Advancements in photovoltaic thermal cooling systems: analysis of nanofluid technologies

Photovoltaic thermal (PVT) systems have emerged as a crucial technology for enhancing solar energy utilization by simultaneously generating electrical and thermal energy, thereby improving overall system efficiency. In recent years, fluid- and nanofluid-based cooling strategies have attracted significant research attention as effective means to mitigate temperature-induced efficiency losses in PVT modules. This study presents a comprehensive bibliometric and thematic analysis of global research on PVT cooling systems, with particular emphasis on fluid and nanofluid technologies. Using Scopus-indexed publications published between 2015 and 2025, bibliometric mapping and science visualization techniques are employed through VOSviewer to examine publication trends, influential authors, leading journals, collaborative networks, and keyword co-occurrence structures. The analysis reveals a rapid growth in research output over the last decade, with dominant contributions from Asia and increasing international collaboration. Key thematic clusters are identified, highlighting the evolution of nanofluid-assisted cooling, system performance optimization, hybrid cooling configurations, and computational modeling approaches. This study integrates bibliometric mapping with thematic analysis to elucidate how nanofluid-based PVT cooling strategies have evolved, exposing limitations, thermohydraulic trade-offs, and system-level challenges that constrain practical deployment. The findings provide a structured perspective on current research directions and knowledge gaps, offering valuable guidance for researchers, designers, and policymakers toward the development of efficient and scalable PVT cooling solutions.