[Stoves] Advocacy action: ask the GACC to stop promoting the WBT

Tom Miles tmiles at trmiles.com
Wed Feb 15 13:14:00 CST 2017


Roger, Crispin, Frank,

Great comments and references. 

What do we know about what stoves have failed and what have succeeded? Which stoves sell and which don’t? In a given local I would think that some designs succeed and others don’t. I have seen manufactured stoves (e.g. LPG) abandoned for locally made stoves. There are probably studies of stove life and use based on long term monitoring programs in organizations like GERES. Are there links to those studies? 

Thanks

Tom

-----Original Message-----
From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Roger Samson
Sent: Wednesday, February 15, 2017 8:18 AM
To: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] Advocacy action: ask the GACC to stop promoting the WBT

just to add a bit more about  Crispins point about using locally available fuels to design stoves....

One of the reason so many stoves don't find user acceptance is that they are designed remotely from the user and their accessible fuels. We use a constructivist approach with end users to construct together a technology that fully meets users needs and available fuels. We did this with our rice hull stove in the rural Philippines 15 years ago and more recently with our clay brick stove in Gambia.  We are concerned with performativity at the user level not the published journal results using a sub-optimal stove test and cooking fuels that are not typical of those used by communities. 

The opposite approach is positivism, you independently develop the technology from the users, publish the results in journals, and effectively push it on communities through various means like fuel subsidies and free stoves that certain agencies promote. 

Douthwaite describes sustainable and unsustainable pathways to technology development. One of the reasons improved stoves are failing is the donors dont understand sustainable approaches to enabling technology innovation.  

Read the work of Douthwaite: 
http://boru.pbworks.com/f/ag_syst_IPE.pdf

A youtube video on it
https://www.youtube.com/watch?v=wM6mpqTrFLM

and what's supposed to be a good book that I haven't read yet
http://www.amazon.com/Enabling-Innovation-Practical-Understanding-Technological/dp/1856499715

regards

Roger


Roger Samson
Executive Director
Resource Efficient Agricultural Production (REAP)- Canada Centennial Centre
21,111 Lakeshore Rd.
Ste. Anne de Bellevue, Quebec, H9X 3V9
Tel. 1-514-398-7743
www.reap-canada.com
https://www.researchgate.net/profile/Roger_Samson2

--------------------------------------------
On Wed, 2/15/17, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:

 Subject: Re: [Stoves] Advocacy action: ask the GACC to stop promoting the WBT
 To: "Stoves" <stoves at lists.bioenergylists.org>
 Received: Wednesday, February 15, 2017, 2:39 AM
 
 
 
 Dear Frank
 
 
 
 
 
 Just a quickie:
 
 
 
 
 
 "4) develop a form to be included with
 each stove as to the biomass properties that work best in  this stove."
 
 
 
 
 
 This is probably backwards and it is
 important to get it the other way round: tell us what fuels  are available and characterise them correctly. Then we will  develop a stove that burns ‎it well, in a controllable  fashion, with
  the cooking and heating power adequate for the anticipated  tasks. 
 
 
 
 
 
 Yes, I realise that people 'invent a technology' and  then hunt around for a set of fuels it can burn, but that is  technology-centric, not customer-centric. 
 
 
 
 
 
 Tell me about the fuel and the task, and I will tell you  about the stove that can do it. Something like that. 
 
 
 
 
 
 Thanks for the thoughts
 
 Crispin 
 
 
 
 
 Dear Crispin,
 
 
 
 We have spent years and years and
 come up with a list of WBT trying to get some Efficiency  calculation. Who cares? Does anyone out there care about  efficiency calculations? The only possible way that could be  at all helpful is if you add half
  the energy of biomass into the combustion chamber you get  the same efficiency value. That is the amount of energy in  the biomass will heat the same amount of water. Due to  changes in air flow, waste heat in the walls, how the fuel  is packed, type and shape
  of biomass etc it will never do that. You can’t give a  stove an Efficiency value. 
 
