A laboratory assessment of how biomass pellets could reduce indoor air pollution, mitigate climate change and benefit health compared to other solid fuels used in Ghana

Abstract

To reduce indoor air pollution, the government of Ghana in 2019 formulated the renewable energy master plan to help disseminate biomass pellets and stoves to 2,000,000 households by 2030. But pellets have neither been included in Ghana's energy mix nor have their surmised climate and health benefits been empirically assessed. This laboratory study tested emissions by burning wood, charcoal and pellets in improved cookstoves. It further modelled their associated indoor air pollution reduction, personal exposure, health benefits and climate impact for comparison. The emission factors based on useful energy delivered of CO, CO2 and PM2.5 were 3.506 ± 0.704, 306.6 ± 43.35, and 0.229 ± 0.039 g/MJdelivered, respectively, for wood rocket 1 stove; 2.115 ± 0.695, 272.8 ± 16.70, and 0.256 ± 0.166 g/MJdelivered for wood rocket 2 stove; 4.820 ± 1.098, 205.3 ± 60.49, and 0.051 ± 0.044 g/MJdelivered for charcoal 1 stove; 4.474 ± 1.525, 221.8 ± 65.71, 0.043 ± 0.040 g/MJdelivered for charcoal 2 stove; and 0.511 ± 0.325, 338.1 ± 45.41, and 0.041 ± 0.023 g/MJdelivered for pellet stove. The forced air supplied by the gasifier stove reduced pollutant emissions from pellet combustion. The 100-year global warming contribution of the pellet stove was lower than that of charcoal stoves, and was influenced by upstream emissions of fuel processing. The WHO (World Health Organization) models showed that a complete transition from wood to pellets in one million households could significantly improve health with most benefits for children below five years. However, the reported benefits can only be achieved if pellets are added to Ghana's energy mix. The government of Ghana can ensure a sustained adoption of pellets by fostering market enablers for supply and demand of pellets and gasifier stoves, and mitigating the factors that impact pellet production and use. Field evaluation of the economic, health and climate co-benefits of using pellets in Ghana is recommended for future study.