Experimental performance assessment of a photovoltaic/thermal stepped solar still

Abstract

In this paper, the performance analysis of a stepped solar still connected to photovoltaic thermal collector is carried out numerically and experimentally. A transient thermal model is obtained by writing energy balance for the various components of solar still system (i.e. glass cover, saline water, absorber plate, photovoltaic thermal collector). Also, an expression for the energy efficiency of system is derived. An experimental setup is designed and fabricated. The simulation results are validated by the measured experimental data. Finally, parametric studies are carried out and the effect of various operating and design parameters on the energy efficiency, freshwater productivity, and output electrical power is investigated. It is observed that there is a desired value for the mass flow rate of saline water and the area of photovoltaic thermal collector, which maximizes the energy efficiency. The desired value of the mass flow rate and photovoltaic thermal collector area is 0.068 kg/min and 1.33 m2, respectively. Furthermore, the connection of photovoltaic thermal collector to the stepped solar still improves the freshwater productivity and energy efficiency and it provides additional electrical power for other applications.