Sustainable Solar Cabinet Dryers: A Review of Design Innovations, Thermal Storage Integration, Hybrid Systems, and Techno‐Environmental Assessment

Abstract

ABSTRACT Although solar cabinet dryers (SCDs) represent an alternative to open sun drying (OSD) in the preservation of agricultural products, there are still challenges for SCDs such as the solar intermittency, unequal drying, and poor thermal efficiency. This systematic review brings together 30 peer‐reviewed studies from 2017 to 2026 using a systematic thematic review based on four thematic areas: design innovations, integration of thermal energy storage (TES), hybrid regimes and modeling, control and techno‐environmental performance. The studies conducted under different climatic conditions, system configurations, and product types suggest that forced convection (FC) systems can decrease drying time by about 42% compared to OSD with moisture content being reduced from 86.2% (wet‐basis) to 13.75% (wet‐basis) in 16 h under solar irradiance conditions typical of tropical and semi‐arid regions. A solar radiation gain of up to 23%–38% has been reported in systems installed at higher latitudes, having collector surface areas of 1–3 m 2 , which include reflective north wall integration. Reflective north wall integration is found to increase the solar radiation uptake up to 23%–38% within the systems installed at higher latitude with collector surface area of 1–3 m 2 . Phase Change Materials (PCMs) enhance overall drying efficiency by up to 39.9% when integrated with evacuated tube solar collectors (ETSCs) under average irradiance levels of 500–800 W/m 2 , while hybrid geothermal‐solar systems contribute 49.5%–58.4% of total energy demand across varying seasonal and meteorological conditions. From a techno‐economic perspective, payback periods ranging from 0.17 to 1.16 years have been reported across systems of differing capacities, locations, and initial investment costs, with CO 2 mitigation reaching 18,953 kg over system lifetime and sustainability indices of 1.14–1.65. Multi‐point air supply configurations minimize temperature non‐uniformity by 52.2% and reduce energy consumption by 23.3% relative to single‐inlet designs, while fuzzy logic control systems maintain optimum drying temperatures within the range of 45°C–50°C and reduce drying time by 22% compared to conventional proportional‐integral‐derivative (PID) controllers under equivalent loading and airflow conditions.