[Stoves] ABCEG deceit and conceit (Re: Crispin, Andrew) ON THE SIDE
Crispin Pemberton-Pigott
crispinpigott at outlook.com
Thu Jan 12 16:52:13 CST 2017
Dear Ron
The problems I have with the equation applied in the WBT are:
1. The resulting number is not what it claims to be (the thermal efficiency). It is also not the energy efficiency, nor the heat transfer efficiency, nor the % of energy available from ‘missing fuel’ that was transferred to the pot.
2. It does not report a number that can be used to compare the fuel efficiency of two or more stoves, its primary function and specific claim, as applied in UN contracts, the GACC contracts, as well as the CDM and Gold Standard methodologies. Relative fuel consumption in those projects are all calculated incorrectly.
3. Producing char (or not) is not a cooking task and does not enter its efficiency rating. Anything that interferes with the energy in the denominator misleads the reader as to the product’s cooking performance.
4. The energy content of recovered char is not the same number as the energy ‘not used for cooking’. It is a portion of the ‘not used’ number. In short, if the stove made a lot of small ‘unrecoverable bits of char’ the energy in the recoverable char is significantly less than the energy in the residual solids. Subtracting the energy ‘not released by burning’ from the total energy available in the fuel fed in, would give a close approximation of the heat transfer efficiency (the error being partially combusted gases). But that is not what is happens with the WBT formula. Only a portion of the energy in the solid residue is subtracted – the ‘recoverable portion’. Well, who says what is recoverable and what is not? Opinions differ. And, after making this subtraction, what is the proper description of the result of the calculation? It describes no standard reporting metric of thermal performance. It is just a number. It is not even a useful number.
5. Users of the WBT have, for years, been led to believe that it represents the fuel consumption and that comparing the two ‘WBT efficiency’ numbers from two stoves will show the comparative fuel savings by using the formula
(1-(Stove 1/Stove2))*100%
The answer is the fuel saved in % (or increase). The answer is only correct if the energy in remnant char. Recoverable or not, is not subtracted from the denominator.
Using the WBT ‘thermal efficiency’ numbers, it gives the wrong answer. The fuel use is under-reported. The reason it gives the wrong answer is because it makes the calculation incorrectly. Mathematically, the method employed treats the recoverable portion of the remnant char as if it is unburned raw fuel.
The End
It is junk science and always was. It is an error introduced in 1985 by VITA against the objections of Feu do Bois and Eindhoven University. Upon review in 1991 (Rani et al) it was rejected as a calculation by the government of India. Good for them.
I do not care how much people have invested in this WBT test. It lies. It is fatally flawed. It doesn’t give an answer people can believe. It has no place at the table. It has to go. It is cheating people out of their investments in stove programmes. Everything based on it is fundamentally flawed – all decisions, all ratings, all money spent and wasted – and Lord knows there has been enough of that.
Ron: If you want to report something about the char, use conventional methods and metrics, don’t piggy-back on junk science from Berkeley. So they made a mistake. Fine. Get over it. Extending the deception will not help anyone. At this very moment it is deceiving the UN which is purchasing 10,000 stoves for refugees that will not live up to their performance ratings – because, and only because, they were tested using the WBT 4.2.3 and its defective spreadsheet v4.2.4 (Don’t ask me why the numbers don’t match – it doesn’t matter.)
Char production is a function of the mass in and mass produced, expressed as a %. It also has an energy content. Fine. Report it. The downstream uses of char from char-making stoves do not affect in any way the cooking efficiency which is a measure of the fuel needed to conduct a cooking session.
It is pointless to try to convince us who are working in the field and spending other people’s money to report that a stove using 1.3 kg per of dry fuel cooking cycle uses 650 g ‘because it makes char’. I do not care what type of fuel is going in – if it takes 1.3 kg per time, then the fuel consumption will be reported to be 1.3 kg, efficiency x. If it produces 400 g of char doing so, and you want to report it, the report can say: dry fuel consumption is 1.3 kg per replication; char produced 400 g per 1.3 kg of fuel (31%); cooking efficiency x. There is no free lunch.
There is nothing wrong with reporting the fuel consumption of a stove. There is nothing wrong with reporting the mass or energy of char produced. There is a lot wrong with subtracting any number from the mass of fuel in the denominator representing the fuel needed to perform the cooking task. That is called ‘cheating’.
