7E analysis of a low-temperature geothermal and solar energy integrated hybrid system for sustainable power and hydrogen generation

The growing global population and increasing energy demand have made the need for sustainable and renewable energy sources more critical than ever in order to reduce environmental challenges and ensure energy security. This study examines a hybrid energy system that combines low-temperature geothermal energy with solar energy to enhance energy production capacity. The hybrid system integrates solar energy collected through a parabolic trough collector (PTC) with geothermal resources to support efficient energy generation. The system is based on a configuration that combines a steam Rankine cycle (SRC) and an organic Rankine cycle (ORC), forming a synergistic thermodynamic structure. The energy obtained from solar and geothermal sources is effectively utilized through the integration of these two thermodynamic cycles, creating a highly efficient system. The electricity generated by the system is used for hydrogen production through electrolysis, providing a sustainable energy storage solution. To evaluate the thermodynamic and economic performance of the system, comprehensive energy, exergy, economic, environmental, energoeconomic, exergeoeconomic, and enviroeconomic analyses (7E analysis) were conducted using the Engineering Equation Solver (EES) program. In other words, a better understanding of the system was achieved by employing the 7E evaluation method. The results show that the integration of solar energy significantly increases the utilization of low-temperature geothermal resources and enables sustainable hydrogen production. As a result of the study, an energy efficiency of 20.13 %, an exergy efficiency of 22.87 %, a hydrogen production rate of 0.05283 kg/s, and a levelized cost of energy (LCOE) of 0.182 USD/kWh were obtained, demonstrating the potential of this hybrid system for clean energy applications.