Access to clean cooking energy remains a critical challenge in sub-Saharan Africa despite abundant solar irradiance. This study presents a systematic review and meta-analysis of box-type solar cookers published between 2015 and 2025, integrating first-law and second-law thermodynamic assessment. Nineteen experimental and field-based studies were synthesized using a random-effects model. The pooled thermal efficiency was 34.7% (95% CI: 32.9–36.5%), while reported exergy efficiency ranged between 8–15%, indicating substantial irreversibility primarily due to radiative and convective losses. Standardized mean difference analysis (Hedges’ g = 0.82) confirms that double-reflector configurations produce statistically significant performance improvements compared to single-reflector systems. Insulation improvements contributed moderately but with diminishing marginal gains. A generalized predictive efficiency correlation and uncertainty propagation framework are proposed to enable standardized cross-study benchmarking. Despite thermodynamic advancement, adoption rates remain below 20% in several semi-arid regions, demonstrating that engineering optimization alone does not guarantee large-scale deployment. The study provides an integrated analytical foundation for evaluating thermodynamic ceilings and socio-technical scalability of solar cooking technologies.
Sunday et al. (Fri,) studied this question.