I have already reported on this list a method for calculating the performance of a pair of stoves like that produced by Dr Nurhuda wherein the second uses the char produced by the first as its input fuel. Any such evaluation can produce the correct answer for the system efficiency of the pair only by correctly calculation the performance of the first stove, which means avoiding the WBT thermal efficiency formula. This is a matter of science, not opinion.
Regards
Crispin
From: Ronal W. Larson [mailto:rongretlarson at comcast.net]
Sent: 12-Jan-17 17:08
To: Discussion of biomass <stoves at lists.bioenergylists.org>; Crispin Pemberton-Pigott <crispinpigott at outlook.com>
Cc: miata98 at gmail.com
Subject: Re: [Stoves] ABCEG deceit and conceit (Re: Crispin, Andrew) ON THE SIDE
List,
This exchange below has reminded me that Crispin and I have not closed the loop on an important stove reporting equation of the form e3 = e1 / (1- e2). About half way down in this message, Crispins says about this equation:
The error in the WBT is to deduct something from the denominator. This was never correct. The fuel fed is the fuel fed, not something less. Char produced as a co-benefit goes in the top line, not deducted from the bottom.
This is to disagree with Crispin’s “never” - and to defend the WBT equation.
I will start by suggesting we look at a set of data saying that stove measurements on five successive days gave these results:
E1=thermal(%)
E2=char( %)
Monday
30
20
Tuesday
28
23
Wednesday
32
17
Thursday
29
21
Friday
31
18
Ave’s
30
19.8
Max difference
4/28 (14%)
6/17 (35%)
No-one following this topic would be surprised if I posited that Crispin would prefer the Wednesday stove which has 14% more water boiling than the lowest, while I should prefer Tuesday with 35% more char than his Wednesday choice.
So what does the equation in dispute say about this matter? This additional column says that our two choices differ by only 2.2% (and my Tuesday choice is the “loser”)
E1=thermal(%)
E2=char( %)
Estove=E1/(1-E2)
Monday
30
20
37.5
Tuesday
28
23
36.4
Wednesday
32
17
38.6
Thursday
29
21
36.7
Friday
31
18
37.8
Ave’s
30
19.8
37.4
Max difference
4/28 (14%)
6/17 (35%)
2.2/36.4 (6%)
The important point (which I have so far hidden in this hypothetical example) is that these are not different stoves. These are posited results all for the same stove. The differences are caused by having different operators, different types of fuel, moisture content, , etc. Multiple tests are needed (and are being undertaken) to be able to report a more accurate answer.
The subtraction of E2 in the denominator is NOT leading up to a statement about charcoal production efficiency. It is the exact opposite. The denominator after subtraction is the amount of energy available for boiling water. The resultant answer (about 37.5%, within about 1 %) is the efficiency of the stove if no char had been produced.
So I am fully happy with using this equation, as long as there is no intent to make and keep produced char. It is NOT an incorrect equation. But it is meaningless if one is intentionally trying to produce char. Crispin and I agree on this.
Ron
On Jan 11, 2017, at 9:32 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com<mailto:crispinpigott at outlook.com>> wrote:
Again I ask that you press CTRL+A and then choose one size of font for your whole message. It is really distracting to have a tiny font that includes a quote and then more from you. It is hard to see when your citations stop and you begin.
Thanks
Crispin
PS I Will leave here about the 20th and go to Jakarta, Singapore, then Bishkek, returning to Canada about the 27/28 Feb. Maybe via Beijing.
From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Traveller
Sent: 11-Jan-17 10:48
To: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>>
Subject: [Stoves] ABCEG deceit and conceit (Re: Crispin, Andrew)
Crispin:
You meant AABCEG. And forgot Gates, Clinton, ISO and WHO.
I don't know about your ruckus and don't particularly care.
To me, WBT is to cooking as Playboy is to love.
I am struck by your "if the gravity of the implications of making flippant claims about stove 'impact' are (sic) apparent and accepted." I decided decades ago that the stovers' love quarrels had no gravity, but only now I have come to realize that trivial things like testing protocols are at the base of outright deceit and conceit.
***********
You wrote, "The metric for fuel consumption relates to the energy in it and what happens to it. "
That's dogma for stove theologians. I don't know which prophet dictated the commandment.
My question has long been - WHY DOES IT MATTER?
An economist would see no need to economize on an input that is "free". I always found it rather silly that people would try to sell stoves on the promise of lowering fuel consumption.
