Techno-economic Analysis of Standalone Zambian Solar Home Systems considering the Geo-placement and Plot-area constraints

The electrification rate for Zambia was 43% in 2022 with grid connection the most preferred option for most residential households located near the grid. However, some households are positioned far from the nearest substation. Consequently, a discrete solar home system is the most promising option. The aim of this research is to assess the financial and energy yield feasibility of rooftop solar home systems for a typical Zambian residential plot size and residential load categories. The Zambian standard home has a plot size of 20 m by 30 m(600 m
²
) with an average energy demand of 200 kWh per month. A survey from 202 randomly selected households was conducted to capture information about the locations, energy usage behavior, state of electrification and demographic data for the various households. The analysis considered only eleven (11) geospatially positioned districts in Zambia. A total of 140,256 hourly solar irradiance and temperature values were considered from 2005 to 2020 for each location. The results indicated a very high positive correlation of above 0.9 in the irradiance and temperatures of the locations. The load profile for each load category was obtained using the probability coefficients based on occupants device sharing. The central limit theorem with confidence interval of 95% was used to provide the upper and lower limits of the expected energy yields for three (3) types of panels. The 415 W panel type gave the optimal daily kWh of 174±17kWh for low cost plots, 281±28kWh for medium cost plots, 839±84kWh for high cost plots and 4690±470kWh for farm plots. It was observed that when fully utilized solar home systems could provide enough energy to meet the local loads with an excess of 70 – 90% daily kWh. The Levelized cost of electricity of ${\$}$0.0833/kWh was obtained.