Comprehensive thermodynamic and economic analyses and optimization of a novel poly-generation setup utilizing solar and geothermal sources

Abstract

• An innovative poly-generation system based on renewable energy sources is designed. • Thermodynamic and thermo-economic analyses and optimizations are implemented. • The simultaneous production of electricity, cooling, hydrogen, and fresh water is considered. • CO 2 utilization in transcritical power and cooling generation cycles is appraised. • Optimum thermal and exergy efficiencies are attained as 32.3% and 19.5, correspondingly. This work studies the 3E aspect (energy, exergy, and economic) of a poly-generation setup via a novel and innovative configuration based on two renewable energy sources through converting the thermal energy to useful energies and energy-based products. This system embraces geothermal energy via a flash-binary cycle and solar power employing a parabolic trough solar collector-based solar field. The other subsystems are a carbon dioxide-based transcritical organic Rankine cycle integrated with a modified transcritical refrigeration cycle to generate electricity and cooling, a humidification-dehumidification desalination unit to provide freshwater, and a proton exchange membrane electrolyzer to produce hydrogen. In this way, the newly designed system has been evaluated respecting the weather data of Beijing city in China throughout the year. Subsequently, the first and second laws of thermodynamics together with thermo-economic analysis and net present value assessment have been implemented. The sensitivity of principal variables regarding crucial design parameters has been examined via a parametric study. Also, the genetic algorithm was the optimization tool to optimize the calculations in different modes. The results indicated that the exergy-cost case of optimization correspondingly led to exergy efficiency and levelized cost of products of 19.2% and 13.9 $/GJ with a payback period of 3.96 years.