Total Solar Irradiance: Recalculated by N. Scafetta
Posted by jennifer, August 20th, 2009 - under News, Opinion.
Tags: Climate & Climate Change
THE popular view on global warming is that the sun has had a negligible influence on climate – at least over the last few decades compared to carbon dioxide. But taking into account the entire range of possible total solar irradiance (TSI) satellite composite since 1980, Nicola Scafetta, just published in Journal of Atmospheric and Solar-Terrestrial Physics, concludes that the solar contribution to climate change could range from a slight cooling to a significant warming, as large as 65% of the total observed global warming.
Here’s a short extract suggesting the science is far from settled:
“DETERMING how solar activity has changed on decadal and secular scales is necessary to estimate the solar contribution to climate change. Unfortunately, how solar activity has changed in time is not known with certainty.
“Direct TSI observations started in 1978 with satellite measurements. For the period before 1978 only TSI proxy reconstructions have been proposed. These TSI proxy models significantly differ from each other, in particular about the amplitude of the secular trends.
“Unfortunately, TSI satellite composites since 1978 are not certain either. Two major composites have been proposed: the PMOD TSI composite which shows an almost constant trend from 1980 to 2000; and the ACRIM TSI composite which shows an increasing trend during the same period. GCMs and EBMs adopted by the IPCC (2007) assumed that TSI did not change significantly since 1950 and that, consequently, the sun could not be responsible for the significant warming observed since 1975.
“These estimates are based on TSI proxy models such as those prepared by Lean (2000) and Wang et al. (2005) which are apparently supported by PMOD. However, the above TSI proxy models would be erroneous if the ACRIM TSI composite more faithfully reproduces the TSI behavior during the last decades. The ACRIM-PMOD controversy is quite complex and, herein, a detailed discussion on this topic is not possible.
“A recent work by Scafetta and Willson (2009) reopened the issue by providing a careful analysis of the most recent TSI proxy model (Krivova et al., 2007) based on magnetic surface fluxes. This has been done by establishing that a significant degradation of ERBE TSI satellite likely occurred during the ACRIM-gap (1989–1992.5), as the ACRIM team has always claimed. Moreover, Scafetta and Willson invalidated the specific corrections to Nimbus7 that the PMOD TSI composite requires and confirm the opinion of the original Nimbus7 experimental team that no sudden increase of the Nimbus7 sensitivity occurred on September 29, 1989 (see Hoyt’s statement in Scafetta and Willson, 2009). Finally, Scafetta and Willson (2009) showed that the agreement between PMOD and the proxy reconstruction about the absence of a trend between the TSI minima in 1986 and 1996 is coincidental because a careful comparison between the proxy model and the unquestioned satellite data before and after the ACRIM-gap proves that the TSI proxy model by Krivova et al. (2007) is missing an upward trend…
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Notes and Links
Empirical analysis of the solar contribution to global mean air surface temperature change. Journal of Atmospheric and Solar-Terrestrial Physics (2009), doi:10.1016/j.jastp.2009.07.007 By Nicola Scafetta, Department of Physics, Duke University, Durham, NC 27708, USA
Abstract
The solar contribution to global mean air surface temperature change is analyzed by using an empirical bi-scale climate model characterized by both fast and slow characteristic time responses to solar forcing. Since 1980 the solar contribution to climate change is uncertain because of the severe uncertainty of the total solar irradiance satellite composites. The sun may have caused from a slight cooling, if PMOD TSI composite is used, to a significant warming (up to 65% of the total observed warming) if ACRIM, or other TSI composites are used. The model is calibrated only on the empirical 11-year solar cycle signature on the instrumental global surface temperature since 1980. The model reconstructs the major temperature patterns covering 400 years of solar induced temperature changes, as shown in recent paleoclimate global temperature records.
The photograph of the sun was taken from Lammermoor Beach, Central Queensland, last week by Jennifer Marohasy.
