[scientizscht (OP)]

Hello!

Is it correct to convert kWh to kW by dividing by 3600?

Thanks!

[Halc]

One is a measure of energy, the other a measure of power.
They cannot be directly translated by any means since they're different things.

You can translate kWs to kWh by dividing by 3600.

[scientizscht (OP)]

One is a measure of energy, the other a measure of power.
They cannot be directly translated by any means since they're different things.

You can translate kWs to kWh by dividing by 3600.

That's 100% wrong.

[Janus]

One is a measure of energy, the other a measure of power.
They cannot be directly translated by any means since they're different things.

You can translate kWs to kWh by dividing by 3600.

That's 100% wrong.

No, it's 100% correct.  kWs are Kilowatt-seconds and kWh are Kilowatt-hours.  There are 3600 second to an hour.

To convert from kWh to kW, you'd have to divide by h or hours.
kWh and kW are different types of measurements.   The first is a measure of energy, and the second is power, or the rate at which energy is delivered.   A 1000 w light, burning for 1 hr uses 1 kWh of energy.    But so would a 100w light burning for 10 hrs. There is no direct numerical conversion between kW and kWh.

[Bored chemist]

One is a measure of energy, the other a measure of power.
They cannot be directly translated by any means since they're different things.

You can translate kWs to kWh by dividing by 3600.

That's 100% wrong.

Two things.
It's 100% right and
if you think you are so damned knowledgeable about it, why did you ask?

[Petrochemicals]

Watts are power kwh are energy,

Kwh convert to joules calories etc.

Watts convert to horse power etc. They are a instants. Lightning is many many watts but short lived. Many watts but reduced joules

To convert watts into joules equals 1 watt is equivalent to 1 joule  per second.

1000watts acting for 3600 seconds is equal to 1 kwh or 3.6 megajoules.

[scientizscht (OP)]

kW is kiloWATT
Watt = Joules/second
So kW is POWER not energy

Joules is energy

What you are saying that kW is energy and kWh is power is totally wrong. Both are units of POWER.

[evan_au]

Perhaps I can clarify the confusion...

Let's say you have a steady, ongoing load drawing 1kW (say a pump, filling a dam from a river).
If you leave it running for an hour, then your electricity meter will tell you that the pump has consumed 1 kWh.
1 kW x 1 hour = 1 kWh

Another example (closer to the OP): If you have a 1kW load (say a microwave oven), which you leave running for just 1 second. After this 1 second, your electricity meter will tell you that you have consumed 1/3600 kWh.
1 kW x 1 second = 1kW x 1hour/3600 = 1/3600 kWh

Effectively,  the kWh meter does a time-integral of the power consumption.
- Instantaneous Input = Volts x Amps = power P(t), which you convert to kiloWatts
- Output = ∫ P(t) dt = Energy (E), in kWh

For a constant load of P kW running for n hours, this simplifies to E = P x n kWh.

...I actually did some utility testing of remotely-readable electronic power meters that my team developed in the late 1980s. Ahead of their time

[Janus]

kW is kiloWATT

Kilo is just a prefix that means 1000, so a kilowatt = 1000 watts

Watt = Joules/second

which is what makes watts a measure of power and not energy.  Joules are a measure of energy, if you divide this by time, you get a different type of measure.
 A Joule is a watt-second.  Which is 1/3600000 of a killowatt-hour (kWh)

So kW is POWER not energy

which is what everyone else has said.

Joules is energy

What you are saying that kW is energy and kWh is power is totally wrong. Both are units of POWER.

No one else has said that KW are energy and KWh is power. They have said it the other way around.
And they are not both units of power.  1 kWh is 1 kilowatt x 1 hr.  It is the equivalent of 1000 joules/sec * 3600 sec. The time units (seconds) cancel out, leaving 3,600,000] joules.     1 kW is just 1000W or 1000 joules/sec.

It's no different than mph being a measure of speed( rate of travel) and Miles a measure of distance.
 1 mph is 1 mile/1hr  and is a speed.  Miles are a measure of distance.   Saying kW and kWh are both power is like saying that mph and miles are both a measure of speed.

[Bored chemist]

What you are saying that kW is energy and kWh is power is totally wrong

That's the opposite of what was actually said.

Both are units of POWER.

No.

[simplex]

kWh is measured in Joules
kW is measured in Joules/second
You can not compare two quantities that do not have the same unit of measurement.

A 1 kW electric motor will draw 1 kWh in one hour but the same 1 kW engine will only consume 0.33 kWh if it runs only 20 minutes.

[Petrochemicals]

kW is kiloWATT
Watt = Joules/second
So kW is POWER not energy

Joules is energy

What you are saying that kW is energy and kWh is power is totally wrong. Both are units of POWER.

No, speak for yourself.

[Petrochemicals]

It's no different than mph being a measure of speed( rate of travel) and Miles a measure of distance.
 1 mph is 1 mile/1hr  and is a speed.  Miles are a measure of distance.   Saying kW and kWh are both power is like saying that mph and miles are both a measure of speed.

Best answer !

[ugbest]

KW is power, and KWH is a unit of electrical work, which is obtained by multiplying power by time.

KWH refers to the time for doing work. KWH is the unit degree of electrical energy that we often say.

1 kWh is the electrical power consumed by an electrical appliance of 1 kW in an hour, and 1 kWh is 1 degree

[evan_au]

1 kWh is 1 degree

I agree with the rest of the definition.

But can you clarify this last part, please? Eg:
- 1 degree of temperature?
- 1 degree of angle? (if so, the angle of what?)
- 1 degree/level of integration?

[alancalverd]

What you are saying that kW is energy and kWh is power is totally wrong. Both are units of POWER.

May I strongly advise you to study dimensional analysis and check your arithmetic before writing anything? It is the key to understanding physics, on which all other sciences depend.

[vhfpmr]

kW is kiloWATT
Watt = Joules/second
So kW is POWER not energy

Joules is energy

What you are saying that kW is energy and kWh is power is totally wrong. Both are units of POWER.

Power is rate of change of energy, ie: energy divided by time. What seems to have escaped you is that if you then take power (in W or kW) and multiply it by time you are back to energy.

P =E/t
therefore
E =Pt (=Et/t)

A Watt is one Joule per second, so a Watt second is a Joule, and a Watt hour is 3600J.

[vhfpmr]

Every time I see someone getting in a mucking fuddle with kWh, I wonder how we ended up with such a barmy unit for metering electricity in the first place. We should have dumped kWh at the same time we abandoned BTU for gas, and switched to MJ for both.

[alancalverd]

Not a lot of help, really, as electrical appliances are rated in watts and stuff tends to be used for hours rather than seconds during the billing periods. The only people to whom it really matters, are those entirely capable of making whatever conversions they need. 

[chiralSPO]

I agree that MJ is often simpler than kWh, but kWh are also convenient because we typically use hours when making economic calculations (for example: hourly wages). If we used metric units of time for times longer than seconds, then it would be a non-issue (fm, ps, ns, µs, ms, and s are all very common, but I have never come across ks or Ms).

Sometimes units are chosen for simple application to the problem at hand rather than ease of mathematical manipulation, like lightyears are more easily used than Tm (Terameters, not thulium). I also routinely use eV as a unit of energy rather than J when analyzing electrochemistry of molecular species because I measure the potential in V and I know how many electrons are involved in the reactions.