Off-grid communities in Ethiopia rely on solar-powered irrigation systems to enhance agricultural productivity. There is a need for robust methodological approaches to evaluate these systems effectively. A comprehensive search strategy was employed to identify relevant studies. Studies were assessed based on their methodology, data quality, and whether they utilised DiD models effectively for yield improvement measurement. The review identified several studies applying DiD models, but there is variability in the implementation of these models across different regions. Some studies reported significant improvements in yields with solar irrigation systems, while others noted mixed results due to varying environmental conditions and system designs. While DiD models offer a powerful tool for evaluating yield improvement from off-grid solar irrigation systems, their effectiveness is contingent upon proper model specification and robustness checks. Future research should focus on refining the application of DiD models through more detailed econometric analyses and cross-validation with other methodological approaches. Additionally, studies should consider incorporating additional control variables to enhance model validity. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.