New Energy Exploitation and Application

Review

A Critical Review of Trends in Performance Evaluation of Hybrid Solar Dryers: Focus on Energy Efficiency

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https://doi.org/10.54963/neea.v5i2.1705
Andrade, K. S., Correia, G. A., Souza, M. F. F., & Prado, M. M. do. (2026). A Critical Review of Trends in Performance Evaluation of Hybrid Solar Dryers: Focus on Energy Efficiency. New Energy Exploitation and Application, 5(2), 1–22. https://doi.org/10.54963/neea.v5i2.1705
Volume 5 Issue 2: June 2026
Copyright (c) 2026 Keyse Santos Andrade, Gustavo Aragão Correia, Marcos Fábio Farias Souza, Manoel Marcelo do Prado
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Authors

  • Keyse Santos Andrade

    Department of Chemical Engineering, Federal University of Sergipe, São Cristó vão 49100‑000, Brazil
  • Gustavo Aragão Correia

    Department of Chemical Engineering, Federal University of Sergipe, São Cristó vão 49100‑000, Brazil
  • Marcos Fábio Farias Souza

    Department of Chemical Engineering, Federal University of Sergipe, São Cristó vão 49100‑000, Brazil
  • Manoel Marcelo do Prado

    Department of Chemical Engineering, Federal University of Sergipe, São Cristó vão 49100‑000, Brazil

Received: 15 October 2025; Revised: 21 April 2026; Accepted: 6 May 2026; Published: 13 May 2026

Solar drying of biomass has gained prominence as a pretreatment step for biofuel production. The literature presents a wide diversity of definitions and terminologies for evaluating solar dryer performance, particularly in systems with supplementary energy inputs, limiting consistent comparisons between studies. This review provides a critical analysis of the main energy-based performance indicators, with emphasis on hybrid systems. Collector and drying chamber efficiencies are examined based on thermal and energy concepts, considering different dryer configurations. Standardized formulations are proposed to better represent the underlying processes and clarify the distinctions between PV and PVT-assisted systems. The analysis shows that collector performance in active systems is more consistently represented when based on absorbed solar energy and electrical power consumed by the fan. Accurate assessment of drying performance requires accounting for the heat of moisture desorption, sensible heating of the product, useful solar energy for air heating, fan power and supplementary energy inputs. Instantaneous efficiencies are more informative than cumulative ones, as they enable identification of less efficient drying periods and provide insights for optimizing operating conditions and reducing energy consumption. Continuous monitoring of key process variables including solar radiation intensity, air and product temperatures, and product mass is therefore required. Overall, this review establishes a consistent framework for the assessment of solar dryers, enhancing comparability and supporting more reliable analyses across studies. Future research should focus on the effects of intermittent and variable airflow rates on system performance.

Keywords:

