<p>This study investigates the integration of offshore renewable energy systems, specifically combining Ocean Thermal Energy Conversion based on Organic Rankine Cycle and solar water heating in two different working fluids—1,1,1,2-Tetrafluoroethane and 1,1,1,3,3-Pentafluorobutane in Andaman and Nicobar Islands, India. Two main software tools, Solkane 8.0 and Aspen Plus, were utilized for simulation and analysis. The Solkane analysis focused on comparing the detailed properties, revealing insights into their suitability for Solar Heated combined Ocean Thermal Energy Conversion applications. The Aspen Plus software was employed for evaluating the performance of various components within the system, including the heat exchanger, pump, turbine, and condenser with the properties of 1,1,1,3,3-Pentafluoropropane. Results from Solkane Analysis showed that while both refrigerants exhibit wet vapour states, 1,1,1,2-Tetrafluoroethane operates at a higher pressure and specific enthalpy compared to 1,1,1,3,3-Pentafluorobutane. However, factors such as energy output, system design, efficiency, and environmental impact were considered when choosing the refrigerants. The total power output is calculated as 11.38&#xa0;kW, yielding a thermal efficiency of 6.21% and exergy efficiency of 27.97%. This efficiency surpasses previously reported values for the systems, demonstrating a significant improvement in performance. Sensitivity analysis from Aspen plus revealed a clear relationship between pressure ratio and the work required, emphasizing the importance of optimizing pump performance for overall system efficiency. Overall, the study provides valuable insights into the design and optimization of offshore renewable energy systems with other optional refrigerants, highlighting the potential of integrating multiple energy sources to enhance system efficiency and sustainability.</p> Graphical Abstract <p></p>