This paper presents results on simulation, optimization and control of hybrid solar based energy system to power a desalination plant. The principal objective is to design a clean energy system to meet the desired electric load of the desalination plant with high renewable fraction, low cost of energy, and low carbon dioxide gas emissions. Hourly simulations and optimization were performed to determine the performance and life cycle cost of the different hybrid power configurations. The results of the baseline or the actual power system from the grid are compared with two new renewable power systems: (1) grid tied solar system: solar PV/grid/inverter power system, and (2) Off grid solar power system: PV/diesel generator/battery/inverter power system. The results show that the solar PV/grid/inverter power system offers the best performance compared to PV/diesel generator/battery/inverter. The total energy from the hybrid grid tied solar system is used to meet the AC load of the desalination plant with almost no excess electricity and power shortage. The proposed hybrid power system for the desalination plant is sustainable, economically viable and environmentally friendly: high renewable fraction (47.3%), low excess power (0.15%), low levelized cost of energy (90 $/MWh), and low CO2 gas emissions (264.25 kg CO2/MWh).