Evaluation of existing solar home systems performance in Rwanda: Case-study, Rulindo district

Abstract

In Rwanda, electricity access is still low especially in rural villages and 82.79% of the population lives in rural areas. The government decentralized the education where the students study, and back home at the evening time. Electricity access in rural areas is only 12%, this is a challenge for the students to revise the lessons and also a challenge for families in general to meet households’ demand, this leading them to use biomass energy that covers about 85% of primary energy use in Rwanda and this results in various health hazards, environmental pollution, etc. The use of Solar Energy Technology rationally may contribute effectively to solutions of the above problem. The Energy Development Corporation Ltd (EDCL) has signed with 21 Solar companies to facilitate the people getting the solar home systems (SHS) easily, However, some installed SHS fail to give the expected power output to meet home electricity demand and others are not functioning. This causes shortage of electric power and limits electricity extension works. This research evaluated the performance of SHS by measuring the output values of the system components with the help of Multimeter and tape meter for measuring the dimension of panels and make a comparison between calculated and installed efficiencies. Also, the data further collected through visiting 32 SHS, interviewing their owners and personal observation. SPSS software used to display collected data using frequency tables, pie charts, and bar charts. Matlab Software/ Simulink used for modelling, and run simulation to analyze the effect of some factors on I-V and P-V characteristics curves of selected solar panel The calculated efficiencies of panels were 10.7% and 9.7% while their installed efficiencies are 16% and 17% respectively, which shows that SHS are not properly working. The study found that the performance of SHS is mostly affected by the output of PV module, as its efficiency is affected by irradiance of the Area, roof form and inclination angle, maintenance activities etc. The measures taken focused on inspection and maintenance of SHS components especially PV module. The formulated solutions including: cutting tree leaves blocking sun rays from reaching panel, checking and cleaning the panel surface periodically, changing its direction for daily hours, Keeping battery in adequate area (dry area at room temperature), etc. The follow of guidance solutions boosts the efficiency of SHS and the periodic maintenance is the key factor for sustaining the components lifespan. The use of optimal SHS result in CO2 reduction and satisfy users through enough power for lighting, charging telephones, and help some of them to start small business