Horsepower (hp)

Definition

Horsepower (hp) measures power output, the rate at which work is done. Mechanical horsepower ≈ 745.7 watts, metric horsepower ≈ 735.5 watts. Boiler horsepower is less common, used for steam engines.
<h4\>History

The term horsepower was introduced by James Watt in the 18th century to compare steam engine output with the power of draft horses. Earlier, Thomas Savery referenced horses for engines in 1702.

Kilowatt (kW)

Definition

1 kilowatt (kW) = 1,000 watts. It is the SI unit for power, representing the rate of energy transfer or work per second, commonly used for engines, motors, and electricity consumption.

History

Named after James Watt, kilowatt was first proposed by Sir Charles William Siemens in 1882 and adopted officially in 1908 as a standard unit for power measurement.

Use

Kilowatts are widely used to measure engine output, electric motors, tools, heaters, and electricity consumption. Household electricity is measured in kWh (kilowatt-hours), larger industrial usage in MW or GW.