[Stoves] [Biochar] Embers from Three Stone as Biochar - Who has done this?

Sat Apr 3 00:35:39 CDT 2021

 List:  and 4 ccs
 (Not going to the biochar list - ss this digression has nothing to do with biochar.

	Too late at night to respond fully.  I disagree with virtually every Crispin sentence below, and will try to explain why soon. 

	I strongly support the WBT as a valid way of comparing standard and char-making stoves.    This is a multi year ISO topic that I believed was approved unanimously (repeat unanimously) by many dozens of stove activists - g;pbally.  It somehow seems to relate to Crispin’s disdain for charcoal-making stoves.

	Nothing in Crispin’s response below or the earlier one in this thread has anything to do with the biochar topic (“Who has done this”) under discussion.

Ron

	Andrew and Paul -  see my response to you below.

> On Apr 2, 2021, at 4:09 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:
> 
> Dear Andrew 
>  
> Your response was rational, in the sense of seeking an explanation for why the stove would use about the same amount of fuel.
>  
> The WBT (which was the method used for evaluation) is not rational.  It doesn’t report that the mass of fuel used per session was the same, it said the number spit out by the WBT was about the same. That is a very different thing.
>  
> The WBT reports the dry fuel mass equivalent of energy released, so for any amount of energy gained by the pot, the energy released by the fire would almost always be the same. The actual mass of fuel fed is almost independent of the quantum energy released, especially if you compare while making or while not making char.   It is obviously misleading to compare fuel performance using a WBT calculation.
>  
> The fact that this reality has not sunk into a great fraction of stove builders is the greatest failure of the modern stove promotion cabal of testers.
>  
> Suppose you compare two hot plates to see which is “more efficient”.   One has 1 plate which goes on and off, and the other has 2 plates.  When turned on, both get hot at the same time.  Put one pot on each appliance and turn them on.  The two pots get heated at an identical rate, and reach boiling point at the same time.
>  
> The WBT assess how much energy was available to each pot.  It does not assess how much total energy went into the cord from the wall plug.  The WBT reports that both stoves “used” the same amount of power and therefore they have the same efficiency.  Any sensible person will point out that the total energy going into the cord is different by a factor of 2, the two plate stove being half as efficient as the single plate stove when cooking one pot.  The WBT doesn’t notice that – that’s how dumb it is.
>  
> As long as these legacy organisations keep using the discredited WBT to report stove “performance”, we will continue to see these gross misrepresentations polluting the literature.  It is plain and obvious to any observer that a stove burning all the fuel requires less biomass than an identical stove that produces char as a remnant.  The WBT was crafted (in ignorance) to hide this fact and its purveyors will not admit it, because doing so will invalidate thousands of performance tests, CDM projects and even portions of the ISO’s work to date.
>  
> Imagine if Sam Baldwin had corrected the conceptual errors of the 1985 VITA test instead of adding two new errors.  Imagine if Colorado State had removed all the errors instead of adding two more in its “EPTP” protocol!  Imagine if the EPA had the confidence and competence to push for wholesale correction of performance tests instead of pushing the already discredited WTB at the IWA meeting in 2012, with its meaningless low power metrics and erroneous fuel consumption numbers. 
>  
> We are still suffering from the refusal of Berkeley to publicly abandon the WBT and admit that all previous ratings are defective, and should be ignored. Every WBT-based rating of performance made at the CCA website should be deleted because they are meaningless to the real world.
>  
> If char making stove advocates do not understand what they are rating, they are dooming their projects and initiatives to failure because of their incompetent misrepresentation, egged on by the usual suspects.
>  
> Who is a “usual suspect”?  Anyone who tells you that a stove that burns 2 pounds of wood to accomplish something that another stove needs 1 pound of wood to do has, “about the same fuel consumption” because it produced ½ a pound of char.  Tell that to the forest.
>  
> Sincerely
> Crispin
>  
> From: Stoves <stoves-bounces at lists.bioenergylists.org <mailto:stoves-bounces at lists.bioenergylists.org>> On Behalf Of ajheggie at gmail.com <mailto:ajheggie at gmail.com>
> Sent: Friday, April 02, 2021 6:46
> To: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org <mailto:stoves at lists.bioenergylists.org>>
> Subject: Re: [Stoves] [Biochar] Embers from Three Stone as Biochar - Who has done this?
>  
>  
> On Fri, 2 Apr 2021 at 05:21, Ron Larson <rongretlarson at comcast.net <mailto:rongretlarson at comcast.net>> wrote:
>  
> On Mar 31, 2021, at 8:37 PM, K McLean <kmclean56 at gmail.com <mailto:kmclean56 at gmail.com>> wrote:
>  
> Using tongs to remove embers, women can make 300-800g of char daily.  Because they've reported that firewood usage does not increase, SNV did a simplified WBT <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F10aUtzXfo_y9AlmCBr5zMo-tLZbQ8qq48%2Fview%3Fusp%3Dsharing&data=04%7C01%7C%7Ca65e8dd895a147540dc208d8f5d6a3f2%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637529649511739554%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=BwoHlAO4RhPaJ2Ohq4r5DXTApkHVnUN8I6dnBOGvPyA%3D&reserved=0>and, counterintuitively, SNV found only an insignificant increase in fuel usage.
>  
> [RWL3:  I’ve. reviewed this SNV work (in Viet Nam) and have asked for the raw data as well as the finished reports.  
>  
> But I can believe the results. - because the embers that are being collected (by SNV and by women being paid for the char) had already mostly given up its hydrogen.  The fallen ember necessarily came from near the bottom of the fuel bed - where it was not contributing much to water boiling.
>  
> The  experience that there is little change in total wood used, even though there is char removed is interesting. May it be because the cooking fire is "LOSSY" and depends on flames reaching the pot whereas the embers would just sit glowing at the bottom of the fire, so their radiant and convected heat never reaches the pot or because the cooking is finished and the embers would otherwise just burn away to nothing..

	[RWL2:  Agree mostly,  Exception - the embers have been collected over a fairly long regular cooking period - not just when “finished”.    I guess by “lossy”,  you mean that not all the possible available energy reaches the cook pot?  I agree.   Note that TLUDs do not have this drawback. -ALL the available (not in the char) energy at least has a chance at boiling water.

	Note these embers have fallen through a bed of maybe 7 or  8  golf-ball-sized stones - and would not have fallen if any un-charred wood remained inside.  

	[RWL3.  This last observation in response to a later message from Paul Anderson -  the embers seem to only rarely have any uncharted interior.

Ron

>  
> Andrew
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