The unit of measurement for electrical energy used in the home is the kilowatt hour, and this is the unit which the electricity supply company uses to work out your bill.
The word you're looking for is "watt." A watt is a unit of power that measures how fast electrical energy is used.
In SI, the same unit is used for any type of energy: the joule.
Watt is a unit of power. 1 Watt = 1 Joule/second; joule is the unit for energy.
The kWh (kilowatt-hour)
One energy unit starting with C is a calorie, which is a unit of energy commonly used in nutrition to measure the energy content of food. Another energy unit is a coulomb, which measures electrical charge.
In SI, the same unit is used for any type of energy: the joule.
The unit to measure the amount of electrical energy is the kilowatt-hour (kWh). It is commonly used by utility companies to bill customers for electricity consumption.
kilowatt-hour (kWh)
Power; its SI unit is watt. Please note that this is notspecifically an electrical unit; "power", and the unit "watt", is the rate of energy conversion, and can be used anywhere where energy is converted - whether "work" is involved, or some other (non-mechanical) energy.
The unit used to describe the amount of electrical energy provided by an energy source is the kilowatt-hour (kWh). It represents the amount of energy consumed or produced by using 1 kilowatt of power for 1 hour.
Watts. Also for any other type of power (energy / time), that is, for transfer of energy that is not electrical in nature.
All forms of energy are measured using the same units. The SI unit for energy is the joule (J). However, the unit used by electrical utility companies is the kilowatt hour (kW.h).