Solar Energy Infrared Radiation Hybrid Drying Biomass Performance Parameters

References

  1. Khazaee, M.; Zahedi, R.; Faryadras, R.; et al. Assessment of Renewable Energy Production Capacity of Asian Countries: A Review. New Energy Expl. Appl. 2022, 1, 25–41. DOI: https://doi.org/10.54963/neea.v1i2.51
  2. Konyannik, B.Y.; Lavie, J.D. Valorization Techniques for Biomass Waste in Energy Generation: A Systematic Review. Bioresour. Technol. 2025, 435, 132973. DOI: https://doi.org/10.1016/j.biortech.2025.132973
  3. Joshi, N.C.; Sinha, S.; Bhatnagar, P.; et al. A Concise Review on Waste Biomass Valorization through Thermochemical Conversion. Curr. Res. Microb. Sci. 2024, 6, 100237. DOI: https://doi.org/10.1016/j.crmicr.2024.100237
  4. Ndukwu, M.C.; Augustine, E.B.; Ugwu, E.; et al. Drying Kinetics and Thermo-Economic Analysis of Drying Hot Water Blanched Ginger Rhizomes in a Hybrid Composite Solar Dryer with Heat Exchanger. Heliyon 2023, 9, e13606. DOI: https://doi.org/10.1016/j.heliyon.2023.e13606
  5. Faria, D.J.; Carvalho, A.P.A.d.; Conte-Junior, C.A. Fermentation of Biomass and Residues from Brazilian Agriculture for 2G Bioethanol Production. ACS Omega 2024, 9, 40298–40314. DOI: https://doi.org/10.1021/acsomega.4c06579
  6. Chojnacka, K.; Mikula, K.; Izydorczyk, G.; et al. Improvements in Drying Technologies—Efficient Solutions for Cleaner Production with Higher Energy Efficiency and Reduced Emission. J. Clean. Prod. 2021, 320, 128706. DOI: https://doi.org/10.1016/j.jclepro.2021.128706
  7. Yi, J.; Li, X.; He, J.; et al. Drying Efficiency and Product Quality of Biomass Drying: A Review. Dry. Technol. 2020, 38, 2039–2054. DOI: https://doi.org/10.1080/07373937.2019.1628772
  8. Kherrafi, M.A.; Benseddik, A.; Saim, R.; et al. Advancements in Solar Drying Technologies: Design Variations, Hybrid Systems, Storage Materials and Numerical Analysis: A Review. Sol. Energy 2024, 270, 112383. DOI: https://doi.org/10.1016/j.solener.2024.112383
  9. Kedar, S.A.; More, G.V.; Watvisave, D.S.; et al. A Critical Review on the Various Techniques for the Thermal Performance Improvement of Solar Air Heaters. Energy Sources Part A Recover. Util. Environ. Eff. 2023, 45, 11819–11852. DOI: https://doi.org/10.1080/15567036.2023.2264228
  10. Kong, D.; Wang, Y.; Li, M.; et al. A Comprehensive Review of Hybrid Solar Dryers Integrated with Auxiliary Energy and Units for Agricultural Products. Energy 2024, 293, 130640. DOI: https://doi.org/10.1016/j.energy.2024.130640
  11. Nnamchi, O.; Tom, C.; Akpan, G.; et al. Solar Dryers: A Review of Mechanism, Methods and Critical Analysis of Transport Models Applicable in Solar Drying of Product. Green Energy Resour. 2025, 3, 100118. DOI: https://doi.org/10.1016/j.gerr.2025.100118
  12. Ahmadi, A.; Das, B.; Ehyaei, M.A.; et al. Energy, Exergy, and Techno-Economic Performance Analyses of Solar Dryers for Agro Products: A Comprehensive Review. Sol. Energy 2021, 228, 349–373. DOI: https://doi.org/10.1016/j.solener.2021.09.060
  13. Shimpy; Kumar, M.; Kumar, A. Performance Assessment and Modeling Techniques for Domestic Solar Dryers. Food Eng. Rev. 2023, 15, 525–547. DOI: https://doi.org/10.1007/s12393-023-09335-5
  14. Kudra, T. Energy Aspects in Food Dehydration. In Advances in Food Dehydration; CRC Press: Boca Raton, FL, USA, 2009; pp. 423–446.
  15. Kudra, T. Energy Aspects in Drying. Dry. Technol. 2004, 22, 917–932. DOI: https://doi.org/10.1081/DRT-120038572
  16. Lingayat, A.B.; Chandramohan, V.P.; Raju, V.R.K.; et al. A Review on Indirect Type Solar Dryers for Agricultural Crops—Dryer Setup, Its Performance, Energy Storage and Important Highlights. Appl. Energy 2020, 258, 114005. DOI: https://doi.org/10.1016/j.apenergy.2019.114005
  17. Andrade, K.S. Design, Construction and Performance Evaluation of a Hybrid Solar Dryer for Drying Cassava Peel. Master’s Thesis, Universidade Federal de Sergipe, São Cristóvão, Brazil, 2024. (in Portuguese)
  18. Nidhul, K.; Kumar, S.; Yadav, A.K.; et al. Computational and Experimental Studies on the Development of an Energy-Efficient Drier Using Ribbed Triangular Duct Solar Air Heater. Sol. Energy 2020, 209, 454–469. DOI: https://doi.org/10.1016/j.solener.2020.09.012
