What does a Killowatt per hour equate to?

Question

Does that mean that when I leave my heat on for my air conditioning for ONE HOUR that it equals 1 KwH ?

SK

Answer 1

The unit of Energy is the Joules.

Power is the rate of energy usage per unit time.
Power = Energy / time.
The unit of power is called the watt.

1 kW hour (kWh) is a unit of energy. The unit of time (the hour) is multiplied by the unit of power to give a unit of energy.

1000 watts = 1 kilowatt (1 kW) = 1000 Joules per second = 1 kJ / s


The unit of a kW per hour refers to the rate of change of power with respect to time....how fast your energy usage is changing (similar to the idea of acceleration [kW / h] compared to velocity [kW] in terms of kinematics).

If you had several air conditioners that had a power rating of 1 kW and you kept turning one air conditioner on per hour...then the rate of change of your power usage would be 1 kW per hour.
At hour 1 you would be using 1 kW of power. Then another hour goes by and you are using 2 kW of power. Hour 3....3 kW of power. And so forth.

That said, you will not find the unit of kW/h used very commonly.


EDIT:
****Please Note****
The asker of the question asked about Killowatt, "per", hour, not about Kilowatt-hours.
kW per h does not equal kWh.

Answer 2

A kilowatt hour is a measure of energy = power * time
A watt is a measure of power = energy / time

The energy is the same is you have a 100 watt light
bulb on for an hour, or a 10 watt light bulb on for 10
hours you are using energy at a different rate.

Electric companies do not care how fast you use your
energy, they care how much energy that you do use.
So, they base your electricity bill on energy. Your
meter measures the product of voltage and current
flowing through your house and turns a wheel fast
or slow adding in all the power you use.

As far as your airconditioning, most window air conditioners
are 800-1500 watts, some even more. So one hour for
the 1500 watt A/C would be 1.5 kWhrs and for the 800
watt unit .8 kWhrs.

Answer 3

A watt is a measurement of power. It is an easy formula to remember P=IE (pie), or the power is equal to current multiplied by the voltage. Just a little background information.

A kilowatt hour is kinda like the miles per hour thing; kilowatt is 1000 watts of power, an hour is, well, 60 minutes. So 1 kilowatt hour is 1000 watts per hour "usage". You are billed by how many watts you use.

Wikipedia is where most people get their answers if they want to sound smart. I go there sometimes just to make sure that I know that I'm not giving bad advice. I figured that if you didn't know what a kilowatt hour was you wouldn't know what a joule was. Anyway, type in Wikipedia in your search tab, its a great site.

Answer 4

You have not given enough information to get an answer. If you give the heater wattage and the amount of time the heating element is operated, you can get the KW-HRs. But you can't place a watt value on a gallon of water unless you can give an amount of water used over a period of time. This information will be hard to come up with, in most cases. TexMav

Answer 5

If you have a 100 watt light bulb, and light it for 10 hours, you will have used 1 KWH.

Answer 6

The unit of measurment for electricity is the watt. What 1 kw means is that you used 1000 watts in an hour.

Answer 7

This is simply a convenient unit of energy. Rather than having the electricity company charging us by joules, they charge us by kW*h.

Most appliances indicate how much power they use, so just multiply that by the number of hours to find out how much energy you are using.

Answer 8

If you use resistance heating 1 KWh = 3412 BTU.

Answer 9

There is no unit for KW/h
1kwh= 1000*3600 (J)
=3600000 (J)