Definition:SI/Energy/Kilowatt-Hour

Definition

The kilowatt-hour is an SI unit of energy.

It is defined as being:

the energy expended when a power of $1$ kilowatt is applied for $1$ hour.

Conversion Factors

\(\ds \)

\(\)

\(\ds 1\)

kilowatt-hour

\(\ds \)

\(=\)

\(\ds 10^3\)

watt-hours

\(\ds \)

\(=\)

\(\ds 10^6\)

milliwatt-hours

\(\ds \)

\(=\)

\(\ds 3 \cdotp 6\)

megajoules

\(\ds \)

\(=\)

\(\ds 3 \cdotp 6 \times 10^6\)

joules

\(\ds \)

\(\approx\)

\(\ds 860 \cdotp 0\)

kilocalories

\(\ds \)

\(\approx\)

\(\ds 3413\)

British thermal units

Symbol

$\mathrm {kWh}$ or $\mathrm {kw \, hr}$

The symbol for the kilowatt-hour is $\mathrm {kWh}$ or $\mathrm {kw \, hr}$.

The $\LaTeX$ code for \(\mathrm {kWh}\) is \mathrm {kWh} .

The $\LaTeX$ code for \(\mathrm {kw \, hr}\) is \mathrm {kw \, hr} .

Linguistic Note on Kilo

The prefix kilo- derives from the Greek word χίλιοι (khilioi), which means thousand.

Sources

• 1969: J.C. Anderson, D.M. Hum, B.G. Neal and J.H. Whitelaw: Data and Formulae for Engineering Students (2nd ed.) ... (previous) ... (next): $2.$ Unit Conversion Factors
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): kilowatt-hour
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): kilowatt-hour