The improvement of heat transfer in any system stores latent heat as a thermal energy enhances the system's efficiency. In this study, nanoparticles were dispersed in paraffin wax (as a phase change material) to increase the thermal conductivity of the latter compared to the base material. The mixing of nanoparticles with the wax changes the thermophysical properties of the used wax. The thermophysical properties as density, viscosity, and thermal conductivity showed increasing values in contrast to the specific heat where it reduced relatively. Three distillers were made to study the effect of adding these nanoparticles to simple solar distillers. The first of which was without any modification and the second had paraffin wax as additional material. In the third distiller, a combination of paraffin wax with a nano-Al2O3 spread on it that was used to promote thermal conductivity. The addition of nanoparticles to paraffin wax increased significantly the rate of heat transfer, resulting in higher yields of the solar distiller. Paraffin wax addition caused an increase in the daily distillation yield up to 10.38% while the addition of nano-Al2O3 to paraffin wax improved distillate yield up to 60.53% compared to the simple distiller yield due to continuous distillation after the sunset.