Watching the Smoke Rise Up: Thermal Efficiency, Pollutant Emissions and Global Warming Impact of Three Biomass Cookstoves in Ghana

In Ghana, about 73% of households rely on solid fuels for cooking. Over 13,000 annual deaths are attributed to exposure to indoor air pollution from inefficient combustion. In this study, assessment of thermal efficiency, emissions and total global warming impact of three cookstoves commonly used in Ghana was completed using IWA water boiling test (WBT) protocol. Statistical averages of three replicate tests for each cookstove were computed. Thermal efficiency results were: wood-burning cookstove 12.2 ± 5.00% (Tier 0), coalpot charcoal stove 23.3 ± 0.73% (Tier 1-2) and Gyapa charcoal cookstove 30.00 ± 4.63% (Tier 2-3). The wood-burning cookstove emitted more CO, CO2 and PM2.5 than coalpot charcoal stove and Gyapa charcoal cookstove. Emission factor for PM2.5 and emission rate for the wood-burning cookstove (Tier 0) were over four times higher than the coalpot charcoal stove (Tier 3) and Gyapa charcoal cookstove (Tier 2). To complete WBT, the study results showed that using Gyapa charcoal cookstove instead of the wood-burning cookstove, global warming impact could be potentially reduced by approximately 75% and 50% using Gyapa charcoal cookstove instead of coalpot charcoal cookstove. We conclude that there is the need for awareness, policy and incentives to enable end-users switch to and adopt Gyapa charcoal cookstoves for increased efficiency, reduced emissions/global warming impact.