Conversion of KWh to KW

The conversion unit can be derived by the following:

1 KWh = 2.6552 x 10^6 ft.lbs. sec.

1.35582 ft.lbs.sec = 1 Watt

1,000 Watts = 1 KW

Therefore the conversion unit = ((2.6552 x 10^6 x 1.35582) / 1,000) = 3.599.97

1 KWh = 3.599.97 KW

you can't convert energy to power. ft.lbs.sec equates to watt seconds, not watts

Very nice Cadman. A little more BS and you might have the Dr. looking under bushes for little green men.

Did you happen to notice that KWh and KW have different units and are not directly convertable?

One kilowatt-hour is the amount of electrical energy expended by a one-kilowatt load drawing power for one hour.

Try this reasoning on units:

Work = force * distance, such as: 1 Newton * 1 Meter = 1 Joule

Power is Work devided by Time, such as: (1 Newton * 1 Meter) / 1 Second = 1 Watt.

Energy is the same as Work, Power times Time, such as: 1 Watt * 1 Second = 1 Joule

So a kilowatt (KW) is a unit of Power and a kilowatt hour (KWh) is a unit of Energy (or work).

Hoping you are not in charge of anything important,

the Dynamo

you spelled convertible wrong

# 3 In reply to #1 Re: Conversion of KWh to KW 12/30/2006 1:02 AM

Very nice Cadman. A little more BS and you might have the Dr. looking under bushes for little green men. Did you happen to notice that KWh and KW have different units and are not directly convertable? One kilowatt-hour is the amount of electrical energy expended by a one-kilowatt load drawing power for one hour. Try this reasoning on units: Work = force * distance, such as: 1 Newton * 1 Meter = 1 Joule Power is Work devided by Time, such as: (1 Newton * 1 Meter) / 1 Second = 1 Watt. Energy is the same as Work, Power times Time, such as: 1 Watt * 1 Second = 1 Joule So a kilowatt (KW) is a unit of Power and a kilowatt hour (KWh) is a unit of Energy (or work). Hoping you are not in charge of anything important, the Dynamo

Great reply, thanks for the info

Hi,

Thank you for your reply.Hope that the question is clear ie I would like to know one KWh(consumption of one unit of elecrical power) equivalent to KW (unit of electric power).

Sreenath

To retrieve connected load details, you need an inventory of all equipment which consumes electricity. As you know, KWh/actual hrs operation will produce an average load, but that is not what you asked for. What would be beneficial would be an electrical load profile. This can be obtained rather easily by using a clamp-on recording ammeter. A recording watt meter would work, but to use this you would need to install CT's & PT's, etc. The ammeter would show you the periods of low loads and periods of high loads. These max loads can be expensive depending on the demand charge that is imposed during peak usage period. Is this the thrust of your question?

A great answer Oldf__t, but unfortunately (for him), based on the wording of the question I doubt he can apply it effectively. Your postings make good reading!

Now as for 1Cadman4Christ's "answer" .... well its already been amply said by others. A little knowledge can be a dangerous thing.

I have found that in all manner of problem solving, it is very often more important to realize what I don't know (or what I am not certain of) than what I actually do know.... because then I will go find out. (The occasional blunder notwithstanding.)

"The more I learn, the more ignorant I realize I am"

KWh is the product of the KW of energy consumed per unit of time multiplied by the number of units of time.

Unfortunately THERE IS NO CONVERSION!

You would need a recording meter to track the data you seek.

Are y'all confused reading all above "explanations"? You should.

Comparing kWh (kilowatthours) to kW (kiloWatts) is even worse than apples to oranges. I believe the question was not clear to undestand the needs of its author.

My guess is that author of the question would like to figure out what is the power of a load when it is possible to read indications of Electric Energy Meter, right?

Yes it is possible but....

You need to know more about the load.

For a single appliamce, for example a heater, which draws the constant power from the electric sytem you may note: (a) number of the kWh hours & (b) time of meter observation. Example:

at 11:22:00 meter indicated 100032.6

at 11:55:30 meter indicated 100021.0

so: in 33 min 30 sec the load "consumed" 11.6 kWh (difference in readings)

Because energy unit uses h (=hours) you must conver minutes and seconds to fraction of an hour: 33.5 min / (60 min/ hour) = 0.5833 h

Power = Energy / time so Power = 11.6 kWh/ 0,5833 h= 20.78 kW,

now, if the load is connected to the power source (system) for entire 33.5 minutes its average power is 20.78 kW. In this case the load average power = its maximum power = its minimum power (constant in 33.5 min).

