The kilowatt (kW) equals 1,000 watts and is the standard unit for measuring the power output of engines, electric heaters, and industrial machinery. Electricity bills use kilowatt-hours (kW × hours), making the kilowatt the most familiar power unit for consumers. One kilowatt equals approximately 1.341 horsepower.

The megawatt (MW) equals one million watts, used to express the output of power plants, large industrial facilities, and data centers. A typical wind turbine generates 2–3 MW, while a large coal plant may produce 500–1,000 MW. One megawatt can power roughly 800–1,000 homes simultaneously.