Nanofluids are synthesized by doping solvents with nano-particles at minute concentrations (typically less than 1 percentage by volume). Experimental studies have shown that nano-particles can dramatically enhance thermal conductivity of various liquid solvents. This is also associated with enhancement of other transport properties (e.g., viscosity, specific heat, diffusivity, etc.). Hence, nanofluids are attractive materials for solar thermal applications. The objective of this study is to investigate the optimum performance of various nanofluids for solar thermal storage applications. Dimensional analyses and similitude techniques will be used to theoretically estimate the enhancement of transport properties of various nanofluids to predict their efficacy for solar thermal storage applications.