compared to say a 100 watt lightbulb, how much energy does a running Dell PC consume in say an hour (with monitor on)? an estimation is all i am looking for.
if i am downloading and playing music and watching a dvd and all kinds of other things, does it use more energy than if the PC was just sitting idle, with disks and monitor on?
thanks in advance.
I think that it would vary greatly depending on your PC’s configuration and periphrials. I found something that said between 50 and 100 watts an hour average from this site http://www.wyse.com/overview/energy/
watts is the correct unit. Watts an hour is meaningless.
Most PC power supplies are around 300 - 400 Watts, but that doesn’t include monitor.
Are CRT screens and LED screens comparable in their power consumption?
I’ll assume that you meant LCD screens. From Howstuffworks
A 300 W supply doesn’t necessarily consume 300 W. The rating means that it’s capable of supplying 300 W.
If it is actually delivering an output power of 300 W, then it’s consuming an input power from the mains greater than 300 W, probably about 350 W.
However, a 300 W supply is also capable of delivering an output of, say, 85 W whilst consuming 100 W. Hence neutron star’s figures above.
Picky, picky. tell that to the author of the website I derived the source from, I never claimed to know the least bit about electricity. All I know is that it’s not the watts that kill you, it’s the amps 
.
[aside]
Honest-to-God real life conversation I once had with a Bavarian:
Him: Rudolf Diesel was much more important historically than that English guy who invented the steam engine. What was his name again?
Me: Watt.
Him: You know, that guy that invented the steam engine.
Me: Watt.
Him: You know exactly what I’m talking about, don’t be a smartass. What was the #$%@%'s name?
Me: Watt.
At this point half of the people around the table were rolling on the floor, and other half were trying to restrain the Bavarian.
[/aside]
I don’t know. I feel he has a right to be picky about the site, and I don’t think he’s being picky with you per se. It irritates people like sailor and myself when people who ought to know better (like people making energy-oriented sales pitches) don’t know what they are talking about.
You should see how picky I get over coal issues.
Oops! Yes, an unfortunate typo. And thanks!
My understanding (which could be wrong, but I was told this by someone who should have known) is that a 300 W power supply draws 300 watts. The usual rule of thumb is that the maximum it can supply is half of what it draws, so it can supply up to 150 W. Of course, if less is consumed, then it draws less.
If it weren’t rated by what it draws, you could not add it up with whatever else was on the circuit to see if you have overloaded it. Although in theory, a single circuit (in North America) could supply 1,650 watts, in practice it is good to limit it to 1,500.