Thermodynamic Analysis of ORC-GT Hybrid Cycle and Thermal Recovery from Photovoltaic Panels

Biomass and solar energy are considered attractive renewable energy sources for power generation plants. In this research, the thermodynamic analysis of the organic Rankine cycle (ORC)-gas turbine-photovoltaic panel (PV) is investigated. Biogas is used as a heat source in the gas turbine cycle. Photovoltaic panel is also used for heating the combustion air. In a gas turbine cycle, the passing air passes through a photovoltaic system and heats up before entering the combustion chamber. Biogas, 60% methane and 40% carbon dioxide, is used as fuel in gas turbines. Sensitivity analysis was performed for cycle input variables. Results display that the output power of the modified cycle is increased by about 28% compared to the base cycle. The use of photovoltaic panel increases the power of the cycle by 23%-25%. The results of the analysis of the second law of thermodynamics show that the most exergy destruction belongs to the combustion chamber. The use of a photovoltaic panel reduces the amount of exergy destruction in the combustion chamber. Increasing condenser pressure and steam turbine pressure reduces power cycle energy efficiency. The lowest and highest exergy efficiencies are related to condenser and gas turbine, respectively. Findings display that the overall cost of the proposed cycles increases with the increase of the compressor pressure ratio and the temperature of the inlet fluid to the turbine.