Enhancing Solar Dryer Performance with Combined Flat Plate Absorber and Parabolic Trough Collector: A Comprehensive Techno-Economic and Environmental Study

In this study, the drying performance of a new solar collector was evaluated. The parabolic trough collector transfers heat to the water flow, which is then sent to the airflow through metallic spiral tubes. Techno-economic and environmental indicators were compared between single arrangement of flat-plate collector, and the combined arrangement of flat-plate and parabolic trough collectors. The results indicated that both arrangements reduced drying time by 7 h compared to direct sunlight. Additionally, the combined arrangement increased efficiency by 8 %, reduced the moisture ratio by 18 %, and enhanced the drying rate by 6 % compared to the single arrangement. The combined configuration achieves a higher ΔT, averaging 11–16 °C daily, despite lower solar intensity, compared to the 5–14 °C range observed in the single configuration. The economic analysis showed a levelized cost of heat of $0.16 USD/kWh for the combined arrangement. The environmental benefit is promising, with a reduction of 104–219 kg CO<inf>2</inf> annually instead of burning natural gas. Utilizing such an integrated movable device should be encouraged in locations capable of exploiting solar energy while facing environmental contamination issues. © 2025 Elsevier Ltd