Out of curiosity’s sake and putting some real numbers to the “green” movement, I bought an electricity usage meter. I chose the P3 International P4460 Kill A Watt EZ Electricity Usage Monitor. It’s pretty simple to use and just tells you how many KWH consumed over a certain time period and if you input a rate of cost (off of your electric bill, for example) it will then multiply how much it cost you for that time period.
Eager to play with the new toy, I started measuring a lot of the computer related equipment around my place and at work. Below, you can find the numbers that I collected.
I measured a lot of this equipment in a state that I dubbed “average use.” For these numbers to be relevant, average use must be defined. For printers, this means just printing whatever jobs were sent to it; not a particularly heavy work load but not just sitting idle either.
For computers, this gets a little more complicated to describe. Average use for the computers during my recording typically consisted of web browsing and word processing, only the initial boot up and not a whole lot of hard drive access (assuming disk defragmenting would take more electricity than doing nothing). I also did a test of playing a video game Team Fortress 2 for the sake of comparing the electricity usage difference between a machine when idle, in average use, and when gaming. I assumed gaming would use more power as the video card, fans, and other components are all employed.
Monitors
Flat-panel 20″ widescreen Samsung 205BW
1 hour: .03 KWH
1 hour 41 minutes: .05 KWH
CRT 19″ IBM G97
1 hour .08 KWH
Laptops
Compaq Presario V5000
3 hours in sleep mode : 0.00 KWH
1 hour 40 mins of average use: .03 KWH
Fujitsu S2110
1 hour of average use: .02 KWH
Compaq 6910p
1 hour of average use: .03 KWH
1 hour of average use and 1 hr 20 minutes idle: .05 KWH
Desktops
HP dc5750 (small form factor)
1 hour of average use: .06 KWH
1.5 hours of average use: .09 KWH
HP 7800 (ultra slim desktop)
1 hour of average use: .03 KWH
1.5 hour of average use: .05 KWH
My computer (expand/collapse)
1 hour of average use: .15 KWH
1 hour of playing Team Fortress 2: .24 KWH
9 hours 10 minutes idle: 1.36 KWH (or averaging .148 KWH for a one hour period)
Printers
HP Laserjet 4250N
1 hour idle: .01 KWH
4.5 hours idle: .05 KWH
3 hours of average use: .16 KWH
HP Laserjet 4700
24 hours of average use: 1.84 KWH
Calculated to 1 hour: .077 KWH
Summary
Things appear to be moving in a positive direction. Flat-panels use less energy than CRTs, this year’s model use less than last year’s model. But at the same time I learned that leaving my computer on for the 9 hours I’m away at work costs me about 8 cents. Now, it just doesn’t seem worth it to turn it off, especially when there are times that I would like to access it remotely using LogMeIn. But, like all things, it adds up. Multiply the daily cost by 365 (or 260 if you just want work days) to find the annual cost and multiply by the number of computers, monitors, and printers you have in your organization and the numbers could easily reach into the thousands.
The long-term costs alone are not enough to justify jumping to newer products. You will save money on your electric bill, but it will take a while for the initial cost of the purchase to be made up by the electric savings. Your motivation has to include altruistic reasons like helping the environment and reducing dependency on foreign oil. If you’re shopping around you’ll want to take into account electricity usage and efficiency of any new products. The site 80 Plus has a lot of information regarding 80% plus efficient and Energy Star certified power supplies; they also have a calculator to discover your savings.