Kilowatt (kW)
The kilowatt (kW) is 1,000 watts. As electricity became essential in the late 19th and 20th centuries, the kilowatt became the common unit for household appliances, motors, and power generation. Household energy use is measured in kilowatt-hours (kWh), which track energy consumption over time. Kilowatts are also used for engines, renewable energy, and national grids. By scaling up from the watt, the kilowatt lets us express real-world power needs and production more easily. As we consider other systems for measuring power, it is useful to explore both non-metric and higher-magnitude units such as horsepower and the megawatt.
Watt (W)
The watt (W) is the standard unit of power in the International System of Units, named in honor of James Watt, a Scottish engineer renowned for advancing steam engine technology during the 1700s. Watt’s innovations were pivotal to the Industrial Revolution, making the measurement of power increasingly important. The watt was formally recognized as a unit of power in 1889 and later became part of the global SI system. Defined as one joule per second, it quantifies how quickly energy is transferred or converted. The watt is essential in fields such as electricity, mechanics, and thermodynamics, and it is commonly used to describe the power of household devices, industrial equipment, and energy systems. For larger-scale measurements, units like the kilowatt are used to represent higher amounts of power efficiently.