Desktops forum

General discussion

Leaving Computer on -How much will it increase your energy

by dbdan / November 25, 2004 4:09 PM PST

I ahve two computers that I leave on continuously. a 667 MHZ HP
and a 2300 MHZ emachine

I also have two printers and a scanner

Anyone know approx. how much energy in kilowatts this would be per month?

Discussion is locked
You are posting a reply to: Leaving Computer on -How much will it increase your energy
The posting of advertisements, profanity, or personal attacks is prohibited. Please refer to our CNET Forums policies for details. All submitted content is subject to our Terms of Use.
Track this discussion and email me when there are updates

If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.

You are reporting the following post: Leaving Computer on -How much will it increase your energy
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.
Collapse -
Without measing...
by R. Proffitt Forum moderator / November 25, 2004 10:50 PM PST

Figure 100 Watts for under 1GHz machines, 200 for above 2GHz. Printers vary widely with my old Laserjet II sucking up 1,000 Watts when the heater element kicks in to today's laser that sips 4 or less Watts when just sitting there.

If the printers/scanners are newer, guesstimate 10 Watts each.

If you feel you don't want to guess, go to Radio Shack and buy the wall mount AC Watt Meter.


Collapse -
Re: Leaving Computer on -How much will it increase your ener
by Dan Hoad / November 25, 2004 11:06 PM PST

Let's assume that your computer has a 250 watt power supply and your monitor runs at 100 watts. For a 24 hour period the energy consumption for just these two items is 8400 watt-hours or 8.4 KWhs. If these items are on for 30 days each month - you are using 252 KWattHours per month. If we assume a conservative estimate of $0.10 per KWh from your electric company, then you are spending $25 per month by leaving your computer running 24 hours each day.

Collapse -
Just try to pull 250 Watts from a 250 Watt supply.
by R. Proffitt Forum moderator / November 26, 2004 12:04 AM PST noted that 6 out of 21 supplies were not able to deliver on their ratings.

As such, the rule of thumb for a reliable PC is to fit a power supply that your machine will draw about 1/2 the rated Watts.

I'd peg the 250 Watt supply to, on average consume about 100 Watts on a pre-built machine. And about 150 Watts if the user upgraded the machine.

Collapse -
Look at it another way also
by Steven Haninger / November 26, 2004 9:53 AM PST

Most of the electricity used becomes heat. In the winter, this actually means reduces the amount of heat your furnace needs to produce. In the summer, if you have an air conditioner, it works a little harder.

Popular Forums

Computer Newbies 10,686 discussions
Computer Help 54,365 discussions
Laptops 21,181 discussions
Networking & Wireless 16,313 discussions
Phones 17,137 discussions
Security 31,287 discussions
TVs & Home Theaters 22,101 discussions
Windows 7 8,164 discussions
Windows 10 2,657 discussions


Your favorite shows are back!

Don’t miss your dramas, sitcoms and reality shows. Find out when and where they’re airing!