What is the definition of Watt-hour and kilowatt-hour?

Answer 1

Watt-hour (Wh) is a unit of energy.

1 watt-hour is the energy that is consumed by power consumption of 1 watt during time period of 1 hour:

1 Wh = 1W x 1hr

1000 watt-hour are equal to 1 kilowatt-hour:

1000 Wh = 1 kWh

Answer 2

The watt-hour (symbolized Wh) is a unit of energy equivalent to one watt (1 W) of power expended for one hour (1 h) of time. The watt-hour is not a standard unit in any formal system, but it is commonly used in electrical applications. An energy expenditure of 1 Wh represents 3600 joules (3.600 x 103 J). To obtain joules when watt-hours are known, multiply by 3.600 x 103. To obtain watt-hours when joules are known, multiply by 2.778 x 10-4. In general, energy (E) is equivalent to power (P) multiplied by time (t). To determine E in watt-hours, P must be expressed in watts and t must be expressed in hours. Suppose a 60-W bulb burns for 3 h. Then P = 60 and t = 3, so the energy E in watt-hours is: E = Pt = 60 x 3 = 180 Wh If P and t are not specified in watts and hours respectively, then they must be converted to those units before determining E in watt-hours. from wikianswers

Answer 3

1 kW hr or 1 kilowatt hour is one thousand watts used for one hour. It is the unit that electric utility companies use to bill costumers. For example; you turn on ten 100 watt light bulbs, that is 1000 watts, leave them on for one hour and that is one kW hr. If your electric utility company charges $0.20/kW hr burning those ten bulbs cost you $0.20.

Answer 4

A kilowatt hour is 1000 watt hours.

Answer

A watt hour is the amount of energy consumed, over a period of one hour, at the rate of one watt. The rate of consumption of energy being 'power'.