Quantifying the Efficiency and Fuel Consumption of Cooking with Traditional Wood and Charcoal Stoves in Malawi, Ghana, and Kenya

Carbon emission reductions and other results-based financing determinations for clean cooking projects are heavily dependent on the fuel savings generated by a new technology. Historically this calculation is based on the difference in thermal efficiency between the traditional and new device measured in the laboratory. However, efficiency varies with technological and operational factors that can be accurately accounted for only by field-based measurements. In this research, an uncontrolled cooking efficiency test (UCET) was developed and implemented to measure baseline efficiency and fuel consumption during meal preparation for a planned total of 360 charcoal stove tests and 360 wood stove tests. Results show average thermal efficiencies of 11.8 ± 5.3% for traditional wood and 22.1 ± 9.8% for traditional charcoal cookstoves, demonstrating good agreement with the previous and current UNFCCC baseline values of 10% and 15% for wood and 20% and 25% for charcoal. Single meal fuel use was extrapolated to 0.17 ± 0.07 tonnes/capita/year of wood and 0.04 ± 0.02 tonnes/capita/year of charcoal, conservative compared to the UNFCCC global default of 0.4 tonnes of wood/capita/year. Multiple regression analysis indicated a strong statistical association of efficiency with firepower, pot/pan dimensions, and the cooking method. Results demonstrate the utility of the UCET for evaluating cookstove efficiency and fuel consumption in households to more accurately support the determination of emissions reductions.