Kilowattstunde

Kilowattstunde is a unit of energy. It is commonly used for billing electricity consumption. The symbol for kilowatt hour is kWh. One kilowatt hour is equal to the energy transferred by one kilowatt of power in one hour. Therefore, 1 kWh = 1 kW × 1 h. Since a kilowatt is 1000 watts, one kilowatt hour is equivalent to 1000 watt-hours. Furthermore, since an hour is 3600 seconds, one kilowatt hour is also equal to 3.6 megajoules. The kilowatt hour is a practical unit for everyday energy use because it relates to familiar power ratings of appliances and the duration of their operation. For example, if a 100-watt light bulb is left on for 10 hours, it consumes 100 W × 10 h = 1000 Wh, which is 1 kWh of energy. Electricity providers typically measure and charge customers based on the number of kilowatt hours consumed over a billing period.