Banana (Musa acuminata) is a vital staple food, but it suffers from high postharvest losses due to rapid ripening and poor processing. This study designed and evaluated a low-cost solar dryer for banana flour production to reduce postharvest losses. The dryer, constructed using local materials with surfaces of aluminium foil paper and aluminium tall-list (aluminium alloy 6061 (Magnesium and Silicon) drying, incorporated solar-powered fans for forced convection. It is backed with a tall black aluminium list to trap solar radiation. Experiments compared five treatments in quadruplicate: aluminium foil paper without a fan (T1), aluminium tall-list without a fan (T2), aluminium foil with a fan (T3), aluminium tall-list with a fan (T4), and open air drying (control, T5). Economic analyses were performed to assess the economic viability of the drying systems. Results revealed that there was no significant difference between treatments T1, T2, T3 and T4, which performed better than the control. Aluminium surfaces enhanced heat retention, with internal temperatures reaching 53.1 °C in T1 compared to ambient (30 °C). Fan-assisted drying reduced drying time by 50% compared to natural convection, while aluminium surfaces alone (T2) also outperformed the control. Passive dryers (T2) are optimal for short-term return on investment (26-day Payback Period (PBP). Fan-assisted dryers (T4) maximise long term profitability (4.760,000M CFA net profit). The study concludes that solar assisted drying with aluminium surfaces and forced convection significantly improves efficiency, offering a cost-effective solution for small-scale processors in tropical regions. Future research should explore hybrid designs for further optimisation.