Nick Stokes “Watts per hour, watts per day, are equally nonsensical units. Such juvenile mistakes do not encourage readers to delve into your harebrained cosmic speculations”.
The standard term is watt-hour (or kilowatt-hour), which the electrical utility uses to charge you for your electrical consumption. It’s the number of watts of electrical ‘energy’ you consume in an hour, so what’s so hard to understand about watts per hour?
Power = EI = voltage x current. The voltage is generally held constant, with alternating voltage having an equivalent direct voltage called the RMS, or root mean square voltage. In North America, we use 120 volts AC. So, if I’m driving a 100 watt light bulb, I am delivering 120 volts @ 0.83 amps. That only tells you the number of charges flowing per second at a fixed voltage, or the rate of work being done.
None of this tells you what the total energy expended is in one hour. The time factor comes in when you calculate the ‘energy’ used over a time frame, which is watts x time. Energy has a time component but power is a rate of doing work.
Energy is measured in watt-hours or kilowatt-hours which is pretty much the same as watts per hour. I looked up the Wiki article on insolation and I think they are out to lunch with their description of power and energy. Then again, I’m just a skeptical scumbag.
Louis Hissink re permanent magnets…”But one fact is clear, to generate a magnetic field we need electricity….”
Louis…the magnetism in a permanent magnet is apparently due to the motion of the electrons about the nucleus in ferromagnetic material. In any orbiting body, there is a centripital force between the orbiting body and the focus, directed toward the focus, like someone swinging a ball of a string. The string pulls in on the ball, which is a centripital force as opposed to a centrifugal force which would point out the way.
The orbiting electrons spin on an axis, in an similar analogy to the Earth spinning on its axis. As they spin, they form a magnetic dipole which tends to add to the centripital force and oppose any external magnetic field. In ferromagnetic material, billions of atoms exist in domains in which the dipole momentums from the electrons add together. The domains are normally in a random order, but when an external magnetic field is applied, they align.
You’re right about magnetic fields requiring electricity because electrons are electricity and they cause the magnetic dipoles that form the permanent magnet. There is a distinction, however, between charges acting as point charges and those under the influence of an electric field, which produce ordered currents. Under those conditions, a current encountering a magnetic field will create an electromagnet.
I found it interesting that charges create an electric field but there is no equivalent magnetic charge. It is being sought but so far it’s either elusive or it isn’t there. We have a long way to go in the understanding of nature.
BTW…about the eye and light (electromagnetic wave). The only way an eye can work is if it has a water base. It has to pass light frequencies and the resistance to those frequencies increases something like 10 million times on either side of the visible light spectrum. I can’t bring myself to accept this all happened by a fluke. I am not hinting at a religious explanation, just that we have no idea what is going on or where we came from. We also have no idea how light signals get translated by the brain from an electrochemical form to a form of intelligence.
Gordon,
Thanks for that technical explanation about magnetism at the atomic scale – and indeed we know so very little!
As for human vision – Michael Talbot in his book “The Holographic Universe” described an experiment with how the mind fills in visual gaps by way of a simple visual experiment he included in the book, so my memory informs. If you can hold of it, the experiment is described on page 164, which demonstrates our visual blind spot inside the eye. So vision is essentially holographic.
I tend to follow Amit Goswami’s ideas set out in his book “The self aware Universe” in which he posits that physical reality is an epiphenomenon of consciousness, in contrast to the prevailing view that consciousness is a phenomenon derived from physical matter. By that I mean the consciousness underlying our physical organism which seems incredibly intelligent, and not the mechanics of our egos which are the products of our brain’s activities. Talbot touches on this as well, I add, and David Bohm introduced the idea of an implicate order.
I’ve also noticed the intellectual habit of assuming that electricity is electrons only, wrong! It just happens that plasma in solid matter is restricted to electrons but when matter is disassociated it’s then the motion of charged particles, and those generate magnetic fields. But then what underlying “thing” ends up producing a magnetic field when electrically charged particles move through it?
