Development and Design of a portable off-grid photovoltaic system with contingency functions for rural areas : Case study Rwanda

Sammanfattning: This project is initiated by Engineers without Borders at Kungliga Tekniska Högskolan(KTH) in collaboration with the non-governmental organization Rwanda Village Concept Project at the University of Rwanda. It is funded by KTH Opportunities Fund with an amount of 20 000 SEK. The aim of the project is to design a portable off-grid photovoltaic(PV) system for a typical rural household in Rwanda, more specifically in the village Nyamabuye where there is no access to electricity. The requirements for the system are to have a total cost under 20 000 SEK, a weight under 25 kg and a capacity that meets the energy demand for a rural household. The system consists of PV modules, a battery, a charge controller and a converter. A literature study on off-grid PV systems and the components was conducted. For the case study, an estimation on the energy demand was made based on answers from a survey for locals in Nyamabuye and the current energy situation in Rwanda. To dimension the PV system according to the estimated energy demand, calculations based on a mathematical model for PV systems were conducted in MATLAB. A comparison regarding cost, weight, efficiency etc. of components that currently are available at the market was made. Components could then be chosen to make the system meet the set requirements. The result is a PV system that has a total cost of 10670 SEK and a weight of 13.6 kg. It is dimensioned to meet a daily energy consumption of 1022 Wh. There are several factors that could affect the performance of the system, for example different outdoor temperatures, that were not considered for simplicity. Therefor it is recommended that the system should be tested in different conditions.