Energy and exergy-based performances of a natural-convective solar dryer (NCSDR) integrated with sodium sulfate decahydrate (Na2SO4 center dot 10H(2)O) and sodium chloride (NaCl) as thermal storage medium are presented. The NCSDR was operational in Nigerian climate and applied for red chilli. The objectives of this study were to evaluate the thermal storage potential of Na2SO4 center dot 10H(2)O and NaCl with focus on energy consumption and exergy-sustainability indicators. The performances were compared to control experiment conditions. The results showed that NCSDR integrated with Na2SO4 center dot 10H(2)O, NaCl, and the control-experiment reduced the moisture content of red chilli from 72.27% to 7.6, 10.1 and 10.3% respectively. While, the overall drying efficiency and energy consumption of the three scenarios varied from 10.61 to 18.79% and 7.54-12.98 MJ respectively. The exergy efficiency for the drying system during sunshine-hours ranged from 66.79 to 96.09%. The exergy efficiency of drying using Na2SO4 center dot 10H(2)O thru off-sunshine hours and overall exergy-efficiency of the entire drying process were 81.19 and 66.82% respectively. Furthermore, the exergy-based sustainability indicators, waste-exergy ratio, sustainability index and improvement potential for sunshine-hours ranged from 0.166 to 0.174, 3.01 to 8.15 and 1.285-1.295 W respectively. Approximately 602 tonnes/year of CO2 could be limited from entering the air using Na2SO4 center dot 10H(2)O as thermal storage medium compared to diesel powered dryer. (C) 2017 Elsevier Ltd. All rights reserved.