Abstract: In this paper autonomous water desalination unit driven by solar energy was discussed in details. Photovoltaic method by using semiconductors. The algorithm changes the duty cycle of the dc/dc converter to maximum the power output of the module and make it operate at the peak power point of the module. a class of switching-mode power supply (SMPS) containing at least two semiconductor switches and at least one energy storage element.

Keywords: Water, Desalination, Solar, Photovoltaic, Algorithm.