Parametric analysis of a hybrid solar concentrating photovoltaic/concentrating solar power (CPV/CSP) system

This paper presents a parametric study of a recently proposed concentrating photovoltaic/concentrating solar power (CPV/CSP) hybrid system based on the energy and exergy analyses. A steady-state physical model is established for the hybrid system to carry out the energy and exergy analyses, in which a more general trapezoidal-shaped distribution of concentrated solar energy flux density is employed. Effects of various parameters are investigated including the average optical concentration ratio, the outlet temperature of R134a from the solar thermal receiver, and the coolant saturation vapor temperature. The results show that the generating efficiency and the power output of the hybrid system can increase by about 20% compared with the CPV-alone system, which indicates that the proposed hybrid system has a great potential to increase the utilization ratio of solar energy. Increasing the average optical concentration ratio or decreasing the outlet temperature of R134a from the solar thermal receiver can result in evident increases of both the energy efficiency and the exergy efficiency of the hybrid system. It is also shown that the energy and exergy efficiencies of the organic Rankine cycle (ORC) subsystem are nearly independent of the Direct Normal Irradiance (DNI), and the hybrid system can be always operated with a high efficiency despite of the DNI change at different moments or days.