If you have a reasonably current PC or Mac, and if you leave it plugged to the charger 24/7. Operating in this way this machine works all day every day to transfer about $34 annually from you to the fossil fuel industry, leaving you poorer and them with enough money to buy a Senator. If it's a real old mother, it's giving them even more. Turn it off when you sleep and unplug the vampire charger. If you can't get a raise out of your stingy boss, learn to cut costs, sha-zam you have the same result, more cash.
If your in the market look at a new tablet computer, your electric bill will be between $1.50 and $3.00 for the year. That's a big damn savings on the utility bill alone. Also the purchase price is less than most PC's. When my old beast kick the bucket, I will open it, fuck up the hard drive, then drop it at the recycle center, then buy a tablet.