Hybrid nano-fluid for solar collector based thermal energy storage and heat transmission systems: A review

Solar-based thermal energy storage (TES) systems, often integrated with solar collectors like parabolic troughs and flat plate collectors, play a crucial role in sustainable energy solutions. This article explores the use of hybrid nanofluids as a working fluid in thermal storage units, focusing on their potential to increase system efficiency. The review highlights the popularity of hybrid nanofluids, composed of oil and nanoparticles, as effective heat transfer fluids in solar energy-based thermal energy storage and heat transmission systems. Key findings highlight the superior heat transfer capabilities of multi-walled carbon nanotubes (MWCNT) and alumina nanoparticles when dispersed in various base fluids. Additionally, PCMs such as erythritol and nitrate salt emerge as optimal choices for efficiently storing thermal energy. The stored energy becomes invaluable during non-sunlight hours, offering a continuous and reliable energy supply. This study highlights the potential of hybrid nanoparticles as heat transfer fluids for solar-based thermal energy storage systems, opening the path for progress in sustainable and efficient energy use. Future directions may include further optimization of hybrid nanofluids, the incorporation of improved PCMs, and novel techniques to improve the overall efficiency of solar energy storage systems. •The incorporation of hybrid nanofluids in different solar collectors is presented from previous studies.•Thermal properties of nanofluids and different mathematical correlations for estimating properties are discussed.•Research studies on heat transfer analysis of solar thermal systems incorporating hybrid nanofluids are presented.•Focus on the challenges involved in implementing hybrid nanofluids in solar thermal applications with future directions.