Techno-economic examination and optimization of a combined solar power and heating plant to achieve a clean energy conversion plant

Renewable energies are one of the best alternatives to fossil fuels, which have disadvantages such as exhaustibility and emission of environmental pollution. An alternative system consisting of a parabolic trough collector (PTC) and a photovoltaic thermal (PVT) is used to produce electric power and heating. By using the Kalina cycle and the organic Rankine cycle (ORC) coupled with the PVT unit, an attempt was made to recover as much as possible heat from the solar energy. Exergy and exergy-economic analyzes were performed on the proposed system, and appropriate criteria for evaluating the system were defined based on energy, exergy, and economic analyses. The exergy analysis results indicate that the highest exergy destruction rate in the ORC sub-system is associated with the PVT unit. The value of electrical cost for three studied cities, Doha, Tehran, and Ankara were calculated. Results present that the highest and lowest net output power were for Doha and Ankara and these cities also have the maximum and minimum electrical cost. In addition, using multi-objective optimization, the optimum states of introduced system in the Pareto diagram are presented and with the help of ideal point concept, the final optimum state is determined.