What is a kilowatt-hour?

A kilowatt-hour is defined as a unit of energy that represents the consumption of one kilowatt of power over a duration of one hour. This means that if a device operates at a power level of one kilowatt and runs for one hour, it has used one kilowatt-hour of electrical energy. This measurement is commonly used by electric utilities to calculate energy usage and billing for consumers. It provides a clear and practical way to quantify energy consumption over time, which is essential for understanding electricity usage, especially in residential and commercial settings.

The other choices do not adequately define a kilowatt-hour. Measures of electrical resistance are represented in ohms, and power ratings in watts, while electrical storage devices, such as batteries or capacitors, serve entirely different functions in energy management and are not related to the concept of kilowatt-hours.