I recently bought a Antec 550w True Power and was wondering if it saves electricity when I just leave the comp on and doing nothing.
PSU dont really output 550w all the time does it? Or does it just output how many watts that you cpu and components need at the time?

I really dont know much about PSUs.

it only uses as much as it needs. If your computer is at 100% CPU usage, it'll wind up needing more power than if it's only at 1%, and it also depends on the components you have as well. If you're worried about electricity and have some ccfls, you can turn them off when you're not home, for example.

But unless you have a 6800ultra, and are playing a game, i doubt you're using all 550 watts ever.

Yeah.. most PSU manufacturers use the peak output to rate its products.. so 550w will be the most output it can handle (maybe it will do more, but unlikely without being completely unstable).
So yeah, it only outputs what the components need.. if you are worried about electricity consumption you shouldn't be too worried about the PSU. Your monitor will use alot more electricity than your base unit anyway.

It depends on what your computer is doing Running more things like cd drives floppy makes the power go up. Running things on stand by lowers it down. but watts means how much power for somthing to start a computer part. so when you start a computer it uses a lot when it is running normal goes down a lot. If you don t like using power shut it down at night. I run my computer about 14 hours on weekends and 4 hours on week days.

Very sound advices, thank you all.

About shutting down at night, have you heard about bittorrents? It so addicting, espeacially animes.