One thing I’ve always wondered about was proton spin – why do protons spin? Apart from the mundane use of that property in proton precession magnetometers, what really drives that motion?
As for electricity and magnetic fields – I’ve discovered it’s a chicken an egg conundrum – you seem not to be able to have one without the other, which leads to the philosophical conclusion that maybe the universe always existed.
But I do feel a little jealous of our AGW folk here – it must be a blessing to be so totally certain one is right.
Gordon, watts per hour does not mean power*time. Does miles per hour mean distance*time?
But even if it did, the statement was that insolation was ~670 W/m^2 per day. If you interpret that as insolation =~670 watt-days/m^2, then what on earth does that mean?
Nick Stokes,
Isn’t this getting into a terminological mess?
If insolation ~ 670 watts/m^2 per day simply means that over 24 hours the amount of radiation the Earth receives over a square area of 1 meter is 670 watts. What else could it mean.
Nick Stokes,
I think I see what you are getting to – the Watt is defined in SI terms as 1 joule per second of time.
So 670 watts in terms of insolation are the emission of radiant energy of 670 joules per second.
So the statement of 670 watts/m^2 per day is somewhat tautological, to say the least.
So you are right, it’s a bloody nonsense as AGW was in the first place.
Comment from: Louis Hissink August 23rd, 2009 at 6:58 pm
Nick Stokes,
I think I see what you are getting to – the Watt is defined in SI terms as 1 joule per second of time.
So 670 watts in terms of insolation are the emission of radiant energy of 670 joules per second.
So the statement of 670 watts/m^2 per day is somewhat tautological, to say the least.
So you are right, it’s a bloody nonsense as AGW was in the first place.
Dear Louis,
Nick also said it was futile to write kWh/m^2 per day. However, we have to make the distinction with respecti to kW alone because we are considering total radiation energy.
1 kWh = 3600 J These are units of energy
1kW = 1 J/s These are units of power.
So we must write kWh.
I made a mistake. It should have said:
“1 kWh = 3600 <bkJ These are units of energy
1kW = 1 J/s These are units of power.”
OK! And when expressing total incident solar radiation energy on one square meter during one day, we must write it as follows:
kWh/m^2/day.
Then it is absolutely essential that we express energy in kWh units so that the expression is not considered as power. Writing only kW (dropping the unit hour) is a tremendous lack of knowledge of physics.
OK… Now that we have clarified that it is correct to express insolation in units of “kWh/m^2 per day”, the next step is that Nick Stokes must to support scientifically what he wrote in his post above:
“Such juvenile mistakes do not encourage readers to delve into your harebrained cosmic speculations.
Nick Stokes “Gordon, watts per hour does not mean power*time. Does miles per hour mean distance*time?”
I realize the term watts/hour is fundamentally incorrect but I think the implication should be fairly easily understood. When we say miles per hour, we are usually refering to distance in the numerator with time in the denominator. A watt-hour, on the other hand, has both in the numerator. Something per something only refers to a numerator/denominator setup.
An electrical watt is the amount of work done by those electrons to produce the heat/light we relate to a light bulb. Electrical energy is defined as power x time, and there is no denominator, therefore we say watt-hour rather than watts/hour. I don’t see what is wrong with using the latter, however, even though it is technically wrong.
WRT insolation, it seems they are only adding units of area to express a flux density. I get a little frustrated with the math, not because I dislike math or don’t appreciate it, rather, I find that math sometimes gets in the way of what is being said. When you come down to it, what is it they are saying? You have a mass of atoms making up a surface and they have been agitated by solar radiation. In their excited state, they radiate their own energy which interferes with the energy that excited them, producing interference patterns. None of that is talked about or regarded by the equations. What does it all mean?
Nasif, yes, kW-hr/m2 per day is a feasible unit. Not a very sensible one, though, unless you are thinking about solar power for electricity. 1 kW-hr per day is just a roundabout way of saying 1/24 kW. And I’m sure it isn’t what you meant by “The fact is that here, in Monterrey, we have recorded ~670 W/m^2 per day of insolation.”. 670 kW-hr/m2/day is about 28,000 W/m2, which is getting to the sort of insolation you might get on Mercury. Or if you meant 670 W-hr/m2/day, that’s somewhere out beyond Jupiter.
