usually only get to use them meaningfully over weekends anyway) I am sure these are not the culprits when it comes to electricity bills. Those would be:
High usage:
1) AC (in the summer)
2) Stove, oven & refrigerator (year round)
3) Washer and dryer (year round)
4) Flat screen televisions (year round)
5) Lights throughout and outside the house (year round)
Seepage:
6) Computers & monitors (year round)
7) Garage door motor (year round)
8) Cordless phones (year round)
9) Vacuum machine (year round)
Unfortunately there is no real way of significantly saving money unless we switch off the AC and switch from our electrical stove & oven to the propane Weber grill (but that is expensive with average $ 20 a tank of propane).
 
@ carlsson
Yeah, I tried a compact fluorescent bulb once. Even if you wait for them to warm up, the light doesn't seem to equate to what it's supposed to be.
With the phase out of incandescent bulbs starting in the US next year (to be completely phased out by 2014), I've recently stocked up on 40, 60, 75 and 100 watt incandescent bulbs - I've got enough to last me as long as I'm going to last. Wal-Mart even said they're going to stop selling incandescent bulbs before the phase out starts - like now.
I hate those CFL bulbs !

@ Ole Juul
Yes, the meter measures in watts too. I'll check that out and see what i get. I'm going to check the printers in their powersave/sleep mode too.
 
I hate those bloody CFLs, not only do they give me a terrible headache, it makes reading even more difficult for me than it already is.
This is your fault David Suzuki!
 
I turn computers off when I'm finished with them.

The exception is my XP laptop (my main Internet machine) which I tend to put in hibernation mode, which saves the state to the hard drive then switches off (I just can't tolerate those long Windows boot-ups!).

My wife leaves her Apple I-Mac on standby all day and all night unless I sneak in and turn it off before I go to bed!

Tez
 
...I'm not going to be saving much - it's pretty clear that it's the air conditioning driving the size of the electrical bills [in the Summertime]...

As an off-topic inquiry for the heat of Phoenix, do you run a swamp cooler or refrigerated air?...

That's the killer on the bill, and worth attacking to find out a way to knock it down. We don't have quite the heat at a higher elevation, and get by on a single swamp cooler and ceiling fans. Another thing I found by happenstance several years ago was to put a metal roof on the house (vented to get rid of the heat in the attic) that has a white finish.

At least that doesn't soak up the heat like the dark shingles did before...
 
One interesting calculation I saw last year (to throw even more off-topic,) was that on a year-long-average it takes less energy to cool housing in Phoenix than it does to heat housing in the Northeast.
 
@ jorg
In Phoenix, Arizona, we don't need heating balls, we need cooling balls.

@ IBMMuseum
Refrigeration (DX heat pump unit) here. Swamp coolers are used in some industrical applications, and in some really old houses, but with the humidity we get in monsoon season they don't work, and that is when you need the cooling the most.
A lot of commercial buildings are starting to use white roofs, and some even have water misting/evaporation systems on them to create a cooling effect from the roof down.
The HOA wouldn't let me put on a metal roof in a million years - it's all concrete tile here (and I'm well insulated too with R30 walls and R19 (I think) for the roof).
To top it off, I only cool to 80 F in the summer - it'd be a killer if I tried to get to 72 F inside.

@ Anonymous Freak
And it'll be costing even more to heat in the Northeast right about now.
 
Lorne: Yeah, I tried a compact fluorescent bulb once. Even if you wait for them to warm up, the light doesn't seem to equate to what it's supposed to be.

For outside use I see them get very dim after a week. Their claimed efficiency in many locations is a downright lie. In a cold climate like this a 12W CFL appears to be less bright than 15W incandescents which I also use.


TheLazy1: I hate those bloody CFLs, not only do they give me a terrible headache, it makes reading even more difficult for me than it already is.

There are different qualities but the problem is they don't say on the package. I hate them too.

BTW, they are full of electronics and of course we all know about the mercury. To top it off they go straight in the landfill. At least the incandescents are easily recyclable but if they go in the landfill they won't poison anybody.

Jorg: Don't worry. You now can buy some heat balls.

I wrote a related article. The banning of incandescents isn't based on any science.

tezza:
I turn computers off when I'm finished with them.

The exception is my XP laptop (my main Internet machine) which I tend to put in hibernation mode, which saves the state to the hard drive then switches off (I just can't tolerate those long Windows boot-ups!).

Ha, a BSD bootup isn't any too fast either. It's only DOS that can boot fast. My main Linux machine boots in under a minute but that is just with a limited definition of "boot". I'm very internet oriented, so I have to wait for 50 or so web pages to reload before I can consider my machine "booted". With my connection that can take 10 minutes. Add in the time to set up 6 terminals and log in, and the time doubles. That's why I leave my machine on.

