Solar energy intermittency is one of the main challenges encountered by thermal energy storage systems in concentrated solar power plants due to the low heat transfer rates during charging operations. The critical thermophysical property to be considered for combating this problem is the thermal conductivity. Thus, base fluids with dispersed nanoparticles, better known as nanofluids, have become materials with great potential since they enhance efficiency during charging intervals by increasing the charged material's thermal conductivity by up to 89 %. By gathering and analyzing results from various studies in nanofluids, it was observed that there is a considerable improvement in the thermal storage material compared with the base fluid alone. There is also an increase in the thermal conductivity as nanoparticles are added. Obtaining an increase as great as 99 % allows faster rates of heat transfer. Overall, this may significantly improve the efficiency of thermal energy storage systems in concentrated solar power plants.
New materials for thermal energy storage in concentrated solar power plants