The role of nanofluids in the performance augmentation for the solar collectors used in solar water heating

The dawn of ‘zero fuel world’ is no farther than 2060 if the current rate of burning fossil fuels continued with the existing reserves. Consequently, solar energy is considered as a vital alternative not only because it is renewable but also due to zero emissions. The important part of any Solar Water Heater (SWH) is the collector. The solar radiation is get absorbed by it and is transferred to a fluid that is flowing through the collector. The output of such heat transfer always depends on the heat transfer capability of the fluid. Hence, nanofluids with augmented heat transfer characteristics and thermophysical properties can be utilised for better performance of the solar collector. This article presents a complete integrated review related to potential applications of various nanofluids for SWHs. A significant study is performed for the SWH focusing on its two vital components, viz., solar collectors and heat transfer fluids. The review is conducted in various aspects such as the increase in efficiency of the SWHs with nanofluids and the challenges while using nanofluids as the heat transfer fluids in SWH. Subsequently, some conclusions are made to suggest the use of nanofluids in different solar collectors for SWHs. © 2023 Informa UK Limited, trading as Taylor & Francis Group.