Development and evaluation of a sustainable solar cooker for operations in Uganda

Abstract

The high level of increasing technological advancements and human population globally have resulted into escalated energy demands. With cooking accounting for almost 90% of all the household energy consumption in developing countries, traditional firewood stoves and improved charcoal stove are still dominant regardless of their negative impact. In Uganda, there is need of adopting clean and renewable non-depleting alternative energy sources among which includes solar cooking technologies. Many regional areas across Uganda and especially in the Northern and Eastern, receive approximately 4–5 kWh/m² per day of solar energy which is commendable for most solar cooking technologies. This study deals with the development and evaluation of a novel box-type direct solar cooker while putting in to consideration the existing cooking dynamics, solar irradiation and locally available materials for operation in Ugandan. For optimization, the cooking energy requirements for common foods like rice, matoke, and cassava, along with the average solar irradiation in Uganda, were considered to determine the cooker’s aperture area, which was calculated to be 0.1897 m². The cooker was further developed with internal side-wall reflectors to improve its performance efficiency and these were calculated as 340, 560, 430, and 430 due to south, north, west, and east respectively. Solar data and geographical data for Mbarara city (Having the lowest amount of daily Global Horizontal Irradiation (GHI) among the selected regional areas) were considered in the module design and simulation for performance feasibility. Using COMSOL Multiphysics 5.5 software, thermal analysis and optical analysis were conducted for the systems performance validation. Finally, locally available materials were considered for costing and construction of the developed solar for both economic and manufacturing feasibility. The cooker was costed at 210 USD with a payback period of 1 and 1.3 years while transitioning from cooking using charcoal and electricity respectively.