In his quest to solve social development issues, Mr Chris Bradnum, Head of the Industrial Design Department at the University of Johannesburg (UJ), worked with low-income households in the HaMakuya district in Limpopo to design a wood burning stove to better serve the needs in these households.
The result is a safe, efficient and sustainable wood burning stove, called the Tshulu Stove, named after Tshulu Trust, who partnered with Bradnum to develop a safer and more efficient biomass stove for rural and low-income households that reduce deforestation, alleviate issues of respiratory illnesses from open fire cooking, and reduce the risks of burning associated with open fire use.
|“The majority of low-income households in South Africa rely on open fires or use paraffin as their primary fuel source for heating and cooking needs. A recent study by the Global Alliance for Clean Cookstoves estimates that 3 billion people in the developing world cook food and heat their homes with traditional cookstoves or on open fires,” explains Bradnum. “More than 4-million premature deaths occur every year due to smoke exposure from cooking on open fires or using inefficient stoves in the homes.”|
Bradnum says that his research found that as an alternative to electricity, gas could be ideal in terms of clean cooking and efficiency, but there is a general mistrust of gas stoves. In many areas, paraffin is the fuel of choice for cooking. However, in the Ha-Makuya, Vhembe District in Limpopo, where Bradnum conducted research, the community tends to use wood fires for cooking.
“The cutting down of trees is strictly controlled in the area by village headmen and the local chiefs, so households can only use wood that has fallen off the trees or specific areas that have been demarcated for tree felling,” says Bradnum.
Bradnum pointed out that “this means that the community must spend extended periods searching for wood. The fallen branches are of little use in open fires as these burn up very quickly and don’t generate enough heat for cooking. However, these smaller branches burn extremely well in the Tshulu Stove.”
The Tshulu Stove that reduces wood use for cooking and reduces the amount of smoke and emissions given off by fires, is based on the ubiquitous ‘rocket stove’ design developed by Aprovecho in the United States, which includes a burn chamber and directed chimney of heat to the base of the cooking pot. “The Tshulu Stove, however, includes innovations such as introducing air below the burn chamber, a removable ashtray, standing height cooking, an inner sleeve that reduces the amount of heat loss from the burn chamber and an outer sleeve that reduces the chance of burning the stoves users,” says Bradnum.
In laboratory testing conducted at the University’s SeTAR (Sustainable Energy Technology and Research Centre), the stove has proved to be incredibly efficient.
“The combustion efficiency levels are ideal at: 2% for paraffin, 5% for charcoal and 10% for wood, with lower percentage indicating better efficiency. The Tshulu Stove achieves an average efficiency of 3%, a fraction above the ideal paraffin stove,” says Bradnum.
Bradnum concludes: “In effect the Tshulu Stove will save an average household, cooking three meals a day on the stove, 7kg wood per day over that of a three stone fire. This translate to a saving of 2 500kg of wood for one household in a year.”