In a world where potable water is just about to run dry, it is necessary to introduce new technologies and methods of solar-based water purification systems. Developing countries like Pakistan are cladding a shortage of purified water and its storage process. Our proposed design for water gets purified by using multijunction solar cells, cationic polyacrylamide alum, and lime. Multijunction solar cells are utilized to enhance the efficiency of the system. They utilize the complete spectrum of sunlight and absorb the different colors of light by different materials, and each material has its own bandgap energy. The solar cells generate power which is used to boil the contaminated water for 30 minutes up to 120 degrees for the purification purpose and remove bacteria, protozoa, and viruses because all germs become dead when water boils for 30 minutes. Alum is used for the purpose of purification because alum, cationic polyacrylamide, and lime or coagulant are utilized to remove arsenic from water. To remove COVID-19 from water, ozone gas O3 is injected. Charcoal filter paper is utilized to filter the boiling water energy stored in the battery to drive the system for nighttime purposes. The proposed design is economical, environmentally friendly, and works at maximum time. Nowadays, an IOT-based smart water purification system has been installed which works on solar energy.