A comprehensive thermodynamic study of a solar integrated energy system consisted of a solar flat plate collector, an organic Rankine cycle, a thermoelectric generator, and a proton exchange membrane electrolyser is undertaken to generate power and hydrogen. The Matlab and Engineering Equation Solver software are linked, and various optimisation scenarios are investigated. The results of computational analysis indicate that with adding a thermoelectric generator unit in the system about 14 kW of energy in the form of electricity can be obtained from the waste heat of condenser. Various optimisation schemes with exergy efficiency, exergy destruction rate, as well as hourly hydrogen generation as optimisation targets are considered. The optimisation results comparison between base case and optimum design shows that exergetic efficiency improves by about 2.3% and rate of exergy destruction decrease by about 0.791 MW.