Efficient utilization of hybrid photovoltaic/thermal solar systems by nanofluid-based spectral beam splitting: A review

Nanofluid-based spectral beam splitting (SBS) hybrid photovoltaic/thermal (PV/T) systems are a promising and efficient way to achieve full-spectrum utilization of solar energy. It utilizes the spectrum above bandgap of PV cells for power generation and the other sunlight for thermal output, decoupling PV and PT while having high total conversion efficiency. In this work, it is presented the opportunities and unique advantages of nanofluids in the field for SBS. The required properties of nanofluids as solar spectrum splitter, namely dispersion stability, thermal and optical properties are summarized. Furthermore, recent advances in SBS applications for PV/T systems are highlighted based on the classification of nanomaterials (metal, metal oxide, carbon-based as well as core@shell structures of metal and metal oxide composites). Finally, cost-effective analysis of nanofluid-based SBS applications is provided. Although efficiency has increased substantially and applications are promising, the issues of nanofluid stability under high solar radiation，full spectral matching and imperfect economic analysis still need to be addressed for the wide application of SBS in PV/T systems. Finally, nanofluid-based SBS is one of the most prospective approaches to achieve efficient utilization of the full solar spectrum.