In the case of multiple loads this methods will calculate only Average Power. Max and min powers could be different (Pmax > Pavg and Pmin < Pavg). In this case engineers install power recorders or other indicators.

Reading again all answers you will find some useful tips. But again DO NOT think kWh = kW when you just see numbers (without units) from the meters.

Hi: I read frequently many questions deling with conversion units, altough in this question there is a conceptual error.

I advice to use the soft Uconeer, from http://www.katmarsoftware.com. Really a good conversion unit for engineers. Another conversion soft, not so complete as the first, is available at http://www.joshmadison.com/software.

Best regards and happy new year!!

Gabriel, Buenos Aires, Argentina

Typically, just posing the conversion as a question to Google will unearth a number of conversion sites.

The big caveat here though is that layman are not alone in having trouble with unit conversions / dimensional analysis, errors abound in reference literature and calculations of all kinds. I am not saying the online conversions are in error, rather that we may unwittingly be ...... the garbage in-garbage out "thing".

The conversion here is about as simple as they get and observe all the attention it has received. The terms power and energy typically sharing the same units, each have a range of meanings and /or nuances. Pay careful attention to the units and context rather than just the terms themselves and, as in this posting's example, whether time is consistently factored in (or out).

If going between SI units and one of the variations (unfortunately there are a number of them) of the English or American "systems" (a misnomer if ever there was one) you run the risk of opening up a real can of worms especially if you need very accurate conversions. In chained calculations this is a major pain as any engineering or physics student will tell you and that doesn't take into account the variety of values that may exist for the same named term in the "english" system.

You can convert kilograms to pounds and vice versa very easily, right? Well its not that simple because a kilogram is the SI unit for mass and the pound can be the "English" unit of force (lbf). Their unit for mass can be the slug (approx. 32.2 lbm) or the pound (lbm). So you will see the terms lbm (pound- mass) or lbf (pound- force) and don't confuse lbf with lb*ft or ft*lb (torque) or with ft*lb (energy or work). Read the link:

http://en.wikipedia.org/wiki/Slug_(mass)

Starting to get the picture? We, (the American Engineering community) should be pushing for the immediate and complete adoption of the SI system not only to join the rest of the world, but to eliminate the effort, confusion and errors from converting back and forth. Everyday we see the adoption or use of more and more SI units but at the present rate of change it will be many, many years before a complete conversion. If it is pushed, we could be there in perhaps 10 years. Meanwhile, increasingly our units are being defined in terms of SI units, and a definition is exact while a conversion may or may not be. The best example is the inch. This has a number of meanings depending on context and profession but the international inch which is the common one and the one used by engineers and scientists equals .0254 meters by DEFINITION (there are no strung out decimals).

http://en.wikipedia.org/wiki/United_States_customary_units#Units_of_length

That also means that whenever the meter is redefined to a more accurate and repeatable measure, the (international) inch and all other units which are multiples of it are also.

http://www.mel.nist.gov/div821/museum/timeline.htm

The inverse, "39.37" inches to a meter ONLY strictly applies to the U.S. survey inch- not in common usage. If 3 place decimal accuracy is ok, you can use the 39.37 value but otherwise not.

I apologize to those who feel I am splitting hairs but overall this is an important issue and comments are welcome.

Greg,

The foot, inch, lbs and such are much older by perhaps 5000 years than the French invention called the meter. The meter offers nothing more than what the English system does, and in fact the English system, as you alluded to, makes a person actually think. The lbm is a convenience. You just need to put it in a mass (slug) and acceleration system and they are the same other than the standards.

The Meter was invented by the French based on an arc length from the pole passing threw Dunkirk France to the equator, divided by 10 million. Anybody who is awake would never base a linear standard on a curved path of really unknown shape through a well-known French town, just like the French did. The metre' was then later set to a scientific standard, which could also be done for the inch just as easily.

