A kilowatt (kW) is a unit of power equal to 1,000 watts. It is part of the International System of Units (SI) and is used to quantify the rate of energy transfer. The exact definition is 1 kW = 1,000 W.
The term "kilowatt" emerged in the late 19th century, coinciding with the rise of electrical engineering. The unit was popularized by engineers like James Watt, who developed the steam engine. The kilowatt was adopted as a standard unit for electrical power in the early 20th century.
Kilowatts are commonly used to measure electrical power in homes and industries. Appliances like heaters, air conditioners, and electric vehicles are rated in kW. In the energy sector, power plants' output is often expressed in megawatts (MW), where 1 MW equals 1,000 kW.