There is a more serious objection -- fuel is but one of the inputs to "delivered energy", the other being capital and labor. Determining total costs with a combination of lab tests and Discounted Cash Flow gives a pretense of "analysis. The end-product is NOT delivered energy but FOOD. Food has taste, smell, temperature, of immense variety and - most importantly - requires food input plus the cook's skills and brains. Cook is God - no, not you, Cecil - and these theologians are clowns.
Cooking is the problem. Not the stove or the fuel. The stovers - and IWA pretenders - have hijacked cooking. For ages. They should be driven out of the kitchen, then brought in as they can watch the cooks and cooking. Not in front of Imperial Hotel or the back of White House.
Because I also have another gripe -- why do emission rates matter? I can see some rationale in CO measurements -- the degree of completeness of combustion -- because that also determines hydrocarbon emission rates. There is no reason to link emission rates to "safe exposures" -- if somebody has bothered to define an hourly or daily average exposure limit -- which is what one is finally interested in, but I won't quibble with CO.
The more significant issue is with PM2.5 rates, and the assumptions of concentrations, exposures, equitoxicity, and dose-response ratios.
I happen to think all of that is cooked up - Ron hates the term "manufactured", but these things are "model estimates" based on "model estimates" ad nauseum - but again, the main question is, what has it got to do with cooks and cooking?
************
If the precision of "efficiency" is not relevant to household cooks using solid fuels, I doubt precision of emission rates is either.
GACC propaganda about "clean fuel" and "clean cookstoves" begs the question, what is "clean"? And who is to optimize "cleanness" of combustion (fuel, device), convenience, monetary cost, nuisance value, for Joy of Cooking<https://en.wikipedia.org/wiki/The_Joy_of_Cooking>?
"Stand Facing the Stove"<http://www.smithsonianmag.com/history/review-of-stand-facing-the-stove-the-story-of-the-women-who-gave-america-the-joy-of-cooking-auguste-escoffier-memories-of-my-life-131118641/>, IWA testers must have in their protocols.
Except that they are not tasters. They are not cooks, just helpers, sous chefs so that the head chefs at EPA and IHME can cook up numbers that GACC can dish out as "evidence base". How can DfID be so dumb?
Andrew learned a bitter lesson about the purposes of setting standards or procurement specifications. That, I suspect, is why you are so damn serious
I return to what Fernando Manibog wrote in 1983 -
"To sort out this welter of confusion, a meeting of international stove experts (ref.) has introduced provisional international standards for testing the fuel performance of wood-burning cook stoves and for preparing results in terms of specific consumption and time required for cooking measures that can be more easily explained to users than can efficiency. Three types of tests are recommended: water boiling, controlled cooking, and kitchen performance. For each, detailed instructions on required equipment, testing procedure, and data calculation and reduction are provided along with reporting forms for the test series."
That is, forget "efficiency". And if WBT is used, so must two other types of tests; protocols for any are open to debate.
First define "cooking".
Everything is contextual, as Cecil would say.
Nikhil
----------------------------------------------------------------------
Message: 1
Date: Sun, 25 Dec 2016 13:15:15 -0700
From: "Ronal W. Larson" <rongretlarson at comcast.net<mailto:rongretlarson at comcast.net>>
To: Crispin Pemberton-Pigott <crispinpigott at outlook.com<mailto:crispinpigott at outlook.com>>, Discussion
of biomass <stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>>
Subject: Re: [Stoves] personal pollution monitors (Andrew)
Message-ID: <A9AA25FB-33CA-4283-8951-963AF927ABF8 at comcast.net<mailto:A9AA25FB-33CA-4283-8951-963AF927ABF8 at comcast.net>>
Content-Type: text/plain; charset="utf-8"
Crispin cc stoves (being added back in)
1. Let me try again. I said: "How about picking two pages/equations here that you think has been done incorrectly? (No more than 2, please, at first.)? (from the site and the attachment).
I presume many on this list were waiting to see what you disliked the most in this sort-of official ?bible?.
2. We agree on one thing. I have been arguing against the subtraction in the denominator (described below) for at least a decade. Not for your reason though. That approach under- (not over-) estimates the efficiency I want reported. (Not in your analysis below, because you threw away part of the char that I was trying to obtain - char of the size you want to forget about is ?exactly? ready for the garden.)
3. Maybe we will agree if you show us your calculation of the various Inefficiencies (emphasis only on the ?in? part) in your example. Where exactly do you see ?wasted? or ?non-useful? energy?
4. I?d rather not have hundreds of us waste time looking up the ?dreadful 2016 paper from BUCT and Kirk Smith? , even though I am willing. Could you supply that cite please?
