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Summary A hybrid solar photovoltaic/wind system is proposed and investigated theoretically. The hybrid system is based on attaching a converging inclined duct beneath the photovoltaic (PV) panels and directed upward after the end of the panels. A wind turbine is attached at the exit of the converging duct. The converging duct will capture wind currents that at its inlet and enhances these current by buoyancy effect created by the rejected heat from the panels. The mixed convection air flow is used in cooling the PV panels and in generating electricity by driving the wind turbine at the duct exit. A mathematical model is proposed to describe the system hydrodynamic and thermal behavior. In addition to the mixed convection case, the pure free convection case, when there is no wind speed, has been tested. The design of the wind duct capturing system is not included in this study, which should be carefully manufactured to eliminate the reversed flow. The simulation results show that the integration of both systems not only enhances the performance of PV cell due to the effective cooling but also generates more electric power from the inserted turbine. At low wind speeds, it is found that the ducting system helps more in cooling the panels rather than driving the wind turbine. At these low wind speeds, the buoyancy effect may have a significant effect. However, at high wind speeds, the ducting system acts in both cooling the panels and driving the turbine, and at these high speeds, the buoyancy effect is insignificant.

Summary This work introduces a novel hybrid system which uses the cooling water of a concentrated PV/T as a preheated water for lithium bromide‐water‐based Kalina cycle. The PV/T is a combination between solar photovoltaic cells and solar thermal collector. The solar cells convert the sunlight into electricity, and the remaining heat gets absorbed by the collector for additional power generation. As well as, extracting the excess heat from PV cells enhances its electrical efficiency. The Kalina power cycle is mainly driven by concentrated solar parabolic collectors (CSP). The advantage of combining these 2 systems is to employ the heat rejected from the concentrated solar‐based PV cells for further electricity generation, thus increasing the system overall efficiency. The system of concentrated solar collectors is divided into 2 parts to avoid getting very high temperature for the PV cells: concentrated solar collectors with PV cells and without PV cells. Due to the high temperature of water which returns from the Kalina cycle, a cooling tower is employed to cool the water before entering the concentrated PV/T system. The mathematical model of the proposed system has been presented and simulated to investigate the effect of the main controlling variables on the proposed system performance: generator temperature, solar radiation, wind speed, and the ambient temperature. The results show that the amount of solar radiation is the primary variable for the investigated system energy productivity, while the design temperature of generator is found to be the most parameter that affects the system overall efficiency. While the overall efficiency is around 18% to 23%, combining PV/T with the proposed solar Kalina cycle increases the system overall efficiency by 22% to 27%. The electrical conversion efficiency of the proposed system is 40% to 68% much more compared to PV/T alone system.

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This paper investigates a novel hybrid system combining thermal electrical generators (TEGs) and a wind turbine. The mathematical model of the system is derived and solved to investigate the performance of the proposed system. In the proposed system, solar energy is converted to heat by an absorber plate. Some portion of this heat is converted to electricity using TEG, while another portion of the heat is used to heat up air flowing in an inclined duct placed underneath the absorber plate. Heating the air inside the system enhances the current speed because of the effect of buoyancy. A wind turbine is placed inside the duct parallel to air flow before it exits to the atmosphere. The wind current is accelerated before passing through the turbine by using venture effect. The TEGs are exposed to the concentrated solar radiation. This can be obtained using a compound parabolic concentrator. The proposed configuration has multiadvantages: (1) the wind is used to drive a wind turbine; (2) air cools the rear surfaces of TEGs to increase the temperature difference between the opposite surfaces, thus generates more electrical power; and (3) it uses buoyancy effect to increase the wind stream speed, thus enhancing the power generated from turbine. It is found that the solar concentration ratio is the most important factor contributing to enhancing the TEG efficiency. The buoyancy effect leads to turbine power boost at high wind speeds more than at low wind speeds.