Standby power also sometimes known as vampire energy, is the power that electronic appliances consume when they have been put in standby mode or even when they have been switched off.
Some appliances like audio players, microwave oven, printers, gaming consuls or even a laptop consume energy even when they have been switched off but are still plugged into the energy source. Most Americans have almost 20 to 30 such appliances at home that suck away at the energy, increasing the electricity bill.
A desktop computer even when it is in the sleeping mode, uses almost 33.5 watts that over the course of an year might cost somewhere near $34 and a microwave oven when plugged in by in standby mode, consumes on an average 70 watts-hours per day that is equal to the time taken in making a bag of popcorn.
So even without using any of the energy, your appliances are costing you quite a lot in electricity bills.