Tsuanyo et al. Sustainable Energy Research (2023) 10:3 https://doi.org/10.1186/s40807-023-00072-1 REVIEW © The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Open Access Sustainable Energy Research Design models for small run-of-river hydropower plants: a review David Tsuanyo 1* , Boris Amougou 1,2 , Abdoul Aziz 1 , Bernadette Nka Nnomo 3 , Davide Fioriti 4 and Joseph Kenfack 2 Abstract Hydropower plants are among the most efficient and reliable renewable energy systems in the world as far as elec- tricity production is concerned. Run-of-river hydropower plants seem more attractive than conventional hydroelectric plants since they can be a cheaper and environmentally friendly alternative. However, their expected energy produc- tion pattern heavily depends on several construction variables that need an appropriate design using specific models. This paper analyzes several existing models used for the calculation of the diameter and thickness of a penstock, the optimal selection and implantation (admissible suction head) of a turbine, to estimate the energy produced and expected cost of small hydropower projects for grid-connected and off-grid/micro-grid applications. This review particularly brings out the specificities of each of the models to suggest the most appropriate model according to the context of study and proposes methods to use them more efficiently. This review can be used as a guide in the design and simulation of run-of-river hydropower plants, thus helping in the assessment of the economic feasibility of projects that usually requires a high level of experience and expertise. Highlights • A critical review focused particularly on run-of-river hydropower plant design models was carried out. • Several calculation models including diameter and thickness of a penstock, admissible suction head of a turbine, and cost and energy production estimation for grid-connected applications are collected and analyzed. • Hydropower models for design and generation profle prediction presented can be used to optimally come against the variability problem of run-of river plants. • Te paper can be used as a guide in the design and simulation of run-of-river hydropower plants with appropri- ate models. Keywords Run-of-river, Hydropower plant, Optimal design, Energy system modeling, Mini-grids *Correspondence: David Tsuanyo david.tsuanyo@gmail.com 1 National Center for Development of Technologies-Ministry of Scientific Research and Innovation, PO Box 1457, Yaoundé, Cameroon 2 National Advanced School of Engineering/ L3E, University of Yaoundé I, PO Box 8390, Yaoundé, Cameroon 3 Institute of Geological and Mining Research- Hydrological Research Centre (IRGM-CRH)-Ministry of Scientific Research and Innovation, PO Box 1457, Yaoundé, Cameroon 4 Department of Energy, Systems, Territory and Construction Engineering, University of Pisa, Largo Lucio Lazzarino 1, 56122 Pisa, Italy