Development of a Solar-powered Cold Storage for Tomato Fruits Preservation.

Abstract

Post-harvest losses of tomato fruits present a significant challenge in agricultural production, especially in areas lacking reliable electricity. This research developed and assessed a solar-powered cold storage system designed to extend tomato shelf life. The system featured a 4-liter insulated chamber with two Peltier modules, heat sinks, CPU fans for air circulation, a 12V-12Ah battery, a 100W solar panel, a charge controller, and temperature control. Design calculations indicated a cooling power requirement of 23W with a total system load of 158W. Performance evaluation indicated 67.71% cooling efficiency, decreasing chamber temperature from 31°C to 21.6°C within 60 minutes under no-load conditions and maintaining 23.3 to 24.5°C during loaded operation. Comparative storage trials conducted over 12 days showed substantial differences between cold-stored and ambient-stored tomatoes. Cold storage prevented physiological weight loss to 3.39% compared with 26.73% for ambient storage, maintained firmness at 163.67 N/m² compared to 207.33 N/m² for controls, preserved moisture content at 11.41% against 10.07%, and minimized color changes. Both conditions maintained stable pH values (4.1 for cold storage versus 4.0 for ambient). The research confirms that solar-powered cold storage offers a practical, sustainable solution for minimizing tomato losses in regions with inadequate grid electricity, substantially extending shelf life while preserving marketability qualities.