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

Sun Feb 19 20:50:28 CST 2017

Dear Xavier

I understand that the equipment or parts of it were upgraded in January last year but the announcement did not give details.

David Beritault, a long time user of the equipment and former head of the GERES Lab in Phnom Penh, and I investigated the limits and stability of the gas detector using a very accurate Agilent multiplexer. The purpose was to find out how precise the output was. We then calibrated it with zero and span gases while bypassing all the analytical software so as to be able to use the raw signal directly.

The CO cell is quite good. The CO2 is not. It doesn't have an O2 cell so the O2 is inferred from the CO2 and it uses a carbon balance method.

One way to assign a limit is to accept a signal that has a drift of 1/3 of value. There are other opinions.

I believe the minimum precision for an EPA certified cell such as the NRID bench from Infrared Industries in California is 0.01% ±0.02% is typical. Enerac uses a slightly shorter cell which reports 0‎.1% but in fact reads to 0.01% however the software can't be hacked to access the second digit. It has approval for some uses.

Only an assessment of the whole system ‎can give an upper limit of the clean stove assessment. While that has been done at least once for the PEMS/LEMS (the equipment box is the same) I have not seen it published yet. Maybe it was.

The standard deal with the LEMS is that the equipment is sent 'home' once a year for recalibration. ‎The PM background, which is a form of calibration from zero, is done by software which subtracts it. There are different ways this can be done and I have tried a couple. Using a non-standard method on one of the RKTC round robin tests (round one) I was able to obtain a much more accurate result. This shows that the overal result can be improved significantly by considering the system as a whole.

Because the spreadsheet is incorporated into the system I have an alternative sheet that removes a number of the errors in that method, and applies the LEMS readings directly in a different calculation.

Regards
Crispin

Dear Crispin,

I did not know it was known the equipment from Aprovecho was having issues.
Maybe this is why there was a lot of problems with the PEMS calibration at Prakti.
I'll check with the guys at Prakti and see what's the update on that.

Best,

Xavier

On 2/19/17 15:50, Crispin Pemberton-Pigott wrote:
"For $3,000 ARC will test your cook stove in our Oregon lab and provide an ISO certificate of Tier performance ratings."

To my knowledge ARC is not an ISO certified lab. They are not empowered to issue 'an ISO certificate' of any kind.

The only lab I know for sure that is testing domestic stoves in a developing country that is ISO certified is the SEET Lab in Ulaanbaatar. The certificate is for ISO 17025, something achieved shortly after the lab director and manager both received their PhD's in stove testing.

‎The SEET Lab is therefore able to conduct tests (with any protocol) and issue an 'ISO' related certificate of performance.

There is no set of ISO tiers for cooking stoves because there is no ISO standard (yet).

To obtain ISO 17025 certification the lab is required to replicate the results of another qualified lab (plus a lot of other things). As is now widely know, labs using the WBT have been unable to replicate their own work within the requirements of the IWA 2012:11, let alone the WBT results of another lab. ‎The first reason for this is the WBT produces inherently uncertain outputs because of conceptual errors leading to improper calculations of metrics. That is the reason the GACC should disavow it.

The GACC has been giving LEMS equipment to RKTCs funded by earmarked grants from Shell. ‎Todd reported the persistent problems with that equipments when he had to deal with them. My experience is with LEMS not PEMS, so I can't comment. I do know that Aprovecho, GACC, CSU, the EPA and Berkeley are aware of a review of that equipment which concluded that it cannot place a stove on a benchmark above tier 3.5, were it to exist, due to sensitivity and accuracy limitations. That is independent of the WBT protocol issues.

The implications of this are obvious. How can one lab replicate the result of a tier 4 stove if both are using equipment that cannot do it confidently in the first place.

So this issue of testing and rating and certificates has some issues with both smoke and mirrors.

Regards
Crispin

Dear Nikhil,

  1.  I didn't want to spend time delving in the past to see who did what, how much the GACC promoted the WBT. The GACC was among the parties who was, I believe, pushing for an agreement at the IWA meeting. In the agreement, the writers wrote the sentence: "the WBT is not the only valid protocol". I don't know who said the WBT was valid in the first place. It has never been reviewed, as far as I know. But we were given this agreement to agree upon. I think the GACC has most often communicated about the WBT than other protocols, but that would be understandable, the WBT is quite convenient to use, and quite easy to learn. It was one of the main protocols, with the CCT and KPT, that was taught to the Regional Testing and Knowledge Centers (RTKC), an initiative of the GACC. But testers usually don't do so many CCTs, it is too costly, too many efforts to organize and it takes too much time. I believe it was mostly the VITA WBT, but I believe the GACC promoted also other protocols.
     *   The abstract Tom sent us is really interesting on how the WBT is commonly viewed: "as per the world standard protocol WBT 4.2.3"
     *   I think the GACC was supporting and promoting the updating of the WBT:
        *   http://cleancookstoves.org/about/news/02-28-2013-new-version-of-the-water-boiling-test-released-at-ethos-conference.html
        *   http://cleancookstoves.org/about/news/03-25-2014-stove-testing-update-release-of-water-boiling-test-protocol-4-2-3.html
        *   It is said here: "The Alliance and partners have been working over the last few months to finalize updates to the Water Boiling Test (WBT) to address comments from a public comment period on the WBT 4.1.2."
        *   Was there the same support for development of other protocols?
  2.  I don't know, but I don't believe so. I think the Aprovecho equipment was often the only suggested option, I don't know of other supplier of testing equipment. Maybe the Setar?

Another point: some people think the WBT is still good as a tool to develop stoves. I don't believe that is the case, and additionally I would like to remind everyone that the WBT has been used for years, and is still used to certify stoves, not only to help the first phases of their development. The WBT would say if a stove is clean or not, if it's good or not, regardless of the fuel and regardless of the cultural context.
The website of the Aprovecho Research Center says:

"For $3,000 ARC will test your cook stove in our Oregon lab and provide an ISO certificate of Tier performance ratings. The same tests results can be submitted to the Gold Standard as part of the carbon credit requirements."

I didn't know we could get ISO certificates for a stove tested.

As I said, what is the past is the past. What counts is what the GACC and us all do from now on.

Best,

Xavier

On 2/19/17 14:00, Xavier Brandao wrote:
Dear Nikhil,

  1.  I didn't want to spend time delving in the past to see who did what, how much the GACC promoted the WBT. The GACC was among the parties who was, I believe, pushing for an agreement at the IWA meeting. In the agreement, the writers wrote the sentence: "the WBT is not the only valid protocol". I don't know who said the WBT was valid in the first place. It has never been reviewed, as far as I know. But we were given this agreement to agree upon. I think the GACC has most often communicated about the WBT than other protocols, but that would be understandable, the WBT is quite convenient to use, and quite easy to learn. It was one of the main protocols, with the CCT and KPT, that was taught to the Regional Testing and Knowledge Centers (RTKC), an initiative of the GACC. But testers usually don't do so many CCTs, it is too costly, too many efforts to organize and it takes too much time. I believe it was mostly the VITA WBT, but I believe the GACC promoted also other protocols.
  2.  I think the GACC was supporting the updating of the WBT:

  1.  I don't know, but I don't believe so. I think the Aprovecho equipment was often the only suggested option, I don't know of other suppliers of testing equipment. Maybe the Setar?

Another
As I said, what is the past is the past.

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