# What is energy?

Energy can be defined as the capacity to do work. It can also be defined as “stored work”. The terms energy and power are confusing and are interchanged most of the times. Consider that you are riding a bicycle at a speed of 20km/hr for an hour. A certain amount of work is done by you here. The amount of work done by you is known as energy. The unit of energy is Joule.

## Electric energy

Now consider that you are driving an electric car at a velocity of 100km/hr for an hour. An electric car basically consists of an electric motor. A certain amount of work is done by this motor during this displacement. An electric motor is a device that converts electric energy into mechanical energy. Hence the amount of electric energy converted by the motor is known as the electric energy consumed by it.

## Definition of Electric energy

All electric devices convert electric energy into any other forms of energy such as mechanical energy, heat, light etc. or vice versa. Hence electric energy can be defined as follows:

Electric energy can be defined as the amount of energy consumed by or generated by an electric device. It depends on the applied or generated voltage, current flow and duration of current flow.

Electrical Energy = Current x Voltage x time in hours = Power x time

## Unit of electric energy

Electric energy is expressed in watt-hour or kilowatt-hour. One kilowatt-hour is equal to the energy consumed by a piece of electrical equipment having rated power of 1 kW, operated at full load for an hour. It is measured using energy meter or kWh meter.