Almost all pitching machines need to be plugged into a 120 volt power source and this one is no exception. That can be a standard wall outlet, a gas generator or a battery inverter with a generator.
The only pitching machines listed on this website that do not need to be plugged in are the Zooka ZS720 and the Zooka ZS740, which operate off of an internal battery. They do not throw softballs; however, I am not aware of any softball pitching machine that works off of an internal battery.