  19. Nidhul, K.; Yadav, A.K.; Anish, S.; et al. Thermo-Hydraulic and Exergetic Performance of a Cost-Effective Solar Air Heater: CFD and Experimental Study. Renew. Energy 2022, 184, 627–641. DOI: https://doi.org/10.1016/j.renene.2021.11.111
  20. Prajapati, S.; Naik, N.; V.P., C. Numerical Solution of Solar Air Heater with Triangular Corrugations for Indirect Solar Dryer: Influence of Pitch and an Optimized Pitch of Corrugation for Enhanced Performance. Sol. Energy 2022, 243, 1–12. DOI: https://doi.org/10.1016/j.solener.2022.07.044
  21. Mohana, Y.; Mohanapriya, R.; Anukiruthika, T.; et al. Solar Dryers for Food Applications: Concepts, Designs, and Recent Advances. Sol. Energy 2020, 208, 321–344. DOI: https://doi.org/10.1016/j.solener.2020.07.098
  22. Duffie, J.A.; Beckman, W.A. Solar Engineering of Thermal Processes, 1st ed.; Wiley: Hoboken, NJ, USA, 2013.
  23. Farahat, S.; Sarhaddi, F.; Ajam, H. Exergetic Optimization of Flat Plate Solar Collectors. Renew. Energy 2009, 34, 1169–1174. DOI: https://doi.org/10.1016/j.renene.2008.06.014
  24. Shaker, L.M.; Al-Amiery, A.A.; Hanoon, M.M.; et al. Examining the Influence of Thermal Effects on Solar Cells: A Comprehensive Review. Sustain. Energy Res. 2024, 11, 6. DOI: https://doi.org/10.1186/s40807-024-00100-8
  25. Imre, L. Solar Drying. In Handbook of Industrial Drying; Mujumdar, A.S., Ed.; CRC Press: Boca Raton, FL, USA, 2006; pp. 308–356.
  26. Goud, M.; Reddy, M.V.V.; V.P., C.; et al. A Novel Indirect Solar Dryer with Inlet Fans Powered by Solar PV Panels: Drying Kinetics of Capsicum Annum and Abelmoschus Esculentus with Dryer Performance. Sol. Energy 2019, 194, 871–885. DOI: https://doi.org/10.1016/j.solener.2019.11.031
  27. Şevik, S.; Aktaş, M.; Dolgun, E.C.; et al. Performance Analysis of Solar and Solar-Infrared Dryer of Mint and Apple Slices Using Energy-Exergy Methodology. Sol. Energy 2019, 180, 537–549. DOI: https://doi.org/10.1016/j.solener.2019.01.049
  28. Ebadi, H.; Zare, D.; Ahmadi, M.; et al. Performance of a Hybrid Compound Parabolic Concentrator Solar Dryer for Tomato Slices Drying. Sol. Energy 2021, 215, 44–63. DOI: https://doi.org/10.1016/j.solener.2020.12.026
  29. Mugi, V.R.; Gilago, M.C.; Chandramohan, V.P.; et al. Performance Evaluation of Indirect Solar Dryer under Passive and Active Modes during Drying Beetroot Slices. Heat Transf. Eng. 2025, 46, 645–659. DOI: https://doi.org/10.1080/01457632.2024.2332113
  30. Mugi, V.R.; Chandramohan, V.P. Energy and Exergy Analysis of Forced and Natural Convection Indirect Solar Dryers: Estimation of Exergy Inflow, Outflow, Losses, Exergy Efficiencies and Sustainability Indicators from Drying Experiments. J. Clean. Prod. 2021, 282, 124421. DOI: https://doi.org/10.1016/j.jclepro.2020.124421
  31. Mugi, V.R.; Chandramohan, V.P. Energy, Exergy and Economic Analysis of an Indirect Type Solar Dryer Using Green Chilli: A Comparative Assessment of Forced and Natural Convection. Therm. Sci. Eng. Prog. 2021, 24, 100950. DOI: https://doi.org/10.1016/j.tsep.2021.100950
  32. Mugi, V.R.; Chandramohan, V.P. Energy, Exergy, Economic and Environmental (4E) Analysis of Passive and Active-Modes Indirect Type Solar Dryers While Drying Guava Slices. Sustain. Energy Technol. Assess. 2022, 52, 102250. DOI: https://doi.org/10.1016/j.seta.2022.102250
  33. Kumar, B.; Szepesi, G.; Szamosi, Z. Optimisation Techniques for Solar Drying Systems: A Review on Modelling, Simulation, and Financial Assessment Approaches. Int. J. Sustain. Energy 2023, 42, 182–208. DOI: https://doi.org/10.1080/14786451.2023.2185870
  34. Ghasemi, G.; Moradi, M.; Zare, D.; et al. Energy and Exergy-Based Threshold Setting for the Auxiliary Heating Source of a Hybrid Solar/IR Drying System. Sustain. Energy Technol. Assess. 2023, 59, 103400. DOI: https://doi.org/10.1016/j.seta.2023.103400
  35. César, L.-V.E.; Ana Lilia, C.-M.; Octavio, G.-V.; et al. Energy and Exergy Analyses of a Mixed-Mode Solar Dryer of Pear Slices (Pyrus communis L). Energy 2021, 220, 119740. DOI: https://doi.org/10.1016/j.energy.2020.119740
  36. Akpinar, E.K.; Koçyiğit, F. Energy and Exergy Analysis of a New Flat-Plate Solar Air Heater Having Different Obstacles on Absorber Plates. Appl. Energy 2010, 87, 3438–3450. DOI: https://doi.org/10.1016/j.apenergy.2010.05.017
