[Stoves] ETHOS 2013: Where is the New Data on Stove

[rongretlarson at comcast.net]

Crispin with cc to List: 

This partly influenced by similar response sent this PM to Kevin. 

----- Original Message -----
From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com> 
To: "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org> 
Sent: Wednesday, November 28, 2012 9:50:54 PM 
Subject: Re: [Stoves] ETHOS 2013: Where is the New Data on Stove 




Dear Ron 




The two messages seem to have crossed in the post but I will try to catch up. 

[RWL1_ I don't think there is a need to respond to anything in the "crossed" mail.] 





> Forget everything about joules as the fundamental variable. 



My second response did not include Joules. Just Carbon and how to make a CO2 production comparison. 



>… do appropriate computations where the fundamental variable is kgs of C or CO2 . Think about comparing the carbon neutrality and carbon negativity values of stoves. 




The carbon neutrality of the source is judged on 2 counts by the UNFCCC, meaning there is non-renewable use of biomass and renewable. As I understand their present formulas (they allow mixing of the two) you will have to include the concept and consider coal to be in the same non-renewable category. 

[RWL2. I don't know this l iterature - and would appreciate a lead to it from anyone. A bi g disappointment to me is the failure of the UNFCCC to talk much about carbon negativity at all. Thanks goodness for Jim Hansen and Bill McKibben. But my note assumes renewable biomass. ] 




So if I get you right you want to consider first the renewable or non-renewable aspect, right? That is not an attribute of the stove but it is an attribute of a programme with stoves in it, or could be. 

[RWL3: No. this is not "first" to me. I a m presuming that all char-making stoves will be operated only with renewable fuels. Carbon credits will certainly be dependent on a certified renewable source.] 




Next you want to consider the turning of a renewably sourced biomass converted into a sequestered carbon, right? 

[RWL4: No - I want to simultaneou sl y consider both the carbon neutral and carbon negative aspects of stoves. 







A non-renewably sourced biomass turned into sequestered carbon would cancel, are we agreed? Because it is unsustainably removed then put back. 




[RWL5: Maybe. I think there could also be worse than "cancel". M uch char production in the boondocks is in that "worse" category.] 

Is your point also that in doing so, we can get the H2 energy out? 
[RWL6. That has not been my point - but H2 is an important part of the computations. 

If so, then something that was about 50% not-sustainable could be changed into equally-sustainable, right? And I mean in terms of Carbon only, right? 
[RWL7: Probably both not "right". I don't understand the question. I have not quantified anything about the measurements as being sustainable or not. I am assuming that the teste rs will assure sustainability. ] 



What it boils down to is that you could grow biomass using carbon that was not only recycled into new biomass after taking out some of the energy, but there would be a net sequestration. Is this the idea? 

[RWL8: You are extending my note to a "stoves" list way further tha n I intended. All these thoughts are better discussed on the sister "biochar" list. P robably I can agree to the general thought here, but this is not the place to get into that. 





The stove would be part of that equation though it is not a contribution directly by the stove, it is a contribution or achievement of the programme that manages the char and the biomass. 


[RWL9: Disagree. I am only dealing with the stove at this point.] 





For that reason I can’t see how you would attach the sequestration to the stove. If it an attribute of the system of which the stove is an integral part. But without the programme, the stove would not achieve it. 

[RWL 10 : Maybe my numerous "No's" above will clarify that I am only trying to analyze a stove (not a system) in C/CO2 terms. You have not convinced me that the stove can't be analyzed this way.] 




RWL: I am certainly claiming that a stove with favorable carbon negative attributes needs to be recognized by stove performance monitoring groups. 



So my point is that the stove is not itself carbon negative. 

[RWL11: I didn't say it was. I am saying that enough stove data (energy, char, emissions, etc) is being collected to talk , in a me aningful way, about the carbon negativity of one stove's operation vs another's.] 





It is the behaviour of people who use it, or a programme that uses it. And that programme would qualify as the creator of that sequestration, not the stove. It is not a feature, metric of attribute of the stove. 

[RWL12: Disagree - rationale above.] 




> I do happen to believe that many char-making stoves are more energy efficient (because they can easily control power level and excess air) 



I expect them to be and have been disappointed lately as people copy one product or another and don’t get the basics right. I see a digression of opinion from forestry people and stove carbon people coming. The forestry people want to know how much raw fuel a stove takes from the stock of trees and they view ‘efficiency’ as the work done and the amount of wood taken. So ‘efficient’ has two quite different meanings. I think the heat transfer efficiency of gasifiers should or could be great but I approach things from an engineering perspective – efficiency of mass transfer! No so the boys with the seedlings. 

[RWL13: A ll of this paragraph seems to not relate to my note (where my single sentence was intended as an energy-aside). I think you underestimate the interest of foresters in stoves and carbon issues. There is some wonderful biochar literature from foresters - and I think man y (pr imarily in developing countries) will often be interest ed in stoves and C /CO2 topics.] 








>> Totally agree. There is to be [NO] double-counting. 




RWL. I don't understand last sentence. 



Because I left out a word. J I meant that, as you said, you can’t claim both to be using less fuel while simultaneously creating masses of char, when that ‘less fuel’ is a number calculated from the energy used, not the fuel used. 


[RWL14: All this (sort of, now) understood. Jim Jetter's note today is partly on your last sentence - and not part of my dialog, I think/hope. I look forward to your response to Jim.] 





A stove can’t use ½ the fuel AND yield ½ of the energy in the form of char AND cook a meal with ‘the other ½’. That is three halves. 

[RWL15: This part I don't understand. I only see two halves here - your first and third "halves" seem identical to me. Ron] 




Regards 

Crispin 


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