As to the rest of my statement, well, if it can be this hard to sort out something so elementary, it doesn’t encourage me to follow you into your more fanciful speculations.
Louis Hissink “…and David Bohm introduced the idea of an implicate order”.
Bohm was one of my favourite physicists, and he and Einstein were friends. I have waded through Bohm’s implicate order theory but I was far more interested in the explorations of the human mind he did with Jiddu Krishnamurti. They make quite clear the difference between the ego-mind, which is conditioned thought, and the intelligent mind, which acts independently of conditioned thought but which can be submerged by it. The Cosmic Joke refered to in Zen seems to be that we tend to live in the distorted ego-mind, which does not work very well, yet we are oblivious to the natural intelligence available to us simply by getting the ego-mind to shut up long enough to allow the intelligence to operate.
I’m not a religious person in the traditional/orthodox sense but I can’t help thinking there was a significance to the life of Jesus Christ. I realize a lot of that is romanticized in my mind but something Thomas Didymous said about Jesus coincided with what Bohm and Krishnamurti talked abou. In some recently found scrolls, Didymous refered to Jesus as having said ‘everything we humans need in life is already within’. To me, that was a reference to the natural intelligence we are all born with.
That’s the message of Krishnamurti in a nutshell. He claims we need look no further than the intelligence available in our unconditioned minds to understand reality and our realtionship to it. He claimed further that we create images in our minds through which we filter reality. Bohm concured, and coming from a theoretical physicists of his emminence, I found that very meaningful.
Most people who go through university don’t even have a clue about how their minds work. Some scientists seem to come about that naturally, like a Bohm, an Einstein, a Pauling or a Feynman. Each one to a man has a humility about himself which suggests to me he has an awareness of ego and its stupidity. From what I am seeing today in the world with regard to scientists, there are too many who care more about their self-images and about being right than they do about science.
Thanks to Gordon Robertson at 11.31 am 23 August for advice on possible role of solar cycles on climate via magnetic effects. I think I’ve got the idea now.
Comment from: Nick Stokes August 24th, 2009 at 7:17 am
Nasif, yes, kW-hr/m2 per day is a feasible unit.
Nope… It’s the correct unit for insolation.
Not a very sensible one, though, unless you are thinking about solar power for electricity. 1 kW-hr per day is just a roundabout way of saying 1/24 kW. And I’m sure it isn’t what you meant by “The fact is that here, in Monterrey, we have recorded ~670 W/m^2 per day of insolation.”. 670 kW-hr/m2/day is about 28,000 W/m2, which is getting to the sort of insolation you might get on Mercury. Or if you meant 670 W-hr/m2/day, that’s somewhere out beyond Jupiter.
1. It’s not what I’m thinking, but what clean and good physics establishes.
2. Nope… You cannot express kWh/m^2/day like W/m^2 per day. You can convert kWh/m^2/day to kJ/m^2/day; yes, that is, energy units to energy units, power units to power units, etc. You can also convert kWh/m^2/day to BTU/ft^2/day.
As to the rest of my statement, well, if it can be this hard to sort out something so elementary, it doesn’t encourage me to follow you into your more fanciful speculations.
Good!!! So go ahead, then! Write a single word about my “fanciful speculations”.
Nasif, you just don’t read stuff properly. I didn’t say that you can “express kWh/m^2/day like W/m^2 per day”. I said “1 kW-hr per day is just a roundabout way of saying 1/24 kW”. So you can express kWh/m^2/day like W/m^2. The conversion factor is 1000/24.
And you haven’t dealt with the fact that expressed in what you now claim are the correct units, your “insolations” are ridiculously large.
What did you mean?
