Mapping renewable energy research in healthcare facilities: Publication trends, thematic evolution, and future research directions

Healthcare facilities are among the most energy-intensive public infrastructures, making the adoption of renewable energy increasingly important for improving environmental sustainability, energy security, and operational resilience. Although research on renewable energy in healthcare facilities has expanded considerably in recent years, the overall intellectual landscape and thematic development of this field have not been comprehensively synthesized. This study aims to provide a bibliometric overview of renewable energy research in healthcare facilities and to identify its publication trends, intellectual foundations, conceptual structure, and emerging research directions. A total of 139 publications indexed in the Web of Science database between 2011 and 2026 were systematically identified following the PRISMA framework and analyzed using R-based Bibliometrix software. Performance analysis, reference co-citation analysis, keyword co-occurrence analysis, thematic mapping, and thematic evolution analysis were conducted to examine the development of the research field. The findings reveal a substantial increase in scientific output over the past eight years, reflecting the growing importance of renewable energy in healthcare facilities. The intellectual structure of the field is primarily shaped by studies on hybrid renewable energy systems, hospital energy optimization, and sustainable energy access, while the conceptual structure demonstrates an increasing emphasis on sustainability, resilience, energy efficiency, and healthcare facilities. Furthermore, thematic evolution indicates a transition from technology-oriented research toward broader multidisciplinary perspectives integrating environmental sustainability, healthcare management, and resilient healthcare infrastructure. Overall, this study provides a comprehensive knowledge map of renewable energy research in healthcare facilities, identifies current knowledge gaps, and offers an evidence base to support future interdisciplinary research and evidence, informed decision, making for the sustainable energy transition of healthcare facilities.