Hi,
I did my master's on a similar project but involved on a high level coupling of solar energy with other components (PEM/SOE, Power convertors, Storage options for heat, electricity) to produce hydrogen. I have since thought to couple solar (CSP/PV, especially CSP) to carryout the desalination because, I believe, they are a good fit. I cannot model the coupling in Matlab (since I do not have experience in Matlab) but I can model this coupling in Python which I am well acquainted with. I can further suggest you optimization of parameters starting from the size of the plant required according to the demand of water (and solar irradiance) to the operating parameters for the respective equipment (all will be done in python where you can later do dynamic simulations). Open source libraries for solar, desalination and other equipment will be used, if not present, I will model them using their respective governing equations.
Looking forward to hearing from you.