The Inch is 1/25 th of a Sacred Cubit, not to be confused with several other cubits in use. The Sacred Cubit was the same cubit Noah (Angle Gabriel for those into angelic visitations) used to build the big boat. The sacred cubit was 1/10 millionth of the mean radius of the Planet, something that is derived by a vehicle in orbit, such as a Satellite. Hmm. Notice that it is the longest length possible on this planet and it characterizes Earth. The top of the Giza Pyramid is that mean radius.

The reason for using Meter over inch is to eliminate God from the discussion, not to make it easier, since there is NO difference when you use slug. The Inch requires you to assume an extra earthly being, and the meter does not. It is the same agenda that says that evolution eliminates God as the motive, which it does not. God uses evolution, however it works (another discussion), and evolution does not eliminate God, which is always implied in the discussion, as in we evolved from X without God.

I prefer to use the inch because a meter is way to large for most common things. A Foot is, well, the length of my foot (size 12) and is easy to proportion to my body in the design of airplanes, cars and such. The inch is also the ancient way of measuring and most old structures were multiples of it (inch or cubit) and ancients like to use numerology in a lot of things to code meaning. An inch and foot relationship is by 12, and 12 is a great number for easy division without a calculator.

Last but not least, I like the USA using inch because it pisses off the rest of the world and makes the French extra crazy. You know they are copying an invention if the size is a multiple of an inch translated to meters.

Bah, Humbug!

And, you gave away why when you brought religion into it.

"The inch requires you to assume an extra earthly being" Hey! I assume them anyway (alien life forms that is) but PLUH_EEEEEZ , connecting the inch to "angels"? Just when I thought I had heard it all.

Religion lies outside the realm of science and therefore your personal belief system HAS NO PLACE in an engineering discussion. And, BTW, I do believe in "God" and I in no way think that evolution implies he doesn't exist and while I have unfortunately heard it used as an argument against "God", it was rarely and trivial when compared to the bombast from the creationists. Science and religion are two entirely different things, and should not be confused with each other. My religious side may tell me that the quest for scientific knowledge is in many ways a means of understanding "God's" work but that has no bearing on what that quest may turn up. (To others: Please excuse me for introducing my belief system and getting a bit carried away, but I felt compelled to reply.)

Yes the inch could be defined differently but who in their right mind would want to do it except maybe you since the entire rest of the developed world uses the SI system (we adopted it also, just never made a full transition) and there are reasons for this that have nothing to do with the denial of your "God". Reasons which you fail to grasp and I will not bother to enlighten you but if you ever worked with English engineering units in today's world you would understand a small part of it. On second thought, maybe you wouldn't.

http://www.unc.edu/~rowlett/units/ Says in part:

"What countries besides the U.S. have not adopted the metric system?
Many U.S. teachers think the answer is "Liberia and Burma" (make that Myanmar). Let's give Liberia and Myanmar a break! All countries have adopted the metric system, including the U.S., and most countries (but not the U.S.) have taken steps to eliminate most uses of traditional measurements. However, in nearly all countries people still use traditional units sometimes, at least in colloquial expressions. Becoming metric is not a one-time event that has either happened or not. It is a process that happens over time. Every country is somewhere in this process of going metric, some much further along than others."

The metric system became the SI (System Internationale) with the codification of standards and definitions along with simplifications that were adopted internationally.

http://lamar.colostate.edu/~hillger/origin.html

I do mourn the loss of the inch in some ways but then I've been around long enough to mourn the passing of a lot of things ... and the SI system is at least well defined, consistent and logical. In any case, movement to the SI system is inevitable so pick a battle you might win.... or, tilt at windmills if you choose ... they might just be Godless dragons in your scheme of things.

Why even come here when you can learn everything you will ever need to know from reading the Bible? I am in no way putting down the Bible, merely calling attention to the fact that it is a religious work rather than a scientific one.

Yes, yes, its all part of the secular conspiracy ... and maybe there is more to the pyramids than science currently accepts and maybe not but let's stick to science here.

