said by sporkme :

This will tell you:

»www.amazon.com/gp/product/B00009···ing=UTF8

quote:

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Two years ago, my electricity consumption jumped about 40% and I ignored the problem until this fall's rate increases. I wanted to find out what I bought back in 2003 that's still eating power today. Enter the P4400 Kill-A-Watt unit, which is the only low-cost product of its type on the market today. I tried but failed to find its specifications online. So I bought a couple of these things to try them out. Here are the details on what it can do.

* How big is the display: 4 digits.
* What are the front-panel button capabilities: volts, amps, watts, volt-amps, power-factor, frequency (hz), KWH, timer (since reset).
* Does it lose its data in a power failure: yes.
* You have to plug the unit into a nonswitched wall outlet, it can't measure overhead lighting or large appliances.
* It will report the amount of time (hours:min up to 99:59, then hours for about a year) since last reset but won't tell you how much of that time the attached device was powered on.

How did I figure out usage? I created an Excel spreadsheet with the following columns: Device, estimated wattage, estimated hours/month, kilowatts avg/month, measured kwh/day, measured kilowatts, annual cost. I went through the house and inventoried everything I could find, entering it into a row of the spreadsheet. Then I filled in the estimates:

- Hours/month: if I use a TV 3 hours a day, I enter the formula 3*365/12; if I use a treadmill 45 minutes on 10 days a month, the formula is 0.45*10*365/12.
- Kilowatts (average over the month): formula is watts*hours/(24*365/12)/1000. If you have a 60-watt light left on 24/7, you should see the value 0.060; if you have it on a 12-hour timer, you should see the value 0.030.
- Annual cost: formula is kilowatts*365*24*cost. Locally the cost is 13.5 cents so a 100-watt device works out to $118.26 per year.

OK once I have that chart I then plug in the Kill-A-Watt to measure the items that might be chewing up more power than my estimates. For a device that you leave on all the time and which uses a steady number of watts, you can simply measure it for a moment and enter the kwh/day figure into your spreadsheet quickly. For devices like refrigerators or computer monitors or TV sets, you will want to leave the unit plugged in anywhere from a day to a week before entering your kwh/day figure.

The first thing that leaped out at me was how much it costs to run those econo-box desktop PCs. Sure enough, the culprit turned out to be those hot AMD and Intel processors: the tech industry wants you to focus on gigahertz and other performance numbers; they'll never tell you how many watts the computer will draw--because no one asks, not even Consumer Reports. A modern desktop easily draws 100 watts: refer to my earlier figure to see how much that costs, a dollar amount bound to go up in the future. Laptops would save power (though not necessarily enough to make up for the purchase price). Turning off the PC when not in use would save money, but at the cost of productivity: if you value your time, you don't like waiting 2 minutes every time you want to check an email (add those 2 minutes up over the course of a year!)

Bottom line: the Kill-A-Watt device will focus your attention on some of the devices that are costing you unnecessary money, and will definitely change the questions you will be asking as you purchase future household devices. I'd like to see a more feature-laden version, but not if it makes the Kill-A-Watt cost much more than the $25 I paid.

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said by rjackson :

This is in French, but it should be easy enough to understand.

said by Frenchy :

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Conclusion:
You included/understood it, it is strongly advised:
* to extinguish any PC as of 30 to 60 minutes of inactivity.
* always to disconnect the catch sector when the machine is extinct, or to use a switch.
* to take account of the consumption of energy at the time of the purchase. PowerMac G5 consumes as much as 11 iBook G4 14". Now you know from which the "Power" in "PowerMac comes";).

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