Comment from: Nick Stokes August 24th, 2009 at 10:07 am
Nasif, you just don’t read stuff properly. I didn’t say that you can “express kWh/m^2/day like W/m^2 per day”. I said “1 kW-hr per day is just a roundabout way of saying 1/24 kW”. So you can express kWh/m^2/day like W/m^2. The conversion factor is 1000/24.
And you haven’t dealt with the fact that expressed in what you now claim are the correct units, your “insolations” are ridiculously large.
What did you mean?
I read what you wrote:
You said: “670 kW-hr/m2/day is about 28,000 W/m2″.
You’re wrong because kW/h/m^2/day are not equivalent to W/m^2. :)
You said: “Gordon, watts per hour does not mean power*time. Does miles per hour mean distance*time?”
You’re wrong because in clean physics, Watt is power. If you write W*s, it is power per time, that is, energy. :)
You said: “Nasif “However, the units for insolation are kW h/m^2/day.” Yes. but kWh is a unit of energy. A watt is a unit of power, as is kWh/day. But I don’t think that is what you meant. 10 kWh/m2/day is a typical insolation.”
And you’re wrong because kWh/day is not expressed correctly and kWh alone is a unit of energy, not power. :)
You wrote: “And you haven’t dealt with the fact that expressed in what you now claim are the correct units, your “insolations” are ridiculously large.”
Again, you’re wrong because I wrote “670 Wh/m^2/day”. Convert 670 Wh/m^2/day to kWh/m^2/day, please?
0.67 kWh/m^2/day. Heh! :)
Mine is clean, clear and cool physics… ;)
Now, please, tell me about my “fanciful speculations”.
OK, Nasif, we’ve finally (?) got a figure. Insolation 670 Wh/m2/day.
That is 670*3600 J/m2/day, or, 670 * 3600 / (3600*24) J/m2/s
which is 27.92 W/m2.
TSI (direct solar power at TOA) is about 1364 W/m2.
No wonder your physics is cool there in Monterey!
If you’re going to tell the world’s scientists that they have their atmospheric science all wrong, and it’s all due to tunneling of hyperexcited photons or whatever, you need all the credibility you can get. If you can’t even get this elementary starting figure right, you have none.
Comment from: Nick Stokes August 24th, 2009 at 11:24 am
OK, Nasif, we’ve finally (?) got a figure. Insolation 670 Wh/m2/day.
That is 670*3600 J/m2/day, or, 670 * 3600 / (3600*24) J/m2/s
which is 27.92 W/m2.
TSI (direct solar power at TOA) is about 1364 W/m2.
No wonder your physics is cool there in Monterey!
Amazing! You keep yourself on the same errors you have made in your past posts… You cannot express insolation as “W/m^2″; this is irradiance, radiant emittance, that is, power per unit area! I am talking about insolation… Energy per unit area per unit time. Got it?
Besides, you are doing it wrong: 670 Wh/m^2/day = 2 412 kJ/m^2/day, or 0.67 kWh/m^2/day.
If you’re going to tell the world’s scientists that they have their atmospheric science all wrong, and it’s all due to tunneling of hyperexcited photons or whatever, you need all the credibility you can get. If you can’t even get this elementary starting figure right, you have none.
Is it your “scientific” argument against my assertions? It’s a very poor argument, Nick. Could you go a bit more technical and specific, please?
Do you think “tunneling” and “hyperexcited photons” don’t exist?
I don’t think the whole atmospheric science is wrong; it is just that there are some people which have “unexplainably” forgotten many real phenomena. Think for example in solar photon streams, plasma, energy stored by subsurface materials of land and oceans, total emittancy, negative induced absorption, etc. Have you heard about this “things” from AGW proponents?
With this post I’m finishing this nonsensical “dialogue” with Nick Stokes.
Nick wants to express insolation in terms of energy. Well… the energy implied in 670 Wh/m^2/day is 2412 kJ/m^2/day.
Watts is a unit of power. 1 Watt = 1 Joule / second.
1 kW = 1 kJ/second.