5. To repeat, for emphasis, I am looking for specifics in the 2014 version of the ?bible?. Especially the part about not reporting weights.
Ron
> On Dec 25, 2016, at 12:42 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com<mailto:crispinpigott at outlook.com>> wrote:
>
> Dear Ron
>
> Thanks for the well-phrased questions.
>
> No char-making stove I have seen has a high fuel efficiency.
>
> The reason I personally brought the new Nurhuda stove to the group instead of waiting for him to say something is because of the relevance of the double-fuel design to the reporting of the fuel efficiency metric.
>
> The metric for fuel consumption relates to the energy in it and what happens to it. The delivered energy, cooking or space heating or water heated in a low pressure boiler is the 'delivered energy'. That is the numerator of the efficiency metric. Energy contained in char produced is not 'delivered', it is retained in the remnant solid fuel. Char is definitely 'produced' but the energy it contains is not. It was already there.
>
> The energy in the fuel fed into the system needed to deliver the benefit ?(cooking or whatever) is the number in the denominator. The result is the efficiency expressed as a fraction or % if you wish:
>
> Work done/input energy = efficiency
>
> The error in the WBT is to deduct something from the denominator. This was never correct. The fuel fed is the fuel fed, not something less. Char produced as a co-benefit goes in the top line, not deducted from the bottom.
>
> The efficiency of Nurhuda's stove is the same calculation done twice in sequence. That is, the efficiency as a char maker, then the efficiency as a char burned, then the combination.
>
> If one chooses not to burn the char, the fuel consumption of the first operation is not 'increased' as a result.
>
> As a practical example, the same in principle as I provided a few years ago, is:
>
> Wood energy into Nurhuda's char maker with the larger fuel chamber: ?10 MJ worth of wood pellets.
>
> Delivered energy to the pot, 3.5 MJ
> Efficiency 3.5/10=35%.
>
> Char recovered after cooking: 4 MJ worth of char pellets.
>
> Char energy not recovered due to its being too small and dispersed, 1.0 MJ which is a mechanical loss.
>
> ?Char loaded into the small chamber and lit to continue cooking: 4 MJ worth of charred pellets.
>
> Delivered energy to the pot, 2 MJ.
> Efficiency, 2/4=50%.
>
> As I have mentioned many times before, running two incompatible cooking operations means the efficiencies cannot be averaged directly because the denominators are different. ?Basic rule of math. This is another error in the WBT but I will ignore that for now.
>
> The efficiency of the system evaluated as a 'pair of burns' is the total energy delivered divided by the total energy entering the system.
>
> Session 1 energy gained plus Session 2 energy gained ?divided by the total energy going in. This treats the entire sequence as a single cooking event.
>
> (3.5+2)/10 =55%
>
> The fuel efficiency (which I prefer to call the energy efficiency in line with other devices) of the char making cooking operation is 35%, not 55%. The WBT reports the efficiency of Session 1 as
>
> 3.5/(10-4)= 58.3%.
>
> I just checked to be sure. ?It is incorrect, obviously. 58.3 is more than 35.
>
> The WBT would rate Session 2 as being perhaps 60% efficient, assuming there is some char left, for a total of 118.3% of the original energy, or some other crazy construct.
>
> I believe in Christmas miracles but not that one. ?The reason it is so wrong is because of the double counting and the irregular subtraction from the denominator.
>
> The error in the WBT formula is to deduct something from the denominator, is that now clear?
>
> The efficiency of cooking in the Session 1 is 35%. The efficiency of retaining recoverable char energy during that session is 40%. The efficiency of cooking in the second event is 50%. All three of these results are determined by a number in the numerator. That is how to calculate efficiencies.
>
> At no time does one subtract a delivered energy value from the denominator. Suppose you measured the space heating energy and the co?oking energy at the same time. Suppose the energy gained was the same for each: 3.5 MJ. The cooking efficiency is
>
> 3.5/10=35%
>
> The space heating efficiency is
>
> 3.5/10=35%
>
> The cooking efficiency is NOT found by dividing the 3.5 MJ delivered to the pot by (the energy in the fuel supplied minus the space heating energy). That would be ridiculous. Space heating is a co-benefit.
>
> If the cooking was done inside the ?heated space, then the total delivered space heating energy is (3.5+3.5)/10=70%.
>
> If you treat recoverable char as a co-benefit, it is considered in the numerator. It is not subtracted from the denominator. Char has well known properties of mass and specific energy content. It's production efficiency (however you assess the portion of it as 'recoverable') is ?mass of char per unit of dry mass of fuel fed in. In the example above the yield I used is 20%. The specific energy content I assigned was 30 MJ/kg.