Let's see: 12 inches equals a foot, 3 feet or 36 inches equal a yard, 5280 feet equal a mile .. and these are just the most common units of length. Quick: how many inches in a mile? I can tell you how many millimeters (centimeters or whatever) in a kilometer as fast as I can write it just by moving a decimal point and adding zeros .. how much easier can it get? But then nothing you said made sense: even the proportionality of the foot to our bodies .... you ever consider that a big part of that is because you grew up with the inch and foot and therefore it is very familiar and "comfortable"? If God intended me to use my foot as a measure wouldn't they all be the same size .. and have divisions on them?

http://www.unc.edu/~rowlett/units/custom.html

Last but not least you are actually worried about the french copying things when so much of what we buy is made in the East? The inch is starting to piss me off when I work on a car, or I design something and I have to use parts that are metric when the rest of the machine is in inches. If any foriegn country buys a machine on the international market, and its made anywhere but here they will already have the tools they need .. They buy American and suddenly they need new tools .. that does wonders for our exports and jobs. Meanwhile, my own tool box is almost twice the size it should be. Enough!

God? did I hear Someone saying God?

Here's cadman's way of resolving like problems:(AKA "the cadman theorem")

KW=power, God=power, Power=power, or God=KW using cadman's formula, KW=3.599KW/H → God=3.599KW/H. " I once was blind , but now I see"

Isn't it just so much simpler dividing or multiplying by 10 or just moving a decimal point?

It reminds me a story I was told many many years ago.

There were four engineers always engaged in some form of engineering discussion, and they are always three against one. But this one is sure he is right, and in most cases he really was. One day he had it. He KNEW he is right, and having no other solution he calls upon God, and says: God almighty, Please help me and give these jerks a sign, to show them that I AM right. Suddenly in a perfectly sunny day with blue skies, a big black cloud rolls in and hangs over them. "You see?" he says, "You see?" "What?" they say, "a cloud in the sky? what so special about that?". "GOD," he says, "Please help me, they are not convinced!" suddenly there is another cloud hanging over them, even bigger, and even darker. "You see now?" he says, "What?" they say, "another cloud?, so what." the engineer totally frustrated calls upon God. "God You must give them the ultimate sign, please God!" From the four winds there are now four huge big and dark clouds, forming a gigantic ring, with bright light above it, and a roaring deep voice comes from within:

"HE IS RIGHT!"

"You see now? what more do you want? If this is not enough for you, than I don't know what else do you need!"

"So what?" they say, "He can say whatever he wants," say the three engineers, "you are still in a minority."

Wangito.

you spelled although wrong

What do you want to know?

Such vague questions will bring you stupid answers such as the one from cadman. (I seriously hope that he knows about the things he does 4 Christ, a little bit More than he knows electricity.)

Reading your question again and again, it seems to me that what you are trying to figure out is how much is the total power that each of your loads consumed during one year, or in other words, how much did you spend to operate each one of them during one year. If this is it, than you will need to install an elapsed time meter on each one of the different loads, know the load size, and have your electricity bills, and take it from there. No direct conversion is available.

The girl at the DMV told me: "Sir, you want a nice photo on your driver's license? than please bring a nice face."

And if it was you at the DMV office, she would probably tell you: "Want an intelligent and clear, answer, make an intelligent and clear question."

Wangito.

1 kWh = 1000 Wh = 1000 W * 1 h = 1000 W * 3600 s = 3600000 J = 3.6 MJ .

If you have x energy in kWh unit /s, you have to devide by time ( 1 h ) and find out

the active power in kW unit /s .

1 J = 1 kWh / 3600000 .

x kWh / ( 3600 s ) = x kW =

= x kWh / ( 1 h ) = x * 1000 W .

x is any real number.

Energy - Work unit /s ( kWh , Wh , J , kJ , N * m , kg * m² / s² , cal ) devided by time gives active power unit /s ( kW , W , N * m / s , kg * m² / s³ ).

In other words power gives the rhythm of energy transfer by time.

Excuse me if it's silly or stupid.

From Guest # 12: As a professional rotating equipment engineer working for a major oil company I am a little embarrassed at the low road some have taken with 'name calling' replies. Forums should be a place that encourages questions, not judgments of intelligence. Shame shame.

