Capacitors themselves do not consume power in the traditional sense because they do not dissipate energy like resistors or other elements that convert electrical energy into heat or other forms.
If you charge a capacitor, it will slowly lose its charge due to its internal resistance. The capacitor therefore consumes energy, but in practice it is negligible. Ideal capacitor does not consume energy.
The amount of electrical energy a capacitor can store depends on its capacitance. The capacitance of a capacitor is a bit like the size of a bucket: the bigger the bucket, the more water it can store; the bigger the capacitance, the more electricity a capacitor can store. There are three ways to increase the capacitance of a capacitor.
What is the difference between a capacitor and a battery?
Both capacitors and batteries store electrical energy, but they do so in fundamentally different ways: Capacitors store energy in an electric field and release energy very quickly. They are useful in applications requiring rapid charge and discharge cycles. Batteries store energy chemically and release it more slowly.
Capacitors are also known as 'condensers' and are a basic component when building an electrical circuit. They store electrostatic energy in an electrical field, and then dispense this energy to a circuit as it is needed.
Capacitors are widely used as parts of electrical circuits in many common electrical devices. Unlike a resistor, an ideal capacitor does not dissipate energy, although real-life capacitors do dissipate a small amount (see Non-ideal behavior).
In electrical engineering, a capacitor is a device that stores electrical energy by accumulating electric charges on two closely spaced surfaces that are insulated from each other. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the condenser microphone.