Development of a solar farm powered quadric system with thermal energy storage option

Abstract

Due to the increase in energy and fresh water demands and the expected hydrogen economy, it is important to find solutions that can meet these various energy demands. In this study, an investigation of a PV/T powered integrated system for a quadric generation of electricity, hydrogen, fresh water and space heating with a novel thermal energy storage unit is considered. This study introduces for the first time the upgrading of thermal energy using a high-temperature heat pump for thermal energy storage by using a combination of excess electric power and waste heat from a PV/T solar farm. After establishing and validating a thermodynamic model to analyze this integrated system, the results show that the energy and exergy coefficients of performance of this heat pump are 1.18 and 0.336, respectively at the base case. Also, the temperature lift is 132.6 K up from 333 K at the PV/T solar farm. The overall energy and exergy efficiencies of the integrated system are found to be 11.6% and 6.49%, respectively. In addition, parametric studies are conducted to investigate how the system performance is affected by changing the operating conditions and state properties, and their results show that, in general, improving the isentropic efficiencies of compressors of the heat pump, enhances the overall performance energetically and exergetically. In regards to the hydrogen production rate, increasing this rate reduces the overall energy and exergy efficiencies of the integrated system respectively from 12.9% and 6.83% at a mass flow rate of 0.01 kg s−1 down to 8.17% and 5.71% at a mass flow rate of 0.035 kg s−1, respectively.