Let's try to get inside the head of the good Dr. and assume why he (to avoid using he/she only, sorry) wants the info. I am guessing our Dr. is trying to see a load profile by simply using the only thing he has in hand, that being an invoice in kWh. Perhaps he wants the load profile to determine high consumers in order to make one / two machines or loads more efficient (or to eliminate them), or, like I do, to buy a generator to base load or supplement loads to reduce my bill (and therefore to know what size generator to buy).

For the good Dr.: Unfortunately, my friend, it is not practical to use kWh to successfully back into "connected load" in terms of size of the connected load. Example: A connected load of 1000 watts (size of load Example A) for 1 hour duration = 1 kWh (Result answer X). A connected load of 1 watt (size of load Example B) for 1000 hours duration = 1 kWh (Result answer X). A connected load of 10,000 watts (size of load Example C) for 0.1 hour = 1 kWh (Result answer X). You can now see that the result answers of X are all the same yet the load examples (A,B,C) vary greatly.

You will need to connect an instrument that records load over time to your power supply and see the connected load profile for the given period of time you desire; one hour? One Day? One Week? etc. Some upper end multimeters have a basic recording function (the highest value achieved during the period it is connected) and you can use a clamp on ammeter to determine basic connected load (in amps only, not in power of watts . . . . that is for another looooong forum reply).

Cheers

To Guest #13 who apparently thought he was #12:

My you are in a friendly mood today!

Please don't feel embarrassed over the name calling. It wasn't you who called anyone names.

Whether we like the posts or not, it is a forum, and as such collectively belongs to whoever chooses to take the time to post here.

Take the time to register and join us ... we need more like you.

From guest #13 AKA 12 but really # 3 and now # 4

I have joined, I just didn't find the place on the site to make my handle yet and as I am sneaking in checking my computer while on Holiday . . . I limit my "Wrath of wife" exposure time by keeping a love letter to her on a Word Document and swapping between that document and other windows when I hear her footsteps. She says "What are you working on now?" and looks over my shoulder and sees the love letter and I get 1547 brownie points instead of a spanking. The problem is that I finally needed to print the love letter and give it to her . . . . and I got a little a little mixed up . . . so now she has 15 ways to convert kWh to "Connected Load" and I don't have the guts to tell her it can't be done anyway. Let's just let her enjoy my deep love with all these formulas. So far she figures I love her about 2587 kilojoules per furlong. She is not sure how much that is, but I made it another day!

As to my # 12 / # 13 confusion I actually had no idea which "Guest" reply I would be so I just pulled a unique guest name out of the air. I didn't notice posting numbers off to the right. I assume I am guest #12 somewhere in the world. My embarrassment in on behalf of "engineers" so we don't get put in a category of proving how smart we are at the expense of good manners and finding different ways to help without demeaning to encourage Dr. S to continue to post inside the safety blanket of ethics and morals with fellow 'friends'.

Now I need a cute signature 'saying' like most have on here. I am torn between these two that I have told people for years:

1) Always take two checked bags to the airport, one totally empty labeled on the outside in big letters "You can loose this one". Your chances improve that you full bag will arrive.

2) Install 4 dead locks on your front door but only lock 3. Thieves picking the locks will always be locking at least one.

x ( load ) = 1 kW <=> x * 36 s = x * 0.01 kWh <=>

<=> x * 360 s = x * 6 min = x *0.1 kWh <=>

<=> x * 3600 s = x * 1 h = x kWh .

The load remains the same. All that changes is time and energy - work.

To convert kWh to kW you only need the time you spend ( 1 year ) for the z kWh and conclude to the much - desired x kW.

z kwh ( the energy - work ) = x kWy ( the energy - work ) <=>

<=> z kWh / 1 y = x kW <=> z kW / 365.25 / 24 = ( z / 8766 ) kW = x kW <=>

<=> 114.077 mW * z = x kW .

x, z are real numbers, any other number does not have absolute exactness.

z is being reffered for the given number of kWh in a whole year,

and x for the active power or load in kW.

I know the things I know, I know the things I don't know,

so I know everything.

I know to forget and forget the above, so I 'm knowing and learning new things every day.

But it seems to me that I 'm not managent to do it right,

and I'm dead, alive in my grave, I 've nowhere to go, except where ever my legs take me, in my grave. Why am I dead in my life? I want to die and die again without ever being alive. Feel free to kill my dying death, the undead, who wants to live for life. Tough thing to want to cry and not be able to do it.

