How to calculate energy consumption?

Discussion in 'Community Discussion' started by indiochano, Sep 1, 2008.

  1. indiochano macrumors regular

    Jun 7, 2008
    Hi everyone, i want to calculate energy consumption per month of a theoretical scenario...

    Say I have a computer with a 750W power supply and I leave it on all day for a month. Judging by the fact that the computer wont be using its full power during idle time (meaning CPU usage is well below 5%), how can I make an accurate calculation of the consumption per month?

    I think the electric bills in NY are about 7 cents per kilowatt hours...

    I came up with 5 dollars a month but I know that's wrong lol...

    Any help would be greatly appreciated!
  2. Cave Man macrumors 604

    Cave Man

    Feb 12, 2007
    Neander Valley, Germany; just outside Duesseldorf
    energy consumption = Payroll check - (food+rent+beer+liquor+internet+trash+sewer+savings)

    sorry, best I can do...
  3. dmr727 macrumors G3


    Dec 29, 2007
    The easy way to do it is to get a meter that'll measure the current draw by the device. Otherwise, it's just going to depend on what you have installed in your PC. Most of my computers, even the ones with large power supplies, seldom draw over 100W total under a load. Most average 50-60W.

    But even then it can be hard to calculate. My electric company (Socal Edison) have so many tiers of consumption, peak vs. non-peak, and so on - it's hard for me to know exactly what I'm paying per kilowatt hour anyway.

    I'd just leave the thing on for a month and see what the difference in your bill is.
  4. greg555 macrumors 6502a

    Mar 24, 2005
    People usually recommend the Kill a Watt, so I will too:

    That will give you an accurate measure of how much energy (kWh) your computer or other appliances use in a day (or week if you want to measure for that long).


Share This Page