Watts*second (W*s) is a unit of energy and it is equal to 1 Joul.
kWh is a unit of energy and it is equal to 3600 kJoules.
Units of power per unit area, irradiance, radiant emittance, brilliance = W/m^2
(Notice that W is power, not energy).
Units of insolation are kWh/m^2/day, or Wh/m^2/day, or J/m^2/day, or kJ/m^2/day.
(Notice that kWh is unts for energy, not power)
Annual average of insolation in Monterrey = 182530.9 kJ/m^2/year = 50.7 kWh/m^2/year = 50703.03 Wh/m^2/year = 0.14 kWh/m^2/day = 140 Wh/m^2/day = 504 kJ/m^2/day.
So, 0.67 kWh/m^2/day, or 2412 kJ/m^2/day is not a “cool” August day in Monterrey, as Nick has said.
Question @Nick: Why is it so hard for you to accept real magnitudes?
A last thing:
I made a mistake in the next paragraph:
“…the energy implied in 670 Wh/m^2/day is 2412 kJ/m^2/day.”
It should have said:
“…the energy implied in 670 Wh/m^2/day is 2412 kJ.”
Soooorry… :)
So Monterrey gets average 0.14 kWh/m2/day? And 0.67 kWh/m2/day in August? Well, here is a table of data from a solar heater supplier. It doesn’t show Monterrey, but SF gets 4.89 kWh/m2/day on average, and 6.51 in August. You still haven’t got this units thing right.
Comment from: Nick Stokes August 24th, 2009 at 2:25 pm
So Monterrey gets average 0.14 kWh/m2/day? And 0.67 kWh/m2/day in August? Well, here is a table of data from a solar heater supplier. It doesn’t show Monterrey, but SF gets 4.89 kWh/m2/day on average, and 6.51 in August. You still haven’t got this units thing right.
Earth is not flat, the solar beams don’t strike on the surface completely perpendicular with respect to the horizontal surface, and the horizontal surface is not regular. Monterrey also has a very rich orography.
Nick… Divide 6.51 kWh/m^2/day by, precisely, 22 days. Got it? The daily average is 0.3 kWh/m^2/day.
Why you cannot accept real measurements? Forget your models, Nick! This is the real world!
You know what? I don’t know why I’m following your… irrational “dialogue”. I have had enough pacience with you.
Take a book of 101-Physics and learn physical units.
patience
@Nick Stokes…
Start your lessons with this one:
http://www.gcse.com/maths/averages.htm
Well, Nasif, that table I linked had about 80 places in the lower 48. The annual average varied from 3.6 kWh/m2/day to 5.5. Lots of rich orography there. Are you still telling me that Monterrey gets 0.14 kWh/m2/day? Do you have a source?
Comment from: Nick Stokes August 24th, 2009 at 3:23 pm
Well, Nasif, that table I linked had about 80 places in the lower 48. The annual average varied from 3.6 kWh/m2/day to 5.5. Lots of rich orography there. Are you still telling me that Monterrey gets 0.14 kWh/m2/day? Do you have a source?
Are you joking? Hah! The length of daylight period in Monterrey in August is about 12:50 hours! Assuming the insolation was 0.67 kWh/m^2 for each measurement during the 12:50 hours, the total insolation would have been ~ 8.7 kWh/m^2/day. However, considering the factors which modify insolation, it was 4.8 kWh/m^2/day.
You have to learn how to differentiate “total radiation received by insolation during one month” from “average daily insolation”. :)
Please, don’t tell me I have to teach you multiplication…
Ask for a source? Well, Nick, here it goes:
http://eosweb.larc.nasa.gov
Enjoy it!
:)
No, Nasif, your statement was:
Annual average of insolation in Monterrey = 182530.9 kJ/m^2/year = …= 0.14 kWh/m^2/day
Now it’s 4.8 kWh/m^2/day.. How does 0.14 become 4.8? Does /day mean /hour?
You are babbling.
