Any task which has beeen scheduled wakes up a computer from sleep. So u can schedule the scan and let the computer sleep. Similarly, automatic backups and windows updates also wake up the computer from sleep mode.
However, in hibernation mode, ur computer is almost turned off. So cant do anything in hibernation mode.
I charge my cellphone via a mini USB cable. And u know how, I switch on the computer, pause the startup (by going into boot device menu), and then leave my cellphone connected and it get charged. So u see, I charge with the computer virtually turned off.