PeterNY:
. . .
6) Computers & monitors (year round)
7) Garage door motor (year round)
Cordless phones (year round)
9) Vacuum machine (year round)
Unfortunately there is no real way of significantly saving money unless we switch off the AC and switch from our electrical stove & oven to the propane Weber grill (but that is expensive with average $ 20 a tank of propane).

Surely you don't run your garage door motor for any significant amount of time. :) But you're right about motors, they really eat the juice. I've got lots of motors and when I turn on the 2HP dust extractor I wonder just what it's costing me. The water pump is 3/4 HP and I wonder how much that costs too. Regarding cooking, none of my electric stoves are hooked up and I just use a propane burner now (way good!). The proverbial $20 tank lasts me about 3 months for all my cooking.
 
With the phase out of incandescent bulbs starting in the US next year (to be completely phased out by 2014), I've recently stocked up on 40, 60, 75 and 100 watt incandescent bulbs - I've got enough to last me as long as I'm going to last. Wal-Mart even said they're going to stop selling incandescent bulbs before the phase out starts - like now.
I hate those CFL bulbs !

Look for the new halogen incandescent bulbs, which should be available at most supermarkets and big box stores by now: Philips EcoVantage, Sylvania SuperSaver, or GE Reveal Halogen. These typically advertise 25% reduced energy usage compared to a traditional incandescent bulb of similar lumens output (brightness). I've been using EcoVantage bulbs for the past 6 months or so and have been very happy with them. They still use a wire filament in a glass bulb, so it's still Edison's technology, just in a more efficient form -- with no warmup time, no mercury hazardous waste, no radio interference, fully dimmable, and the same pleasing color spectrum as with regular incandescents.

ShowImage.aspx
 
...Swamp coolers are used in some industrial applications, and in some really old houses, but with the humidity we get in monsoon season they don't work, and that is when you need the cooling the most...

I knew that the humidity in Phoenix has increased from irrigation. We get the same monsoons here, in the mountains with narrow canyons that gives flashflood potential. But the elevation (6000') knocks off most of the edge on the heat in Summertime.

Refrigerated air really sucks the electricity, you need to find as many PPro heatsinks as you can to stick on your roof!...
 
@vwestlife: I've used Philips halogen bulbs for at least the last 15 years in strategic places--yours look a bit different. The ones I have installed are made of very thick glass. I have CFLs installed where I don't care much about the quality of light. The warm white ones aren't too bad in terms of color, but the daylight white ones are glaringly bright and look unnatural. I've experimented with some LED illumination and find that I like it less than CFL. The colors are also strange and it's very hard to conceal the fact that they're basically point-sources.

@Lorne: We use a heat pump here mostly for heating; having a house on the west side of a hill almost 1000' above the valley floor and lots of trees reduces the need for any sort of air conditioning down to perhaps three days. Most of the time, just a simple floor fan is sufficient to make warmer days more comfortable. The heat is supplemented by a wood stove and management of temperature. Winter daytime has the thermostat set to 62F, with nighttime 56F--after you get used to it, it's quite comfortable.

I keep a Linux server on all of the time to collect mail and provide internet radio broadcasts (via a small FM transmitter) as well as firewalling and IP masquerading. It's an HP e-PC with an 800 MHz Celeron and; uses a Seagate Microdrive for storage --the whole shebang runs from a wall wart. Other systems around here are powered down using a switched power strip so they're really "off", not just "soft-off". Every little bit helps.
 
Regular light bulbs ahve been banned in BC since January 1, 2011. Most of the bulbs in stores then got hoarded or ended up on craigslist...
I found a select few CFL bulbs to be okay. There's this one bulb I can get at the dollarama and Ikea whose color temperature is pretty damn close to that of a regular bulb and I love them.
 
Regular light bulbs ahve been banned in BC since January 1, 2011. Most of the bulbs in stores then got hoarded or ended up on craigslist...
The U.S.'s so-called "incandescent ban" has many exceptions, so I assume the Canadian law is similar:

"Incandescent Lamp Ban?: What This Means, How to Handle It"
http://members.misty.com/don/incban.html

Here's another take on the situation: Incandescent bulbs have not been banned in the USA at all. They simply have been mandated to increase their efficiency by 25% -- a challenge which has been met successfully:

"No ban on incandescent light bulbs"
http://www.startribune.com/blogs/90608939.html
 
Ok, how many of you misread Tezza's message?
.. oops, it said I-Mac = iMac.

Why? Couldn't it be that Tezza's wife is still perfectly satisfied with the capabilities of her Apple I for daily use?

(until you tell her how many pair of shoes its worth :D - npi)
 
Back
Top