Nasif,
According to Wikipedia, in SI units, 1 Watt = 1 joule/second. They seem to conflate power with energy as well, so I suspect we are obsessing over the picking of nits, rather than fundamentals.
Naturally our in house PC censors here cannot join in this nit-picking, not being credentialed in this area.
Gordon,
Jiddu Krishnamurti influenced me profoundly – and U.G. Krishnamurti even more. I was introduced to JK’s ideas as a teenager but quickly left it once I understood his point. Those who remained in the JK circle, in my view, listened to JK’s ideas but didn’t hear anything, hence the incessant repetition of JK’s teachings – and how religions come to exist, I suppose.
But today I am like U.G Krishnamurti – and I only discovered his ideas by accident a decade ago – much to the disapproval of the JK’s I know.
But as mentioned earlier, I find Goswami’s ideas useful in understanding physical reality as a starting point, (subject to the usual caveats when blatant contradictions force one to change one’s mind).
Comment from: Louis Hissink August 24th, 2009 at 8:59 pm
Nasif,
According to Wikipedia, in SI units, 1 Watt = 1 joule/second. They seem to conflate power with energy as well, so I suspect we are obsessing over the picking of nits, rather than fundamentals.
Naturally our in house PC censors here cannot join in this nit-picking, not being credentialed in this area.
You are right. Obviously, Wikipedia is confusing the terms. That’s why I decided not following the nonsensical Nick Stokes’ game, because his main source is Wikipedia; This is not a scientific dialogue, but Nick’s obsession for finding something wrong where there is nothing wrong.
@Nick… The lenght of daylight in Monterrey is 12:50 hours. You must learn multiplication.
Source of the 182530.9 kJ/m^2/year:
Manrique, Jose Angel V. Heat Transfer. 2002. Oxford University Press. England. Page 287.
Divide that number by 365 days. Notice that the units are kJ/m^2/year and I converted them to kWh/m^2/day.
You must focus on the scientific aspects of my assertion, which you say are “speculations”.
End of this nonsensical discussion.
Nick Stokes “1 kW-hr per day is just a roundabout way of saying 1/24 kW”.
Actually, it’s not. I realize that when you use parameters such as Kw and hr, they should cancel when multiplied. You seem to be saying 1 Kw-hr/24 hr = 1/24 Kw. However, it’s really 1 kw x 24 hr = 24 Kw-hr. Otherwise, the longer you applied power to a load the less it would cost, which would be great.
Also, it makes no sense that the longer you use power the smaller it gets. 1 Kw-hr is the amount of energy consumed in an hour when 1 Kw of power is supplied constantly. It only makes sense that in 24 hours the amount of energy consumed is 24 times greater.
Gordon, this is yet more nonsense. 1 kWh is 3,600,000 J. And 3,600,000 J per day is 150,000 J/hr, or 150000/3600=1000/24 J/sec
Which is 1000/24 W, or 1/24 kW.
This stuff is really elementary.
Comment from: Nick Stokes August 25th, 2009 at 6:00 pm
Gordon, this is yet more nonsense. 1 kWh is 3,600,000 J. And 3,600,000 J per day is 150,000 J/hr, or 150000/3600=1000/24 J/sec
Which is 1000/24 W, or 1/24 kW.
This stuff is really elementary.
The problem with you, Nick, is that you don’t know how to differentiate units of energy from units of power. Again:
1 kWh (energy) = 3 600 000 Joules (energy)
1W*s (energy) = 1 Joule (energy)
The concept changes when you imply area, time and period.
If you say 1 kW (dropping “h” for hour) you are no long referring to energy, but to POWER:
1 kW (power) = 1000 Joules/second (power)
1 W (power) = 1 J/second (power)
1 kWh/m^2 per day (insolation) = 3600 kJ/m^2 per day (insolation)
1 Ws/m^2 per day (insolation) = 1 J/m^2 per day (insolation)
And yes, it is elementary stuff; the problem is that you, Nick, confound physical concepts and units.
Here an excellent energy units converter:
http://www.biocab.org/Converter.html