Performance assessment of an improved cook stove (Esperanza) in a typical domestic setting: implications for energy saving

Abstract

Background: Much of the Malawi’s energy source, which is biomass, is consumed using traditional household technologies. These technologies contribute to over consumption of biomass leading to increased forest degradation, and they release various gases and particulate matter that often cause indoor air pollution which is a health hazard to the users. To combat deforestation and pollution, improved cookstoves were introduced in Malawi from early 2000. A number of improved stoves were introduced including Esperanza which is reported to have 60% wood fuel saving under controlled conditions compared to the traditional 3-stone stove. The efficiencies of improved stoves were obtained through controlled cooking test, but very limited studies have evaluated them under normal household settings. Therefore, this study sought to compare the performance of the Esperanza stove with a 3-stone stove in a typical domestic setting. Methods: A Volunteer in Technical Assistance (VITA) standardized questionnaire was administered to households that were using the Esperanza stove. A cross-sectional Kitchen Performance Test (KPT) was conducted to compare the wood-saving performance of exclusive use of Esperanza stove and the 3-stone stove using the VITA KPT tool. Results: In the study area, a policy of banning household use of other cooking technologies has been in place with the main goal of encouraging the use of new technologies. There is evidence that the Esperanza stove was used more often, though it was used in combination with other technologies. Although Esperanza stove had earlier been reported to be more fuel efficient than the 3-stone stove, results revealed that due to improper use, the Esperanza stove consumed 86% more wood fuel compared to 3-stone stove. Conclusions: Three-stone stoves are still the preferred mode of cooking technology in most rural and peri-urban environments in Malawi. The shift to the improved stove technologies therefore requires urgent government intervention to ensure total use of these technologies that save energy and the environment. Additionally, the optimum efficiency of the Esperanza stove can be viable with training to new users. Thus, the importance of training on the proper use of Esperanza stove is recommended in order to optimize its performance and maximize energy saving.