Assessment of an indirect solar dryer for small-scale resin production: Energy, exergy, economic (3E), and sustainability analysis

This study evaluates an innovative domestic indirect solar dryer (ISD) for drying grapes (Vitis Vinifera L.), focusing on energy, exergy, economic, and sustainability performance. Two trials with crop loads of 15% (Trial-1) and 33% (Trial-2) were conducted. Trial-2 exhibited higher energy efficiencies in the solar collector (SC) and drying chamber (DC) compared to Trial-1, with efficiencies of 61.4% and 58.5% for SC, and a 13% increase in DC efficiency. The daily average exergy efficiencies for SC and DC ranged from 11%-13% and 54%- 58%, respectively. Trial-2 also showed a 113% higher life cycle savings, a 54.4% decrease in payback period, and a 23% lower waste exergy ratio compared to Trial-1. Pre-treatment of grapes resulted in superior dried product quality. The study highlights the ISD's potential as an economically and environmentally sustainable solution for small-scale agricultural ventures, providing insights for renewable energy sectors