>
> So Dr Nurhuda's new stove can be assessed as a char making cooking stove, or as a char maker, or as a char making, char burning stove treating the entire session as a single cooking event. All three are legitimate and the above formulas are what one needs to report it properly.
>
> The highest efficiency I have seen for a char making stove is in the low 40's and the mass of char recovered is about 20% of the dry fuel mass fed in.
>
> Incidentally, just to save time, the phrase 'energy credit for char' can be applied to these formulas. It goes in the top line, and is not subtracted from the bottom because the mass or energy of the char does not reduce the mass of raw fuel consumed. You could create a 'cooking plus char energy' efficiency. Nothing wrong with that though it wo?uld be non-standard. Doing so would not raise the cooking efficiency, however.
>
> You could also have a 'cooking plus space heating' efficiency. Perfectly legitimate, but adding in the space heating efficiency would not increase the cooking efficiency either.
>
> Finally, if you wanted to know the heat transfer efficiency as per that dreadful 2016 paper from BUCT and Kirk Smith, that is an internal metric referring to something happening within the stove and any similarity to the energy efficiency is purely coincidental?. Usually they are not similar for solid fuel stoves. The heat transfer efficiency for a char making stove is often twice the value of the energy efficiency.
>
> Regards
> Crispin
>
>
------------------------------
Message: 5
Date: Mon, 26 Dec 2016 11:57:47 +0000
From: Andrew Heggie <aj.heggie at gmail.com<mailto:aj.heggie at gmail.com>>
To: Discussion of biomass cooking stoves
<stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>>
Subject: Re: [Stoves] personal pollution monitors (Andrew)
Message-ID:
<CAPSaZeZUSw0BVxYHwYhk5_+v0jfXMFFTeTyPsX8RnSsJZEXNAg at mail.gmail.com<mailto:CAPSaZeZUSw0BVxYHwYhk5_%2Bv0jfXMFFTeTyPsX8RnSsJZEXNAg at mail.gmail.com>>
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On Sun, 25 Dec 2016 14:32:09 +0000,Crispin Pemberton-Pigott
<crispinpigott at outlook.com<mailto:crispinpigott at outlook.com>> wrote:
>I was really asking if the gravity of the implications of making flippant claims about stove 'impact' are apparent and accepted.
>For ten years now, as confirmed by Dean Still, I have been raising a rukus about the multiple conceptual and mathematical errors still contained in the WBT.
Hold hard Crispin, we were discussing particulates.
It's not that I'm not interested in stove testing but rather I'm disinterested, I don't move in those circles that get to decide these things.
I do have a little anecdote about wanting standards that favour personal wishes: some 20 years ago the prices of timber I harvested were dropping in the face of a recent exposure to world trade. I thought wood for heat and pellets were a way forward for our smaller
diameter trees.
The standard that was eventually set didn't suit my wishes as the requirement for low ash couldn't be met by smaller trees.
Little did I realise the standard did suit imports of pellets from many thousands of miles away and we now burn imports in far greater quantities than can be grown in these islands in order to meet a renewable energy target.
I suggest you change the subject to the specific bit of stoves testing that you are concerned about.
Andrew
------------------------------
Message: 6
Date: Mon, 26 Dec 2016 13:36:42 +0000
From: Crispin Pemberton-Pigott <crispinpigott at outlook.com<mailto:crispinpigott at outlook.com>>
To: Stoves <stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>>
Subject: Re: [Stoves] personal pollution monitors (Andrew)
Message-ID:
<YTOPR01MB0235E6B3AC00E123F83CB608B1960 at YTOPR01MB0235.CANPRD01.PROD.OUTLOOK.COM<mailto:YTOPR01MB0235E6B3AC00E123F83CB608B1960 at YTOPR01MB0235.CANPRD01.PROD.OUTLOOK.COM>>
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Dear Andrew
Was the ask content considered to be an important factor in the level of particles emitted, the total mass per ton burned?
When looking into what ambient air contains, the sources like power stations and fireplaces have very different profiles. In general: Homes produce PIC's and power stations produce flyash. Ho?mes produce PM related to the quality of the burn. Big burners produce things that are inherent in the fuel because the quality of the burn is very high and constantly adjusted.
You get my drift?? So if the ash was considered to be a major 'cause' of PM it is understandable, but is really a statement of something like, "Our burners produce a lot of flyash and rather than fixing them, let's limit the ash content of the fuel input."
