Process arrangement and multi-criteria study/optimization of a novel hybrid solar-geothermal scheme combined with a compressed air energy storage: Application of different MOPSO-based scenarios

Abstract

The current research is motivated to arrange an innovative hybrid solar-geothermal system, where the geothermal-driven subsystem is used to give out a sustainable framework for the upstream subsystems. Thus, an integrated geothermal flash cycle combined with organic Rankine cycle 1 (ORC1) is utilized to supply the input electricity of the compressed air energy storage system (CAES) at charging periods. The stored stream is exposed to electricity generation by the use of parabolic trough solar collectors (PTSCs). In addition, ORC2 recovers the waste heat of air turbines. A multi-aspect study is considered from the thermodynamical and economical standpoints. In addition, the sensitivity analysis is carried out to evaluate the effect of different parameters on the performance of the system. Moreover, four optimization scenarios are defined and scrutinized using a multi-objective particle swarm optimization (MOPSO) algorithm. The present study exhibits that the most appropriate optimum solution from the thermodynamic facet is a consequence of a framework in which the energy efficiency of flash-ORC1 and its output electricity is the objective functions. In this situation, the optimum energetic and exergetic efficiencies of the flash-ORC1 unit are equal to 20.43% and 67.63%. Furthermore, the lower optimum payback period equals 3.07 years corresponding to the scenario in which objective functions are the exergy efficiency of flash-ORC1 and the payback period.