Off-grid communities in South Africa face significant challenges in accessing reliable energy sources, with a particular focus on solar home systems (SHS). A mixed-method approach combining quantitative data analysis and qualitative field observations was employed. A difference-in-differences (DiD) econometric model was applied to assess system performance and economic benefits over time. The DiD model revealed that SHS significantly reduced energy costs by 40% in off-grid communities compared to grid-connected areas, with a robust standard error of ±5%. The findings suggest that the DiD approach effectively captures the impact of solar home systems on cost-effectiveness. Policy recommendations include promoting SHS adoption and infrastructure development to enhance energy access in off-grid communities. solar home systems, off-grid communities, difference-in-differences, cost-effectiveness, South Africa The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.