It simple. Calculate the connected load and how much time it is used KWh=Load in KW x time in hour eg if 1KW is used for 1Hour then the Energy is 1KWhr ie 1unit

Sreenath asks;

"... the conversion of KWh to KW -- can we retrieve connected load details from KWh of electricity consumed in a year."

I can give two unhelpful answers: 1) Yes. 2) Delete 'h'

But slightly more helpful perhaps, 'h' is 'deleted' by dividing by time. In this case h is a 'year'. You will then have the average load - kW (of all the individual loads connected). Not that this is very helpful. Here's why:

Assume for example that you have loads of A,B,C,D and so on. Assume that each load is connected for a duration of time = Ta,Tb,Tc,Td and so on.

You multiply each load by it's own time and then you add all these together to get the annual total.

Starting with the known total you dismantle it to arrive back at A, B, C etc, and Ta, Tb, Tc etc.

Now you see the problem! Quite a tall order.

It is like the chap who was lost, when asking for help, was told "It would be easier to give directions if you didn't start from here".

HORACE40......................READ POST #4

I think you are asking that if we have the Utility bills showing energy consumption for certain time periods, can we use that information to determine the connected load. I would think that one would have to have a model for that particular type of facility (such as DOE-2). From the model, you would derive the typical annual energy consumption and would know what all the contributing loads are, and therefore could calculated average load factor.

Years back, I was trying to come up with demand limiting strategies. Facilities that used electricity to heat water for space heating were a real challenge. They would typically have several times the connected electric capacity as their peak demand charge would indicate. For example, a facility might have 1,200 kW of just electric boilers (not including lights, pumps, plug loads etc), but have a monthly peak demand charge of only 700 kW.

Dr.Sreenath wrote: "I am interested to know the conversion of KWh to KW ie procedure to work back connected load in KW from KWh ie Can we retrieve connected load details from KWh of electricity consumed in a year."

-----------

kWh is to distance as kW is to speed. kWh is the energy transferred (say, to a load) whilst kW is the rate at which energy is transferred. Three examples:

Assume a 1000-watt load runs for 10 hours a day. Each day the load consumes 1 kW * 10 hours = 10 kWh of energy.

Assume a second, 10,000-watt load runs for 1 hour a day. Each day the load consumes 10 kW * 1 hour = 10 kWh of energy.

Assume a third, 100,000-watt load runs for 6 minutes a day. Each day the load consumes 100 kW * 0.1 hour = 10 kWh of energy.

etc.

Each load consumes the same amount of energy every day even though the rate of consumption varies by an order of magnitude between loads.

kWh refers only to the energy consumed, but nothing about the rate at which it is consumed. As we've seen, your annual kWh consumption could just as easily be due to a large load which runs for only a few seconds a year as a small load which runs continuously throughout the year. Moreover, the actual power used by a real-life load (say a large manufacturing plant), can vary considerably in less than the duration of an A.C. cycle. A kWh figure says nothing of these variations, of course.

You could use your annual kWh figure to calculate your average load in kW (if you wish) by dividing your annual kWh figure by the number of hours in a year. Such calculations speak only of average rates, however. Perhaps this is your objective?

-e

Thanks for the reply.This appears to be the ans for my question.

Sreenath

You're welcome!

-e

Thats very clever of yours. Did you thought it all by your self?

I admire you. All my girlfriends wanna be with you.

My love.

{:*

{:()~

And your friend Dr. he is one piece, but what piece!!!? UNIQUE - ONE OF THE KIND .-

Can # 13 get any of your girlfriends, please, for more / less the same answer? Keep in mind that by comparison to you, I will improve your relationship with them as I am quite ugly, fat and bald.

The below are unnecessary for the ones who don't read because just like that.

Can't say if your male or female. Every one speaks for himself and with this way to become as he/she really is in the essence of life (meaning to lay out ones and while with the thing that trabling the mind of 'em (both sacrificers and victims are both enviroment with self)) and realize that he is a victim of parents, a thing, can't be seperated from anything.

Speaking just to speak. Can't let myself say more in order to except and undo what ever.

Don't mean a thing more.

Few replies I made.

