1. The Uncontrolled Cooking Test: Measuring Three-Stone Fire Performance in Northern Mozambique
J. Robinson1,2, M. Ibraimo2,3, C Pemberton-Pigott1
1. SeTAR Centre, University of Johannesburg
2. Department of Geography, Environmental Management and Energy Studies, University of Johannesburg
3. Department of Physics, Eduardo Mondlane University, Maputo, Mozambique
DUE th April 2011

2. Background Importance of domestic biomass use in Mozambique
80% energy consumed is biomass
71% live in rural areas
Characterize energy baseline of rural villages
2010 field research programme
2008 socio-economic study by M. Ibraimo
Muculuone village, Nampula Province, northern Mozambique
Rural, poor, off-grid, subsistence farming
Heavy reliance (92%) on firewood and three-stone fire
Aims
Measure baseline cooking energy patterns
Provide data and experience for testing methodology devt.

3. Study Site
Nampula Province
Muculuone Village
DUE 2011

4. Cooking Technology and Fuel
Three-stone fire
Cooking Xima
DUE 2011

5. Measuring Stove Performance
Laboratory or Field
Trade-off between variability and relevance (task)
Kitchen Performance Test (KPT)
Fuel savings averaged over 3-7 days (kg/person/day)
Resource intensive
High variance (CoV 30-50%)
Controlled Cooking Test (CCT)
Fuel consumed in cooking a standard meal (kg wood/Kg food)
Less intensive
Moderate variance (CoV 10-30%), representative?
Middle ground?
DUE 2011

6. The Uncontrolled Cooking Test (UCT)
Measure real world performance of a cooking system
Meal not constrained, measuring as a household cooks
Wood used, food cooked (MJ wood/kg food)
Shorter time per test = more tests or less people
Stronger and more representative data set with a better measure of inherent variability of real world use
But can the test method show less variance than the KPT and in doing so use the same or less resources?
i.e. Detect a significant difference between a baseline and ‘improved’ scenario with a smaller sample size
If yes, of real use to carbon and development projects
DUE 2011

7. General Results
29 UCT’s in 24 households over 4 days, 3 tests rejected
Wood Average MCwet 13.1%, LHV (ARAF) 16.7 MJ kg-1
General observations
All households disposed of char
Average 5.0 ± 1.6 people per household
77% households cooked using 2 pots sequentially
58% cooked indoors
Uniform operating method for three stone fire
DUE 2010

8. UCT Results (1) Results presented as ‘no char’ and ‘with char’
High variance for time and food mass
20% difference in SFC due to char
SFC (no char) of 12.1 MJ wood per kg food
SFC CoV 25-30% is less than for KPT

9. UCT Results (2) Specific Fuel Consumption (no char case)
R2 = 0.79 shows strong correlation
Linear relationship
Variance around best fit
DUE 2011

10. Conclusions and Recommendations
UCT proved a capable and viable method
Captured key user behaviour
Less variation than typically reported by KPT (one case)
Offers potential to detect a statistically significantly difference between baseline and ‘improved’ stove by using less resources
Future work
Variability, error and sample size
Statistical treatments (non linear)
Correlate laboratory and field performance

11. Acknowledgements Vincent Molapo (UJ SeTAR) and Fabiano Simao (UEM)
Village elders and households in Muculuone
NRF/ NRI funded SAMOZ programme - Prof H. Winkler (UJ) and Prof M. Falcão (UEM)
UJ Quick Wins Programme, Volkswagen Stiftung Biomodels project through the IER, Uni. of Stuttgart
GTZ BECCAP/ProBEC for funding of UJ SeTAR centre and loan of vehicle.

12. Questions?