A bibliometric analysis of small hydroelectric power plants: major trends, gaps, and challenges for future research

Purpose This study aims to conduct a comprehensive bibliometric analysis of the scientific literature on Small Hydropower Plants (SHPs), mapping the field’s conceptual structure, intellectual foundations and emerging research fronts. By examining publication patterns, co-authorship networks, citation and cocitation structures and keyword co-occurrence, the study identifies the most influential authors, institutions, journals and countries. The goal is to provide researchers and policymakers with an integrated overview of the main trends, gaps and challenges in SHP research, supporting future investigations and evidence-based decision-making in renewable energy planning. Design/methodology/approach This study uses bibliometric methods to analyze the scientific production on Small Hydropower Plants (SHPs). Data were extracted from the Web of Science database, covering the period from 1945 to 2023. VOSviewer and CiteSpace were used to map co-authorship, cocitation, bibliographic coupling and keyword co-occurrence networks, as well as to detect emerging trends through citation burst analysis. This approach enables the examination of the field’s intellectual structure, identification of the most influential authors and journals and assessment of thematic, collaborative and geographic evolution within the SHP research domain. Findings The findings show a consistent increase in scientific output on SHPs, particularly after 2005. China, India and the USA lead in publication volume, while India and Spain stand out in citation impact. Co-authorship networks reveal geographic concentration and limited cross-regional collaboration. Cocitation analysis highlights Renewable and Sustainable Energy Reviews, Renewable Energy and Energy Policy as core journals. Keyword patterns emphasize sustainability, environmental impacts, optimization and flow regime analysis. Emerging research fronts include climate-related assessments, fish and aquatic ecosystem studies, flow-based modeling and multicriteria decision-making approaches. Originality/value This study provides the most comprehensive bibliometric synthesis to date on Small Hydropower Plants (SHPs), integrating co-authorship, cocitation, bibliographic coupling and emerging trend analyses. By consolidating more than five decades of scientific output, the research uncovers persistent gaps, particularly concerning environmental impacts, long-term sustainability and alignment with energy policy. The study also offers novel quantitative evidence on the field’s thematic and geographic evolution, supporting future research agendas, improving energy planning strategies and informing evidence-based decision-making for sustainable hydropower systems.