I've been hard at it, the last five weeks or so, doing a rush job coding a web application. I initially had intentions of doing this coding on my desktop computer downstairs. Somehow, though, I kept putting that idea off, because the couch is so damn comfortable..... It ends up I did the whole thing on my notebook, a 2 year old Dell Inspiron 1150 with a sticky keyboard.
Last year, I bought this little gadget (Kill-A-Watt meter) that can track energy consumption for individual devices, e.g. a stereo, a TV, a computer. I bought it initially to prove to myself that the freezer in the garage was an energy hog and that it had to go. Wrong....., it only consumed a kilowatt a day. So the freezer is still there. I also had it plugged into my desktop computer for a while and that device seemed to consume around 120 W an hour. If you think that the power supply on it is rated at 480W, that doesn't seem too bad. After that, I forgot about the gadget for a while. It was gathering dust until I decided last week to plug it in between my notebook computer and the wall outlet.
Turns out that the notebook is a real enery mizer as compared to a desktop computer. First off, I never turn off the notebook, though it does go into hibernation after half an hour. While up, it runs a slew of applications such as Visual FoxPro, SQL Server Express, Visual Web Developer Express. Still in all, while running, it only consumes around 22 wats. It's funny to look at the meter while you're opening an application: it shoots up to 40 or 50 watts for a few seconds and then fall back to 22 or so.
On average, it consumes 11 watts an hour for each of the 130 hours or so that it has been plugged in. Not bad eh?
Just think of the phenomenal energy savings that could be had by replacing all desktops with notebooks....
By the way, just for fun I plugged in my USB light to see what it consumes. Answer: 1 watt....too bad it's bloody useless.