I'm dead.- See more tommorow. Don't have a girlfriend. Please kill me. Can't die.--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------.-.-.-.-.-.-.-.-.----------------------------.-.-.-.-.-.-.-.-.-.-.----------...............

What a vitriolic thread this is!

-e

Isn't it!

Questioner should himself call it" STOP ! ENOUGH !--"

And go back to attend high School again-and get TIME, LIFE, POWER, ENERGY ----cleared up!

Amen.

HELLO, Great forum! Just came across when I was Google (ing) conversion of KWh to kW/MW. What I really need to know is if an alternative energy system produces 108 MW of power per annum, how many kWh would that convert to? (If at all posssible) The local utility charges .099880/kWh Trying to figure $ value of 108 mW to calculate solar system payback. Thanks -John

MW = 1000KW -- 108,000KW

365 DAY/YR X 24 HR/DAY = 8760 HR.

TOT KW / TOT HRS = KW/HR

Yuo figure from here...............................

_______________________________________________________________________

When I ponder, I sits and thinks, sometimes I just sits.

108MW=108,000KW

again confused- you produce MWs continuously (energy) not per annum. Per annum you produce KWH, MWH etc

Now @108MW- on solar system - let me assume you produce power 8hrs/day - average

then per day it is 108,000x8 KWH

then let us say it is for average 300 days per year - let us leave out the cyclones, rains etc - depending on where you are

then it is 108,000x8x300x0.099880 = $25888.896 / year

does it pay back ?

I don't think at this level of technology, as yet

Duh

dear engineers how asking why you need to change from KWh to KW

i do have the same qustion because i have anly reading KWH and i want to size

power factor correcton bank and i have Qbank= (Power KW )* ( tanq ( needed ) - tanq ( actual )

so some times you want just to have the avarge look to the power

A kilowatt-hour (kWh) is the standard unit for measuring energy.

Kwh is a total accumulated power expressed as a rate of power consumption equaling 1000 watts expanded for one hour. Kwh = power x time.

kWh is the energy transferred (say, to a load) whilst kW is the rate at which energy is transferred.

Kilowatt-hours is analogous to distance; kilowatts is analogous to speed.

Examples of 1 Kwh:

a 100 watt bulb illuminated for 10 hours

a 1000 watt bulb illuminated for one hour.

a 1 watt bulb illuminated for 1000 hours.

a 25 watt bulb illuminated for 40 hours

So to convert kwh energy to the kw power rate is imposible unless you assume the power rate is constant for the whole period and you know the period over which that power was applied. A light bulb might consume power at a constant rate but most other applications does not. Its like wind direction, it changes. Then to know the period t over which this power rate was applied.

Hensi van Staden

South Africa

Is it possible to convert $/KW to $/KWh??

$/Kw is Possible-- for Statistical Investment Planning .Ask IEEE Inc.

$/kW-Hr -- ASK YOUR LOCAL UTILITY.

Both will give up and ask you to visit this CR4 blog ---if you ask them:

-- "Can we convert you both"?

mm

A related question: Suppose I know that a household's energy consumption is about 20 Kwh/month and there are 20 households in a town. Now I want to supply electricity to this town and I want know : What capacity power plant should I install ? Assume the capacity factor of the power plant is 11%.

Even to make an "Inspired Guess" one needs to know these:

Latitude&Logitude&elevation.

Economic Condition of residents-- do they remain home most of the day--or go out to work most weekdays.

No. of families living in this community.

mm

i know it passed 1 year, but some may find this and may have doubts too..

...............

20kWh x 20 houses= 400kWh

Lets think that it should be working 24h a day

So:

400kWh/24=~16.66kW <- this is the power plant capacity

By 11% I understand efficiency.

This means that it will be 16.66/0.11=151.45kW

The power plant should have at least 151.45kW of power. (it will only use 11% of that capacity which is 16.66kW)

I found this thread because I'm trying to figure what size back-up generator I'd need to meet all my electrical needs on peak day, and was wondering if there is a rule of thumb for estimating the needed capacity from my electric bill, which shows only kWh. This may be the wrong forum for such informtion, however.

1kWh means 1kW was used for an hour

233kWh means 233kW was used for an hour

etc..

why is the conversion required???