International Science Community Association Research Journal of Engineering Sciences 15 2 2026 05 26 Main indicators evaluating the performance of Solar Dryers 21 35 EN Alimova Zebo 1 Candidate of Technical Sciences, Professor, Department of Transport Energy Devices, Tashkent State Transport University, Tashkent, Uzbekistan Qurbonov Akrom 2 Tashkent State Transport University, Tashkent, Uzbekistan P.O. Isi 1 Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria Ofuaro 2 Department of Electronics and Computer Engineering, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria S. 3 Department of Electronics and Computer Engineering, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria Chinedu 4 Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria B.C. 5 Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria Ikenga 6 Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria O.A. 7 Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria Muomeliri 8 Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria C.B. 9 Department of Parasitology and Entomology, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria (TET Fund Centre of Excellence in Biomedicine, Engineering and Agricultural Translation Studies) Orizu 10 Department of Physics, University of Abuja, Nigeria G.E. 11 Ndukwe 12 F.O 13 Alor 14 K.P. 15 Aribodor 16 D.N. 17 Isah 18 J. 19 Sirojiddin Muradov 1 Department of Occupational Safety and Health, Karshi State Technical University, Karshi, Uzbekistan, Albertos Kabimba Mupa 1 Laboratory of Electrical Engineering and Electronic, Polytechnic Superior National School, Marien Ngouabi University, Brazzaville, Congo Flory Lidinga Mobonda 2 Laboratory of Electrical Engineering, ISTA-Kinshasa, Democratic Republic of the Congo André Bandekela Kazadi 3 Laboratory of Electrical Engineering, ISTA-Kinshasa, Democratic Republic of the Congo Timothée Nsongo 4 Faculty of Sciences and Techniques, Marien Ngouabi University, Brazzaville, Congo TOSSA Alain K. 1 Laboratoire d’Énergétique et de Mécanique Appliquée (LEMA), École Polytechnique d’Abomey-Calavi (EPAC), Benin ABALLO Saïd 2 Takaz-Eng, 01 BP 2197, Cotonou, Bénin SEHOU Houindo O. Maxime 3 Laboratoire d’Énergétique et de Mécanique Appliquée (LEMA), École Polytechnique d’Abomey-Calavi (EPAC), Benin FOKAPU Odette 4 Biomechanics and Bioengineering, University of Technology of Compiegne, Compiegne, France and Laboratory of Innovative Technologies, University of Picardie Jules Verne, Compiegne, France and Diasporeines Africa Association, Paris, France > Review Paper 2026 2 12 2026 05 26 This article presents a concise review of thirty (30) key performance indicators used to evaluate and optimize the efficiency of solar dryers during the design phase. Solar dryers play a crucial role in food preservation, food safety, and the promotion of sustainable practices. By examining these indicators, the study provides a solid basis for the design, optimization, and assessment of sustainable solar drying systems. The identified indicators are classified according to their relevance in energy, exergy, environmental, and economic analyses. From an energy perspective, drying energy efficiency (η_d) is the most commonly used parameter. At the environmental level, CO₂ emissions dominate performance assessment, while the discounted payback period (PBP) is the most widely applied economic indicator. However, the study emphasizes that relying on a combination of indicators leads to more robust decision-making. For example, in agro-food processing units, both the discounted payback period and net present value are critical economic metrics. Furthermore, the review highlights the exergo-economic indicator (Rex) as essential for optimal solar dryer design. This parameter integrates technical and economic considerations and identifies potential performance improvements at the component level. Consequently, minimizing Rexshould be a primary objective in solar dryer design. Copyright@ International Science Community Association