Performance Evaluation of Solar–Biogas Hybrid Cold Storage System for Transient Storage of Horticultural Produce

Abstract

Cold storage systems are predominantly used in production catchment area to minimize post harvesting losses for horticulture produce. Commercially available cold storage systems use huge amount of electricity and therefore are expensive. Renewable energy-based cold storage systems could be a clean, efficient, and cost-effective choice that can benefit farmers in rural areas, where electricity is scarce. We have developed a solar–biogas hybrid cold storage system that comprises of a vapour absorption machine (VAM), solar-evacuated tube collector (ETC) water heater, and solar photovoltaic module to meet the auxiliary power requirements. The system is integrated with all-brick masonry biogas plant of 50 m3/day capacity to supplement the energy requirement during non-sunshine hours. Three cold chambers, each of 2–3 MT storage capacities have been set up. A comprehensive performance evaluation of the VAM and ETC with heat pipe was carried out. The maximum coefficient of performance (COP) of hot water driven VAM was found to be 0.71 and maximum efficiency of the ETC with heat pipe system was calculated to be 46%. This system has the potential to store 6–8 ton of horticultural produce for a period of 2–3 weeks at the desired temperatures range of 12–16 °C.