if i leave my pc on 24/7

[GepperRankins]

how much does it cost?
how much does turning my monitor off save?
how much does turning my hard-drives off save?

[{I}{K}{E}]

depends...

do you have a TFT or an old school monitor?


but why keep your monitor on when you sleep?

[DanB]

Don't know.
Fuck all I would have thought.
Whats the point of having your pc on if you unplug the hard drives?

[GepperRankins]

depends...

do you have a TFT or an old school monitor?


but why keep your monitor on when you sleep?

old school

even if i'm not downloading i leave my PC because it's needed for internet connection sharing. so i'm wondering if i use power saving how much money i'll save.


incase you're wondering why i care, my mum just got an electricity bill for £197

[Mr. Mulder]

harsh, you could try tallying it all up on one of those wattage/power calculators? Haven't a clue where to find a good up-to-date one though'

[Gripper]

I found this info hope it helps

How much electricity do computers use?

Computers

Desktop Computer

65 watts

Screen saver

65 watts
(no savings)

Processor-intensive task

90 watts

Sleep / standby

3 - 35 watts

Laptop

15-45 watts

Monitors

Typical 17" CRT

80 watts

Apple MS 17" CRT,
mostly white (blank IE window)

63 watts

Apple MS 17" CRT,
mostly black (black Windows desktop with just a few icons)

54 watts

Typical 17" LCD

35 watts

Screen saver (any image on screen)

same as above (no savings)

Sleeping monitor (dark screen)

0-15 watts

Monitor turned off at switch

0 watts

Apple iMac G5 w/built in 20" LCD screen

Doing nothing

97 watts

Monitor dimmed

84 watts

Monitor sleep

62 watts

Copying files

110 watts

Watching a DVD

110 watts

Opening a bunch of pictures

120 watts

Computer sleep

3.5 watts
A typical desktop computer uses about 65 watts. Add another 80 watts for a 17" CRT monitor, or 35 for an LCD. When your computer sleeps ("standby") the the computer uses 3 to 35 watts, while the monitor uses next to nothing. A screensaver that shows any image on the screen doesn't save any energy at all -- you only save energy if the monitor goes dark by going into standby mode. Of course, you can turn the monitor off at the switch too and then it uses 0 watts.

Let's not forget laptops, they use only about 15 watts.

With most devices you can look at the label to see how much energy they use, but that doesn't work so well with computers because the label gives the theoretical maximum, not the typical amount used. A computer whose label says 300 watts might only use about 60 watts when it's actually running, and only 90 even in peak times with serious number-crunching and all the drives spinning.

To put this into perspective, a light bulb uses about 75 watts. So a typical computer uses about 1.5 to 2 light bulbs' worth of energy.

To calculate the costs use this formula:
Watts x Hours Used


x Cost per kilowatt-hour = Total Cost
1000

For example, let's say your computer uses 65 watts and your LCD monitor uses 35. That's 100 watts total. You use your computer for two hours a day, five days a week. That's ten hours a week, or 520 hours a year. So your 100 watts times 520 hours = 52,000 watt-hours. Divide by 1000 and you have 52 kilowatt-hours (kWh). If you're paying 10¢ per kilowatt-hour, then you're paying $5.20 a year to run your computer.

It's a myth that it takes more energy to start a computer than to keep it running. It doesn't. You will always save energy by turning your computer off when you're not using it. If that's inconvenient you can always use the sleep or standby mode.

Computers account for only a fraction of worldwide electrical use, even with the burgeoning Internet. Air conditioning, lighting, and refrigeration account for a LOT more. The myth that computers are exploding the demand for electricity was given wings by an article in Forbes, which was debunked here. In fact, as inefficient CRT monitors are being phased out in favor of newer LCD screens, computer energy use is likely to remain flat or even go down over the next several years.

Of course, energy use varies from model to model -- Apple Macs tend to be a little more efficient than their PC counterparts. And newer models are generally more efficient than older models. And word processing uses less power than work that makes your computer really think, like running Photoshop filters. But all this is kind of academic, because if you're trying to estimate your computer's energy consumption, the figures above will do just fine. (If you need more accuracy then you can buy a $35 watt-hour meter to measure your electrical use.)

It's also academic because for home use, your computer accounts for only a tiny fraction of your total household energy use. Sure, you can save some money by putting your computer into sleep mode when you're not using it and swapping your CRT monitor for an LCD one, but you'll save a lot more by addressing your heating, cooling, and lighting use. For most people, their computers' energy use is not a significant portion of their total use, even if they use their computers a lot.

My recommendations:

* Use a laptop computer. They use lots less energy than desktops.
* If you use a desktop, use an LCD monitor. They use lots less energy than CRT's.
* Set the Power settings on your computer to automatically go into Sleep/Standby mode after 15 minutes or so of inactivity.
* Turn your computer off when you're done for the day.

I have had to start turning mine off at night cause it soon mounts up leaving them on 24/7

[DanB]

You'd be surprised how much not leaving the lights on in empty rooms saves

[GepperRankins]

if a light's on in the forest and no-one's around to see it. does it use electricity?

ps thanks gripper

[DanB]

yesh it does

[JPaul]

Very comprehensive answer.

As this question is answered the thread belongs in the Lounge.