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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoPlainText>Dear Paul and participating Conversants<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>This is a really valuable discussion and it will bring into sharp relief some issues that have to be urgently addressed by the stove community even if it takes several years.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><a href="http://www.snvworld.org/en/sectors/renewable-energy/news/gaining-a-user-perspective-on-improved-cookstoves-in-cameroon"><span style='color:windowtext;text-decoration:none'>http://www.snvworld.org/en/sectors/renewable-energy/news/gaining-a-user-perspective-on-improved-cookstoves-in-cameroon</span></a> <o:p></o:p></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText>> Earlier lab results, which designated the Mwoto gasification stove as <o:p></o:p></p><p class=MsoPlainText>> the highest performing one of the five based on its fuel consumption <o:p></o:p></p><p class=MsoPlainText>> and heating capacity, were not mirrored at the household level, the <o:p></o:p></p><p class=MsoPlainText>> women being overall quite reluctant to utilize a stove whose <o:p></o:p></p><p class=MsoPlainText>> modalities of use differed so widely from that of models traditionally <o:p></o:p></p><p class=MsoPlainText>> being employed.<o:p></o:p></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>While it is not clear what the exact meanings of ‘highest performing’ and ‘heating capacity’ are, I can already guess that the test applied, and the calculation method used to provide the values for those metrics may have differed substantially from the ones used in the field.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>This is quite separate from the obvious differences in operating modes. I am referring to the ‘ratings’ stoves achieve.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>As everyone by now knows, I have been harping on this for several years because it <i>really makes a difference</i> and I hate to see people wasting time and money promoting stoves that won’t be accepted or don’t work ‘as tested’.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText>>Observations for all readers:<o:p></o:p></p><p class=MsoPlainText>>1. Mwoto is the TLUD gasifier developed for and used in the BEIA study by CREEC in >Uganda in 2011 - 2012, and is related to the Quad TLUD and Troika Bingwa TLUD in >Uganda by Awamu, and to the Champion TLUD by Servals in India.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><span style='color:black'>I would like to confirm that the test applied was some version of either the UCB-WBT or the GACC-WBT 4.x.x. It may be that ratings provided by these testse are not very close to what would be expected in the field ‘by direct observation’. Let me explain that I mean by that.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>If you test a stove using some burn cycle and apply a calculation method to the measurements taken during the test, you get a result.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>If you watch people in the field and measure the ‘’input data’ (for example how much fuel is needed each day) you are making a direct measurement, not calculating some sort of rating based on formulas.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>The comparison between the mass of fuel used in the lab and the mass of fuel used in the field might not vary much at all if the fuels are similar and have similar moisture contents. Obvious there is little point in testing a stove with a fuel the people in the field don’t have because the emissions and burn rate etc will otherwise be quite different. Let’s assume you have that variable under control: you tested them using similar fuels.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>If you are using some ‘emission per x’ method of reporting performance and the calculation of that number is in any wat defective, you will get a skewed result. This cam explain a lot of differences between lab and field. Further, if there are conceptual errors in the calculations whereby you are performing a calculation that is not really valid, you will get all sorts of results that vary strangely and have little relation to actual performance.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Again suppose you have that under control (assume nothing in this regard, however).<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>If the ‘cooking power’ is the thing being rated, that is really easy – put on a pot and compare the time to heat a certain mass of water, for example. That tells you the relative cooking power. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText>>2. We know from repeated testing that these gasifier stoves are also very favorably rated concerning low emissions of CO and PM.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><span style='color:black'>The same questions arise: very favourably according to what method? Have the emissions been reported per MegaJoule of heat reaching the pot? Maybe a stove is very clean-burning per kg of fuel but has a poor heat transfer efficiency. It needs to be clean burning per unit of work done in a pot.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText>>3. Therefore, to have such good results about a stove in the lab and to have such a poor response for use by the local women in Cameroon is a cause of serious concern.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><span style='color:black'>Acceptance of the stove for non-technical reasons is the major course of programme failure. We should not beat around the bush. Social acceptability can be assessed using Cecil Cook’s 9 dimensions, which he likes to put in a spider chart with 5 (best/acceptable) in the centre and 1 at the outside edge. The dots are connected producing a ‘web’. Highly acceptable stoves have the points (scores) clustered in the centre with perhaps some outlying arms here and there. Poorly accepted stoves have a large diameter web mostly traced around the periphery. This can kind of social acceptance can be conducted best in focus groups where the influence of the observer is least exerted and the responses to questions most likely to be factual.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText>>There can be numerous issues that related to the stove itself and other issues that relate to social and cultural aspects of the study as conducted with the sample of users. Number of users, length of time using the stove, instruction on the stove usage (ignition, changing after batches of fuel, etc), and fuel issues (type and preparation etc) are all possible sources of accumulating difficulties.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><span style='color:black'>Agreed. Local cooking practices were examined in Central Java first, for the programme being implemented this month. We have a pretty good idea what people do, when, with what pots, for how long and at what heat level. This allows the stove selection process, which is ongoing at the moment, to address what will late be pretty obvious problems if there is a mismatch between what a candidate stoves does and what people want.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText>>…If only 10% of the households (not just the sample) in Cameroon found that the TLUD stove was acceptable, that would be 300,000 stoves. (population 20 million >>> about 3 to 4 million households). And if improvements in the pot supports or training or fuel supply or other issues could increase the acceptance levels, the numbers could be even higher.<o:p></o:p></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>It is likely that more than 10% of the people have two or three stoves used for different tasks. Unless this sort of information is known, it is difficult to assess which test to apply to the stoves to give them a rating, social of technical. The testing has to reflect reality or the comparative results are rarely helpful. <o:p></o:p></span></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>>…I am delighted that SNV included the Mwoto stove in its study. <o:p></o:p></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Fully agreed and thanks for the candid report. Let’s all try to work out how to help the programme and provide stoves people want, appreciate and use.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Regards<br>Crispin<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><o:p> </o:p></p></div></body></html>