The community-based research initiative led by North-West University (NWU), in partnership with SASOL and the local community of Oranjeville, aimed to evaluate the semi-continuous coal stove (SCCS) as a cleaner, sustainable alternative to traditional stoves in South African low-income households. This campaign sought to assess the SCCS's performance, community acceptance, and its impact on improving the quality of life and advancing the transition towards cleaner energy sources. An interdisciplinary team, including air quality specialists, social scientists, and engineers, collaborated to ensure a comprehensive evaluation through a multi-faceted approach.

NWU low-emission semi-continuous coal stove

The SCCS was developed by improving on the well-known coal gasification cookstove. The stove consists of three distinct sections: the hopper, the combustion chamber, and the heat exchanger chamber.

The fuel is loaded into the hopper, from where the fuel is gravity-fed to the combustion chamber through the grate. A fraction of the fuel is ignited at the bottom of the combustion chamber, which forms the initial combustion zone. After that, as ash and inert compounds fall through the grate, more fuel slides into the combustion zone and consequently ensures the propagation of the combustion zone towards the hopper. The hot flue gas and gaseous combustion products are directed upwards to the upper surface of the stove (the stove cooking surface). The flue gas flows into the heat exchanger chamber, where heat is transferred to the metallic surfaces of the stove. A baffle plate maximizes the heat transfer efficiency in this chamber. Finally, the flue gas exits the stove via the chimney and flows into the atmosphere, minimising indoor pollution and direct contact with the stove user in the combustion zone. After that, as ash and inert compounds fall through the grate, more fuel slides into the combustion zone and consequently ensures the propagation of the combustion zone towards the hopper.

The hot flue gas and gaseous combustion products are directed upwards to the upper surface of the stove (the stove cooking surface). The flue gas flows into the heat exchanger chamber, where heat is transferred to the metallic surfaces of the stove. A baffle plate maximizes the heat transfer efficiency in this chamber. Finally, the flue gas exits the stove via the chimney and flows into the atmosphere, minimising indoor pollution and direct contact with the stove user.

The NWU SCCS has shown potential as a viable alternative to traditional cooking methods in low-income communities, offering environmental and health benefits. The reduction in indoor pollutant levels and the positive community response highlight the stove's effectiveness and acceptability. However, ongoing education on proper stove usage and addressing minor concerns could further enhance its adoption and impact. This study lays a foundation for broader implementation efforts to promote sustainable and healthy energy solutions in South Africa's low-income households.