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In this study, a conceptual geothermal power plant with Non-Condensable Gases (NCGs) reinjection is analyzed from energy, exergy, exergo-economic, and environmental perspectives. The cycle is evaluated in considering both subcritical and supercritical working conditions. A sensitivity analysis comprising the variation of condensing temperature, turbine inlet pressure, and amount of NCGs within the geofluid is performed to assess the system performance from the thermodynamic, economic, and environmental points of view. The exergy efficiency results for the supercritical and the subcritical cycles are 52% and 50.5%, respectively. Results showed increasing the condensing temperature decreases exergy efficiency, net power, and exergetic performance parameters and increases total exergy destruction, exergo-destruction impact, and specific power cost in both working cases. According to the obtained results, an increase in the inlet pressure of the turbine in the supercritical case study reduces exergy efficiency and exergetic performance and increases the exergo-destruction impact factor. However, it increases the cycle exergy efficiency and exergetic performance criteria first and then decreases in a subcritical case. The LCOE for the supercritical cycle is 6.96 ( c € / k W h ) and for the subcritical is 5.52 ( c € / k W h ) . The highest exergy destruction rates are related to the main heat exchanger, condenser, and turbine, respectively.

Thermodynamic, exergy, economic and environmental analysis of a solid oxide fuel cell and gas turbine hybrid cycle have been done in this paper. Also, multi-objective optimization of this cycle has been done by NSGA-II algorithm. In order to defining of the optimum design point, interactive fuzzy multi-objective method has been used. At optimum point, the cost function value, 0.0435 ( U S $ / s ) and exergy efficiency approximately 57.7 % have been obtained. As well, sensitivity analysis of fuel cost per energy unit into objective functions has been done. In addition, rising inlet temperature of gas turbine from 900 up to 1600 ( K ) , has caused an increase in output power up to 8.5 % and entropy generation about 30 % and a reduction in exergy efficiency from 61.9 % to 51.7 % . By evaluation of entropy generation rate, it has been concluded that most of enthalpy generation rate (32 % ) is related to combustion chamber. Increasing of fuel cell stack temperature causes an increase in exergy efficiency from 56.6 % up to 60.2 % and about 34.8% in output power of the cycle and a reduction in exergy efficiency from 62.8 % to 59.1 % and 8.4 % in fuel cell power. Also, payback time of this cycle is about 3.12 years.