Noticed the comment about monitors using as much with screensaver as running Office. Here in Wisconsin (USA) our public library system allows us to borrow a throughput meter (the "Kill-a-watt" meter it's called). I did this, and noticed that on our television, the wattage used depends very much on what is on the screen. A CRT is basically a light-bulb -- up to 60 watts or so when "lit up" with bright or white content, down to very little when dark. This was a TV, so no sleep mode or anything, just what was on the screen. I would presume that the power used by a monitor running a screen saver depends a lot on what the screen saver is showing.

Those curmudgeons who insist on doing everything at the black screen DOS prompt may actually be on the cutting edge of green computing!