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

Fri Mar 3 11:56:44 CST 2017

Dear Xavier,

thank you very much.

I am pleased to inform everybody that we’ve just published a third article on this topic: a review of traditional and improved stove used in humanitarian contexts. The title is: “Cooking in refugee camps and informal settlements: A review of available technologies and impacts on the socio-economic and environmental perspective”. I attach the pdf of the article in press.

What it may be relevant for you, as claimed by Samer in some articles, is that although in most cases we found that the substitution of traditional devices by ICSs and modern-fuels cooking stoves seem to be an effective strategy to mitigate the negative impacts of traditional cooking operations, it is important to underline that in most cases the results are not clearly supported by scientific evidence. Indeed, as regards firewood-based ICSs, some recent studies suggest and report some doubts concerning their benefits in terms of reduction in fuelwood consumption, and the related social problems (viz. GBV firstly), on the field.

I hope you’ll enjoy the reading,

Best regards,

Fabio

Fabio Riva, Eng.
Researcher at Department of Energy
UNESCO Chair in Energy for Sustainable Development
www.unescochair-e4sd.polimi.it<http://www.unescochair-e4sd.polimi.it/>
Politecnico di Milano, Via Lambruschini, 4 – 20156 – Milano
Mobile: +39 349 2416259<tel:%2B39%20329%207291136>
Office: +39 02 2399 3866<tel:%2B39%2002%202399%203816>
[logo_unesco_chair]

Da: Xavier Brandao [mailto:xvr.brandao at gmail.com]
Inviato: sabato 25 febbraio 2017 21:15
A: Francesco Lombardi <francesco.lombardi at polimi.it>; Cecil Cook <cec1863 at gmail.com>; miata98 at gmail.com
Cc: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org>; Crispin Pembert-Pigott <crispinpigott at outlook.com>; Fabio Riva <fabio.riva at polimi.it>; Samer Abdelnour <samer.abdelnour at gmail.com>; Harold Annegarn <hannegarn at gmail.com>; Zhou Yuguang <zhouyuguang at china.com>; Frank Shields <franke at cruzio.com>
Oggetto: Re: [Stoves] Advocacy action: ask the GACC to stop promoting the WBT

Dear Francesco,

Thank you for sharing the link with all of us.
I feel we must create more bridges between the researchers who have worked and work on the protocols, and the people discussing on this List. The recent article from Anna University in Chennai is an illustration of that.

I feel your paper is a major contribution to the current debate, and a major step. You've expressed the issues in a very clear and documented way.

About the WBT, a few quotes:

p 64

"Therefore, the dominant practice of solely relying on WBT results may negatively affect both stove dissemination programs and climate impact estimates. As this practice has been further encouraged by the definition of stoves performance rankings, by the GACC and the ISO-IWA, based on the WBT, a deeper analysis of the possible implications is critically needed."

p 80-81

"Still, some of WBT critical issues remain unsolved, with a number of researchers claiming the protocol would need to be reviewed in terms of precision and accuracy [76] [57] [77].
A lot of debate has been made around metrics formulation, primarily on thermal efficiency, which is often interpreted as the most immediate and distinctive stove performance parameter."

"The scientific meaningfulness of η at Low-Power has been also questioned by Zhang et al. [57], claiming that simmering and low power operation are not synonyms and that a proper way to evaluate Low-Power efficiency would be simply operating the stove at the lower power possible to heat water."

 "Criticism about WBT also concerns thermodynamic subjects. The WBT is a controlled laboratory test, thus supposed to have little uncertainty and to be effective in comparing different stove designs. Nevertheless, the choice to approximate a typical cooking task (boiling and simmering) is not functional to this purpose; in fact, as documented by L’Orange et al. [78], uncertainties related to temperature reading and vaporisation in the boiling region lead to high variability between test replicates."

"Of course, a stove which is specifically designed and optimised for insulated pots would be performing differently without insulation; yet testing all stoves without a lid is not a solution either. To better understand this concept, a simple experiment on a common European electric heater – which was actually experienced by the author on a Severin KP 1092 (1500 Wnom) – may be performed: the appliance, operated at its maximum power, might not be able to heat a small pot of water (2 litres) up to the boiling point, when no lid is placed on it; yet it may be perfectly able to perform the task when the pot is insulated (as commonly done by the average European user). Therefore, the electric heater would fail to perform a WBT (even on a small pot) yet it would be perfectly functioning from a user’s point of view. The example highlights how stove performances are not inherent to the design, but rather depend on several external factors (viz. pot dimensions and insulation, as well as fuel type, moisture content and burn cycle in case of wood burning stoves). Trying to approximate a fixed “task” cannot be representative of the variety of cooking tasks and habits that may be experienced in a real context of use [68]."

To conclude, the WBT strengths:

  *   Highly detailed and user-friendly document, including Excel Spreadsheet
  *   Adaptability to any fuel and stove type
and weaknesses:

  *   Confusion on the protocol purpose and usefulness
  *   Not suitable to assess average field performances
  *   Questions on some metrics meaningfulness
  *   Questions on thermodynamic issues
  *   High variability between test replicates and uncertainty
  *   Misleading statistical considerations
  *   High number of replicates needed to obtain statistically significant data.

Now, the study points out that no protocol is perfect, and all protocols should be improved.

And, about using the WBT and other protocols to design a stove:
"Furthermore, the review analysis seems to suggest that current testing protocols may also provide misleading guidance about stove designs;"

There's a lot of work ahead.

Best,

Xavier

On 2/20/17 11:09, Francesco Lombardi wrote:

Dear all,

I am pleased to inform you that we just published a new article that you may find extremely relevant to this discussion. The title is: "Laboratory protocols for testing of Improved Cooking Stoves (ICSs): A review of state-of-the-art and further developments". This is the link for the downlkoad:  http://www.sciencedirect.com/science/article/pii/S096195341730065X

The paper, published in Biomass and Bioenergy, performs an analysis of strengths and weaknesses for each protocol based on defined indicators. Real-life relevance, repeatability and data evaluation are set as indicators for comparison. Based on the analysis, aternative solutions for design rating and statistical analysis are proposed and moreover we provide an outlook for the definition of a novel standard.

It is very important that the criticalities here identified are properly discussed and solved before the publication of any novel protocol/standard. Accordingly, we hope that you can contribute to share the results of this study as much as possible within the stove community.

Thanks,

Francesco Lombardi

Francesco Lombardi, Eng.
Researcher at Department of Energy
UNESCO Chair in Energy for Sustainable Development
www.unescochair-e4sd.polimi.it<http://www.unescochair-e4sd.polimi.it>
Politecnico di Milano, via Lambruschini, 4 – 20156 – Milano
Mobile: +39 338 2749066
zOffice: +39 02 2399 3866
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