 
 
 We need to find the properties of
 biomass that will work in a combustion chamber. Meaning it  will light, create heat and do a task with approved results.
 1) We need a list of biomass properties that make a  difference. 2) we need to develop test
  methods to quantify those properties 3) we need a procedure  to test stoves to determine the stoves limits for these  properties 4) develop a form to be included with each stove  as to the biomass properties that work best in this stove 5)  test wild biomass for
  those properties and some sort of chart to determine if the  stove will work with that fuel. If it shows it will work  then sell them the stove and be assured it will work and  what handling of the biomass is needed. Whether or not the  people is willing to do
  the necessary preparation needed on the biomass is another  separate issue.  
 
 
 
 When any group is ready to start
 working on the list of properties that make a difference and  develop test methods to measure those properties - let me  know. I am now willing to help if wanted but not likely much  longer. I still have somewhat
  of a lab to work in. 
 
 
 
 
 
 
 
 Aprovecho has claimed many time to have done  exactly that. I challenge this claim. They optimised their  stoves to get ‘good numbers’ on the WBT which does not  report the actual performance.
  Sometimes it is similar to the real values, sometimes is it  not. It largely depends on how much char is produced. The  more the char, the greater the over-claim.
 
 
 
 
 
 
 
 
 I agree with the above - when it
 was used to compare stoves. It worked when determining  optimum setup, information that could be used for all  stoves. As for using to compare stoves, that came when the  time was needed for comparing stoves and there
  was no other procedure for doing so. There is still no  procedure for doing so. Hats off to Aprovecho IMO. 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 Thanks
 
 
 
 Frank
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 On Feb 14, 2017, at 9:27 PM,
 Crispin Pemberton-Pigott <crispinpigott at outlook.com>
 wrote:
 
 
 
 
 
 Dear
 Frank
 
  
 
 The
 problems with the WBT are more fundamental than you  describe.
 
  
 
 It
 must be faced, square on, that the WBT calculation does not provide  the efficiency.
  The formula is wrong!  
 
  
 
 If
 you create a stove as you suggest, and measure the  efficiency using the WBT, and it says the cooking efficiency  is 40%, you would be happy. Then if you used a different  test like the Chinese
  one, it might say the efficiency is 25%. So, which is  it?
 
  
 
 I am
 telling you that there is a problem with the calculation,  not the concept of testing.
 
  
 
 Here
 is something practical you can do to prove it: Get a set of  numbers from a stove test, the fuel consumed, the char  balance and so on, water masses and temps. You can invent  one or use
  a real stove. Then enter the same set of numbers into the  various versions of the WBT:
 
  
 
 VITA
 1985
 
 WBT
 2.0
 
 WBT
 3.0
 
 WBT
 3.1
 
 WBT
 4.0
 
 WBT
 4.1
 
 WBT
 4.1.2 of October 2011
 
 WBT
 4.1.2 of April 2012
 
 WBT
 4.1.2 of June 2012
 
 And
 finally
 
 WBT
 4.2.3 of 2015.
 
  
 
 You
 will get 10 different answers.
 
  
 
 And
 not one of them will be correct because there are systematic  errors in the concepts underlying the calculations plus  errors in the formulas themselves.
 
  
 
 ‘Perfecting’ a stove using incorrectly
 calculated metrics is not going to lead to stove nirvana.
 The Indian, SeTAR and Chinese tests all perform the  calculation more or less correctly. The
  Indian test uses an inappropriate fuel in that the stove  has to be optimised to that (100% dry) fuel in order to  perform well. No one in India uses such fuel so the stove is  optimised to an inappropriate air pre-heating and air-fuel  ratio. They have been advised
  to revise the test.
 
