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

Mon Feb 20 11:43:47 CST 2017

Dear Paul

The same stove was tested with the same fuel and several different test methods at the CAU stove conference a couple of years ago.

The equipment can be used to provide inputs into other calculations, ie not using the WBT calculations.

Remember the WBT includes a method of calculation performance metrics, and a burn sequence. These are independently changeable. ‎You could cook a meal instead of boiling water.

The equipment is separate again. The spreadsheet for the WBT is not directly compatible with the LEMS, there has to be a set of intermediate calculations. That is done with a separate spreadsheet which used to be called version 7 but has been renamed v4.2.3 to make it appear that it goes together with the WBT.

The calculations are not identical, but are very similar. An important difference is that the 'number of litres boiled' according to the LEMS version is the same as the volume in the pot whereas the WBT sheet reports the final volume. Thus the fuel consumption 'per litre boiled' is lower of the LEMS sheet is used.

The bigger issue with the equipment is the accuracy and calibrations. The bigger issue with the burn sequence is its decontextual nature. ‎The bigger issue with the calculations is the invalid efficiency claims and low power metrics which are still being used to allocate funding.

Adding a better gas analyser to the LEMS and a scale under the stove one can generate all sorts of interesting assessments. The first thing to do is to abandon the WBT as a test method.

Regards
Crispin

‎
Anyone,

Can the OTHER tests be conducted using the LEMS equipment?

Where can the tests from India, China or SeTAR be conducted other than in India, China or South Africa?   And do any of those places have the WBT testing also available?

Has anyone done tests of the same stove and same fuel with more than one of the test methods?   If yes, can we see some results?

Have Jim Jetter or others experimented / checked out the other methods?

Unfortunate if this has not been done.    Or has been done but not shared for all to see.

Paul

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
Email:  psanders at ilstu.edu<mailto:psanders at ilstu.edu>
Skype:   paultlud    Phone: +1-309-452-7072
Website:  www.drtlud.com<http://www.drtlud.com>

On 2/14/2017 8:10 PM, Crispin Pemberton-Pigott wrote:
Dear Tom and All

I challenge the idea that the WBT (not all water boiling, just that protocol) is valuable as a design and development tool.

The simple fact is that the WBT gives uncertain and incorrect measures of performance. Using the Indian, Chinese or SeTAR efficiency test (v1.57) will provide a much more accurate and consistent evaluation.

It is unfortunate that the WBT still clings to life as a 'development tool'. The high power metrics are misleading and the low power metrics are scientifically worthless. A much-repeated ‎and incorrect claim is that 'if a stoves performs well on the WBT it will generally performs well in the field'. Another shibboleth is that if a stove doesn't perform well 'in the lab' (hinting that it will be a WBT) it 'will generally not perform well in the field'.

What one would normally call 'proof' of these twin claims is missing. I take it as an admission that the WBT is not useful for performance rating. I already know it is not useful for product development. It is not useful for sorting out what might do well in real life from that which will not.

There are obviously significant implications for this. The obvious first step is that it should not be a requirement that any stove perform 'well' on its metrics in order to be considered for a subsidised improved stove programme.

Regards
Crispin

Xavier,
The donors and participants in GACC who I talked with at ETHOS regard the WBT as a useful tool for stove development but question its use for comparing stove performance in use. A recent study in Germany was cited where WBT tests were different from different labs. There was also a lot of discussion from the GACC working group leaders and participants about the need for contextual evaluation. A detailed approach to contextual evaluation was presented by GIZ which refleted much of what has been discussed here. It was also stated in the WG4 summary that options and exceptions are being delineated. What’s missing here is a clear understanding of what is actually being discussed about WBT, where, and for what purpose. The fears and concerns of negative impacts from  WBT tests were clearly stated by various speaker. It was also discussed that Tiers may not necessarily be relevant to the needs of a community. You might select a lower tier stove to meet those needs.  Who on this list are participants in the working groups?
Tom

From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Xavier Brandao
Sent: Tuesday, February 14, 2017 11:11 AM
To: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org><mailto:stoves at lists.bioenergylists.org>; franke at cruzio.com<mailto:franke at cruzio.com>
Subject: SPAM: Re: [Stoves] Advocacy action: ask the GACC to stop promoting the WBT

Dear Frank,

"the WBT is only an outline for tests that need be done"
Why do an outline when we can do (good) tests instead?
Additionally to these 3 problems you mentioned, you have to add the other ones I quoted previously, some mentioned in Fabio and Francesco's study. See below.
It's not looking too good for me. Sometimes getting something new is much faster and surer than fixing something broken.
I know that a lot of effort from many people went into "fixing" the WBT. But maybe it is beyond fixing. Maybe these are sunk costs.

  *   the WBT is not contextual, as Crispin highlighted many times
  *   several WBT metrics are invalid, as Crispin highlighted many times
  *   there are big thermodynamic uncertainties (viz. variable steam production and boiling point determination)
  *   there are questions about the rationale of some calculations, questions raised by Zhang et al.
We have been talking about the WBT for a few weeks already (not counting the years prior to that), and all these questions haven't been answered.
All, for more details about these questions, please find the links to all the studies I mentioned:

  *   Fuzzy interval propagation of uncertainties in experimental analysis for improved and traditional three–stone fire cookstoves
https://www.researchgate.net/publication/308898807_Fuzzy_interval_propagation_of_uncertainties_in_experimental_analysis_for_improved_and_traditional_three_-_Stone_fire_cookstoves

  *   Key differences of performance test protocols for household biomass cookstoves. Twenty-Second Domestic Use of Energy, IEEE 2014:1–11.
http://energyuse.org.za/document-archive/

To access the file, select DUE [Domestic Use of energy COnference]. Select DUE 2014. Select PROCEEDINGS. Select paper by Zhang etal (PDFs arranged alphabetically).

  *   Performance testing for monitoring improved biomass stove interventions: experiences of the Household Energy and Health Project. Energy Sustainable Dev 2007;11:57–70.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.461.783&rep=rep1&type=pdf

  *   The shortcomings of the U.S. protocol
http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1534&context=etd

  *   Influence of testing parameters on biomass stove performance and development of an improved testing protocol
https://envirofit.org/wp-content/uploads/2016/06/2012-influence-of-testing-parameters.pdf

  *   How many replicate tests are needed to test cookstove performance and emissions? — Three is not always adequate.
http://gadgillab.berkeley.edu/wp-content/uploads/2014/03/D-13-00075-Wang-et-al._final.pdf

  *   Systematic and conceptual errors in standards and protocols for thermal performance of biomass stoves
https://www.researchgate.net/publication/309689616_Systematic_and_conceptual_errors_in_standards_and_protocols_for_thermal_performance_of_biomass_stoves

  *   Quality assurance for cookstoves testing centers: calculation of expanded uncertainty for WBT
http://www.newdawnengineering.com/website/library/Stove%20Testing/Testing%20Protocols/American%20WBT,%20CCT,%20KPT/2014%20March%20WBT%204.2.x%20Uncertainty,%20Gorrity,%20M.pdf

  *   Key factors of thermal efficiency test protocols
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1000.3936&rep=rep1&type=pdf

  *   Towards a standard for clean solid-fuelled cookstoves
             https://www.researchgate.net/publication/274706950_Towards_a_standard_for_clean_solid-fuelled_cookstoves

Looking forward to your comments!

Best,

Xavier

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