Potential of bio-fuel geysers: Characterisation and performance evaluation of the Shiza Manzi bio-fuel geyser

This paper aims to highlight the potential and prospects of bio-fuel geysers in South Africa, notably the Shiza Manzi geyser. The geyser is compared to the imbaula and an improved StoveTec bio-fuel stove using the SeTAR Centre heterogeneous stove testing protocol. The geyser gave a high power of 23 kW and an adequate thermal efficiency of 36%, boiling 20 litres of water in an average of 12-minutes. The CO:CO₂ ratio (indicator of combustion efficiency) was high (12%) during the middle phase of combustion, but averaged 6.9% over the entire burn phase, indicating moderate combustion efficiency. The imbaula and StoveTec both took on average 20 minutes to bring 5 litres of water to the boil, with average fire-powers of 4 kW and 2 kW, respectively. The imbaula had a thermal efficiency of 15% and the StoveTec 28%. Information from this paper can be useful in the development, design and dissemination of more efficient bio-fuel hot water geysers. The rollout of bio-fuel hot water heaters has potential as a CO₂ mitigation strategy and such evaluations are needed as part of emerging air quality management strategies to improve quality of life in countries that are still dependent on bio-fuels to meet their domestic and institutional cooking and hot water needs.