  
 
 The
 Chinese test uses a very different approach conceptually as  it includes a burn-out phase which raises the reported  efficiency by about 11% of value. That is something applied  to all stoves
  and fuels so the result is ‘fair’. There is a small  miscalculation in the efficiency from double-counting. (For  fun, I challenge the readers of this list to find it. It  escaped detection for decades.)  It can easily be  corrected. They have been advised to
  revise that calculation.
 
  
 
 The
 WBT contains several important errors. When the IWA text was  proposed, I reviewed it and reported some of these errors to  the committee. For the most part they did not correct the  errors,
  marking them as ‘too small to worry about’ and ‘to be  handled later’ and ‘for later discussion’, that sort  of thing. Thus there was public input on the IWA text but  the corrective information was not applied to the  result.
 
  
 
 In
 the IWA meeting numerous discussions were held on metrics,  names of metrics, ideas about what could be in the document.
 A lot of the meeting time was taken up with presentations on  how
  the document was prepared. The tiers were presented and as  the numbers were dependent on WBT results, many of us knew  they were unimportant as they would have to change when the  test was corrected. The IWA event was conducted in the  following manner: “We have
  already agreed in Lima on what should be in an  international test method so all we have to do is  rubber-stamp it and we can go home.”
 
  
 
 That
 was of course not acceptable as the Lime event just gave the  WBT 4.1.2 the nod without examining it closely nor  correcting the manifold errors. To get our (South Africa –
 6 delegates)
  agreement, it was critical to have any test method approved  by external, expert reviewers, which obviously had not been  done before. This text was added and we all voted for it. It  would be quite incorrect for anyone to suggest that we  approved of the whole
  content because, for example, the IWA has 9 performance  metrics and the WBT only produced on of them, efficiency,  and calculated that incorrectly. Yet it was the ‘default  method’. With only one metric being produced, and there of  the nine being physically
  invalid, there was little hope the IWA and its testing and  tiers could deliver on the promise of ‘better  stoves’.
 
  
 
 Consider what happened since: the requirement to have  all test method examined externally
  by experts was never implemented
 for the WBT. It would of course fail because of the invalid  metrics and the bad calculations.
 
  
 
 When
 new got to the ISO we were told, “The IWA in ins place and  everyone is using it so all we really have to do is  rubber-stamp it and we can all go home.” That of course  didn’t happen.
  Votes were held kicking out all WBT-forms of test and also  the tiers. Let me repeat: the vote by the experts was that  there should be no WBT and no tiers in the  Standard.
 
  
 
 If
 you find tiers in the ISO standard it is not because the  experts wanted them or voted them to be there. For the IWA  it didn’t really matter because the requirement to have  the test methods
  reviewed would have killed any tiers they were based on –  assuming that the IWA was actually implemented, which of  course it was not. People pick the bits they  like.
 
 
  
 
 >The WBT used exact sized, dry and
 consistent wood type for the testing to establish the best  gaps, insulation, height and etc. measuring performance of  energy entering a pot of water. 
 
  
 
 Aprovecho has claimed many time to have done  exactly that. I challenge this claim. They optimised their  stoves to get ‘good numbers’ on the WBT which does not  report the actual performance.
  Sometimes it is similar to the real values, sometimes is it  not. It largely depends on how much char is produced. The  more the char, the greater the over-claim.
 
  
 
 The
 AWBT from GERES is better on that particular metric, even  though it is not perfect. Bottom line: Do not develop a  stove using the WBT. It will mislead you.
 
  
 
 Regards
 
 Crispin
 
  
 
 
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 Thanks
 
 
 
 Frank
 Frank Shields
 Gabilan Laboratory
 Keith Day Company, Inc.
 1091 Madison Lane
 Salinas, CA  93907
 (831) 246-0417 cell
 (831) 771-0126 office
 fShields at keithdaycompany.com
 
 
 
 
 
 
 
 
 
 franke at cruzio.com
 
 
 
 
 
 
 
 
 
 
 
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