Integrated Solar Cooking : Materials and Manufacturing of Conical Solar Cookers

Sammanfattning: This bachelor thesis is written as a Minor Field Studies (MFS) project and funded by SIDA, Sweden’s International Development Cooperation Agency. The project was made in cooperation with Engineers Without Borders Sweden and the local organization Asulma Centre in Nairobi. As a part of their Integrated Solar Research collaboration between the two organizations, the project strives to contribute to the United Nations sustainable development goals. Most households in Kenya rely on wood, charcoal and other sources of fossil fuel to use for cooking food. Unfortunately, these fuels produce smoke that causes great problems for the environment and for human health and can, in the worst cases, be lethal. It is estimated that 23 000 Kenyans die yearly from household air pollution produced from the fossil fueled stoves. Using the sun to cook food is a cheap alternative to conventional methods that are also more sustainable as it does not produce any smoke. The aim of this research was to study, analyze and optimize the model of a solar cooker called a conical cooker. In order to improve a previously developed concept of the conical cooker, this project focuses on what material and manufacturing methods should be used. A functional means tree was used to generate concepts, which were then analyzed using tools such as EduPack and an evaluation matrix based on a developed specification of requirements. After analyzing all the plausible options, it was suggested that the conical body should be made from a 1 mm (gauge 19) stainless steel sheet that has been mechanically polished and then joined together by crimping to shape the cone. The resulting product would cost 1430 KSH to manufacture, which is just below the cost of today’s cooker. It is also produced to withstand corrosion damage as well as maintain a reflective surface in order to work as a sufficient solar cooking method. This would be a cheap alternative that reduces health risks among the citizens of Kenya. However, as a solar cooker, it must be used together with other solutions as the sun is not always available which is why the project is called the Integradet Solar Cooking project.