Conversion of common power units. Use the calculator below to convert between MW (Megawatt), KWh (Kilowatt), W (watt), Horse Power (HP) and Btu per hour like: KW to BTU, Btu/hour to KW, MW to KW, hp to KW and so on.
Concept of Power
Power is the rate of doing work or the rate of using energy. If you do 10 joules of work in two seconds, the power is 2 x 10 = 20 watts. The word "rate" here we means"per time".
Common Units of Power
- The kilowatt is a unit of power used by electrical utilities. 1 kilowatt-hour is the energy of one kilowatt power flowing for one hour (E = P x t). One kilowatt is a thousand Watts.
- The Btu per hour (often erroneously shortened to Btu) is a unit of power used by the heating, ventilation, and cooling industry (HVAC). One Btu/h equals 0.293 watt.
- A horsepower is a unit of power sufficient to raise 33,000 pounds 1 foot every 1 minute (or 550 lbs, 1 ft, 1 sec) equivalent to roughly 745.70 W. Horsepower is the imperial (British) unit of power, now replaced by the Watt - the new SI unit. The metric horsepower is defined as the power required to raise a mass of 75 kilograms at a velocity of 1 meter per second. This is approximately 735.499 watts a little smaller than the horsepower.