Why is energy storage measured in kWh and not kW?

[brob]

I sort of grasp the concepts of electricity but I don’t really get this distinction between kW and kWh. Why is the amount of energy storage in our cars measured in kWh and not kW? Also, why is it miles per kWh, not miles per kW?

Edit: never mind. Should have googled it first. I found the answer.

Sponsored

 

[Kamuelaflyer]

Kilowatts (kW) measure the rate of electricity use, while kilowatt-hours (kWh) measures the amount of electricity used over time.

https://www.power-sonic.com/blog/kw-vs-kwh-explained/

 

[Trielectric]

From my shop class in the 1960s. I still like it the best.
One amp is defined as 6.24 x 10 to the 18 power electrons per second.
Volt is the pressure or excitement of these electrons even if they do not move from their atom.

1 amp of speed x 1 volt of pressure = 1 watt
2 amps of speed x 1 volt of pressure = 2 watt
1 amp of speed x 2 volts of pressure = 2 watt

Note that there already is a time associated with amps, thus a time is always associated with the watts.

 

[ChasingCoral]

Edit: never mind. Should have googled it first. I found the answer.

Yes.

 

[steve.panse]

Energy (kWh) = Power (kW) * Time (h)

Energy is the ability to do Work. Power is how quickly that energy is delivered.
As an engineer, the common confusion of energy and power drives me nuts.

 

[HuntingPudel]

As an analogy, think of a Watt Hour as an equivalent to a gallon (volume). The measurement of flow is volume over time. This is expressed as gallons/Hour. For electricity it’s expressed as Watt Hour/Hour or simply as Watts if you let the concept of time cancel itself out in both the numerator and denominator. ??

 

[MoonRiver]

I sort of grasp the concepts of electricity but I don’t really get this distinction between kW and kWh. Why is the amount of energy storage in our cars measured in kWh and not kW? Also, why is it miles per kWh, not miles per kW?

Edit: never mind. Should have googled it first. I found the answer.

We are talking about energy. KWH is energy unit but KW isn't . KW is power, like horse power of your engine, KWH is your engine of one KW power running nonstop for an hour, during that hour your engine generates one KWH energy.

 

[MoonRiver]

We are talking about energy. KWH is energy unit but KW isn't . KW is power, like horse power of your engine, KWH is your engine of one KW power running nonstop for an hour, during that hour your engine generates one KWH energy.

To be more physics correct, energy is not generated but covered from chemical energy of the gas to mechanical energy.

Sponsored