Energy and exergy analysis of hybrid solar photovoltaic/thermal (PV/T) system using a thermoelectric generator (TEG) and water spray cooling system

• In this study, a vertical thermal solar desalination system with and without cooling system was constructed, and the freshwater production rate, energy efficiency, exergy efficiency, recovery ratio, economic analysis, environmental analysis, convective heat transfer coefficient, and radiative heat transfer coefficient were examined. • The highest amount of water production in the cooling mode at a flow rate of 100 ( c m 3 m i n ) was 3469 ( m l m 2 ) . The highest amount of water production in the non-cooling mode at the same flow rate was 2771 ( m l m 2 ) . • Using the cooling system improved water production at a flow rate of 100 ( c m 3 m i n ) by 21%. This improvement was due to the increased temperature difference between the glass and the water. Freshwater production is higher on the east side compared to the west side. • The highest energy efficiency, exergy efficiency, and recovery ratio were obtained at 14:00 in the cooling mode and at a flow rate of 100 ( c m 3 m i n ) , which were 35.56%, 1.2%, and 10.8%, respectively. • The most optimal cost of producing per liter of freshwater and production per dollar occurred at a flow rate of 100 ( c m 3 m i n ) and in the cooling mode, which were 0.058 ( $ m 2 l ) and 17.16 ( l m 2 $ ) , respectively. • The shortest energy payback time was 1.9 years in the non-cooling mode at a flow rate of 100 ( c m 3 m i n ) . The highest output energy was 634.94 kWh, which occurred at a flow rate of 100 ( c m 3 m i n ) in the non-cooling mode. Renewable energy, including solar energy, is crucial due to rising energy costs, environmental degradation, and global warming. Photovoltaic/Thermal (PV/T) systems are an effective method for harnessing solar energy, generating both heat and electricity. Energy analysis, based on the first law of thermodynamics, quantifies the amount of energy converted but doesn't account for the quality or usefulness. Exergy analysis, rooted in the second law of thermodynamics, provides a comprehensive understanding of energy conversion processes by identifying true inefficiencies and potential improvements. This study evaluates a hybrid solar PV/T collector integrated with a thermoelectric module and a water spray cooling system, aiming to improve efficiency and evaluate its overall performance. The performance of the PV/T collector in the climate of Semnan, Iran, has been examined in this work both with and without the usage of a thermoelectric generator (TEG), heat sink, fan, and water spray cooling (hybrid system) at different mass flow rates of 100, 200, and 300 cm³/min. According to the results, the hybrid system’s highest power generation was 82.9 W, 86.5 W, and 87.7 W, while the PV/T collector maximum power generation at the three distinct flow rates was around 78.04 W, 80.9 W, and 85.8 W. The PV/T collector maximum electrical efficiency was 14.1% at flow rates of 300 cm³/min, and its maximum thermal efficiency was 31.9% at flow rates of 100 cm³/min. Additionally, it was 14.9% and 27.3% for the hybrid system, respectively. Additionally, at 100 cm³/min, the PV/T collector maximum energy efficiency was 18.4%, and at 300 cm³/min flow rates, its exergy efficiency was 16.05%. Additionally, it was 18.4% and 16% for the hybrid system, respectively.