Combined supercritical CO2 (SCO2) cycle and organic Rankine cycle (ORC) system for hybrid solar and geothermal power generation: Thermoeconomic assessment of various configurations

Hybrid solar and geothermal utilisation is a promising option for effective exploitation of renewable energy sources. Concentrated power (CSP) systems with preheating are acknowledged as an attractive solution, supercritical CO2 (SCO2) cycle adopted generation thanks to the favourable properties offered by working fluid. In order further improve overall performance such systems, organic Rankine (ORC) can be added bottoming cycles recover heat rejected from topping SCO2 system also utilise surplus available after brine used in system. This paper proposes four configurations combined SCO2-ORC hybrid performs detailed thermodynamic economic assessments based on actual conditions Seville, Spain. The results reveal that which geothermal-brine stream split into two parallel flows utilised separately ORC preferable. A geothermal-stream fluid first utilising followed series delivers net output 2940 kW, maximum among all proposed 45% higher than standalone plant. similar reversed flow direction preheated then has specific cost corresponding 2880 $/kW, lowest 22% lower Annual evaluation shows achieve significant improvements, ranging 45%, over total electricity plant, demonstrates potential deploying novel generation.