A hybrid energy utilization system, integrating dish solar SE and salinity gradient based energy storage system, was proposed to realize clean and stable power generation from solar energy. Power output of dish solar Stirling engine was utilized to pressurize the salt water into RO (reverse osmosis) for storing the energy in the form of concentration gradient, and stable power output was generated from the concentration gradient via PRO (pressure retarded osmosis). The system performance was systematically investigated under the ideal and non-ideal models, to evaluate the theoretical and realistic energy conversion ability. Results indicate that higher initial concentration presents better energy efficiency, for it has slower decreasing slope of transmembrane water flux in PRO. Optimal RO and PRO operating pressure exist for achieving the maximal energy efficiency. The ideal maximal overall energy conversion efficiency reaches 9.23% within the research scope. With the detrimental factors being considered, the maximal overall efficiency of 5.07% is achieved.