Development of a Solar Powered Evaporative Cooling Storage System for Tropical Fruits and Vegetables

Abstract

A solar powered evaporative cooling storage system (SPECSS) was developed to improve the shelf life of fruits and vegetables for small-holder farmers in rural Nigeria where an electrical power distribution network is almost nonexistent. The capacity of the SPECSS chamber was 0.39 m3. A suction fan (24 W) and a water pump (18 W) were powered through solar panels (182 W) with a battery (130 Ah) used to store charge and maintain the system's operation. Tomatoes, mangoes, bananas and carrots were then stored in the chamber for 3–4 weeks. The SPECSS chamber temperature depression and relative humidity from ambient conditions varied from 7.8 to 15.4C and from 44 to 96.8%, respectively. The shelf lives of tomatoes, mangoes, bananas and carrots stored inside the SPECSS chamber were 21, 14, 17 and 28 days, respectively, as against 6, 5, 5 and 8 days for ambient storage. Practical Applications Erratic power supply and inadequate facilities hinder storage of perishable crops, leading to postharvest losses. This study was designed to develop a solar powered evaporative cooling system for the storage of perishable crops. Extending produce quality for longer periods makes the solar powered evaporative cooling system suitable for use in rural communities where there is no electricity.