  37. Chowdhury, M.M.I.; Bala, B.K.; Haque, M.A. Energy and Exergy Analysis of the Solar Drying of Jackfruit Leather. Biosyst. Eng. 2011, 110, 222–229. DOI: https://doi.org/10.1016/j.biosystemseng.2011.08.011
  38. Arslan, E. Experimental Performance Analysis of Infrared Assisted Solar Air Heater for Continuous Applications of Drying. Energy Sources Part A Recover. Util. Environ. Eff. 2023, 45, 1168–1185. DOI: https://doi.org/10.1080/15567036.2023.2176572
  39. Maithani, R.; Saini, J.S. Performance Evaluation of Solar Air Heater Having V-Ribs with Symmetrical Gaps in a Rectangular Duct of Solar Air Heater. Int. J. Ambient Energy 2017, 38, 400–410. DOI: https://doi.org/10.1080/01430750.2015.1133455
  40. Hassan, A.; Nikbakht, A.M.; Fawzia, S.; et al. Assessment of Thermal and Environmental Benchmarking of a Solar Dryer as a Pilot Zero-Emission Drying Technology. Case Stud. Therm. Eng. 2023, 48, 103084. DOI: https://doi.org/10.1016/j.csite.2023.103084
  41. Dutta, P.; Dutta, P.P.; Kalita, P. Energy and Exergy Study of a Novel Multi-Mode Solar Dryer without and with Sensible Heat Storage for Garcinia Pedunculata. Energy Sources Part A Recover. Util. Environ. Eff. 2023, 45, 9266–9282. DOI: https://doi.org/10.1080/15567036.2023.2234325
  42. Arslan, E.; Aktaş, M. 4E Analysis of Infrared-Convective Dryer Powered Solar Photovoltaic Thermal Collector. Sol. Energy 2020, 208, 46–57. DOI: https://doi.org/10.1016/j.solener.2020.07.071
  43. Strumiłło, C.; Jones, P.L.; Zyłła, R. Energy Aspects in Drying. In Handbook of Industrial Drying; Mujumdar, A.S., Ed.; CRC Press: Boca Raton, FL, USA, 2006; pp. 1075–1099.
  44. Vijayan, S.; Arjunan, T.V.; Kumar, A. Fundamental Concepts of Drying. In Solar Drying Technology: Concept, Design, Testing, Modeling, Economics, and Environment; Prakash, O., Kumar, A., Eds.; Springer: Singapore, 2017; pp. 3–38.
  45. Kudra, T. Energy Performance of Convective Dryers. Dry. Technol. 2012, 30, 1190–1198. DOI: https://doi.org/10.1080/07373937.2012.690803
  46. Danilov, O.L.; Leontchik, B.I. Energy Economic in Thermal Drying; Energoatomizdat: Moscow, Russia, 1986.
  47. Prakash, O.; Kumar, A. Solar Drying Technology: Concept, Design, Testing, Modeling, Economics, and Environment; Springer: Singapore, 2017.
  48. Brandão, R.J.; Borel, L.D.M.S.; Marques, L.G.; et al. Heat and Mass Transfer, Energy and Product Quality Aspects in Drying Processes Using Infrared Radiation. In Drying and Energy Technologies; Delgado, J.M.P.Q., Barbosa De Lima, A.G., Eds.; Springer International Publishing: Cham, Switzerland, 2016; 63, pp. 111–130.
  49. Ashworth, J.C. Energy Performance of Drying and Application of Heat Recovery Devices. In The Scientific Approach to Solids Drying Problems; Ashworth, J.C., Ed.; Drying Research Ltd.: Birmingham, England, 1982.
  50. Strawinski, A. Proposal for Determination of Thermal Efficiency Factor for a Dryer; Ashworth, J.C.: Birmingham, England, 1982; 1.
  51. Poirier, M.; Kudra, T.; Platon, R. Pulsed Fluid-Bed Technology—Opportunities for Low Temperature Drying of Biomaterials. In Proceedings of the 1st Nordic Drying Conference, Trondheim, Norway, 27–29 June 2001.
  52. Kudra, T. Instantaneous Dryer Indices for Energy Performance Analysis. Inż. Chem. Proces. 1998, 19, 163–172.
  53. Abedini, E.; Hajebzadeh, H.; Mirzai, M.A.; et al. Evaluation of Operational Parameters for Drying Shrimps in a Cabinet Hybrid Dryer. Sol. Energy 2022, 233, 221–229. DOI: https://doi.org/10.1016/j.solener.2022.01.045
  54. Mirzaei, S.; Ameri, M.; Ziaforoughi, A. Energy-Exergy Analysis of an Infrared Dryer Equipped with a Photovoltaic-Thermal Collector in Glazed and Unglazed Modes. Renew. Energy 2021, 169, 541–556. DOI: https://doi.org/10.1016/j.renene.2021.01.046
  55. Rezvani, Z.; Mortezapour, H.; Ameri, M.; et al. Energy and Exergy Analysis of a Water Bed‐infrared Dryer Coupled with a Photovoltaic‐thermal Collector. J. Food Process Eng. 2022, 45, e14058. DOI: https://doi.org/10.1111/jfpe.14058
  56. Singh, A.; Sarkar, J.; Sahoo, R.R. Experimental Performance Analysis of Novel Indirect-Expansion Solar-Infrared Assisted Heat Pump Dryer for Agricultural Products. Sol. Energy 2020, 206, 907–917. DOI: https://doi.org/10.1016/j.solener.2020.06.065