kilowatt hour

Unit whose name includes an SI unit and a non-SI unit accepted for use with SI

Name	Symbol	Quantity	SI units
kilowatt hour	kW h	energy	3.6 × 10⁶ J
The kilowatt hour, symbol kW h, is a non-SI derived unit of energy, accepted for use with the SI. One kilowatt hour is equal to 3.6 megajoules.
Definition			h Δν_Cs
$1 \mspace{4mu} \text{kW h} \mspace{6mu} = \dfrac{3.6 \times10^6}{(6.626 \mspace{4mu} 070 \mspace{4mu} 15 \times 10^{-34})(9 \mspace{4mu} 192 \mspace{4mu} 631 \mspace{4mu} 770)} \mspace{6mu} h \mspace{4mu} \Delta \nu _{Cs}\\ \\ \\ 1 \mspace{4mu} \text{kW h} \mspace{6mu} \approx 5.910 \mspace{4mu} 260 \mspace{4mu} 285 \mspace{4mu} 245 \mspace{4mu} 545 \mspace{4mu} 770 \mspace{4mu} 501 \times10^{29} \mspace{6mu} h \mspace{4mu} \Delta \nu _{Cs}$

One watt is equal to the power required to transfer energy at a constant rate of one joule per second. It follows that, at a constant power of one kilowatt (kW), the amount of energy transferred in one hour (h) is equal to 3.6 megajoules (MJ), or one kilowatt hour (kW h).

The kilowatt hour is derived from the watt (an SI coherent derived unit) and the hour (a non-SI unit accepted for use with the SI).

power	× time	= energy	SI units
1000 W	× 3600 s	= 3 600 000 W s	3.6 MJ
1 kW	× 1 h	= 1 kW h	3.6 MJ

The kilowatt hour is a non-SI unit of energy commonly used for household energy bills.