My second question is, has the price of the small diameter material been depressed by the regulation? Can it be used as a domestic pellet? The PM might drop a lot by changing the airflow speed.
Thanks
Crispin
?
------------------------------
Message: 7
Date: Mon, 26 Dec 2016 09:39:18 -0700
From: "Ronal W. Larson" <rongretlarson at comcast.net<mailto:rongretlarson at comcast.net>>
To: Crispin Pemberton-Pigott <crispinpigott at outlook.com<mailto:crispinpigott at outlook.com>>, Discussion
of biomass <stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>>
Subject: Re: [Stoves] personal pollution monitors (Andrew)
Message-ID: <89D0256A-20DB-4718-9646-71528E81CFBA at comcast.net<mailto:89D0256A-20DB-4718-9646-71528E81CFBA at comcast.net>>
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Crispin (again adding back in the stoves list; I hope it is clear that dialogs like this need to go to the full list)
1. Sorry for the confusion over ?bible?. I have given only one cite (and attachment) today. Here again is what I was jokingly referring to as the ?Bible? (since I believe it is accepted by we ?stove believers?): http://cleancookstoves.org/technology-and-fuels/testing/protocols.html <http://cleancookstoves.org/technology-and-fuels/testing/protocols.html>) (attached earlier)
2. For third time, I repeat my request for two (2) cites from the above document:
At 11:05 AM (Denver) yesterday, I said: I find the weight of the fuel being prominent - so don?t understand your statement below on this topic. How about picking two pages/equations here that you think has been done incorrectly? (No more than 2, please, at first.)
At 1:15 PM yesterday I said: 1. Let me try again. I said: "How about picking two pages/equations here that you think has been done incorrectly? (No more than 2, please, at first.)? (from the site and the attachment).
I presume many on this list were waiting to see what you disliked the most in this sort-of official ?bible?.
3. You also apparently didn?t noticed that I had asked (see the 1:15 PM message) for the cite to the Kirk Smith article (and I now read also was a comment tothis list). I again ask for those. Being told it was ?earlier this year? is not advancing the dialog. In case this is not clear, you used the term: ?dreadful 2016 paper from BUCT and Kirk Smith?.
Ron
> On Dec 25, 2016, at 2:04 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com<mailto:crispinpigott at outlook.com>> wrote:
>
> Dear Ron
>
> I have no idea what you mean by the 'bible'.
>
> The paper was discussed earlier this year on this list including at least one response from Kirk. It makes the fundamental error of assuming that comparing the heat transfer efficiency of two stoves is the same as comparing their fuel consumption.
>
> I don't think anyone on this list is in any doubt about the complaint regarding calling a heat transfer efficiency or a proxy of it anything to do with the fuel consumption or energy efficiency (a mass of fuel being a proxy for an embedded energy content).
>
> >"How about picking two pages/equations here that you think has been done incorrectly?
>
> The WBT reports a dry fuel mass equivalent of the energy theoretically released from burned fuel, disregarding energy contained in unrecovered char and unburned gases. ?It is titled 'fuel consumption' which obviously it is not.
>
> >2. We agree on one thing. I have been arguing against the subtraction in the denominator (described below) for at least a decade. Not for your reason though. That approach under- (not over-) estimates the efficiency I want reported.
>
> Then your calculation is in error.
>
> If it is added to the numerator the result, 55% in my example, is lower than subtracting it from the denominator, 58.3%.
>
> >(Not in your analysis below, because you threw away part of the char that I was trying to obtain - char of the size you want to forget about is ?exactly? ready for the garden.)
>
> I didn't 'throw away' anything. ?I explained how to correctly report the cooking efficiency, the heating efficiency, and the efficiency of retaining fuel energy in the char. It is not complicated nor is it unusual.
>
> >3. Maybe we will agree if you show us your calculation of the various Inefficiencies (emphasis only on the ?in? part) in your example. Where exactly do you see ?wasted? or ?non-useful? energy?
>
> I did not say anything about 'waste'. I showed how to correct the calculation of efficiencies that are at present ?calculated incorrectly in the WBT spreadsheet.
>
> >5. To repeat, for emphasis, I am looking for specifics in the 2014 version of the ?bible?. Especially the part about not reporting weights.
>
> What 'bible'?
>
> Reporting the energy efficiency does not require knowing 'weights' ?except the mass of fuel fed in during each replication of the test.
>
> Regards
> Crispin
>
-------------------
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