Exergoeconomic Analysis of a Solar-Geothermal Hybrid Organic Rankine System

In this study, energy, exergy and exergoeconomic analysis of a solar-geothermal hybrid Organic Rankine Cycle System with nominal 50 [kW] turbine capacity was conducted at a range of 50-90 [°C] geothermal source temperatures in Konya, Turkey. A new generation R1234yf was assumed as the working fluid of the system. An average of 336 [MWh/year] annual electricity generation was obtained for all source temperatures, 8.1% of which was with solar energy effect. Exergy efficiencies were approximately 6.2% for all geothermal temperatures, while the energy efficiencies increased at a range of 4.3%-10.0% with the increase of geothermal source temperatures. Exergoeconomic analysis was performed with the SPECO method. According the exergoeconomic analysis results, electricity generation costs of the system were determined as 32.2, 38.8, 36.1, 36.5 and 37.8 [USD/MWh] with the increase of geothermal source temperature.