Unlike conventional fresh water producing systems, from saline or brackish water, the innovative solar water producing systems are efficient and effective. Experiments were conducted on two identical roof-type solar stills and simultaneously tested under the same weather conditions. One of these stills was modified by integrating a vacuum pump to lower the pressure inside while the other still was used as a reference unit. Different concentrations of Al2O3 nanoparticles were chosen, 0.2%, 0.4%, and 0.6%, and used with water inside the modified still. It was verified that the modified still, without nanoparticles, yields 34.84% more production than the conventional still. In addition, the modified still with a 0.4% of Al2O3 nanoparticles produced the highest percentage of distilled water, 44.42% in comparison to the one without the use of Al2O3 nanoparticles, followed by 37.94% and 24.07% for 0.6% and 0.2% of Al2O3 nanoparticles, respectively.