Various thermal power systems emit flue of gases containing significant amounts of waste energy. The aim of the present research work is to recover that energy to develop a highly efficient desalination system. coupled with solar energy of simple construction, applicable of fresh water production that are constructed near these thermal sites. The study of the performance of this solar collector has been conducted experimentally under actual insolation in Alqassim district in Saudi Arabia, where there is brackish underground water The overall daily potable water productivity of the proposed system was about 160 L/day for a corresponding waste energy varying from 170 to 500 MJ/day and a global solar radiation on a horizontal surface ranging from 15 to 29 MJ/m² day.